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Rodrigues AG, Campos HO, Drummond LR, Marubayashi U, Coimbra CC. Effects of Increased Central Cholinergic Activity on the Metabolic Challenge Induced by Submaximal Exercise in Rats: Adrenomedullary Secretion Influences. Pharmacology 2021; 107:46-53. [PMID: 34788751 DOI: 10.1159/000519807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 09/09/2021] [Indexed: 11/19/2022]
Abstract
AIM The aim of this study was to assess the influence of adrenomedullary secretion on the plasma glucose, lactate, and free fatty acids (FFAs) during running exercise in rats submitted to intracerebroventricular (i.c.v.) injection of physostigmine (PHY). PHY i.c.v. was used to activate the central cholinergic system. METHODS Wistar rats were divided into sham-saline (sham-SAL), sham-PHY, adrenal medullectomy-SAL, and ADM-PHY groups. The plasma concentrations of glucose, lactate, and FFAs were determined immediately before and after i.c.v. injection of 20 μL of SAL or PHY at rest and during running exercise on a treadmill. RESULTS The i.c.v. injection of PHY at rest increased plasma glucose in the sham group, but not in the ADM group. An increase in plasma glucose, lactate, and FFAs mobilization from adipose tissue was observed during physical exercise in the sham-SAL group; however, the increase in plasma glucose was greater with i.c.v. PHY. Moreover, the hyperglycemia induced by exercise and PHY in the ADM group were blunted by ADM, whereas FFA mobilization was unaffected. CONCLUSION These results indicate that there is a dual metabolic control by which activation of the central cholinergic pathway increases plasma glucose but not FFA during rest and exercise, and that this hyperglycemic response is dependent on adrenomedullary secretion.
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Affiliation(s)
| | - Helton Oliveira Campos
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Department of Biological Sciences, Minas Gerais State University-Carangola Unit, Carangola, Brazil
| | - Lucas Rios Drummond
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Umeko Marubayashi
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Cândido Celso Coimbra
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Continuous infusion of physostigmine in patients with perioperative septic shock: A pharmacokinetic/pharmacodynamic study with population pharmacokinetic modeling. Pharmacotherapy 2019; 118:109318. [PMID: 31398669 DOI: 10.1016/j.biopha.2019.109318] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/27/2019] [Accepted: 07/31/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND In the context of the cholinergic anti-inflammatory pathway, the clinical trial Anticholium® per Se (EudraCT Number: 2012-001650-26, ClinicalTrials.gov NCT03013322) addressed the possibility of taking adjunctive physostigmine salicylate treatment in septic shock from bench to bedside. Pharmacokinetics (PK) are likely altered in critically ill patients; data on physostigmine PK and target concentrations are sparse, particularly for continuous infusion. Our objective was to build a population PK (popPK) model for physostigmine, and further evaluate pharmacodynamics (PD) and concentration-response relationship in this setting. METHODS In the randomized, double-blind, placebo-controlled trial, 20 patients with perioperative septic shock either received an initial dose of 0.04 mg/kg physostigmine salicylate, followed by continuous infusion of 1 mg/h for up to 120 h, or equivalent volumes of 0.9% sodium chloride (placebo group). Physostigmine plasma concentrations and acetylcholinesterase (AChE) activity were measured; concentration-response associations were evaluated, and popPK and PD modeling was performed with NONMEM. RESULTS Steady state physostigmine plasma concentrations reached 7.60 ± 2.81 ng/mL (mean ± standard deviation [SD]). PK was best described by a two-compartment model with linear clearance. Significant covariate effects were detected for body weight and age on clearance, as well as a high inter-individual variability of the central volume of distribution. AChE activity was significantly reduced to 30.5%-50.6% of baseline activity during physostigmine salicylate infusion. A sigmoidal direct effect PD model best described enzyme inhibition by physostigmine, with an estimated half maximal effective concentration (EC50) of 5.99 ng/mL. CONCLUSIONS PK of physostigmine in patients with septic shock displayed substantial inter-individual variability with body weight and age influencing the clearance. Physostigmine inhibited AChE activity with a sigmoidal concentration-response effect.
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Marinho CS, Matias MVF, Brandão IGF, Santos EL, Machado SS, Zanta CLPS. Characterization and kinetic study of the brain and muscle acetylcholinesterase from Danio rerio. Comp Biochem Physiol C Toxicol Pharmacol 2019; 222:11-18. [PMID: 30981910 DOI: 10.1016/j.cbpc.2019.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 03/09/2019] [Accepted: 04/08/2019] [Indexed: 11/26/2022]
Abstract
Acetylcholinesterase (AChE) plays an important role in the therapy of Alzheimer's disease and in the detection of pesticides such as organophosphates which are also widely used in chemical warfare. The aim of this study is the physicochemical and kinetic characterization of brain and muscle ChE from Danio rerio (Zebrafish). Optimal activity was found for brain ChE at alkaline pH 9.0 at 30 °C, and for muscle ChE at alkaline pH 8.5 at temperatures between 20 °C and 35 °C. The apparent kinetic constants, Kmapp and Vmaxapp, for brain ChE were determined as 0.191 ± 0.024 mM and 0.566 ± 0.028 U/mg protein, and for muscle ChE as 0.230 ± 0.030 mM and 0.677 ± 0.039 U/mg protein. Both brain and muscle ChE showed inhibition at high substrate concentrations. Brain and muscle ChE showed IC50 values for physostigmine of 0.61 μM and 0.37 μM, respectively. The ChE activity in brain was significantly inhibited by BW254c51 in all concentrations tested, but not by Iso-OMPA, while muscle ChE presented a moderate decrease (13 to 29%) in the activity values, indicating that BuChE is present.
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Affiliation(s)
- Claudiane S Marinho
- Federal University of Alagoas, Institute of Chemistry and Biotechnology, Av. Lourival Melo Mota, S/N, Tabuleiro do Martins, Maceió, AL, Brazil
| | - Marcos V F Matias
- Federal University of Alagoas, Institute of Chemistry and Biotechnology, Av. Lourival Melo Mota, S/N, Tabuleiro do Martins, Maceió, AL, Brazil
| | - Iago G F Brandão
- Federal University of Alagoas, Institute of Chemistry and Biotechnology, Av. Lourival Melo Mota, S/N, Tabuleiro do Martins, Maceió, AL, Brazil
| | - Elton L Santos
- Federal University of Alagoas, Agricultural Sciences Center, BR-104, Rio Largo, AL, Brazil
| | - Sonia S Machado
- Federal University of Alagoas, Institute of Chemistry and Biotechnology, Av. Lourival Melo Mota, S/N, Tabuleiro do Martins, Maceió, AL, Brazil.
| | - Carmem L P S Zanta
- Federal University of Alagoas, Institute of Chemistry and Biotechnology, Av. Lourival Melo Mota, S/N, Tabuleiro do Martins, Maceió, AL, Brazil
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In Vivo Effects of Neostigmine and Physostigmine on Neutrophil Functions and Evaluation of Acetylcholinesterase and Butyrylcholinesterase as Inflammatory Markers during Experimental Sepsis in Rats. Mediators Inflamm 2019; 2019:8274903. [PMID: 30804708 PMCID: PMC6360579 DOI: 10.1155/2019/8274903] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/27/2018] [Accepted: 11/26/2018] [Indexed: 12/17/2022] Open
Abstract
Introduction Recent studies have shown that acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) may serve as important diagnostic and therapeutic targets in sepsis. Since polymorphonuclear neutrophils (PMNs) play a pivotal role in the early phase of sepsis, we evaluated the potential therapeutic effects of cholinesterase inhibitors on PMN functions during cecal ligation and puncture- (CLP-) induced sepsis and investigated the roles of AChE and BChE as inflammatory markers under standardized experimental conditions. Methods Sham surgery or CLP was performed in male Wistar rats (n = 60). Animals were randomized into four groups: physostigmine, 100 μg/kg; neostigmine, 75 μg/kg; 0.9% saline (control group); and sham group, each applied four times over 24 h. The levels of reactive oxygen species (ROS) production and CD11b/CD62l expression were quantified by flow cytometry at t = 0, 6, 15, 20, and 24 h. Blood gas analysis as well as AChE and BChE activity levels was measured by validated point-of-care measurements. Clinical scores and survival times were determined. Results CLP induced a significant increase in ROS production and CD11b upregulation by rat PMNs. Treatment with physostigmine or neostigmine significantly reduced ROS production and CD11b upregulation by PMNs 20 h after CLP induction. In physostigmine-treated animals, survival times were significantly improved compared to the control animals, but not in neostigmine-treated animals. While AChE activity significantly decreased in the control animals at t > 6 h, AChE activity did not change in the sham group. BChE activity decreased at t > 20 h in the control animals. Conclusion While AChE activity may serve as an acute inflammatory marker, BChE activity shows a delayed decrease. Administration of centrally acting physostigmine in CLP-induced sepsis in rats has protective effects on PMN functions and improves survival times, which may be of interest in clinical practice.
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Dubrovskii VN, Shalabodov AD, Belkin AV. Effects of Neostigmine and Physostigmine on Activity of Na +,K +-ATPase in Various Subdivisions of Rat Brain. Bull Exp Biol Med 2018; 166:50-53. [PMID: 30450520 DOI: 10.1007/s10517-018-4287-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Indexed: 11/26/2022]
Abstract
The effects of intramuscular administration of neostigmine and physostigmine on Na+,K+-ATPase activity in various cerebral subdivisions were examined in rats. In CNS and peripheral tissues, both agents rapidly and significantly reduced activity of cholinesterases by 30-50%. The development of intoxication did not change the marker indices of stress reaction. In the cerebral cortex, physostigmine increased Na+,K+-ATPase activity, whereas neostigmine suppressed it. In addition, neostigmine decreased activity of this enzyme in the cerebellum. In contrast, both agents produced no effects on Na+,K+-ATPase activity in the striatum. The data corroborate the view on functional interaction between Na+,K+-ATPase and nicotinic cholinoreceptors in rat cerebral cortex.
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Chowdhary S, Bhattacharyya R, Banerjee D. 1-Naphthyl acetate: A chromogenic substrate for the detection of erythrocyte acetylcholinesterase activity. Biochimie 2018; 154:194-209. [PMID: 30201403 DOI: 10.1016/j.biochi.2018.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 09/01/2018] [Indexed: 11/26/2022]
Abstract
Erythrocyte acetylcholinesterase (AChE) is a preferred biomarker for the detection of organophosphorus poisoning. Acetylthiocholine (ATCh) is the most popular substrate for the detection of AChE activity. However, oximolysis is a prominent feature with ATCh. In this context, we have searched alternative substrates for AChE using in silico tools for screening of a better substrate. The in silico approach was performed to understand the fitness and the Total Interaction Energy (TIE) of substrates for AChE. The alternative substrates for AChE were screened in terms of high Goldscore and favorable TIE in comparison to acetylcholine (ACh)-AChE complex and other relevant esterases. Among the screened substrates, 1-Naphthyl acetate (1-NA) exhibited the most favorable interaction with AChE in terms of highest TIE and corresponding high Goldscore. The Molecular Dynamic (MD) simulation of the 1-NA-AChE complex showed a stable complex formation over a period of 5 ns. The results obtained in the in silico studies were validated in vitro using pure erythrocyte AChE and hemolysate. We observed 1-NA to be a better alternative substrate for AChE than ATCh in terms of lower Km value. Its specificity appeared at least similar to ATCh. Therefore, we propose that 1-NA can be an attractive chromogenic substrate for the measurement of AChE activity, and it possess the potential to detect organophosphorus pesticide (OP) poisoning.
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Affiliation(s)
- Sheemona Chowdhary
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Rajasri Bhattacharyya
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Dibyajyoti Banerjee
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India.
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Khan H, Marya, Amin S, Kamal MA, Patel S. Flavonoids as acetylcholinesterase inhibitors: Current therapeutic standing and future prospects. Biomed Pharmacother 2018; 101:860-870. [PMID: 29635895 DOI: 10.1016/j.biopha.2018.03.007] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 03/04/2018] [Accepted: 03/05/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Acetylcholinesterase (AChE), a serine hydrolase, is primarily responsible for the termination of signal transmission in the cholinergic system, owing to its outstanding hydrolyzing potential. Its substrate acetylcholine (ACh), is a neurotransmitter of the cholinergic system, with a predominant effect on motor neurons involved in memory formation. So, by decreasing the activity of this enzyme by employment of specific inhibitors, a number of motor neuron disorders such as myasthenia gravis, glaucoma, Lewy body dementia, and Alzheimer's disease, among others, can be treated. However, the current-available AChE inhibitors have several limitations in terms of efficacy, therapeutic range, and safety. SCOPE AND APPROACH Primarily due to the non-compliance of current therapies, new, effective and safe inhibitors are being searched for, especially those which act through multiple receptor sites, but do not elicit undesirable effects. In this regard, the evaluation of phytochemicals such as flavonoids, can be a rational approach. The therapeutic potential of flavonoids has already been recognized agaisnt several ailments. This review deals with various plant-derived flavonoids, their preclinical potential as AChE inhibitors, in established assays, possible mechanisms of action, and structural activity relationship (SAR). RESULTS AND CONCLUSIONS Subsequently, a number of plant-derived flavonoids with outstanding efficacy and potency as AChE inhibitors, the mechanistic, their safety profiles, and pharmacokinetic attributes have been discussed. Through derivatization of these reported flavonoids, some limitation in efficacy or pharmacokinetic parameters can be addressed. The selected flavonoids ought to be tested in clinical studies to discover new neuro-therapeutic candidates.
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Affiliation(s)
- Haroon Khan
- Department of Pharmacy, Abdul Wali Khan University, Mardan, 23200, Pakistan.
| | - Marya
- Department of Pharmacy, Abdul Wali Khan University, Mardan, 23200, Pakistan
| | - Surriya Amin
- Department of Botany, Islamia College Peshawar, Pakistan
| | - Mohammad Amjad Kamal
- King Fahd Medical Research Center, King Abdulaziz University, Saudi Arabia; Enzymoics, 7 Peterlee Place, Hebersham, NSW, 2770, Australia; Novel Global Community Educational Foundation, Australia
| | - Seema Patel
- Bioinformatics and Medical Informatics Research Center, San Diego State University, San Diego, CA, 92182, USA.
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