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Smith DJ, Bi H, Hamman J, Ma X, Mitchell C, Nyirenda K, Monera-Penduka T, Oketch-Rabah H, Paine MF, Pettit S, Pheiffer W, Van Breemen RB, Embry M. Potential pharmacokinetic interactions with concurrent use of herbal medicines and a ritonavir-boosted COVID-19 protease inhibitor in low and middle-income countries. Front Pharmacol 2023; 14:1210579. [PMID: 37502215 PMCID: PMC10368978 DOI: 10.3389/fphar.2023.1210579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 06/30/2023] [Indexed: 07/29/2023] Open
Abstract
The COVID-19 pandemic sparked the development of novel anti-viral drugs that have shown to be effective in reducing both fatality and hospitalization rates in patients with elevated risk for COVID-19 related morbidity or mortality. Currently, nirmatrelvir/ritonavir (Paxlovid™) fixed-dose combination is recommended by the World Health Organization for treatment of COVID-19. The ritonavir component is an inhibitor of cytochrome P450 (CYP) 3A, which is used in this combination to achieve needed therapeutic concentrations of nirmatrelvir. Because of the critical pharmacokinetic effect of this mechanism of action for Paxlovid™, co-administration with needed medications that inhibit or induce CYP3A is contraindicated, reflecting concern for interactions with the potential to alter the efficacy or safety of co-administered drugs that are also metabolized by CYP3A. Some herbal medicines are known to interact with drug metabolizing enzymes and transporters, including but not limited to inhibition or induction of CYP3A and P-glycoprotein. As access to these COVID-19 medications has increased in low- and middle-income countries (LMICs), understanding the potential for herb-drug interactions within these regions is important. Many studies have evaluated the utility of herbal medicines for COVID-19 treatments, yet information on potential herb-drug interactions involving Paxlovid™, specifically with herbal medicines commonly used in LMICs, is lacking. This review presents data on regionally-relevant herbal medicine use (particularly those promoted as treatments for COVID-19) and mechanism of action data on herbal medicines to highlight the potential for herbal medicine interaction Herb-drug interaction mediated by ritonavir-boosted antiviral protease inhibitors This work highlights potential areas for future experimental studies and data collection, identifies herbal medicines for inclusion in future listings of regionally diverse potential HDIs and underscores areas for LMIC-focused provider-patient communication. This overview is presented to support governments and health protection entities as they prepare for an increase of availability and use of Paxlovid™.
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Affiliation(s)
- Dallas J. Smith
- Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA, United States
- COVID-19 Response International Task Force, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Huichang Bi
- School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Josias Hamman
- Centre of Excellence for Pharmaceutical Sciences (Pharmacen™), Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Xiaochao Ma
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, United States
| | - Constance Mitchell
- Health and Environmental Sciences Institute, Washington, DC, United States
| | - Kumbukani Nyirenda
- Department of Pharmacy, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Tsitsi Monera-Penduka
- Research Unit for Safety of Herbs and Drugs, University of Zimbabwe, Harare, Zimbabwe
| | | | - Mary F. Paine
- Department of Pharmaceutical Sciences, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, United States
| | - Syril Pettit
- Health and Environmental Sciences Institute, Washington, DC, United States
| | - Wihan Pheiffer
- DSI/NWU Preclinical Drug Development Platform, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Richard B. Van Breemen
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
| | - Michelle Embry
- Health and Environmental Sciences Institute, Washington, DC, United States
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Lei K, He GF, Zhang CL, Liu YN, Li J, He GZ, Li XP, Ren XH, Liu D. Investigation of the synergistic effects of haloperidol combined with Calculus Bovis Sativus in treating MK-801-induced schizophrenia in rats. Exp Anim 2018; 67:163-173. [PMID: 29225304 PMCID: PMC5955748 DOI: 10.1538/expanim.17-0091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 10/26/2017] [Indexed: 12/26/2022] Open
Abstract
Clinical studies that focused on treating schizophrenia showed that Calculus Bovis Sativus (CBS), a substitute of Calculus Bovis, when used in combination with haloperidol could significantly lower the dosage of haloperidol compared with treatment with haloperidol alone, whereas efficacy was maintained. The aim of this study was to investigate the synergetic anti-schizophrenia effects in rats using CBS in combination with haloperidol. An open field test was conducted to verify the pharmacodynamic effects of a combination treatment of CBS and haloperidol on MK-801-induced schizophrenic rats. Rat plasma concentrations of intragastric haloperidol and intravenous haloperidol were determined after oral administration of a single dose or 1-week of pretreatment with CBS (50 mg/kg). The pharmacodynamic data showed a significant decrease in locomotor activity and an increase in the percentage of the central distance when haloperidol was concomitantly administered with CBS compared with haloperidol administration alone. The AUC0-∞ and Cmax of haloperidol in the orally coadministered groups were significantly higher compared with the oral treatment with haloperidol alone. In conclusion, oral coadministration of CBS with haloperidol resulted in a synergistic effect in rats. The enhanced oral bioavailability of haloperidol when combined with CBS might be attributed to the interaction between them.
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Affiliation(s)
- Kai Lei
- Department of Pharmacy, Tongji Hospital, Tongji Medical School, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, P.R. China
| | - Guo-Fang He
- Department of Pharmacy, Tongji Hospital, Tongji Medical School, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, P.R. China
| | - Cheng-Liang Zhang
- Department of Pharmacy, Tongji Hospital, Tongji Medical School, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, P.R. China
| | - Ya-Nan Liu
- Department of Pharmacy, Tongji Hospital, Tongji Medical School, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, P.R. China
| | - Juan Li
- Department of Pharmacy, Tongji Hospital, Tongji Medical School, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, P.R. China
| | - Guang-Zhao He
- Department of Pharmacy, Changzhou Tumor Hospital, 68 Honghe Road, Xinbei District, Changzhou 213032, P.R. China
| | - Xi-Ping Li
- Department of Pharmacy, Tongji Hospital, Tongji Medical School, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, P.R. China
| | - Xiu-Hua Ren
- Department of Pharmacy, Tongji Hospital, Tongji Medical School, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, P.R. China
| | - Dong Liu
- Department of Pharmacy, Tongji Hospital, Tongji Medical School, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, P.R. China
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Gouws C, Hamman JH. Recent developments in our understanding of the implications of traditional African medicine on drug metabolism. Expert Opin Drug Metab Toxicol 2017; 14:161-168. [PMID: 29268027 DOI: 10.1080/17425255.2018.1421171] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION The use of traditional herbal medicines has become increasingly popular globally, but in some countries, it is the main or sometimes even the only healthcare service available in the most rural areas. This is especially true for Africa where herbal medicines form a key component of traditional medicinal practices and there is access to a diversity of medicinal plants. Although many benefits have been derived from the use of traditional herbal medicines, many concerns are associated with their use of which herb-drug interactions have been identified to have a rising impact on patient treatment outcome. One type of pharmacokinetic interaction involves the modulation of drug metabolizing enzymes, which may result in enhanced or reduced bioavailability of co-administered drugs. Areas covered: This review highlights the current information available on drug metabolism-associated information with regards to traditional African medicines related to some of the most prevalent diseases burdening the African continent. Expert opinion: It is clear from previous studies that enzyme modulation by traditional African medicines plays a significant role in the pharmacokinetics of some co-administered drugs, but more research is needed to provide detailed information on these interactions, specifically for treatment of prevalent diseases such as tuberculosis and hypertension.
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Affiliation(s)
- Chrisna Gouws
- a Pharmacen™, Centre of Excellence for Pharmaceutical Sciences , North-West University , Potchefstroom , South Africa
| | - Josias H Hamman
- a Pharmacen™, Centre of Excellence for Pharmaceutical Sciences , North-West University , Potchefstroom , South Africa
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Morris C. Biopolitics and Boundary Work in South Africa's Sutherlandia Clinical Trial. Med Anthropol 2017; 36:685-698. [PMID: 28586268 DOI: 10.1080/01459740.2017.1337117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Between 2008 and 2011, South African and American investigators carried out a randomized controlled trial to assess the safety and efficacy of an African traditional medicine in South Africans who were HIV-seropositive but asymptomatic. The medicine was derived from Sutherlandia frutescens, a plant endemic to and widely used to stimulate immune function by people across southern Africa. In this article, I report on the cross-cultural challenges generated by trial investigators' transformation of Sutherlandia into a clinical trial substance and a potential "treatment gap" therapy for persons with HIV. While Sutherlandia is in many respects an unusual addition to evidence-based medicine, it is also familiar in this context-especially in the manner the therapy was biopolitically imagined by trial investigators, and in terms of the indeterminacy the therapy produced.
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Affiliation(s)
- Christopher Morris
- a Department of Sociology and Anthropology , George Mason University , Fairfax , Virginia , USA
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Cytochrome P450 and P-Glycoprotein-Mediated Interactions Involving African Herbs Indicated for Common Noncommunicable Diseases. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:2582463. [PMID: 28250793 PMCID: PMC5307007 DOI: 10.1155/2017/2582463] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 12/26/2016] [Accepted: 01/04/2017] [Indexed: 12/26/2022]
Abstract
Herbal remedies are regularly used to complement conventional therapies in the treatment of various illnesses in Africa. This may be because they are relatively cheap and easily accessible and are believed by many to be safe, cause fewer side effects, and are less likely to cause dependency. On the contrary, many herbs have been shown to alter the pharmacokinetics of coadministered allopathic medicines and can either synergize or antagonize therapeutic effects as well as altering the toxicity profiles of these drugs. Current disease burden data point towards epidemiological transitions characterised by increasing urbanization and changing lifestyles, risk factors for chronic diseases like hypertension, diabetes, and cancer which often present as multimorbidities. As a result, we highlight African herb-drug interactions (HDIs) modulated via cytochrome P450 enzyme family (CYP) and P-glycoprotein (P-gp) and the consequences thereof in relation to antihypertensive, antidiabetic, and anticancer drugs. CYPs are enzymes which account for to up to 70% of drug metabolism while P-gp is an efflux pump that extrudes drug substrates out of cells. Consequently, regulation of the relative activity of both CYP and P-gp by African herbs influences the effective drug concentration at the site of action and modifies therapeutic outcomes.
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Davids D, Gibson D, Johnson Q. Ethnobotanical survey of medicinal plants used to manage High Blood Pressure and Type 2 Diabetes Mellitus in Bitterfontein, Western Cape Province, South Africa. JOURNAL OF ETHNOPHARMACOLOGY 2016; 194:755-766. [PMID: 27780752 DOI: 10.1016/j.jep.2016.10.063] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 10/08/2016] [Accepted: 10/21/2016] [Indexed: 05/24/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The aim of this study was to identify and document medicinal plants used to manage High Blood Pressure and Type 2 Diabetes Mellitus in Bitterfontein, Western Cape Province, South Africa. METHODS One hundred and twelve (112) respondents were interviewed between August 2014 and September 2015 through semi-structured surveys to gather data on the percentage of people who had been diagnosed with High Blood Pressure and/or Type 2 Diabetes Mellitus and to determine the frequency of medicinal plant and allopathic medicine use. Twelve (12) key respondents were subsequently selected, using a non-probability snowball sampling method. They were interviewed in-depth concerning their plant practices and assisted with plant collection. RESULTS Twenty-four plant (24) species belonging to 15 families were identified for the management of High Blood Pressure and Type 2 Diabetes Mellitus. The most frequently reported families were Asteraceae (20.8%), Lamiaceae (16.67%), Crassulaceae (8.33%) and Aizoaceae (8.33%). The remaining (45.54%) were evenly split over eleven families- Fabaceae, Amaryllidaceae, Anacardiaceae, Capparaceae, Geraniaceae, Apiaceae, Convolvulaceae, Apocynaceae, Rutaceae, Asphodelaceae and Thymelaeaceae. The most commonly used plant species overall was Lessertia frutescens (96.55%). The most frequently used plant parts included leaves (57.63%) roots/bulbs (15.25%) and stems (11.86%), mostly prepared as infusions or decoctions for oral administration. CONCLUSIONS Medicinal plants are widely used by High Blood Pressure and Type 2 Diabetes Mellitus sufferers. They employ diverse plant species to manage both conditions. In addition, some sufferers often use prescribed allopathic medication, as well as medicinal plants, but at different intervals. Despite high usage the plants identified are not currently threatened (Red Data list status: least concern).
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Affiliation(s)
- Denver Davids
- Department of Anthropology and Sociology, University of the Western Cape (UWC), Bellville, South Africa.
| | - Diana Gibson
- Department of Anthropology and Sociology, University of the Western Cape (UWC), Bellville, South Africa.
| | - Quinton Johnson
- Nelson Mandela Metro University (NMMU), George, Southern Cape, South Africa.
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Bo L, Baosheng Z, Yang L, Mingmin T, Beiran L, Zhiqiang L, Huaqiang Z. Herb-drug enzyme-mediated interactions and the associated experimental methods: a review. J TRADIT CHIN MED 2016; 36:392-408. [DOI: 10.1016/s0254-6272(16)30054-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Africa LD, Smith C. Sutherlandia frutescens may exacerbate HIV-associated neuroinflammation. J Negat Results Biomed 2015; 14:14. [PMID: 26187042 PMCID: PMC4506629 DOI: 10.1186/s12952-015-0031-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 07/01/2015] [Indexed: 11/10/2022] Open
Abstract
Background Neuroinflammation is central to the aetiology of HIV-associated neurocognitive disorders (HAND) that are prevalent in late stage AIDS. Anti-retroviral (ARV) treatments are rolled out relatively late in the context of neuroinflammatory changes, so that their usefulness in directly preventing HAND is probably limited. It is common practice for HIV+ individuals in developing countries to make use of traditional medicines. One such medicine is Sutherlandia frutescens - commonly consumed as a water infusion. Here its efficacy as an anti-inflammatory modality in this context was investigated in an in vitro co-culture model of the blood–brain barrier (BBB). Methods Single cultures of human astrocytes (HA), HUVECs and primary human monocytes, as well as co-cultures (BBB), were stimulated with HIV-1 subtype B & C Tat protein and/or HL2/3 cell secretory proteins after pre-treatment with S.frutescens extract. Effects of this pre-treatment on pro-inflammatory cytokine secretion and monocyte migration across the BBB were assessed. Results In accordance with others, B Tat was more pro-inflammatory than C Tat, validating our model. S.frutescens decreased IL-1β secretion significantly (P < 0.0001), but exacerbated both monocyte chemoattractant protein-1 (P < 0001) – a major role player in HIV-associated neuroinflammation – and CD14+ monocyte infiltration across the BBB (P < 0.01). Conclusions Current data illustrates that the combined use of HL2/3 cells and the simulated BBB presents an accurate, physiologically relevant in vitro model with which to study neuroinflammation in the context of HIV/AIDS. In addition, our results caution against the use of S.frutescens as anti-inflammatory modality at any stage post-HIV infection. Electronic supplementary material The online version of this article (doi:10.1186/s12952-015-0031-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Luan Dane Africa
- Department of Physiological Sciences, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
| | - Carine Smith
- Department of Physiological Sciences, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
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Wilson D, Goggin K, Williams K, Gerkovich MM, Gqaleni N, Syce J, Bartman P, Johnson Q, Folk WR. Consumption of Sutherlandia frutescens by HIV-Seropositive South African Adults: An Adaptive Double-Blind Randomized Placebo Controlled Trial. PLoS One 2015; 10:e0128522. [PMID: 26186450 PMCID: PMC4506018 DOI: 10.1371/journal.pone.0128522] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Accepted: 04/14/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Sutherlandia frutescens (L.) R. Br. is widely used as an over the counter complementary medicine and in traditional medications by HIV seropositive adults living in South Africa; however the plant's safety has not been objectively studied. An adaptive two-stage randomized double-blind placebo controlled study was used to evaluate the safety of consuming dried S. frutescens by HIV seropositive adults with CD4 T-lymphocyte count of >350 cells/μL. METHODS In Stage 1 56 participants were randomized to S. frutescens 400, 800 or 1,200 mg twice daily or matching placebo for 24 weeks. In Stage 2 77 additional participants were randomized to either 1,200 mg S. frutescens or placebo. In the final analysis data from Stage 1 and Stage 2 were combined such that 107 participants were analysed (54 in the S. frutescens 1,200 mg arm and 53 in the placebo arm). RESULTS S. frutescens did not change HIV viral load, and CD4 T-lymphocyte count was similar in the two arms at 24 weeks; however, mean and total burden of infection (BOI; defined as days of infection-related events in each participant) was greater in the S. frutescens arm: mean (SD) 5.0 (5.5) vs. 9.0 (12.7) days (p = 0.045), attributed to two tuberculosis cases in subjects taking isoniazid preventive therapy (IPT). CONCLUSION A possible interaction between S. frutescens and IPT needs further evaluation, and may presage antagonistic interactions with other herbs having similar biochemical (antioxidant) properties. No other safety issues relating to consumption of S. frutescens in this cohort were identified. TRIAL REGISTRATION ClinicalTrials.gov NCT00549523.
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Affiliation(s)
- Douglas Wilson
- Department of Internal Medicine, Edendale Hospital, Pietermaritzburg, University of KwaZulu-Natal, Durban, South Africa
| | - Kathy Goggin
- Health Services and Outcomes Research, Children’s Mercy Hospital and Clinics, University of Missouri-Kansas City Schools of Medicine and Pharmacy, Kansas City, Missouri, United States of America
| | - Karen Williams
- Biomedical and Health Informatics, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri, United States of America
| | - Mary M. Gerkovich
- Biomedical and Health Informatics, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri, United States of America
| | - Nceba Gqaleni
- AIK Innovations (Pty) Ltd, Durban University of Technology, Durban, South Africa
| | - James Syce
- School of Pharmacy, University of the Western Cape, Cape Town, South Africa
| | - Patricia Bartman
- Department of Internal Medicine Research Unit, Edendale Hospital, Pietermaritzburg, KwaZulu-Natal, South Africa
| | - Quinton Johnson
- George Campus, Nelson Mandela Metropolitan University, George, South Africa
| | - William R. Folk
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
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Calitz C, Steenekamp JH, Steyn JD, Gouws C, Viljoen JM, Hamman JH. Impact of traditional African medicine on drug metabolism and transport. Expert Opin Drug Metab Toxicol 2014; 10:991-1003. [PMID: 24831257 DOI: 10.1517/17425255.2014.920321] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Africa is a continent of rich plant biodiversity with many indigenous plants having a long history of being used for medicinal purposes. A considerable number of patients consult traditional healers in African countries for their primary health-care needs. As Western medicines become more available through governmental programmes to treat diseases such as infections with HIV/AIDS, patients are faced with an increased potential of herb-drug interactions. AREAS COVERED Several medicinal herbs indigenous to Africa are discussed in terms of their effects on pharmacokinetics of allopathic drugs through modulation of enzymes and active transporters. Clinically relevant herb-drug interactions obtained from in vivo studies are discussed, with data from in vitro studies also included to ensure a complete review. EXPERT OPINION Traditional herbal medicines are often used under a false sense of security because of the perception that it is safe due to its natural origin. The potential for interactions between herbal and allopathic drugs is often neglected. Data on clinically relevant herb-drug interactions from clinical trials can be used to educate health-care workers and patients, contributing to improved therapeutic outcomes.
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Affiliation(s)
- Carlemi Calitz
- North-West University, Centre of Excellence for Pharmaceutical Sciences , Private Bag X6001, Potchefstroom, 2520 , South Africa +27 18 299 4035 ; +27 87 231 5432 ;
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Zhang B, Leung WK, Zou Y, Mabusela W, Johnson Q, Michaelsen TE, Paulsen BS. Immunomodulating polysaccharides from Lessertia frutescens leaves: isolation, characterization and structure activity relationship. JOURNAL OF ETHNOPHARMACOLOGY 2014; 152:340-348. [PMID: 24480566 DOI: 10.1016/j.jep.2014.01.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Revised: 01/15/2014] [Accepted: 01/17/2014] [Indexed: 06/03/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Sutherlandia frutescens (syn. Lessertia frutescens) is an indigenous plant in Southern Africa and has been extensively studied from the ethnobotanical point of view. Amongst the various traditional uses, several illnesses involving the immune system have been reported. Due to some of the therapeutic effects observed, in relation to the traditional uses reported by the "khoi san" and "nama" people on cancer related illnesses, the plant has been given the local name kankerbos (cancerbush). Recently the plant has also been used amongst HIV/AIDS patients to stimulate the immune system. MATERIALS AND METHODS Leaves of Sutherlandia frutescens were extracted sequentially with ethanol, 50% ethanol/water, and water at 50 and 100°C. The polysaccharides were extracted with water and fractionated by ion exchange chromatography and gel filtration to obtain enriched polysaccharide fractions. The bioactivities of the fractions were tested in the complement assay. Some of the fractions were treated with the enzyme pectinase, and the fragments thus produced were separated by gel filtration and their activities tested. Monosaccharide compositions and linkage analyses were determined for the relevant fractions. RESULTS The leaves of Sutherlandia frutescens contain polysaccharides of the pectin type. Fractions from both the water extracts of 50 and 100°C were bioactive. Fractions chosen for further studies showed that the fragment with the highest M(W) after the pectinase treatment had a substantially higher biological effect than the parent molecules. Based on a comparison of the different fractions it was concluded that galactose-rich regions were important for the bioactivity, these being of the AGII and AGI type, with the latter probably being more important than the former. Fragments rich in xylose also gave higher activity than those without it. CONCLUSIONS Our theory that the polysaccharides present in the leaves of Sutherlandia frutescens could be of importance as immunomodulating agents was confirmed. It was also shown that certain types of polysaccharides had a higher effect in the complement system than others. Thus both the water extracts obtained at 50 and 100°C contain interesting biologically active polysaccharides.
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Affiliation(s)
- Bingzhao Zhang
- School of Pharmacy, University of Oslo, Oslo, Norway; GIAT-HKU joint Center for Synthetic Biology Engineering Research (CSynBER), Guangzhou Institute of Advanced Technology, Chinese Academy of Sciences, 511458 Nansha, Guangzhou, PR China
| | - Wei Kee Leung
- School of Pharmacy, University of Oslo, Oslo, Norway
| | - Yuanfeng Zou
- School of Pharmacy, University of Oslo, Oslo, Norway
| | - Wilfred Mabusela
- South African Herbal Science and Medicine Institute (SAHSMI), University of Western Cape, Bellville, South Africa
| | - Quinton Johnson
- Nelson Mandela Metropolitan University, George, Southern Cape, South Africa
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Aboyade OM, Styger G, Gibson D, Hughes G. Sutherlandia frutescens: the meeting of science and traditional knowledge. J Altern Complement Med 2014; 20:71-6. [PMID: 23837689 PMCID: PMC3924790 DOI: 10.1089/acm.2012.0343] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Oluwaseyi M. Aboyade
- South African Herbal Science and Medicine Institute, University of the Western Cape, Bellville, South Africa
| | - Gustav Styger
- South African Herbal Science and Medicine Institute, University of the Western Cape, Bellville, South Africa
| | - Diana Gibson
- Department of Anthropology and Sociology, University of the Western Cape, Bellville, South Africa
| | - Gail Hughes
- South African Herbal Science and Medicine Institute, University of the Western Cape, Bellville, South Africa
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Effect of the African Traditional Medicine, Sutherlandia frutescens, on the Bioavailability of the Antiretroviral Protease Inhibitor, Atazanavir. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:324618. [PMID: 24416065 PMCID: PMC3876690 DOI: 10.1155/2013/324618] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 11/05/2013] [Accepted: 11/06/2013] [Indexed: 01/31/2023]
Abstract
The objective of this study was to investigate the effect of Sutherlandia frutescens (SF) on the bioavailability of atazanavir (ATV) in twelve healthy male subjects. During Phase I (Day 1), subjects ingested a single dose of ATV and blood samples were drawn before dose and at 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 5.0, 6.0, 9.0, 12, 18, and 24 hours after dose. From Day 3 to Day 14, a single dose of milled SF was administered twice daily to each subject. During Phase II, Day 15, subjects ingested single doses of ATV and SF. Blood samples were drawn as previously described. Plasma was harvested from blood samples and the concentration of ATV therein was determined. For each phase, the mean ATV plasma concentration-time profile was plotted and the means of AUC0–24 and Cmax for ATV were computed. The geometric mean ratios and confidence intervals (CIs) for Cmax and AUC0–24 hr were 0.783 (0.609–1.00) and 0.801 (0.634–1.01), respectively. The CIs for both PK parameters fell below the limits of the “no-effect” boundary, set at 0.8–1.25, indicating that SF significantly reduced the bioavailability of ATV. This may potentially result in subtherapeutic plasma concentrations and thus reduced anti-HIV efficacy of ATV.
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Iwanaga K, Honjo T, Miyazaki M, Kakemi M. Time-dependent changes in hepatic and intestinal induction of cytochrome P450 3A after administration of dexamethasone to rats. Xenobiotica 2013; 43:765-73. [PMID: 23339625 DOI: 10.3109/00498254.2012.761741] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We investigated the effects of the dose of and the number of times an inducer was administered and the duration of induction of hepatic and intestinal cytochrome P450 3A (CYP3A) in rats using dexamethasone 21-phosphate (DEX-P) and midazolam (MDZ) as an inducer and a substrate to CYP3A, respectively. The number of times DEX-P was administered was not a significant factor in the induction of either hepatic or intestinal CYP3A; however, administration of DEX-P multiple times markedly decreased the bioavailability of DEX-P by self-induction of CYP3A. CYP3A induction in the liver increased depending on the dose of DEX-P, whereas that in intestine showed a mild increase, but the induction level was almost constant regardless of the dose of DEX-P. Administration of a single dose of DEX-P showed a temporal increase in CYP3A activity in both tissues and the induction ratios reached maximum values at 12 h after DEX-P administration. On the other hand, a mild increase of CYP3A activity, which lasted for at least 48 h, was observed in both tissues after administration of multiple doses. Some physiological compounds such as cytokines might be involved in decreasing the CYP3A activity to maintain homeostasis of the body.
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Affiliation(s)
- Kazunori Iwanaga
- Division of Pharmaceutics, Osaka University of Pharmaceutical Sciences, Nasahara, Takatsuki, Osaka, Japan.
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Abstract
There is a growing interest in natural plant-based remedies as a source for commercial products. Around 80% of the South African population use traditional medicines to meet their primary health care needs; however, only a few South African medicinal plants have been exploited to their full potential in terms of commercialization. The opportunity for bioprospecting of plant compounds for novel pharmaceuticals remains largely untapped. Certain renowned medicinal plants of international acclaim including buchu and rooibos are currently contributing to local enterprise; however, other exciting opportunities exist for commonly used plants which have not yet reached the international arena. This paper focuses on the key research and development contributions of 10 commercially important medicinal plants of South Africa. Traditional uses, scientific validation, commercialisation developments, as well as both potential opportunities and setbacks are discussed.
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Müller AC, Kanfer I. Potential pharmacokinetic interactions between antiretrovirals and medicinal plants used as complementary and African traditional medicines. Biopharm Drug Dispos 2012; 32:458-70. [PMID: 22024968 DOI: 10.1002/bdd.775] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The use of traditional/complementary/alternate medicines (TCAMs) in HIV/AIDS patients who reside in Southern Africa is quite common. Those who use TCAMs in addition to antiretroviral (ARV) treatment may be at risk of experiencing clinically significant pharmacokinetic (PK) interactions, particularly between the TCAMs and the protease inhibitors (PIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Mechanisms of PK interactions include alterations to the normal functioning of drug efflux transporters, such as P-gp and/or CYP isoenzymes, such a CYP3A4 that mediate the absorption and elimination of drugs in the small intestine and liver. Specific mechanisms include inhibition and activation of these proteins and induction via the pregnane X receptor (PXR). Several clinical studies and case reports involving ARV-herb PK interactions have been reported. St John's Wort, Garlic and Cat's Claw exhibited potentially significant interactions, each with a PI or NNRTI. The potential for these herbs to induce PK interactions with drugs was first identified in reports of in vitro studies. Other in vitro studies have shown that several African traditional medicinal (ATM) plants and extracts may also demonstrate PK interactions with ARVs, through effects on CYP3A4, P-gp and PXR. The most complex effects were exhibited by Hypoxis hemerocallidea, Sutherlandia frutescens, Cyphostemma hildebrandtii, Acacia nilotica, Agauria salicifolia and Elaeodendron buchananii. Despite a high incidence of HIV/AIDs in the African region, only one clinical study, between efavirenz and Hypoxis hemerocallidea has been conducted. However, several issues/concerns still remain to be addressed and thus more studies on ATMs are warranted in order for more meaningful data to be generated and the true potential for such interactions to be determined.
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Affiliation(s)
- Adrienne C Müller
- Division of Pharmaceutics, Faculty of Pharmacy, Rhodes University, Grahamstown, 6140, South Africa
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