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Yang YH, Fan XX, Ye L, Huang WJ, Ko CY. Examining the molecular mechanisms of topiramate in alleviating insulin resistance: A study on C2C12 myocytes and 3T3L-1 adipocytes. Endocrine 2024; 85:168-180. [PMID: 38308786 DOI: 10.1007/s12020-024-03706-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 01/17/2024] [Indexed: 02/05/2024]
Abstract
PURPOSE Migraine, a severely debilitating condition, may be effectively managed with topiramate, known for its migraine prevention and weight loss properties due to changes in body muscle and fat composition and improved insulin sensitivity. However, the mechanism of topiramate in modulating insulin response in adipocytes and myocytes remains elusive. This study aims to elucidate these molecular mechanisms, offering insights into its role in weight management for migraine sufferers and underpinning its clinical application. METHODS Insulin resistance improvements were evaluated through glucose uptake measurements in C2C12 muscle cells and 3T3L-1 adipocytes, with Oil red O staining conducted on adipocytes. RNA-seq transcriptome analysis was used to identify the regulatory target genes of topiramate in these cells. The involvement of key genes and pathways was further validated through western blot analysis. RESULTS Topiramate effectively reduced insulin resistance in C2C12 and 3T3L-1 cells. In C2C12 cells, it significantly lowered SORBS1 gene and protein levels. In 3T3L-1 cells, topiramate upregulated CTGF and downregulated MAPK8 and KPNA1 genes. Changes were notable in nuclear cytoplasmic transport and circadian signaling pathways. Furthermore, it caused downregulation of MKK7, pJNK1/ JNK1, BMAL1, and CLOCK proteins compared to the insulin-resistant model. CONCLUSION This study provides preliminary insights into the mechanisms through which topiramate modulates insulin resistance in C2C12 myocytes and 3T3L-1 adipocytes, enhancing our understanding of its therapeutic potential in managing weight and insulin sensitivity in migraine patients.
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Affiliation(s)
- Ya-Hui Yang
- The School of Public Health, Fujian Medical University, Fuzhou, Fujian, 350122, China
- Department of Clinical Nutrition, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, 362000, China
| | - Xi-Xin Fan
- The School of Public Health, Fujian Medical University, Fuzhou, Fujian, 350122, China
- Department of Clinical Nutrition, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, 362000, China
| | - Lichao Ye
- Department of Neurology, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian, 3620000, China
| | - Wen-Jian Huang
- Department of Clinical Nutrition, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, 362000, China
- Huidong Center for Chronic Disease Control, Huizhou, Guangdong Province, 516300, China
| | - Chih-Yuan Ko
- The School of Public Health, Fujian Medical University, Fuzhou, Fujian, 350122, China.
- Department of Clinical Nutrition, the Second Affiliated Hospital of Fujian Medical University, Quanzhou, 362000, China.
- The School of Medical Technology and Engineering, Fujian Medical University, Fuzhou, Fujian, 350122, China.
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Individuals Diagnosed with Binge-Eating Disorder Have DNA Hypomethylated Sites in Genes of the Metabolic System: A Pilot Study. Nutrients 2021; 13:nu13051413. [PMID: 33922358 PMCID: PMC8145109 DOI: 10.3390/nu13051413] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/06/2021] [Accepted: 04/16/2021] [Indexed: 02/07/2023] Open
Abstract
Binge-eating disorder, recently accepted as a diagnostic category, is differentiated from bulimia nervosa in that the former shows the presence of binge-eating episodes and the absence of compensatory behavior. Epigenetics is a conjunct of mechanisms (like DNA methylation) that regulate gene expression, which are dependent on environmental changes. Analysis of DNA methylation in eating disorders shows that it is reduced. The present study aimed to analyze the genome-wide DNA methylation differences between individuals diagnosed with BED and BN. A total of 46 individuals were analyzed using the Infinium Methylation EPIC array. We found 11 differentially methylated sites between BED- and BN-diagnosed individuals, with genome-wide significance. Most of the associations were found in genes related to metabolic processes (ST3GAL4, PRKAG2, and FRK), which are hypomethylated genes in BED. Cg04781532, located in the body of the PRKAG2 gene (protein kinase AMP-activated non-catalytic subunit gamma 2), was hypomethylated in individuals with BED. Agonists of PRKAG2, which is the subunit of AMPK (AMP-activated protein kinase), are proposed to treat obesity, BED, and BN. The present study contributes important insights into the effect that BED could have on PRKAG2 activation.
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Cataldi M, Muscogiuri G, Savastano S, Barrea L, Guida B, Taglialatela M, Colao A. Gender-related issues in the pharmacology of new anti-obesity drugs. Obes Rev 2019; 20:375-384. [PMID: 30589980 DOI: 10.1111/obr.12805] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 10/01/2018] [Accepted: 10/13/2018] [Indexed: 12/14/2022]
Abstract
Four new medicines-liraglutide, lorcaserin, bupropion/naltrexone, and phentermine/topiramate-have been recently added to the pharmacological arsenal for obesity treatment and could represent important tools to manage this epidemic disease. To achieve satisfactory anti-obesity goals, the use of these new medicines should be optimized and tailored to specific patient subpopulations also by applying dose adjustments if needed. In the present review, we posit that gender could be among the factors influencing the activity of the new obesity drugs both because of pharmacokinetic and pharmacodynamic factors. Although evidence from premarketing clinical studies suggested that no dose adjustment by gender is necessary for any of these new medicines, these studies were not specifically designed to identify gender-related differences. This observation, together with the strong theoretical background supporting the hypothesis of a gender-dimorphic response, strongly call upon an urgent need of new real-life data on gender-related difference in the pharmacology of these new obesity drugs.
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Affiliation(s)
- Mauro Cataldi
- Division of Pharmacology, Department of Neuroscience, Reproductive Sciences and Dentistry, Federico II University of Naples, Naples, Italy.,Federico II University Hospital, Naples, Italy
| | - Giovanna Muscogiuri
- Division of Endocrinology, Department of Clinical Medicine and Surgery, Federico II University of Naples, Naples, Italy.,Federico II University Hospital, Naples, Italy
| | - Silvia Savastano
- Division of Endocrinology, Department of Clinical Medicine and Surgery, Federico II University of Naples, Naples, Italy.,Federico II University Hospital, Naples, Italy
| | - Luigi Barrea
- Division of Endocrinology, Department of Clinical Medicine and Surgery, Federico II University of Naples, Naples, Italy.,Federico II University Hospital, Naples, Italy
| | - Bruna Guida
- Division of Physiology, Department of Clinical Medicine and Surgery, Federico II University of Naples, Naples, Italy.,Federico II University Hospital, Naples, Italy
| | - Maurizio Taglialatela
- Division of Pharmacology, Department of Neuroscience, Reproductive Sciences and Dentistry, Federico II University of Naples, Naples, Italy.,Federico II University Hospital, Naples, Italy
| | - Annamaria Colao
- Division of Endocrinology, Department of Clinical Medicine and Surgery, Federico II University of Naples, Naples, Italy.,Federico II University Hospital, Naples, Italy
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Coomans CP, Geerling JJ, van den Berg SAA, van Diepen HC, Garcia-Tardón N, Thomas A, Schröder-van der Elst JP, Ouwens DM, Pijl H, Rensen PCN, Havekes LM, Guigas B, Romijn JA. The insulin sensitizing effect of topiramate involves KATP channel activation in the central nervous system. Br J Pharmacol 2014; 170:908-18. [PMID: 23957854 DOI: 10.1111/bph.12338] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 08/01/2013] [Accepted: 08/11/2013] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Topiramate improves insulin sensitivity, in addition to its antiepileptic action. However, the underlying mechanism is unknown. Therefore, the present study was aimed at investigating the mechanism of the insulin-sensitizing effect of topiramate both in vivo and in vitro. EXPERIMENTAL APPROACH Male C57Bl/6J mice were fed a run-in high-fat diet for 6 weeks, before receiving topiramate or vehicle mixed in high-fat diet for an additional 6 weeks. Insulin sensitivity was assessed by hyperinsulinaemic-euglycaemic clamp. The extent to which the insulin sensitizing effects of topiramate were mediated through the CNS were determined by concomitant i.c.v. infusion of vehicle or tolbutamide, an inhibitor of ATP-sensitive potassium channels in neurons. The direct effects of topiramate on insulin signalling and glucose uptake were assessed in vivo and in cultured muscle cells. KEY RESULTS In hyperinsulinaemic-euglycaemic clamp conditions, therapeutic plasma concentrations of topiramate (∼4 μg·mL(-1) ) improved insulin sensitivity (glucose infusion rate + 58%). Using 2-deoxy-D-[(3) H]glucose, we established that topiramate improved the insulin-mediated glucose uptake by heart (+92%), muscle (+116%) and adipose tissue (+586%). Upon i.c.v. tolbutamide, the insulin-sensitizing effect of topiramate was completely abrogated. Topiramate did not directly affect glucose uptake or insulin signalling neither in vivo nor in cultured muscle cells. CONCLUSION AND IMPLICATIONS In conclusion, topiramate stimulates insulin-mediated glucose uptake in vivo through the CNS. These observations illustrate the possibility of pharmacological modulation of peripheral insulin resistance through a target in the CNS.
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Affiliation(s)
- C P Coomans
- Department of Endocrinology and Metabolic Disorders, Leiden University Medical Center, Leiden, The Netherlands; Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
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Chen ML, Yi L, Jin X, Xie Q, Zhang T, Zhou X, Chang H, Fu YJ, Zhu JD, Zhang QY, Mi MT. Absorption of resveratrol by vascular endothelial cells through passive diffusion and an SGLT1-mediated pathway. J Nutr Biochem 2013; 24:1823-9. [PMID: 23927891 DOI: 10.1016/j.jnutbio.2013.04.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 04/01/2013] [Accepted: 04/08/2013] [Indexed: 12/26/2022]
Abstract
Resveratrol is a natural polyphenol that exerts potent effects to suppress atherosclerosis. However, its low concentration in plasma has placed this role in doubt. Thus, resveratrol effects might be dependent on its transport into vascular endothelium, a question not previously addressed in spite of its obvious and fundamental importance. Via high-performance liquid chromatography and liquid chromatography/mass spectrometry, we found that resveratrol was absorbed by human umbilical vein endothelial cells in a temperature-, concentration- and time-dependent manner, suggesting the involvement of passive diffusion and active transport. As determined by confocal laser scanning microscopy, resveratrol primarily distributed throughout the cytoplasm. Furthermore, resveratrol absorption was modulated by serum proteins and sodium-dependent glucose transporter 1 (SGLT1) yet inhibited by glucose (an SGLT1 substrate) and phlorizin (an SGLT1 selective inhibitor), as well as SGLT1 siRNA transfection. Additionally, Sprague-Dawley rats were intragastrically administrated with 100mg/kg of resveratrol and the concentration of resveratrol in blood vessels declined more slowly up to 24h compared to that in the blood. Our results suggested that resveratrol uptake by vascular endothelial cells involved both passive diffusion and an SGLT1-mediated process, at least partially. Moreover, the intracellular resveratrol pool may be more important than the serum level in vivo. These provide new insights into the cardiovascular benefits of resveratrol.
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Affiliation(s)
- Ming-liang Chen
- Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Research Center for Medical Nutrition, Chongqing 400038, People's Republic of China
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Caricilli AM, Penteado E, de Abreu LL, Quaresma PGF, Santos AC, Guadagnini D, Razolli D, Mittestainer FC, Carvalheira JB, Velloso LA, Saad MJA, Prada PO. Topiramate treatment improves hypothalamic insulin and leptin signaling and action and reduces obesity in mice. Endocrinology 2012; 153:4401-11. [PMID: 22822160 DOI: 10.1210/en.2012-1272] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Topiramate (TPM) treatment has been shown to reduce adiposity in humans and rodents. The reduction in adiposity is related to decreased food intake and increased energy expenditure. However, the molecular mechanisms through which TPM induces weight loss are contradictory and remain to be clarified. Whether TPM treatment alters hypothalamic insulin, or leptin signaling and action, is not well established. Thus, we investigate herein whether short-term TPM treatment alters energy balance by affecting insulin and leptin signaling, action, or neuropeptide expression in the hypothalamus of mice fed with a high-fat diet. As expected, short-term treatment with TPM diminished adiposity in obese mice mainly due to reduced food intake. TPM increased anorexigenic signaling by enhancing the leptin-induced leptin receptor/Janus kinase 2/signal transducer and activator of transcription 3 pathway and the insulin-induced insulin receptor substrate/Akt/forkhead box O1 pathway in parallel to reduced phosphatase protein expression in the hypothalamus of obese mice. These effects were independent of body weight. TPM also raised anorexigenic neuropeptides such as POMC, TRH, and CRH mRNA levels in obese mice. In addition, TPM increased the activation of the hypothalamic MAPK/ERK pathway induced by leptin, accompanied by an increase in peroxisome proliferator-activated receptor-coactivator α and uncoupling protein 1 protein levels in brown adipose tissue. Furthermore, TPM increased AMP-activated protein kinase and acetyl-coenzyme A carboxylase phosphorylation in peripheral tissues, which may help improve energy metabolism in these tissues. Together, these results provide novel insights into the molecular mechanisms through which TPM treatment reduces adiposity.
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Affiliation(s)
- Andrea M Caricilli
- Departments of Internal Medicine, State University of Campinas, Rua Pedro Zaccaria, 1300 Jardim. Sta Luiza 13484-350, Limeira, São Paulo, Brazil
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Differential effects of 5-fluorouracil on glucose transport and expressions of glucose transporter proteins in gastric cancer cells. Anticancer Drugs 2010; 21:270-6. [PMID: 20023572 DOI: 10.1097/cad.0b013e328334562c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Although 5-fluorouracil (5-FU) is a widely used chemotherapeutic agent in the treatment of gastric cancer, the underlying mechanism for 5-FU resistant phenotype, has yet to be elucidated. We hypothesized that the sensitivity of gastric cancer to 5-FU treatment might be related to the rate of glucose transport (GLUT), and investigated the expressions of GLUT1, 2, 3, and 4 in two different gastric cancer cells (SNU-216, moderately differentiated gastric adenocarcinoma; and SNU-668, signet ring cell gastric carcinoma). Immunohistochemistry of GLUT1 and GLUT4 and immunoblot analysis of glycogen synthase kinase 3 were also performed. Hexokinase activity was measured. We found that 5-FU suppressed glucose uptake in SNU-216, while it stimulated GLUT in SNU-668. Further analysis revealed that 5-FU decreased the expression levels of GLUT1, 2, and 4 in SNU-216 cells and increased the expression levels of GLUT1, 2, and 4 in SNU-668 cells. Consistent with GLUT expression levels, immunohistochemistry analysis showed that 5-FU increased GLUT1 and GLUT4 levels in SNU-216 and decreased GLUT1 and GLUT4 levels in SNU-668. We also observed that glycogen synthase kinase 3 activity was decreased in SNU-216 and increased in SNU-668 with 5-FU treatment. No significant difference in hexokinase activities was observed with 5-FU treatment. Taken together, these results suggest that 5-FU exerts differential effects on GLUT depending on gastric cancer cell types, which may indicate a possible explanation, at least in part, for the differing responses to 5-FU chemotherapy in gastric cancer.
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McElroy SL, Guerdjikova AI, Martens B, Keck PE, Pope HG, Hudson JI. Role of antiepileptic drugs in the management of eating disorders. CNS Drugs 2009; 23:139-56. [PMID: 19173373 DOI: 10.2165/00023210-200923020-00004] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Growing evidence suggests that antiepileptic drugs (AEDs) may be useful in managing some eating disorders. In the present paper, we provide a brief overview of eating disorders, the rationale for using AEDs in the treatment of these disorders and review the data supporting the effectiveness of specific AEDs in the treatment of patients with eating disorders. In addition, the potential mechanisms of action of AEDs in these conditions are discussed. Of the available AEDs, topiramate appears to have the broadest spectrum of action as an anti-binge eating, anti-purging and weight loss agent, as demonstrated in two placebo-controlled studies in bulimia nervosa and three placebo-controlled studies in binge-eating disorder (BED) with obesity. Topiramate may also have beneficial effects in night-eating syndrome and sleep-related eating disorder, but controlled trials in these conditions are needed. The results of one small controlled study suggest that zonisamide may have efficacy in BED with obesity. However, both topiramate and zonisamide are associated with adverse effect profiles that may limit their use in patients with eating disorders. Phenytoin may be effective in some patients with compulsive binge eating, particularly if co-morbid EEG abnormalities are present, but available data are too varied to allow definitive conclusions to be made. Carbamazepine and valproate may be effective in treating patients with bulimia nervosa or anorexia nervosa when they are used to treat an associated psychiatric (e.g. mood) or neurological (e.g. seizure) disorder; otherwise, both agents, particularly valproate, are associated with weight gain. In conclusion, AEDs have an emerging role in the management of some eating disorders.
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Khanna V, Arumugam S, Roy S, Mittra S, Bansal VS. Topiramate and type 2 diabetes: an old wine in a new bottle. Expert Opin Ther Targets 2008; 12:81-90. [PMID: 18076372 DOI: 10.1517/14728222.12.1.81] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Topiramate, a marketed antiepileptic drug, has been used to treat seizures and allied neurological problems since 1999. Recently, a series of newer findings for the use of topiramate have cropped up, which include Type 2 diabetes and obesity. In a series of clinical studies, a subset of neurological patients with Type 2 diabetes mellitus (T2DM) serendipitously showed better glycaemic control when treated with topiramate. It has since been demonstrated that topiramate can act both as an insulin secretagogue and sensitiser in T2DM animal models. Pathogenesis of Type 2 diabetes involves both beta-cell dysfunction and insulin resistance. Therefore, an agent that has dual action (insulin secretagougue and sensitisation) is preferred for T2DM. Topiramate seems to act through multiple mechanisms to ameliorate diabetic symptoms, some of them unknown. Hence, it becomes imperative to discuss its probable modes of action. Topiramate raises new hope as an antidiabetic agent or a potential new chemotype with a better safety profile for the treatment of T2DM.
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Affiliation(s)
- Vivek Khanna
- Ranbaxy Research Laboratories, Department of Pharmacology, New Drug Discovery Research, R&D III, Plot No. 20, Sector 18, Udyog Vihar Industrial Area, Gurgaon-122015, Haryana, India.
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Shank RP, Maryanoff BE. Molecular pharmacodynamics, clinical therapeutics, and pharmacokinetics of topiramate. CNS Neurosci Ther 2008; 14:120-42. [PMID: 18482025 PMCID: PMC6494007 DOI: 10.1111/j.1527-3458.2008.00041.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Topiramate (TPM; TOPAMAX) is a broad-spectrum antiepileptic drug (AED) that is approved in many world markets for preventing or reducing the frequency of epileptic seizures (as monotherapy or adjunctive therapy), and for the prophylaxis of migraine. TPM, a sulfamate derivative of the naturally occurring sugar D-fructose, possesses several pharmacodynamic properties that may contribute to its clinically useful attributes, and to its observed adverse effects. The sulfamate moiety is essential, but not sufficient, for its pharmacodynamic properties. In this review, we discuss the known pharmacodynamic and pharmacokinetic properties of TPM, as well as its various clinically beneficial and adverse effects.
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Affiliation(s)
- Richard P. Shank
- Research & Early Development, Johnson & Johnson Pharmaceutical Research & Development, Spring House, Pennsylvania 19477‐0776 USA
| | - Bruce E. Maryanoff
- Research & Early Development, Johnson & Johnson Pharmaceutical Research & Development, Spring House, Pennsylvania 19477‐0776 USA
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Bialer M, Johannessen SI, Kupferberg HJ, Levy RH, Perucca E, Tomson T. Progress report on new antiepileptic drugs: a summary of the Eigth Eilat Conference (EILAT VIII). Epilepsy Res 2006; 73:1-52. [PMID: 17158031 DOI: 10.1016/j.eplepsyres.2006.10.008] [Citation(s) in RCA: 220] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2006] [Accepted: 10/30/2006] [Indexed: 12/15/2022]
Abstract
The Eigth Eilat Conference on New Antiepileptic Drugs (AEDs)-EILAT VII, took place in Sitges, Barcelona from the 10th to 14th September, 2006. Basic scientists, clinical pharmacologists and neurologists from 24 countries attended the conference, whose main themes included a focus on status epilepticus (epidemiology, current and future treatments), evidence-based treatment guidelines and the potential of neurostimulation in refractory epilepsy. Consistent with previous formats of this conference, the central part of the conference was devoted to a review of AEDs in development, as well as updates on marketed AEDs introduced since 1989. This article summarizes the information presented on drugs in development, including brivaracetam, eslicarbazepine acetate (BIA-2-093), fluorofelbamate, ganaxolone, huperzine, lacosamide, retigabine, rufinamide, seletracetam, stiripentol, talampanel, valrocemide, JZP-4, NS1209, PID and RWJ-333369. Updates on felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine and new extended release oxcarbazepine formulations, pregabalin, tiagabine, topiramate, vigabatrin, zonisamide and new extended release valproic acid formulations, and the antiepileptic vagal stimulator device are also presented.
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Affiliation(s)
- Meir Bialer
- Department of Pharmaceutics, School of Pharmacy, David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel.
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Cheng Z, Pang T, Gu M, Gao AH, Xie CM, Li JY, Nan FJ, Li J. Berberine-stimulated glucose uptake in L6 myotubes involves both AMPK and p38 MAPK. Biochim Biophys Acta Gen Subj 2006; 1760:1682-9. [PMID: 17049164 DOI: 10.1016/j.bbagen.2006.09.007] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Revised: 09/13/2006] [Accepted: 09/13/2006] [Indexed: 12/22/2022]
Abstract
Berberine is a plant alkaloid used in traditional Chinese medicine and has been reported to have antihyperglycemic activity in NIDDM patients. However, the molecular basis for this action is yet to be elucidated. Here we investigate the effects and signaling pathways of berberine on L6 rat skeletal muscles. Our study demonstrates that berberine stimulates glucose uptake in a time- and dose-dependent manner. Intriguingly, berberine-stimulated glucose uptake does not vary as insulin concentration increases, and could not be blocked by the PI 3-kinase inhibitor wortmannin. Berberine only weakly stimulates the phosphorylation of Akt/PKB, a key molecule in the insulin signaling pathway, but strongly promotes the phosphorylation of AMPK and p38 MAPK. The effects of berberine are not a result of pro-oxidant action, but a consequence of an increased cellular AMP:ATP ratio. Moreover, berberine-stimulated glucose uptake is inhibited by the AMPK inhibitor Compound C and the p38 MAPK inhibitor SB202190. Inhibition of AMPK reduces p38 MAPK phosphorylation, suggesting that AMPK lies upstream of p38 MAPK. These results suggest that berberine circumvents insulin signaling pathways and stimulates glucose uptake through the AMP-AMPK-p38 MAPK pathway, which may account for the antihyperglycemic effects of this drug.
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Affiliation(s)
- Zhe Cheng
- National Center for Drug Screening, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, P. R. China
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