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Sallie FN, Pienaar L, Lubbe A, Xhakaza S, Manne SR, de la Torre BG, Albericio F, Mu Daniels W, Me Millen A, Baijnath S. Neurobehavioral and molecular changes in a rodent model of ACTH-induced HPA axis dysfunction. Brain Res 2024; 1834:148913. [PMID: 38580046 DOI: 10.1016/j.brainres.2024.148913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 04/01/2024] [Accepted: 04/02/2024] [Indexed: 04/07/2024]
Abstract
Hypothalamic-pituitary-adrenal (HPA) axis dysregulation is linked to the pathophysiology of depression. Although exogenous adrenocorticotropic hormone (ACTH) is associated with a depressive-like phenotype in rodents, comprehensive neurobehavioral and mechanistic evidence to support these findings are limited. Sprague-Dawley rats (male, n = 30; female, n = 10) were randomly assigned to the control (male, n = 10) or ACTH (male, n = 20; female n = 10) groups that received saline (0.1 ml, sc.) or ACTH (100 μg/day, sc.), respectively, for two weeks. Thereafter, rats in the ACTH group were subdivided to receive ACTH plus saline (ACTH_S; male, n = 10; female, n = 5; 0.2 ml, ip.) or ACTH plus imipramine (ACTH_I; male, n = 10; female, n = 5;10 mg/kg, ip.) for a further four weeks. Neurobehavioral changes were assessed using the forced swim test (FST), the sucrose preference test (SPT), and the open field test (OFT). Following termination, the brain regional mRNA expression of BDNF and CREB was determined using RT-PCR. After two-weeks, ACTH administration significantly increased immobility in the FST (p = 0.03), decreased interaction with the center of the OFT (p < 0.01), and increased sucrose consumption (p = 0.03) in male, but not female rats. ACTH administration significantly increased the expression of BDNF in the hippocampus and CREB in all brain regions in males (p < 0.05), but not in female rats. Imipramine treatment did not ameliorate these ACTH-induced neurobehavioral or molecular changes. In conclusion, ACTH administration resulted in a sex-specific onset of depressive-like symptoms and changes in brain regional expression of neurotrophic factors. These results suggest sex-specific mechanisms underlying the development of depressive-like behavior in a model of ACTH-induced HPA axis dysregulation.
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Affiliation(s)
- Farhanah N Sallie
- Wits Integrated Molecular Physiology Research Initiative, Wits Health Consortium (PTY) Ltd, School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa; School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa
| | - Leandrie Pienaar
- Wits Integrated Molecular Physiology Research Initiative, Wits Health Consortium (PTY) Ltd, School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa; School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa
| | - Andrea Lubbe
- Wits Integrated Molecular Physiology Research Initiative, Wits Health Consortium (PTY) Ltd, School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa; School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa
| | - Sanelisiwe Xhakaza
- Wits Integrated Molecular Physiology Research Initiative, Wits Health Consortium (PTY) Ltd, School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa; School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa
| | - Srinivasa R Manne
- Peptide Science Laboratory, School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Beatriz G de la Torre
- Peptide Science Laboratory, School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Fernando Albericio
- Peptide Science Laboratory, School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - William Mu Daniels
- School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa
| | - Aletta Me Millen
- Wits Integrated Molecular Physiology Research Initiative, Wits Health Consortium (PTY) Ltd, School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa; School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa.
| | - Sooraj Baijnath
- Wits Integrated Molecular Physiology Research Initiative, Wits Health Consortium (PTY) Ltd, School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa; School of Physiology, Faculty of Health Sciences, University of The Witwatersrand, Johannesburg, South Africa.
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Millen AME, Daniels WMU, Baijnath S. Depression, an unmet health need in Africa: Understanding the promise of ketamine. Heliyon 2024; 10:e28610. [PMID: 38601594 PMCID: PMC11004535 DOI: 10.1016/j.heliyon.2024.e28610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 03/21/2024] [Accepted: 03/21/2024] [Indexed: 04/12/2024] Open
Abstract
In Africa, there is currently a paucity of data on the epidemiology of depression, its treatment and management. The prevalence of depression is severely underestimated, with unique circumstances and societal risk factors associated with depression and its public awareness. Treating and managing depression is confounded by an inaccessibility to efficient and low-cost treatments for patients with depression. The aetiology of depression is multifactorial, with various theories implicating multiple neuronal networks. Despite this, the treatment of depression is one-dimensional focussing on outdated theories of depression and mainly targeting dysfunctional neurotransmitter pathways. Hence, it is not surprising that there is a significant increase in the prevalence of patients suffering from treatment resistant depression (TRD), with a large portion of patients deriving little clinical benefit from these traditional anti-depressant therapies. This highlights the need for more effective treatment strategies for depression, especially applicable to resource limited environments such as Africa, where there is little investment in public healthcare resources towards managing mental health disorders. The clinical potential of using ketamine in managing depression has received considerable attention in the past two decades, with the FDA approving esketamine for the management of TRD in 2019. This widespread attention has significantly increased ketamine's appeal as a novel antidepressant. Consequently, many ketamine infusion clinics have been established in Africa. However, there is little regulation or guidance for ketamine infusions. Furthermore, while esketamine is expensive and hence inaccessible to a large portion of the African population, racemic ketamine is significantly cheaper and has demonstrated clinical potential. However, there is currently a limited understanding of the neurological mechanisms of action of racemic ketamine in treating and managing depression, especially in a diverse African population. Therefore, this review aims to provide an African context of depression and the therapeutic potential of ketamine by highlighting aspects of its molecular mechanism of action.
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Affiliation(s)
- Aletta ME. Millen
- Integrated Molecular Physiology Research Initiative, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - William MU. Daniels
- School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Sooraj Baijnath
- Integrated Molecular Physiology Research Initiative, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Reddy R, Baijnath S, Singh S, Moodley R, Naicker T, Govender N. Hesperidin improves physiological outcomes in an arginine vasopressin rat model of pre-eclampsia. Fundam Clin Pharmacol 2024; 38:341-350. [PMID: 37652562 DOI: 10.1111/fcp.12952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 07/09/2023] [Accepted: 08/17/2023] [Indexed: 09/02/2023]
Abstract
BACKGROUND Hesperidin, a flavanone commonly found in citrus fruits and herbal formulations, has emerged as a potential new therapeutic agent for modulating several diseases. Since pre-eclampsia is a growing public health threat, it may negatively impact the economy and increase the disease burden of South Africa. Phytocompounds are easily accessible, demonstrate minimal side effects, and may confer novel medicinal options as a treatment and preventive preference. OBJECTIVE To investigate the physiological, biochemical, and hematological outcomes of hesperidin in an arginine vasopressin (AVP)-induced rodent model of pre-eclampsia. METHODS Female Sprague-Dawley rats were surgically implanted with mini-osmotic pumps to deliver AVP (200 ng/h) subcutaneously. Animals were treated with hesperidin at 200 mg/kg.b.w via oral gavage for 14 days. Systolic and diastolic blood pressures were measured on GD 7, 14, and 18 using a non-invasive tail-cuff method and were euthanized on GD 21. RESULTS The findings showed that hesperidin administration significantly decreased blood pressure (P < 0.05) and urinary protein levels in pregnant rats (P < 0.001). Placental and individual pup weight also increased significantly in the pregnant hesperidin-treated groups compared to AVP untreated groups (P < 0.001). Biochemical and hematological markers such as white blood cell count and lymphocyte levels differed significantly (P < 0.05) in AVP groups treated with and without hesperidin. CONCLUSION Our results suggest that hesperidin is an antihypertensive agent with modes of action associated with its diuretic and blood pressure lowering effects and reduction of proteinuria in AVP-induced pre-eclamptic rats.
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Affiliation(s)
- Rebecca Reddy
- Department of Basic Medical Sciences, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
| | - Sooraj Baijnath
- Integrated Molecular Physiology Research Initiative, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Sanil Singh
- Biomedical Resource Unit, University of KwaZulu-Natal, Durban, South Africa
| | - Roshila Moodley
- Department of Chemistry, University of Manchester, Manchester, UK
| | - Thajasvarie Naicker
- Discipline of Optics and Imaging, Doris Duke Medical Research Institute, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Nalini Govender
- Department of Basic Medical Sciences, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
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Naidoo V, Mdanda S, Ntshangase S, Naicker T, Kruger HG, Govender T, Naidoo P, Baijnath S. Corrigendum to "Brain penetration of ketamine: Intranasal delivery VS parenteral routes of administration" [J. Psychiatr. Res. 112 (2019) 7-11]. J Psychiatr Res 2023; 165:254. [PMID: 37536188 DOI: 10.1016/j.jpsychires.2023.07.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Affiliation(s)
- Vivian Naidoo
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Panjasaram Naidoo
- Discipline of Pharmaceutical Sciences, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa.
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Kaya I, Schembri LS, Nilsson A, Shariatgorji R, Baijnath S, Zhang X, Bezard E, Svenningsson P, Odell LR, Andrén PE. On-Tissue Chemical Derivatization for Comprehensive Mapping of Brain Carboxyl and Aldehyde Metabolites by MALDI-MS Imaging. J Am Soc Mass Spectrom 2023; 34:836-846. [PMID: 37052344 PMCID: PMC10161219 DOI: 10.1021/jasms.2c00336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The visualization of small metabolites by MALDI mass spectrometry imaging in brain tissue sections is challenging due to low detection sensitivity and high background interference. We present an on-tissue chemical derivatization MALDI mass spectrometry imaging approach for the comprehensive mapping of carboxyls and aldehydes in brain tissue sections. In this approach, the AMPP (1-(4-(aminomethyl)phenyl)pyridin-1-ium chloride) derivatization reagent is used for the covalent charge-tagging of molecules containing carboxylic acid (in the presence of peptide coupling reagents) and aldehydes. This includes free fatty acids and the associated metabolites, fatty aldehydes, dipeptides, neurotoxic reactive aldehydes, amino acids, neurotransmitters and associated metabolites, as well as tricarboxylic acid cycle metabolites. We performed sensitive ultrahigh mass resolution MALDI-MS detection and imaging of various carboxyl- and aldehyde-containing endogenous metabolites simultaneously in rodent brain tissue sections. We verified the AMPP-derivatized metabolites by tandem MS for structural elucidation. This approach allowed us to image numerous aldehydes and carboxyls, including certain metabolites which had been undetectable in brain tissue sections. We also demonstrated the application of on-tissue derivatization to carboxyls and aldehydes in coronal brain tissue sections of a nonhuman primate Parkinson's disease model. Our methodology provides a powerful tool for the sensitive, simultaneous spatial molecular imaging of numerous aldehydes and carboxylic acids during pathological states, including neurodegeneration, in brain tissue.
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Affiliation(s)
- Ibrahim Kaya
- Department of Pharmaceutical Biosciences, Spatial Mass Spectrometry, Science for Life Laboratory, Uppsala University, SE-75124 Uppsala, Sweden
| | | | - Anna Nilsson
- Department of Pharmaceutical Biosciences, Spatial Mass Spectrometry, Science for Life Laboratory, Uppsala University, SE-75124 Uppsala, Sweden
| | - Reza Shariatgorji
- Department of Pharmaceutical Biosciences, Spatial Mass Spectrometry, Science for Life Laboratory, Uppsala University, SE-75124 Uppsala, Sweden
| | - Sooraj Baijnath
- Department of Pharmaceutical Biosciences, Spatial Mass Spectrometry, Science for Life Laboratory, Uppsala University, SE-75124 Uppsala, Sweden
| | - Xiaoqun Zhang
- Section of Neurology, Department of Clinical Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Erwan Bezard
- Université de Bordeaux, Institut des Maladies Neurodégénératives, F-33000 Bordeaux, France
| | - Per Svenningsson
- Section of Neurology, Department of Clinical Neuroscience, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Luke R Odell
- Department of Medicinal Chemistry, Uppsala University, SE-75123 Uppsala, Sweden
| | - Per E Andrén
- Department of Pharmaceutical Biosciences, Spatial Mass Spectrometry, Science for Life Laboratory, Uppsala University, SE-75124 Uppsala, Sweden
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Ramdin S, Baijnath S, Naicker T, Govender N. The Clinical Value of Rodent Models in Understanding Preeclampsia Development and Progression. Curr Hypertens Rep 2023; 25:77-89. [PMID: 37043097 PMCID: PMC10172248 DOI: 10.1007/s11906-023-01233-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2023] [Indexed: 04/13/2023]
Abstract
PURPOSE OF REVIEW Preeclampsia (PE) is a leading global cause of maternal and fetal morbidity and mortality. The heterogeneity of this disorder contributes to its elusive etiology. Due to the ethical constraints surrounding human studies, animal models provide a suitable alternative for investigation into PE pathogenesis and novel therapeutic strategies. The purpose of this review is to compare and contrast the various rodent models used to study PE, in order to demonstrate their value in investigating and identifying different characteristics of this disorder. RECENT FINDINGS Several approaches have been employed to create an appropriate animal model of PE, including surgical, genetic manipulation, and pharmacological methods in an attempt to mimic the maternal syndrome. Despite the absence of a model to completely model PE, these models have provided valuable information concerning various aspects of PE pathogenesis and novel therapeutic strategies and have led to the discovery of potential predictive markers of PE. Rodent and murine models have contributed significantly to the study of the pathology associated with specific aspects of the disorder. As a single fully encompassing animal model of PE remains absent, the use of a combination of models has potential value in understanding its etiology as well as in new treatment and management strategies.
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Affiliation(s)
- Sapna Ramdin
- Department of Basic Medical Sciences, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
| | - Sooraj Baijnath
- Integrated Molecular Physiology Research Initiative, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Thajasvarie Naicker
- Optics and Imaging Centre, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Nalini Govender
- Department of Basic Medical Sciences, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa.
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Reddy N, Girdhari L, Shungube M, Gouws AC, Peters BK, Rajbongshi KK, Baijnath S, Mdanda S, Ntombela T, Arumugam T, Bester LA, Singh SD, Chuturgoon A, Arvidsson PI, Maguire GEM, Kruger HG, Govender T, Naicker T. Neutralizing Carbapenem Resistance by Co-Administering Meropenem with Novel β-Lactam-Metallo-β-Lactamase Inhibitors. Antibiotics (Basel) 2023; 12:antibiotics12040633. [PMID: 37106995 PMCID: PMC10135050 DOI: 10.3390/antibiotics12040633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 04/29/2023] Open
Abstract
Virulent Enterobacterale strains expressing serine and metallo-β-lactamases (MBL) genes have emerged responsible for conferring resistance to hard-to-treat infectious diseases. One strategy that exists is to develop β-lactamase inhibitors to counter this resistance. Currently, serine β-lactamase inhibitors (SBLIs) are in therapeutic use. However, an urgent global need for clinical metallo-β-lactamase inhibitors (MBLIs) has become dire. To address this problem, this study evaluated BP2, a novel beta-lactam-derived β-lactamase inhibitor, co-administered with meropenem. According to the antimicrobial susceptibility results, BP2 potentiates the synergistic activity of meropenem to a minimum inhibitory concentration (MIC) of ≤1 mg/L. In addition, BP2 is bactericidal over 24 h and safe to administer at the selected concentrations. Enzyme inhibition kinetics showed that BP2 had an apparent inhibitory constant (Kiapp) of 35.3 µM and 30.9 µM against New Delhi Metallo-β-lactamase (NDM-1) and Verona Integron-encoded Metallo-β-lactamase (VIM-2), respectively. BP2 did not interact with glyoxylase II enzyme up to 500 µM, indicating specific (MBL) binding. In a murine infection model, BP2 co-administered with meropenem was efficacious, observed by the >3 log10 reduction in K. pneumoniae NDM cfu/thigh. Given the promising pre-clinical results, BP2 is a suitable candidate for further research and development as an (MBLI).
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Affiliation(s)
- Nakita Reddy
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Letisha Girdhari
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Mbongeni Shungube
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Arnoldus C Gouws
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Byron K Peters
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Kamal K Rajbongshi
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
- School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2020, South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Thandokuhle Ntombela
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Thilona Arumugam
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Linda A Bester
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Sanil D Singh
- Department of Pharmaceutical Sciences, University of KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Anil Chuturgoon
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
- Science for Life Laboratory, Drug Discovery & Development Platform & Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Thavendran Govender
- Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban 4001, South Africa
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Peters BK, Reddy N, Shungube M, Girdhari L, Baijnath S, Mdanda S, Chetty L, Ntombela T, Arumugam T, Bester LA, Singh SD, Chuturgoon A, Arvidsson PI, Maguire GEM, Kruger HG, Naicker T, Govender T. In Vitro and In Vivo Development of a β-Lactam-Metallo-β-Lactamase Inhibitor: Targeting Carbapenem-Resistant Enterobacterales. ACS Infect Dis 2023; 9:486-496. [PMID: 36786013 PMCID: PMC10012271 DOI: 10.1021/acsinfecdis.2c00485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
β-lactams are the most prescribed class of antibiotics due to their potent, broad-spectrum antimicrobial activities. However, alarming rates of antimicrobial resistance now threaten the clinical relevance of these drugs, especially for the carbapenem-resistant Enterobacterales expressing metallo-β-lactamases (MBLs). Antimicrobial agents that specifically target these enzymes to restore the efficacy of last resort β-lactam drugs, that is, carbapenems, are therefore desperately needed. Herein, we present a cyclic zinc chelator covalently attached to a β-lactam scaffold (cephalosporin), that is, BP1. Observations from in vitro assays (with seven MBL expressing bacteria from different geographies) have indicated that BP1 restored the efficacy of meropenem to ≤ 0.5 mg/L, with sterilizing activity occurring from 8 h postinoculation. Furthermore, BP1 was nontoxic against human hepatocarcinoma cells (IC50 > 1000 mg/L) and exhibited a potency of (Kiapp) 24.8 and 97.4 μM against Verona integron-encoded MBL (VIM-2) and New Delhi metallo β-lactamase (NDM-1), respectively. There was no inhibition observed from BP1 with the human zinc-containing enzyme glyoxylase II up to 500 μM. Preliminary molecular docking of BP1 with NDM-1 and VIM-2 sheds light on BP1's mode of action. In Klebsiella pneumoniae NDM infected mice, BP1 coadministered with meropenem was efficacious in reducing the bacterial load by >3 log10 units' postinfection. The findings herein propose a favorable therapeutic combination strategy that restores the activity of the carbapenem antibiotic class and complements the few MBL inhibitors under development, with the ultimate goal of curbing antimicrobial resistance.
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Affiliation(s)
- Byron K Peters
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Nakita Reddy
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Mbongeni Shungube
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Letisha Girdhari
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa.,School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Gauteng 2193, South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Lloyd Chetty
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Thandokuhle Ntombela
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Thilona Arumugam
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Linda A Bester
- Biomedical Research Unit, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Sanil D Singh
- Department of Pharmaceutical Science, University of KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Anil Chuturgoon
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa.,Science for Life Laboratory, Drug Discovery & Development Platform & Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa.,School of Chemistry and Physics, University of KwaZulu Natal, Durban 4001, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu Natal, Durban 4001, South Africa
| | - Thavendran Govender
- Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa, Empangeni 3886, South Africa
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9
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Reddy R, Pillay V, Baijnath S, Singh SD, Ramdin S, Naicker T, Govender N. Mating success of timed pregnancies in Sprague Dawley rats: Considerations for execution. Reprod Biol 2022; 22:100682. [PMID: 35930886 DOI: 10.1016/j.repbio.2022.100682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 11/19/2022]
Abstract
This study compares three different mating techniques in Sprague-Dawley rats, using the pregnancy rate as the main indicator of success. It provides recommendations for timed-pregnancy experiments to achieve an appropriate sample size for the study of human pregnancy disorders. The implementation of a preconditioning phase, determination of the estrous cycle, the use of two mating strategies (Lee-Boot and Whitten effect), female: male mating ratios, and cohabitation duration should be considered as they improve the mating success rate.
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Affiliation(s)
- Rebecca Reddy
- Dept of Basic Medical Science, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
| | - Virushka Pillay
- Dept of Basic Medical Science, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
| | - Sooraj Baijnath
- School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Sanil D Singh
- Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sapna Ramdin
- Dept of Basic Medical Science, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
| | - Thajasvarie Naicker
- Optics and Imaging Centre, Doris Duke Medical Research Institute, College of Health Sciences, University of KwaZulu-Natal, South Africa
| | - Nalini Govender
- Dept of Basic Medical Science, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa.
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Baijnath S, Kaya I, Nilsson A, Shariatgorji R, Andrén PE. Advances in spatial mass spectrometry enable in-depth neuropharmacodynamics. Trends Pharmacol Sci 2022; 43:740-753. [DOI: 10.1016/j.tips.2022.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/06/2022] [Accepted: 06/06/2022] [Indexed: 11/24/2022]
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11
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Reddy R, Baijnath S, Moodley R, Moodley J, Naicker T, Govender N. South African medicinal plants displaying angiotensin-converting enzyme inhibition: Potential use in the management of preeclampsia. J Ayurveda Integr Med 2022; 13:100562. [PMID: 35675745 PMCID: PMC9178479 DOI: 10.1016/j.jaim.2022.100562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 03/01/2022] [Accepted: 03/04/2022] [Indexed: 01/13/2023] Open
Abstract
In resource-limited settings, such as South Africa, hypertensive disorders of pregnancy such as preeclampsia, is the most common direct cause of maternal deaths. Current management strategies of preeclampsia primarily involve the use of pharmaceutical drugs, which are frequently associated with undesirable side-effects. Moreover, these drugs are often not easily accessible due to financial and economic constraints. Consequently, many patients rely on traditional medicine obtained from medicinal plants to manage health-related conditions. Angiotensin-converting enzyme inhibitors are widely used drugs for the management of preeclampsia. This narrative review aims to highlight the use of indigenous medicinal plants from South Africa with Angiotensin-converting enzyme inhibitory activity whilst also evaluating their potential use in the treatment of hypertension in pregnancy. This information will influence traditional healers and sangomas in their patient management. Furthermore, the antihypertensive potential of these plants will be unraveled thus facilitating the development of new naturally occurring pharmaceutical products to reduce maternal and neonatal mortality and morbidity.
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Affiliation(s)
- Rebecca Reddy
- Department of Basic Medical Science, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Roshila Moodley
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Jagidesa Moodley
- Women's Health and HIV Research Group, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Thajasvarie Naicker
- Discipline of Optics and Imaging, Doris Duke Medical Research Institute, College of Health Sciences, University of KwaZulu-Natal, Durban, KwaZulu-Natal, 4001, South Africa
| | - Nalini Govender
- Department of Basic Medical Science, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa.
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12
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Govender K, Mdanda S, Baijnath S, Kruger HG, Govender T, Naicker T. The analysis of alcohol content in hand sanitisers (in the Durban region) using gas chromatography-mass spectrometry during the COVID-19 pandemic. S Afr j chem 2022. [DOI: 10.17159/0379-4350/2022/v76a04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
ABSTRACT The COVID-19 pandemic has resulted in an unprecedented surge in the demand for alcohol-based hand sanitisers (ABHS). The Centre for Disease Control (CDC) and World Health Organisation (WHO) recommend alcohol, i.e., isopropanol or ethanol, at a 60-95% concentration in ABHS for sufficient antiviral protection. Consumers need to be vigilant of substandard hand sanitisers being marketed to the public. The frequent exposure of microorganisms to alcohol concentrations below the recommended range for infection prevention may lead to resistant mutations, and above the range may be ineffective. Therefore, this study aimed to verify the stated alcohol content in hand sanitisers from their respective labels. We analysed 50 hand sanitiser samples available to our region in Durban, KwaZulu-Natal, South Africa, using a Shimadzu GC-MS-QP2010 Ultra equipped with a Zebron ZB-wax capillary column. The hand sanitisers analysed had a range of 44-93% alcohol content. The data from our study also revealed that 32% (16) of hand sanitisers did not adhere to the stated alcohol indicated on their labels. 16% (8) contained >80% and 12% (6) contained <60%, while 6% (3) of the ABHS contained 1-propanol and ethyl acetate as contaminants, respectively. This study clearly emphasises manufacturers' exploitation of the pandemic and the need for stricter guidelines and regulations for consistency amongst ABHS manufacturers. The public should also be more alert to the % alcohol stated (ideal range 60-80%) on the sanitizer bottle and note one needs to rub their hands together until it feels dry. Keywords: alcohol-content, ethanol, gas chromatography-mass spectrometry, hand sanitiser, 2-propanol (isopropanol)
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Ramdin S, Naicker T, Pillay V, Singh SD, Baijnath S, Mkhwanazi BN, Govender N. Physiological characterization of an arginine vasopressin rat model of preeclampsia. Syst Biol Reprod Med 2021; 68:55-69. [PMID: 34743622 DOI: 10.1080/19396368.2021.1981486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Rodent models have contributed greatly to our understanding of preeclampsia (PE) progression in humans, however to-date no model has been able to effectively replicate the clinical presentation of the disease. This study aimed to provide a thorough physiological characterization of the arginine vasopressin (AVP)-induced rat model of PE to determine its applicability in studying the pathophysiology of PE. Female Sprague Dawley rats (n = 24) were separated into four groups (n = 6 per group) viz., pregnant AVP, pregnant saline, non-pregnant AVP, and non-pregnant saline. All animals received a continuous dose of either AVP (150 ng/h) or saline via subcutaneous mini osmotic pumps for 18 days. Full physiological characterization of the model included measuring systolic and diastolic blood pressure, and collecting urine and blood samples for biochemical analysis. AVP infusion significantly increased blood pressure and urinary protein levels in the pregnant rats (p < 0.05). Biochemical markers measured, differed significantly in the AVP-treated vs the pregnant saline groups (p < 0.05). Placental and individual pup weight decreased significantly in the pregnant AVP vs pregnant saline group (p < 0.05). The physiological and hematological data confirm the usefulness of this rat model in the study of PE, since AVP-induced vasoconstriction increases peripheral resistance and successfully mimics the pathological changes associated with PE development in humans.Abbreviations: PE: preeclampsia; AVP: arginine vasopressin; ISSHP: International Society for the Study of Hypertension in Pregnancy; ACOG: American College of Obstetricians and Gynecologists; RUPP: reduced uterine perfusion pressure; sFlt-1: soluble fms-like tyrosine kinase; VEGF: vascular endothelial growth factor; PlGF: placental growth factor; AVP: arginine vasopressin; PAVP: pregnant AVP-treated; PS: pregnant saline; GD: gestational day; ALT: alanine transaminase; NAVP: non-pregnant AVP-treated; NS: non-pregnant saline; AST: aspartate aminotransferase; HDL: high-density lipoprotein; RBC: red blood cell; RAAS: renin-angiotensin aldosterone system; HELLP: hemolysis, elevated liver enzymes, low platelet.
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Affiliation(s)
- Sapna Ramdin
- Department of Basic Medical Sciences, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
| | - Thajasvarie Naicker
- Optics and Imaging Centre, Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Virushka Pillay
- Department of Basic Medical Sciences, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
| | - Sanil D Singh
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Sooraj Baijnath
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Blessing N Mkhwanazi
- Discipline of Dietetics and Nutrition, College of Agriculture, University of KwaZulu-Natal, Durban, South Africa
| | - Nalini Govender
- Department of Basic Medical Sciences, Faculty of Health Sciences, Durban University of Technology, Durban, South Africa
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Xhakaza SP, Khoza LJ, Haripershad AM, Ghazi T, Dhani S, Mutsimhu C, Molopa MJ, Madurai NP, Madurai L, Singh SD, Gopal ND, Kruger HG, Govender T, Chuturgoon A, Naicker T, Baijnath S. Alterations in neurotransmitter levels and transcription factor expression following intranasal buprenorphine administration. Biomed Pharmacother 2021; 138:111515. [PMID: 33752062 DOI: 10.1016/j.biopha.2021.111515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 03/12/2021] [Accepted: 03/14/2021] [Indexed: 11/28/2022] Open
Abstract
Buprenorphine is an opioid drug used in the management of pain and the treatment opioid addiction. Like other opioids, it is believed that it achieves these effects by altering functional neurotransmitter pathways and the expression of important transcription factors; cyclic AMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in the brain. However, there is a lack of scientific evidence to support these theories. This study investigated the pharmacodynamic effects of BUP administration by assessing neurotransmitter and molecular changes in the healthy rodent brain. Sprague-Dawley rats (150-200 g) were intranasally administered buprenorphine (0.3 mg/mL) and sacrificed at different time points: 0.25, 0.5, 1, 2, 4, 6, 8 and 24 h post drug administration. LC-MS was used to quantify BUP and neurotransmitters (GABA, GLUT, DA, NE and 5-HT) in the brain, while CREB and BDNF gene expression was determined using qPCR. Results showed that BUP reached a Cmax of 1.21 ± 0.0523 ng/mL after 2 h, with all neurotransmitters showing an increase in their concentration over time, with GABA, GLUT and NE reaching their maximum concentration after 8 h. DA and 5-HT reached their maximum concentrations at 1 h and 24 h, respectively post drug administration. Treatment with BUP resulted in significant upregulation in BDNF expression throughout the treatment period while CREB showed patterns of significant upregulation at 2 and 8 h, and downregulation at 1 and 6 h. This study contributes to the understanding of the pharmacodynamic effects of BUP in opioid addiction by proving that the drug significantly influences NT pathways that are implicated in opioid addiction.
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Affiliation(s)
- Sanelisiwe P Xhakaza
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Leon J Khoza
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Advaitaa M Haripershad
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Terisha Ghazi
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Shanel Dhani
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Cosmas Mutsimhu
- Viro Care (SA) Pty Ltd, 12 The Avenue East, Prospecton, Durban 4113, South Africa
| | - Molopa J Molopa
- Viro Care (SA) Pty Ltd, 12 The Avenue East, Prospecton, Durban 4113, South Africa
| | - Nithia P Madurai
- Viro Care (SA) Pty Ltd, 12 The Avenue East, Prospecton, Durban 4113, South Africa
| | - Lorna Madurai
- Viro Care (SA) Pty Ltd, 12 The Avenue East, Prospecton, Durban 4113, South Africa
| | - Sanil D Singh
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Nirmala D Gopal
- Department of Criminology, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Thavendran Govender
- Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa
| | - Anil Chuturgoon
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, Department of Pharmaceutical Sciences, College of Health Science, University of KwaZulu-Natal, Durban, 4001, South Africa.
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15
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Natarajan S, Govender K, Shobo A, Baijnath S, Arvidsson PI, Govender T, Lin J, Maguire GE, Naicker T, Kruger HG. Potential of brain mast cells for therapeutic application in the immune response to bacterial and viral infections. Brain Res 2021; 1767:147524. [PMID: 34015358 DOI: 10.1016/j.brainres.2021.147524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/21/2021] [Accepted: 05/11/2021] [Indexed: 10/21/2022]
Abstract
A wide range of microorganisms can infect the central nervous system (CNS). The immune response of the CNS provides limited protection against microbes penetrating the blood-brain barrier. This results in a neurological deficit and sometimes leads to high morbidity and mortality rates despite advanced therapies. For the last two decades, different studies have expanded our understanding of the molecular basis of human neuroinfectious diseases, especially concerning the contributions of mast cell interactions with other central nervous system compartments. Brain mast cells are multifunctional cells derived from the bone marrow and reside in the brain. Their proximity to blood vessels, their role as "first responders" their unique receptors systems and their ability to rapidly release pathogen responsive mediators enable them to exert a crucial defensive role in the host-defense system. This review describes key biological and physiological functions of mast cells, concerning their ability to recognize pathogens via various receptor systems, followed by a coordinated and selective mediator release upon specific interactions with pathogenic stimulating factors. The goal of this review is to direct attention to the possibilities for therapeutic applications of mast cells against bacterial and viral related infections. We also focus on opportunities for future research activating mast cells via adjuvants.
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Affiliation(s)
- Satheesh Natarajan
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Kamini Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Adeola Shobo
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa; Science for Life Laboratory, Drug Discovery and Development, Platform and Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Thavendran Govender
- Department of Chemistry, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa
| | - Johnson Lin
- School of Life Sciences, University of KwaZulu-Natal, Durban 4001, South Africa; School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Glenn Em Maguire
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-Block, 6th Floor, Room E1-06-016, Durban, South Africa.
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16
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Ntombela T, Seupersad A, Maseko S, Ibeji CU, Tolufashe G, Maphumulo SI, Naicker T, Baijnath S, Maguire GEM, Govender T, Lamichhane G, Honarparvar B, Kruger HG. Mechanistic insight on the inhibition of D, D-carboxypeptidase from Mycobacterium tuberculosis by β-lactam antibiotics: an ONIOM acylation study. J Biomol Struct Dyn 2021; 40:7645-7655. [PMID: 33719919 DOI: 10.1080/07391102.2021.1899052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Mycobacterium tuberculosis cell wall is intricate and impermeable to many agents. A D, D-carboxypeptidase (DacB1) is one of the enzymes involved in the biosynthesis of cell wall peptidoglycan and catalyzes the terminal D-alanine cleavage from pentapeptide precursors. Catalytic activity and mechanism by which DacB1 functions is poorly understood. Herein, we investigated the acylation mechanism of DacB1 by β-lactams using a 6-membered ring transition state model that involves a catalytic water molecule in the reaction pathway. The full transition states (TS) optimization plus frequency were achieved using the ONIOM (B3LYP/6-31 + G(d): AMBER) method. Subsequently, the activation free energies were computed via single-point calculations on fully optimized structures using B3LYP/6-311++(d,p): AMBER and M06-2X/6-311++(d,p): AMBER with an electronic embedding scheme. The 6-membered ring transition state is an effective model to examine the inactivation of DacB1 via acylation by β-lactams antibiotics (imipenem, meropenem, and faropenem) in the presence of the catalytic water. The ΔG# values obtained suggest that the nucleophilic attack on the carbonyl carbon is the rate-limiting step with 13.62, 19.60 and 30.29 kcal mol-1 for Imi-DacB1, Mero-DacB1 and Faro-DacB1, respectively. The electrostatic potential (ESP) and natural bond orbital (NBO) analysis provided significant electronic details of the electron-rich region and charge delocalization, respectively, based on the concerted 6-membered ring transition state. The stabilization energies of charge transfer within the catalytic reaction pathway concurred with the obtained activation free energies. The outcomes of this study provide important molecular insight into the inactivation of D, D-carboxypeptidase by β-lactams.
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Affiliation(s)
- Thandokuhle Ntombela
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Anya Seupersad
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Sibusiso Maseko
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Collins U Ibeji
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Gideon Tolufashe
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Siyabonga Innocent Maphumulo
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Thavendran Govender
- Faculty of Science and Agriculture, Department of Chemistry, University of Zululand, Richards Bay, South Africa
| | - Gyanu Lamichhane
- Center for Tuberculosis Research, Division of Infectious Diseases, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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17
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Sanusi ZK, Lawal MM, Gupta PL, Govender T, Baijnath S, Naicker T, Maguire GEM, Honarparvar B, Roitberg AE, Kruger HG. Exploring the concerted mechanistic pathway for HIV-1 PR-substrate revealed by umbrella sampling simulation. J Biomol Struct Dyn 2020; 40:1736-1747. [PMID: 33073714 DOI: 10.1080/07391102.2020.1832578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
HIV-1 protease (HIV-1 PR) is an essential enzyme for the replication process of its virus, and therefore considered an important target for the development of drugs against the acquired immunodeficiency syndrome (AIDS). Our previous study shows that the catalytic mechanism of subtype B/C-SA HIV-1 PR follows a one-step concerted acyclic hydrolysis reaction process using a two-layered ONIOM B3LYP/6-31++G(d,p) method. This present work is aimed at exploring the proposed mechanism of the proteolysis catalyzed by HIV-1 PR and to ensure our proposed mechanism is not an artefact of a single theoretical technique. Hence, we present umbrella sampling method that is suitable for calculating potential mean force (PMF) for non-covalent ligand/substrate-enzyme association/dissociation interactions which provide thermodynamic details for molecular recognition. The free activation energy results were computed in terms of PMF analysis within the hybrid QM(DFTB)/MM approach. The theoretical findings suggest that the proposed mechanism corresponds in principle with experimental data. Given our observations, we suggest that the QM/MM MD method can be used as a reliable computational technique to rationalize lead compounds against specific targets such as the HIV-1 protease.
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Affiliation(s)
- Zainab K Sanusi
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Monsurat M Lawal
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Pancham Lal Gupta
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | | | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Adrian E Roitberg
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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18
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Govender K, Naicker T, Baijnath S, Chuturgoon AA, Abdul NS, Docrat T, Kruger HG, Govender T. Sub/supercritical fluid chromatography employing water-rich modifier enables the purification of biosynthesized human insulin. J Chromatogr B Analyt Technol Biomed Life Sci 2020; 1155:122126. [DOI: 10.1016/j.jchromb.2020.122126] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 10/24/2022]
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19
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Govender K, Naicker T, Baijnath S, Kruger HG, Govender T. The development of a sub/supercritical fluid chromatography based purification method for peptides. J Pharm Biomed Anal 2020; 190:113539. [DOI: 10.1016/j.jpba.2020.113539] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/28/2020] [Accepted: 08/05/2020] [Indexed: 11/24/2022]
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Mdanda S, Ntshangase S, Singh SD, Naicker T, Kruger HG, Baijnath S, Govender T. Zidovudine and Lamivudine as Potential Agents to Combat HIV-Associated Neurocognitive Disorder. Assay Drug Dev Technol 2020; 17:322-329. [PMID: 31634020 DOI: 10.1089/adt.2019.941] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The central nervous system has been identified as an anatomical reservoir for HIV due the difficulties in delivering therapeutic agents into the brain and this complication results in HIV-associated neurocognitive disorder that persists in infected patients. The brain regions that are potentially exposed to tissue deficits due to HIV have been reported in previous reports; therefore, it is important to determine the drugs that can enter and localize in brain regions that are known to be susceptible to HIV neurodegeneration. Sprague-Dawley rats received intraperitoneal doses of zidovudine and lamivudine (50 mg kg-1). Mass spectrometry methods were used to determine the pharmacokinetics, of zidovudine and lamivudine, in the brain using liquid chromatography tandem mass spectrometry and mass spectrometry imaging (MSI), respectively. Zidovudine and lamivudine displayed complementary pharmacokinetic curves indicating a rapid absorption and blood-brain barrier penetration of both drugs reaching Cmax at 0.5 h after single dose. MSI of coronal brain sections showed that zidovudine and lamivudine are mostly distributed in corpus callosum, globus pallidus, striatum, and the neocortex region. Mass spectrometry techniques were used to demonstrate that zidovudine and lamivudine drugs are able to reach and localize in brain regions that are targets of HIV neurodegeneration in the brain.
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Affiliation(s)
- Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sanil D Singh
- Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa.,AnSynth Pty Ltd., Durban, South Africa
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21
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Teklezgi B, Pamreddy A, Ntshangase S, Mdanda S, Singh SD, Gopal ND, Naicker T, Kruger HG, Govender T, Baijnath S. Mass Spectrometric Imaging of the Brain Demonstrates the Regional Displacement of 6-Monoacetylmorphine by Naloxone. ACS Omega 2020; 5:12596-12602. [PMID: 32548443 PMCID: PMC7288357 DOI: 10.1021/acsomega.9b03570] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
Overdose is the main cause of mortality among heroin users. Many of these overdose-induced deaths can be prevented through the timely administration of naloxone (NLX), a nonselective mu (μ)-, kappa (κ)-, and delta (δ)-opioid receptor antagonist. NLX competitively inhibits opioid-overdose-induced respiratory depression without eliciting any narcotic effect itself. The aim of this study was to investigate the antagonistic action of NLX by comparing its distribution to that of 6-monacetylmorphine (6-MAM), heroin's major metabolite, in a rodent model using mass spectrometric imaging (MSI) in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Male Sprague-Dawley rats (n = 5) received heroin (10 mg kg-1) intraperitoneally, NLX (10 mg kg-1) intranasally, and NLX injected intranasally 5 min after heroin administration. The animals were sacrificed 15 min after dose and brain tissues were harvested. The MSI image analysis showed a region-specific distribution of 6-MAM in the brain regions including the corpus callosum, hippocampal formation, cerebral cortex, corticospinal tracts, caudate putamen, thalamus, globus pallidus, hypothalamus, and basal forebrain regions of the brain. The antagonist had a similar biodistribution throughout the brain in both groups of animals that received NLX or NLX after heroin administration. The MSI analysis demonstrated that the intensity of 6-MAM in these brain regions was reduced following NLX treatment. The decrease in 6-MAM intensity was caused by its displacement by the antagonist and its binding to these receptors in these specific brain regions, consequently enhancing the opioid elimination. These findings will contribute to the evaluation of other narcotic antagonists that might be considered for use in the treatment of drug overdose via MSI.
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Affiliation(s)
- Belin
G. Teklezgi
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Annapurna Pamreddy
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Sphamandla Ntshangase
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Sipho Mdanda
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Sanil D. Singh
- Department
of Pharmaceutical Science, University of
KwaZulu-Natal, Westville
Campus, Durban 3629, South Africa
| | - Nirmala D. Gopal
- Department
of Criminology, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Tricia Naicker
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Hendrik G. Kruger
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
| | - Thavendran Govender
- Department
of Chemistry, University of Zululand, Richards Bay 3900, South Africa
| | - Sooraj Baijnath
- Catalysis
and Peptide Research Unit, University of
KwaZulu-Natal, Westville Campus, Durban 3629, South Africa
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22
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Maharaj P, Baijnath S, Naidoo P. "Knowledge and practices of HIV infected patients regarding medicine disposal among patients attending public ARV clinics in KwaZulu Natal, South Africa". BMC Public Health 2020; 20:884. [PMID: 32513139 PMCID: PMC7282097 DOI: 10.1186/s12889-020-09018-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 06/01/2020] [Indexed: 11/23/2022] Open
Abstract
Background Recent analysis of drinking water in South Africa found the presence of ARVs, other pharmaceutical and personal care products. The environmental and human health risk that this presents is daunting. The increased use of ARVs with poor disposal practices could be the reason for these substances being present in drinking water. Therefore, this study aimed to determine the knowledge and practices of HIV infected patients, regarding medicine disposal. Method A descriptive, cross sectional, quantitative study that utilised a structured, self-administered, questionnaire was undertaken at 3 different public ARV clinics in the eThekwini Metro of KwaZulu Natal, SA. The variables included questions on demographics, knowledge and practices of medicine disposal of ARV and other medications. Data was captured using excel spreadsheets and analysed using SPSS version 25. Chi square tests were used to compare factors between correct and incorrect knowledge and practice groups. Results Four hundred and eighty four participants agreed to participate in this study, of which the majority (71.1%) were females. Over 87% of the participants knew that improper disposal of medicines were harmful to the environment with only 28.3% knowing that there were laws governing the way medicines should be disposed. Majority of participants that had unused and expired ARVs at home disposed of these medicines. The most common route of medicine disposal for ARVs was by throwing these medicines into the bin (56.4%). Only 24.2% of participants were informed by healthcare professionals about the proper method of medicine disposal. Participants who had secondary and tertiary level of education (p = 0.043) and the ability to speak English (p = 0.001) had appropriate knowledge on medicine disposal. Conclusion This study identified that poor medicine disposal practices and lack of adequate information about the proper methods of medicine disposal were evident among the participant population. There is a need for patient education and healthcare professional intervention to ensure patients are aware of standard proper medicine disposal practices.
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Affiliation(s)
- Pooja Maharaj
- Discipline of Pharmaceutical Sciences, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, University Road, Westville, Private Bag X54001, Durban, 4000, South Africa.
| | - Sooraj Baijnath
- Discipline of Pharmaceutical Sciences, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, University Road, Westville, Private Bag X54001, Durban, 4000, South Africa
| | - Panjasaram Naidoo
- Discipline of Pharmaceutical Sciences, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, University Road, Westville, Private Bag X54001, Durban, 4000, South Africa
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23
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Reddy N, Shungube M, Arvidsson PI, Baijnath S, Kruger HG, Govender T, Naicker T. A 2018–2019 patent review of metallo beta-lactamase inhibitors. Expert Opin Ther Pat 2020; 30:541-555. [DOI: 10.1080/13543776.2020.1767070] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Nakita Reddy
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Mbongeni Shungube
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Per I Arvidsson
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
- Science for Life Laboratory, Karolinska Institutet, Stockhlom, Sweden
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | | | - Tricia Naicker
- Catalysis and Peptide Research Unit, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
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24
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Govender K, Naicker T, Lin J, Baijnath S, Chuturgoon AA, Abdul NS, Docrat T, Kruger HG, Govender T. A novel and more efficient biosynthesis approach for human insulin production in Escherichia coli (E. coli). AMB Express 2020; 10:43. [PMID: 32152803 PMCID: PMC7062966 DOI: 10.1186/s13568-020-00969-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/05/2020] [Indexed: 11/10/2022] Open
Abstract
Insulin has captured researchers' attention worldwide. There is a rapid global rise in the number of diabetic patients, which increases the demand for insulin. Current methods of insulin production are expensive and time-consuming. A PCR-based strategy was employed for the cloning and verification of human insulin. The human insulin protein was then overexpressed in E. coli on a laboratory scale. Thereafter, optimisation of human insulin expression was conducted. The yield of human insulin produced was approximately 520.92 (mg/L), located in the intracellular fraction. Human insulin was detected using the MALDI-TOF-MS and LC-MS methods. The crude biosynthesised protein sequence was verified using protein sequencing, which had a 100% similarity to the human insulin sequence. The biological activity of human insulin was tested in vitro using a MTT assay, which revealed that the crude biosynthesised human insulin displayed a similar degree of efficacy to the standard human insulin. This study eliminated the use of affinity tags since an untagged pET21b expression vector was employed. Tedious protein renaturation, inclusion body recovery steps, and the expensive enzymatic cleavage of the C-peptide of insulin were eliminated, thereby making this method of biosynthesising human insulin a novel and more efficient method.
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25
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Docrat TF, Nagiah S, Naicker N, Baijnath S, Singh S, Chuturgoon AA. The protective effect of metformin on mitochondrial dysfunction and endoplasmic reticulum stress in diabetic mice brain. Eur J Pharmacol 2020; 875:173059. [PMID: 32131023 DOI: 10.1016/j.ejphar.2020.173059] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 02/23/2020] [Accepted: 02/28/2020] [Indexed: 12/26/2022]
Abstract
Diabetes is a metabolic disorder associated with mitochondrial (mt) dysfunction and oxidative stress. The molecular mechanisms involved in diabetes-associated neurological complications remain elusive. This study aims to investigate the protective effect of metformin (MF) on regulatory networks and integrated stress responses in brain tissue of Streptozotocin (STZ)-induced diabetic mice. STZ-induced diabetic mice were treated with MF (20 mg/kg BW), and whole brain tissue was harvested for further analysis. Protein carbonylation was measured as a marker of neuronal oxidative stress. Protein expression of mt chaperones, maintenance proteins, and regulators of the unfolded protein response (UPR) were measured by Western blot. Transcript levels of antioxidant enzyme GSTA4; mt biogenesis markers, ER stress regulators, and miR-132 and miR-148a were analysed using qPCR. The results showed that MF efficiently reduced protein carbonylation and oxidation. Mt function was improved by MF-treatment through upregulation of chaperone proteins (HSP60, HSP70 and LonP1). MF elicits the UPR to attenuate ER stress through a miR-132 repression mechanism. Additionally, MF was found to elevate deacetylases- Sirt1, Sirt3; and mt biogenesis marker PGC-1α through miR-148a repression. This is the first study to demonstrate the epigenetic regulation of mt maintenance by MF in diabetic C57BL/6 mouse whole brain tissue. We thus conclude that MF, beyond its anti-hyperglycaemic role, mediates neuroprotection through epigenomic and integrated stress responses in diabetic mice.
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Affiliation(s)
- Taskeen Fathima Docrat
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, College of Health Science, University of KwaZulu-Natal, South Africa
| | - Savania Nagiah
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, College of Health Science, University of KwaZulu-Natal, South Africa
| | - Nikita Naicker
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, College of Health Science, University of KwaZulu-Natal, South Africa
| | - Sooraj Baijnath
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, College of Health Science, University of KwaZulu-Natal, South Africa
| | - Sanil Singh
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, College of Health Science, University of KwaZulu-Natal, South Africa
| | - Anil A Chuturgoon
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, College of Health Science, University of KwaZulu-Natal, South Africa.
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26
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Anand K, Naicker T, Baijnath S, Mphahlele MJ, Katari NK, Zamisa SJ, Balakumar C, Vijayakumar K, Palanisamy S, Saravanan M, Boomi P, Chuturgoon A. TPGS-mediated one-pot synthesis, XRD structural analysis, antimicrobial evaluation and molecular docking of novel heterocycles as potential inhibitors of p53-MDM2 protein. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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27
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Sanusi ZK, Lawal MM, Govender T, Baijnath S, Naicker T, Maguire GEM, Honarparvar B, Kruger HG. Concerted hydrolysis mechanism of HIV-1 natural substrate against subtypes B and C-SA PR: insight through molecular dynamics and hybrid QM/MM studies. Phys Chem Chem Phys 2020; 22:2530-2539. [PMID: 31942584 DOI: 10.1039/c9cp05639d] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
It is well known that understanding the catalytic mechanism of HIV-1 PR is the rationale on which its inhibitors were developed; therefore, a better understanding of the mechanism of natural substrate hydrolysis is important. Herein, the reaction mechanism of HIV-1 natural substrates with subtypes B and common mutant in South Africa (subtype C-SA) protease were studied through transition state modelling, using a general acid-general base (GA-GB) one-step concerted process. The activation free energies of enzyme-substrate complexes were compared based on their rate of hydrolysis using a two-layered ONIOM (B3LYP/6-31++G(d,p):AMBER) method. We expanded our computational model to obtain a better understanding of the mechanism of hydrolysis as well as how the enzyme recognises or chooses the cleavage site of the scissile bonds. Using this model, a potential substrate-based inhibitor could be developed with better potency. The calculated activation energies of natural substrates in our previous study correlated well with experimental data. A similar trend was observed for the Gag and Gag-Pol natural substrates in the present work for both enzyme complexes except for the PR-RT substrate. Natural bond orbital (NBO) analysis was also applied to determine the extent of charge transfer within the QM part of both enzymes considered and the PR-RT natural substrate. The result of this study shows that the method can be utilized as a dependable computational technique to rationalize lead compounds against specific targets.
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Affiliation(s)
- Zainab K Sanusi
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| | - Monsurat M Lawal
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| | | | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa. and School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
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28
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Singh S, Phulukdaree A, Abdul N, Tiloke C, Baijnath S, Chuturgoon A. Mycotoxin-induced cytotoxicity of commercially available pelleted feline feed in feline peripheral blood mononuclear cells Ex Vivo. ANIM NUTR FEED TECHN 2020. [DOI: 10.5958/0974-181x.2020.00020.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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29
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Ntshangase S, Mdanda S, Singh SD, Naicker T, Kruger HG, Baijnath S, Govender T. Mass Spectrometry Imaging Demonstrates the Regional Brain Distribution Patterns of Three First-Line Antiretroviral Drugs. ACS Omega 2019; 4:21169-21177. [PMID: 31867510 PMCID: PMC6921606 DOI: 10.1021/acsomega.9b02582] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 11/06/2019] [Indexed: 05/04/2023]
Abstract
HIV in the central nervous system (CNS) contributes to the development of HIV-associated neurological disorders (HAND), even with chronic antiretroviral therapy. In order for antiretroviral therapy to be effective in protecting the CNS, these drugs should have the ability to localize in brain areas known to be affected by HIV. Consequently, this study aimed to investigate the localization patterns of three first-line antiretroviral drugs, namely, efavirenz, tenofovir, and emtricitabine, in the rat brain. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) were utilized to assess the pharmacokinetics and brain spatial distribution of the three drugs. Each drug was administered (50 mg/kg) to healthy female Sprague-Dawley rats via intraperitoneal administration. LC-MS/MS results showed that all three drugs could be delivered into the brain, although they varied in blood-brain barrier permeability. MALDI-MSI showed a high degree of efavirenz localization across the entire brain, while tenofovir localized mainly in the cortex. Emtricitabine distributed heterogeneously mainly in the thalamus, corpus callosum, and hypothalamus. This study showed that efavirenz, tenofovir, and emtricitabine might be a potential drug combination antiretroviral therapy for CNS protection against HAND.
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Affiliation(s)
- Sphamandla Ntshangase
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
| | - Sipho Mdanda
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
| | - Sanil D. Singh
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
| | - Tricia Naicker
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
| | - Hendrik G. Kruger
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
| | - Sooraj Baijnath
- Catalysis
and Peptide Research Unit and Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban 4041, South Africa
- E-mail: . Tel: +27 31 260 81799. Cell: +27 84 562 1530(S.B.)
| | - Thavendran Govender
- AnSynth
Pty Ltd., 498 Grove End
Drive, Durban 4000, South Africa
- E-mail: (T.G.)
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30
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Ntshangase S, Mdanda S, Naicker T, Kruger HG, Baijnath S, Govender T. Spatial distribution of elvitegravir and tenofovir in rat brain tissue: Application of matrix-assisted laser desorption/ionization mass spectrometry imaging and liquid chromatography/tandem mass spectrometry. Rapid Commun Mass Spectrom 2019; 33:1643-1651. [PMID: 31240777 DOI: 10.1002/rcm.8510] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/10/2019] [Accepted: 06/18/2019] [Indexed: 05/21/2023]
Abstract
RATIONALE The complexity of central nervous system (CNS) drug delivery is the main obstacle with the blood-brain barrier (BBB) known to restrict access of most pharmaceutical drugs into the brain. Mass spectrometry imaging (MSI) offers possibilities for studying drug deposition into the CNS. METHODS The deposition and spatial distribution of the two antiretroviral drugs elvitegravir and tenofovir in the brain were investigated in healthy female Sprague-Dawley rats following a single intraperitoneal administration (50 mg/kg). This was achieved by the utilization of quantitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) and matrix-assisted laser desorption/ionization (MALDI) MSI. RESULTS LC/MS/MS showed that elvitegravir has better BBB penetration, reaching maximum concentration in the brain (Cmax brain) of 976.5 ng/g. In contrast, tenofovir displayed relatively lower BBB penetration, reaching Cmax brain of 54.5 ng/g. MALDI-MSI showed the heterogeneous distribution of both drugs in various brain regions including the cerebral cortex. CONCLUSIONS LC/MS/MS and MALDI-MSI provided valuable information about the relative concentration and the spatial distribution of the two common antiretroviral drugs. This study has also shown the capability of MALDI-MSI for direct visualization of pharmaceutical drugs in situ.
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Affiliation(s)
- Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
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31
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Mdanda S, Ntshangase S, Singh SD, Naicker T, Kruger HG, Baijnath S, Govender T. Mass spectrometric investigations into the brain delivery of abacavir, stavudine and didanosine in a rodent model. Xenobiotica 2019; 50:570-579. [PMID: 31403353 DOI: 10.1080/00498254.2019.1655605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
HIV replication in the brain is unopposed due to reduced antiretroviral drug penetration into the central nervous system (CNS). Prevalence of HIV-associated neurocognitive disorder (HAND) has increased severely in patients living with HIV despite current treatments. The aims of this study were to evaluate the brain bio-distribution of alternative nucleoside reverse transcriptase inhibitors, abacavir, stavudine and didanosine in the CNS and to determine their localization patterns in the brain.Sprague-Dawley rats received 50 mg kg-1 single i.p dose of each drug. Mass spectrometric techniques were then used to investigate the pharmacokinetics and localization patterns of these drugs in the brain using LC-MS/MS and mass spectrometric imaging (MSI), respectively.Abacavir, stavudine and didanosine reached the Brain Cmax with concentration of 831.2, 1300 and 43.37 ngmL-1, respectively. Based on MSI analysis Abacavir and Stavudine were located in brain regions that are strongly implicated in the progression of HAND.Abacavir and Stavudine penetrated into CNS, reaching a Cmax that was above the IC50 for HIV (457.6 and 112.0 ngmL-1, respectively), however, it was noted ddI showed poor entry within the brain, therefore, it is recommended that this drug cannot be considered for treating CNS-HIV.
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Affiliation(s)
- Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | | | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa.,Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
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32
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Maseko S, Padayachee E, Maphumulo S, Govender T, Sayed Y, Maguire G, Lin J, Naicker T, Baijnath S, Gerhardus KH. Kinetic and thermodynamic characterisation of HIV-protease inhibitors against E35D↑G↑S mutant in the South African HIV-1 subtype C protease. J Enzyme Inhib Med Chem 2019; 34:1451-1456. [PMID: 31409143 PMCID: PMC6713120 DOI: 10.1080/14756366.2019.1636234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Herein, we report the effect of nine FDA approved protease inhibitor drugs against a new HIV-1 subtype C mutant protease, E35D↑G↑S. The mutant has five mutations, E35D, two insertions, position 36 (G and S), and D60E. Kinetics, inhibition constants, vitality, Gibbs free binding energies are reported. The variant showed a decreased affinity for substrate and low catalytic efficiency compared to the wild type. There was a significant decrease in the binding of seven FDA approved protease inhibitors against the mutant (p < .0001). Amprenavir and ritonavir showed the least decrease, but still significant reduced activity in comparison to the wildtype (4 and 5 folds, respectively, p = .0021 and .003, respectively). Nelfinavir and atazanavir were the worst inhibitors against the variant as seen from the IC50, with values of 1401 ± 3.0 and 685 ± 3.0 nM, respectively. Thermodynamics data showed less favourable Gibbs free binding energies for the protease inhibitors to the mutant.
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Affiliation(s)
- Sibusiso Maseko
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Eden Padayachee
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Siyabonga Maphumulo
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Thavendran Govender
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Yasien Sayed
- b Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand , Wits , South Africa
| | - Glenn Maguire
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa.,c School of Chemistry and Physics, University of KwaZulu-Natal , Durban , South Africa
| | - Johnson Lin
- d School of Life Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Tricia Naicker
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Sooraj Baijnath
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
| | - Kruger Hendrik Gerhardus
- a Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal , Durban , South Africa
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Govender N, Ramdin S, Pillay V, Mkhwanazi BN, Singh S, Baijnath S. The development of an arginine vasopressin rodent model for the study of preeclampsia. Placenta 2019. [DOI: 10.1016/j.placenta.2019.06.231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Teklezgi BG, Pamreddy A, Baijnath S, Kruger HG, Naicker T, Gopal ND, Govender T. Time-dependent regional brain distribution of methadone and naltrexone in the treatment of opioid addiction. Addict Biol 2019; 24:438-446. [PMID: 29441714 DOI: 10.1111/adb.12609] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/01/2017] [Accepted: 01/17/2018] [Indexed: 12/15/2022]
Abstract
Opioid addiction is a serious public health concern with severe health and social implications; therefore, extensive therapeutic efforts are required to keep users drug free. The two main pharmacological interventions, in the treatment of addiction, involve management with methadone an mu (μ)-opioid agonist and treatment with naltrexone, μ-opioid, kappa (κ)-opioid and delta (δ)-opioid antagonist. MET and NAL are believed to help individuals to derive maximum benefit from treatment and undergo a full recovery. The aim of this study was to determine the localization and distribution of MET and NAL, over a 24-hour period in rodent brain, in order to investigate the differences in their respective regional brain distributions. This would provide a better understanding of the role of each individual drug in the treatment of addiction, especially NAL, whose efficacy is controversial. Tissue distribution was determined by using mass spectrometric imaging (MSI), in combination with quantification via liquid chromatography tandem mass spectrometry. MSI image analysis showed that MET was highly localized in the striatal and hippocampal regions, including the nucleus caudate, putamen and the upper cortex. NAL was distributed with high intensities in the mesocorticolimbic system including areas of the cortex, caudate putamen and ventral pallidum regions. Our results demonstrate that MET and NAL are highly localized in the brain regions with a high density of μ-receptors, the primary sites of heroin binding. These areas are strongly implicated in the development of addiction and are the major pathways that mediate brain stimulation during reward.
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Affiliation(s)
- Belin G. Teklezgi
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Annapurna Pamreddy
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research UnitUniversity of KwaZulu‐Natal South Africa
| | - Nirmala D. Gopal
- Department of CriminologyUniversity of KwaZulu‐Natal South Africa
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Ntshangase S, Mdanda S, Naicker T, Kruger HG, Govender T, Baijnath S. Rilpivirine as a potential candidate for the treatment of HIV-associated neurocognitive disorders (HAND). J Mol Histol 2019; 50:295-303. [PMID: 31011919 DOI: 10.1007/s10735-019-09826-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/17/2019] [Indexed: 12/20/2022]
Abstract
As the HIV epidemic continues to contribute to global morbidity and mortality, the prevalence of HIV-associated neurological disorders (HAND) also continues to be a major concern in infected individuals, despite the widespread use of combination antiretroviral therapy. Therefore, current antiretroviral drugs should be able to reach therapeutic levels in the brain for the treatment of HAND. The brain distribution of the next-generation non-nucleoside reverse transcriptase inhibitor, rilpivirine (RPV) was investigated in healthy female Sprague-Dawley (SD) rats. The presented study involves the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) to estimate the concentrations of RPV in plasma and brain homogenate samples. The use of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) provided regional spatial distribution of RPV in brain tissue sections. The localization of RPV was found to be relatively high in the hypothalamus, thalamus and corpus callosum, brain regions known to be associated with neurodegeneration during HAND (including the cerebral cortex). This study has shown that RPV has an excellent blood-brain barrier penetrability. Thus, in combination with other antiretroviral drugs, better central nervous system (CNS) protection against HAND can possibly be achieved.
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Affiliation(s)
- Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Westville Campus, E-block, 6th floor, Room E1-06-016, Durban, South Africa.
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Naicker T, Brasil E, Samipillai M, Govender T, Baijnath S. Crystal structure of 2-(4-fluorophenyl)-N-phenyl-2-(phenylamino)ethanesulfonamide – toluene (1/0.5), C23.5H23FN2O2S. Z KRIST-NEW CRYST ST 2018. [DOI: 10.1515/ncrs-2018-0253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractC23.5H23FN2O2S, Mr = 416.50, monoclinic, C2/c (no. 15), a = 27.2594(19) Å, b = 5.7351(4) Å, c = 26.1139(18) Å, β = 102.009(2)°, V = 3993.2(5) Å3, Z = 8, Rgt(F) = 0.0358, wRref(F2) = 0.0958 T = 100(2) K.
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Affiliation(s)
- Tricia Naicker
- University of KwaZulu Natal, Catalysis and Peptide Research Unit, Durban 4000, South Africa
| | - Edikarlos Brasil
- University of KwaZulu Natal, Catalysis and Peptide Research Unit, Durban 4000, South Africa
| | - Marivel Samipillai
- University of KwaZulu Natal, Catalysis and Peptide Research Unit, Durban 4000, South Africa
| | - Thavendran Govender
- University of KwaZulu Natal, Catalysis and Peptide Research Unit, Durban 4000, South Africa
| | - Sooraj Baijnath
- University of KwaZulu Natal, Catalysis and Peptide Research Unit, Durban 4000, South Africa
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Shobo A, Pamreddy A, Kruger HG, Makatini MM, Naicker T, Govender T, Baijnath S. Enhanced brain penetration of pretomanid by intranasal administration of an oil-in-water nanoemulsion. Nanomedicine (Lond) 2018; 13:997-1008. [PMID: 29790418 DOI: 10.2217/nnm-2017-0365] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
AIM To enhance the drug delivery to the brain with an oil-in-water nanoemulsion of pretomanid via intranasal (IN) administration. MATERIALS & METHODS The study involved 70 male Sprague-Dawley rats (160-180 g) that received either 20 mg/kg body weight (b.w.) a nanoemulsion or a 20 mg/kg b.w. of pretomanid in solution via the IN route. The drug was quantified by liquid chromatography-tandem mass spectrometry to investigate whole tissue-drug concentrations, and mass spectrometric imaging to visualize drug localization in the brain. RESULTS Nanoemulsion delivery concentrations of pretomanid in the brain reached peak concentrations (Cmax) of 12,062.3 ng/g that is significantly higher than the required therapeutic level. The mass spectrometric imaging analysis clearly showed a time dependent and uniform distribution in the brain. CONCLUSION The results of this study show that IN delivery of oil-in-water nanoemulsion may be very promising for targeting anatomical tuberculosis reservoirs, such as the brain.
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Affiliation(s)
- Adeola Shobo
- Catalysis & Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa
| | - Annapurna Pamreddy
- Catalysis & Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa
| | - Hendrik G Kruger
- Catalysis & Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa
| | - Maya M Makatini
- Molecular Sciences Institute, School of Chemistry, University of Witwatersrand, Johannesburg 2050, South Africa
| | - Tricia Naicker
- Catalysis & Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa
| | - Thavendran Govender
- Catalysis & Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa
| | - Sooraj Baijnath
- Catalysis & Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa
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Pamreddy A, Baijnath S, Naicker T, Ntshangase S, Mdanda S, Lubanyana H, Kruger HG, Govender T. Bedaquiline has potential for targeting tuberculosis reservoirs in the central nervous system. RSC Adv 2018; 8:11902-11907. [PMID: 35539382 PMCID: PMC9079262 DOI: 10.1039/c8ra00984h] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/05/2018] [Indexed: 01/01/2023] Open
Abstract
Bedaquiline (BDQ) is the first-in-class United States Food and Drug Administration (US FDA) approved anti-tuberculosis (anti-TB) drug, which is a novel diarylquinoline antibiotic that has recently been utilized as an effective adjunct to existing therapies for multidrug-resistant tuberculosis (MDR-TB). BDQ is especially promising due to its novel mechanism of action, activity against drug-sensitive and drug-resistant tuberculosis (TB) in addition to having the potential to shorten treatment duration. Drug delivery to the central nervous system (CNS) is a major concern in TB chemotherapy, especially with the increasing cases of CNS-TB. In this study, we investigated the CNS penetration of BDQ in healthy rodent brain. Male Sprague-Dawley rats (n = 27; 100 ± 20 g) received a single 25 mg kg-1 b.w dose of BDQ via intraperitoneal (i.p.) administration, over a 24 h period. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to determine whole tissue drug concentrations and matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) was utilized to evaluate drug distribution in the brain. BDQ reached peak concentrations (C max) of 134.97 ng mL-1 in the brain at a T max of 4 h, which is within the range required for therapeutic efficacy. BDQ was widely distributed in the brain, with a particularly high intensity in the corpus callosum and associated subcortical white matter including the striatal, globus pallidus, corticofugal pathways, ventricular system, basal forebrain region and hippocampal regions. Using MALDI MSI, this study demonstrates that due to BDQ's distribution in the brain, it has the potential to target TB reservoirs within this organ.
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Affiliation(s)
- Annapurna Pamreddy
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal Westville Campus Durban 4000 South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal Westville Campus Durban 4000 South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal Westville Campus Durban 4000 South Africa
| | - Sphamandla Ntshangase
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal Westville Campus Durban 4000 South Africa
| | - Sipho Mdanda
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal Westville Campus Durban 4000 South Africa
| | - Hlengekile Lubanyana
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal Westville Campus Durban 4000 South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal Westville Campus Durban 4000 South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal Westville Campus Durban 4000 South Africa
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Singh SD, Sheik Abdul N, Phulukdaree A, Tiloke C, Nagiah S, Baijnath S, Chuturgoon AA. Toxicity assessment of mycotoxins extracted from contaminated commercial dog pelleted feed on canine blood mononuclear cells. Food Chem Toxicol 2018; 114:112-118. [PMID: 29452190 DOI: 10.1016/j.fct.2018.02.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 02/07/2018] [Accepted: 02/08/2018] [Indexed: 12/31/2022]
Abstract
Raw ingredients of pet food are often contaminated with mycotoxins. This is a serious health problem to pets and causes emotional and economical stress to the pet owners. The aim of this study was to determine the immunotoxicity of the most common mycotoxins (aflatoxin, fumonisin, ochratoxin A and zearalenone) by examining 20 samples of extruded dry dog food found on the South African market [10 samples from standard grocery store lines (SB), 10 from premium veterinarian lines (PB)]. Pelleted dog food was subjected to extraction protocols optimized for the above mentioned mycotoxins. Dog lymphocytes were treated with the extracts (24 h incubation and final concentration 40 μg/ml) to determine cell viability, mitochondrial function, oxidative stress, and markers of cell death using spectrophotometry, luminometry and flow cytometry. Malondialdehyde, a marker of oxidative stress showed no significant difference between SB and PB, however, GSH was significantly depleted in SB extract treatments. Markers of apoptosis (phosphatidylserine externalization) and necrosis (propidium iodide incorporation) were elevated in both food lines when compared to untreated control cells, interestingly SB extracts were significantly higher than PB. We also observed decreased ATP levels and increased mitochondrial depolarization in cells treated with both lines of feed with SB showing the greatest differences when compared to the control. This study provides evidence that irrespective of price, quality or marketing channels, pet foods present a high risk of mycotoxin contamination. Though in this study PB fared better than SB in regards to cell toxicity, there is a multitude of other factors that need to be studied which may have an influence on other negative outcomes.
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Affiliation(s)
- Sanil D Singh
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa.
| | - Naeem Sheik Abdul
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa.
| | - Alisa Phulukdaree
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa.
| | - Charlette Tiloke
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa.
| | - Savania Nagiah
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa.
| | - Sooraj Baijnath
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa.
| | - Anil A Chuturgoon
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa.
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Singh SD, Baijnath S, Chuturgoon AA. A comparison of mycotoxin contamination of premium and grocery brands of pelleted cat food in South Africa. J S Afr Vet Assoc 2017; 88:e1-e4. [PMID: 29227138 PMCID: PMC6138209 DOI: 10.4102/jsava.v88i0.1480] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 10/05/2017] [Accepted: 10/10/2017] [Indexed: 11/05/2022] Open
Abstract
Contamination with mycotoxins is of concern to pet owners and veterinary practitioners owing to their ability to cause disease and exacerbate the pathological changes associated with other diseases. Currently, there is a lack of information regarding the mycotoxin content of common premium brand (PB) and grocery brand (GB) cat feeds. Therefore, we undertook to determine the mycobiota content of feed samples, from both categories (n = 6 each), and measured the levels of aflatoxin (AF), fumonisin (FB), ochratoxin A (OTA) and zearalenone (ZEA) by high performance liquid chromatographic analysis. There were high concentrations of mycotoxins in both categories of feed, regardless of the notion that PBs are of a higher quality. The concentration of these toxins may contribute to the development of related pathologies in felines.
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Ntshangase S, Shobo A, Kruger HG, Asperger A, Niemeyer D, Arvidsson PI, Govender T, Baijnath S. The downfall of TBA-354 - a possible explanation for its neurotoxicity via mass spectrometric imaging. Xenobiotica 2017; 48:938-944. [PMID: 28859520 DOI: 10.1080/00498254.2017.1375168] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
1. TBA-354 was a promising antitubercular compound with activity against both replicating and static Mycobacterium tuberculosis (M.tb), making it the focal point of many clinical trials conducted by the TB Alliance. However, findings from these trials have shown that TBA-354 results in mild signs of reversible neurotoxicity; this left the TB Alliance with no other choice but to stop the research. 2. In this study, mass spectrometric methods were used to evaluate the pharmacokinetics and spatial distribution of TBA-354 in the brain using a validated liquid chromatography tandem-mass spectrometry (LCMS/MS) and mass spectrometric imaging (MSI), respectively. Healthy female Sprague-Dawley rats received intraperitoneal (i.p.) doses of TBA-354 (20 mg/kg bw). 3. The concentrationtime profiles showed a gradual absorption and tissue penetration of TBA-354 reaching the Cmax at 6 h post dose, followed by a rapid elimination. MSI analysis showed a time-dependent drug distribution, with highest drug concentration mainly in the neocortical regions of the brain. 4. The distribution of TBA-354 provides a possible explanation for the motor dysfunction observed in clinical trials. These results prove the importance of MSI as a potential tool in preclinical evaluations of suspected neurotoxic compounds.
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Affiliation(s)
- Sphamandla Ntshangase
- a Catalysis and Peptide Research Unit, University of KwaZulu-Natal , Durban , South Africa
| | - Adeola Shobo
- a Catalysis and Peptide Research Unit, University of KwaZulu-Natal , Durban , South Africa
| | - Hendrik G Kruger
- a Catalysis and Peptide Research Unit, University of KwaZulu-Natal , Durban , South Africa
| | | | | | - Per I Arvidsson
- a Catalysis and Peptide Research Unit, University of KwaZulu-Natal , Durban , South Africa.,c Science for Life Laboratory, Drug Discovery & Development Platform & Division of Translational Medicine and Chemical Biology, Development of Medical Biochemistry and Biophysics, Karolinska Institutet , Stockholm , Sweden
| | - Thavendran Govender
- a Catalysis and Peptide Research Unit, University of KwaZulu-Natal , Durban , South Africa
| | - Sooraj Baijnath
- a Catalysis and Peptide Research Unit, University of KwaZulu-Natal , Durban , South Africa
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Mdanda S, Baijnath S, Shobo A, Singh SD, Maguire GE, Kruger HG, Arvidsson PI, Naicker T, Govender T. Lansoprazole-sulfide, pharmacokinetics of this promising anti-tuberculous agent. Biomed Chromatogr 2017. [DOI: 10.1002/bmc.4035] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Sipho Mdanda
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal, Westville Campus; Durban South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal, Westville Campus; Durban South Africa
| | - Adeola Shobo
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal, Westville Campus; Durban South Africa
| | - Sanil D. Singh
- Biomedical Resource Unit; University of KwaZulu-Natal, Westville Campus; Durban South Africa
| | - Glenn E.M. Maguire
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal, Westville Campus; Durban South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal, Westville Campus; Durban South Africa
| | - Per I. Arvidsson
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal, Westville Campus; Durban South Africa
- Science for Life Laboratory, Drug Discovery and Development Platform and Division of Translational Medicine and Chemical Biology, Development of Medical Biochemistry and Biophysics; Karolinska Institutet; Stockholm Sweden
| | - Tricia Naicker
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal, Westville Campus; Durban South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal, Westville Campus; Durban South Africa
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Teklezgi BG, Pamreddy A, Baijnath S, Gopal ND, Naicker T, Kruger HG, Govender T. Post heroin dose tissue distribution of 6-monoacetylmorphine (6-MAM) with MALDI imaging. J Mol Histol 2017; 48:285-292. [DOI: 10.1007/s10735-017-9726-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Accepted: 05/23/2017] [Indexed: 12/21/2022]
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Dutta J, Baijnath S, Somboro AM, Nagiah S, Albericio F, de la Torre BG, Marjanovic-Painter B, Zeevaart JR, Sathekge M, Kruger HG, Chuturgoon A, Naicker T, Ebenhan T, Govender T. Synthesis, in vitro evaluation, and 68 Ga-radiolabeling of CDP1 toward PET/CT imaging of bacterial infection. Chem Biol Drug Des 2017; 90:572-579. [PMID: 28328161 DOI: 10.1111/cbdd.12980] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 12/21/2022]
Abstract
Bacterial infections are a major concern in the human health sector due to poor diagnosis and development of multidrug-resistant strains. PET/CT provides a means for the non-invasive detection and localization of the infectious foci; however, the radiotracers available are either cumbersome to prepare or their exact contribution toward the imaging is not yet established. Human antimicrobial peptides are of interest for development as PET radiotracers as they are an integral component of the immune system, non-immunogenic toward the recipient, and show selectivity toward pathogens such as bacteria. Herein we report on the potential of LL37, a human cathelicidin antimicrobial peptide, as a radiotracer for bacterial imaging. Bifunctional chelator 1,4,7-triazacyclononane,1-glutaric acid-4,7-acetic acid was utilized to functionalize the antimicrobial peptide, which in turn was capable of chelating gallium. The synthesized nat Ga-CDP1 showed bacterial selectivity and low affinity toward hepatic cells, which are favorable characteristics for further preclinical application.
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Affiliation(s)
- Jyotibon Dutta
- Catalysis and Peptide Research Unit, School of Health Sciences and School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, School of Health Sciences and School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Anou M Somboro
- Catalysis and Peptide Research Unit, School of Health Sciences and School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Savania Nagiah
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu Natal, Durban, South Africa
| | - Fernando Albericio
- Catalysis and Peptide Research Unit, School of Health Sciences and School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Beatriz G de la Torre
- Catalysis and Peptide Research Unit, School of Health Sciences and School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Biljana Marjanovic-Painter
- The South African Nuclear Energy Corporation (Necsa), Radiochemistry, Pelindaba, Brits, South Africa.,Department of Science and Technology, Preclinical Drug Development Platform, North West University, Potchefstroom, South Africa
| | - Jan Rijn Zeevaart
- The South African Nuclear Energy Corporation (Necsa), Radiochemistry, Pelindaba, Brits, South Africa.,Department of Nuclear Medicine, University of Pretoria, Pretoria, South Africa
| | - Mike Sathekge
- University of Pretoria and Steve Biko Academic Hospital, Pretoria, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences and School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Anil Chuturgoon
- Discipline of Medical Biochemistry, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu Natal, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences and School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Thomas Ebenhan
- University of Pretoria and Steve Biko Academic Hospital, Pretoria, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences and School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
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Shobo CO, Bester LA, Baijnath S, Somboro AM, Peer AKC, Essack SY. Antibiotic resistance profiles of Campylobacter species in the South Africa private health care sector. J Infect Dev Ctries 2016; 10:1214-1221. [PMID: 27886034 DOI: 10.3855/jidc.8165] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 04/12/2016] [Accepted: 05/06/2016] [Indexed: 10/31/2022] Open
Abstract
INTRODUCTION There is a dearth of surveillance data on clinical Campylobacter in South Africa, particularly in the private healthcare environment. We investigated the prevalence of resistance to first-line antibiotics used to treat campylobacterioses in clinical Campylobacter isolates from a private pathology laboratory. METHODOLOGY Identification of the Campylobacter specific genes were confirmed by PCR. Minimum inhibitory concentrations were determined using the broth micro-dilution method against macrolides (erythromycin, azithromycin), fluoroquinolones (ciprofloxacin, gatifloxacin) and tetracycline. RESULTS Seventy-two Campylobacter isolates were identified by PCR, with 54 (75%) being classified as C. jejuni and 18 (25%) as C. coli. Of these, 11 (20.4%) C. jejuni and six (33.3%) C. coli strains were resistant to ciprofloxacin and three (7.41%) C. jejuni and three (16.7%) C. coli strains were resistant to gatifloxacin. The number of C. jejuni strains resistant to erythromycin and azithromycin was 17 (31.5%) and 36 (50%) respectively, while the resistance of C. coli strains to erythromycin and azithromycin were seven (38.9%) and 14 (77.8%) respectively. Resistance to tetracycline was detected in 10 (55.6%) C. coli and 14 (25.9%) C. jejuni strains. CONCLUSION In the light of these resistant profiles, the lack of a South African Campylobacter surveillance program is of concern. Relatively high prevalence of resistance in clinical isolates of C. jejuni and C. coli to the fluoroquinolones, macrolides and tetracycline used in first line treatment is of great concern. The efficacy treating human campylobacteriosis should thus be revisited.
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Affiliation(s)
- Christiana O Shobo
- College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.
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Baijnath S, Shobo A, Bester LA, Singh SD, Kruger G, Arvidsson PI, Naicker T, Govender T. Neuroprotective potential of Linezolid: a quantitative and distribution study via mass spectrometry. J Mol Histol 2016; 47:429-35. [DOI: 10.1007/s10735-016-9685-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 06/13/2016] [Indexed: 10/21/2022]
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Amoako DG, Bester LA, Somboro AM, Baijnath S, Govind CN, Essack SY. Plasmid-mediated resistance and virulence mechanisms in the private health sector in KwaZulu-Natal, South Africa: An investigation of methicillin resistant Staphylococcus aureus (MRSA) clinical isolates collected during a three month period. Int J Infect Dis 2016; 46:38-41. [PMID: 27021530 DOI: 10.1016/j.ijid.2016.03.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 03/04/2016] [Accepted: 03/18/2016] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES Due to the lack of information on the plasmid content of MRSA strains in South Africa (SA), this study investigated the resistance and virulence mechanisms of 27 clinical isolates from the private health care sector over a period of 3 months. METHODS Plasmids were extracted and the presence of MRSA confirmed by the presence of mecA. The isolates were subjected to antimicrobial susceptibility testing and molecular characterization of common resistance encoding genes and frequently encountered virulence factors by PCR using plasmid DNA as the template. The genetic relatedness between the isolates was determined by pulsed field gel electrophoresis (PFGE). RESULTS All isolates were plasmid positive, and displayed ampillicin, ciprofloxacin, gentamicin, rifampicin, tetracycline, erythromycin, and clindamycin resistance. They were all fully susceptible to daptomycin, linezolid, vancomycin, tigecycline and fusidic acid. Multidrug resistance (MDR) was found in 74.1% (20/27) of the MRSA isolates. The frequency of the resistance and virulence genes ranged from 100% to 0%. PFGE analysis revealed 10 pulsotypes, designated A-J, which showed correlation with resistance profile of the isolates in each group. Of note, 85.2% (23/27) of the isolates clustered into six major PFGE types giving an indication of similar circulating MRSA clones. CONCLUSIONS This study highlights the genetic diversity and resistance mechanisms in MRSA strains from the private health sector in SA hence the need for implementing effective infection control programs.
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Affiliation(s)
- Daniel G Amoako
- Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Linda A Bester
- Biomedical Resource Unit, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa.
| | - Anou M Somboro
- Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Chetna N Govind
- Lancet Laboratories, Durban, KwaZulu-Natal & Honorary Research Fellow, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Sabiha Y Essack
- Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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Baijnath S, Shobo A, Bester LA, Singh SD, Kruger G, Naicker T, Govender T. Small molecule distribution in rat lung: a comparison of various cryoprotectants as inflation media and their applicability to MSI. J Mol Histol 2016; 47:213-9. [DOI: 10.1007/s10735-016-9658-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 01/08/2016] [Indexed: 11/25/2022]
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Munyeza CF, Shobo A, Baijnath S, Bratkowska D, Naiker S, Bester LA, Singh SD, Maguire GEM, Kruger HG, Naicker T, Govender T. Development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of tigecycline in rat brain tissues. Biomed Chromatogr 2015; 30:837-45. [DOI: 10.1002/bmc.3616] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 07/23/2015] [Accepted: 09/14/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Chiedza F. Munyeza
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal; Westville Campus Durban 4000 South Africa
| | - Adeola Shobo
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal; Westville Campus Durban 4000 South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal; Westville Campus Durban 4000 South Africa
| | - Dominika Bratkowska
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal; Westville Campus Durban 4000 South Africa
| | - Suhashni Naiker
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal; Westville Campus Durban 4000 South Africa
| | - Linda A. Bester
- Biomedical Resource Unit; University of KwaZulu-Natal; Westville Campus Durban 4000 South Africa
| | - Sanil D. Singh
- Biomedical Resource Unit; University of KwaZulu-Natal; Westville Campus Durban 4000 South Africa
| | - Glenn E. M. Maguire
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal; Westville Campus Durban 4000 South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal; Westville Campus Durban 4000 South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal; Westville Campus Durban 4000 South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit; University of KwaZulu-Natal; Westville Campus Durban 4000 South Africa
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Shobo A, Baijnath S, Bratkowska D, Naiker S, Somboro AM, Bester LA, Singh SD, Naicker T, Kruger HG, Govender T. MALDI MSI and LC-MS/MS: Towards preclinical determination of the neurotoxic potential of fluoroquinolones. Drug Test Anal 2015; 8:832-8. [PMID: 26382199 DOI: 10.1002/dta.1862] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Revised: 07/29/2015] [Accepted: 07/30/2015] [Indexed: 01/19/2023]
Abstract
Fluoroquinolones are broad-spectrum antibiotics with efficacy against a wide range of pathogenic microbes associated with respiratory and meningeal infections. The potential toxicity of this class of chemical agents is a source of major concern and is becoming a global issue. The aim of this study was to develop a method for the brain distribution and the pharmacokinetic profile of gatifloxacin in healthy Sprague-Dawley rats, via Multicenter matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) and quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS). We developed a sensitive LC-MS/MS method to quantify gatifloxacin in plasma, lung, and brain homogenates. A pharmacokinetic profile was observed where there is a double peak pattern; a sharp initial increase in the concentration soon after dosing followed by a steady decline until another increase in concentration after a longer period post dosing in all three biological samples was observed. The imaging results showed the drug gradually entering the brain via the blood brain barrier and into the cortical regions from 15 to 240 min post dose. As time elapses, the drug leaves the brain following the same path as it followed on its entry and finally concentrates at the cortex. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Adeola Shobo
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa
| | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa
| | - Dominika Bratkowska
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa
| | - Suhashni Naiker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa
| | - Anou M Somboro
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa
| | - Linda A Bester
- Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa
| | - Sanil D Singh
- Biomedical Resource Unit, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4000, South Africa
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