Siriporn Chattipakorn

Chiang Mai University, Amphoe Muang Chiang Mai, Chiang Mai, Thailand

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Publications (83)223.11 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Oxidative stress in the obese-insulin resistant condition has been shown to affect cognitive as well as brain mitochondrial functions. Garlic extract has exerted a potent antioxidant effect. However, the effects of garlic extract on the brain of obese-insulin resistant rats have never been investigated. We hypothesized that garlic extract improves cognitive function and brain mitochondrial function in obese-insulin resistant rats induced by long-term high-fat diet (HFD) consumption. Male Wistar rats were fed either normal diet or HFD for 16 weeks (n = 24/group). At week 12, rats in each dietary group received either vehicle or garlic extract (250 and 500 mg·kg(-1)·day(-1)) for 28 days. Learning and memory behaviors, metabolic parameters, and brain mitochondrial function were determined at the end of treatment. HFD led to increased body weight, visceral fat, plasma insulin, cholesterol, and malondialdehyde (MDA) levels, indicating the development of insulin resistance. Furthermore, HFD rats had cognitive deficit and brain mitochondrial dysfunction. HFD rats treated with both doses of garlic extract had decreased body weight, visceral fat, plasma cholesterol, and MDA levels. Garlic extract also improved cognitive function and brain mitochondrial function, which were impaired in obese-insulin resistant rats caused by HFD consumption.
    Journal of Applied Statistics 10/2014; 39(12):1-7. · 0.45 Impact Factor
  • Nattayaporn Apaijai, Siriporn C Chattipakorn, Nipon Chattipakorn
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    ABSTRACT: The incidence of obesity with insulin resistance is increasing worldwide. This condition is also known as a risk factor of coronary artery disease and associated with increased arrhythmias, impaired left ventricular function, and increased infarct size during cardiac ischemia-reperfusion (I/R) injury. The proposed mechanisms are due to impaired glucose utilization and pro-survival signaling molecules, and increased inflammatory cytokines, which have been demonstrated in the I/R hearts in various models of obese-insulin resistance. However, the cardiac effects of diets in the I/R heart are still unsettled since several studies reported that high-caloric diet consumption might protect the heart from I/R injury. Although several therapeutic strategies such as anti-diabetic drugs, natural compounds as well as treadmill exercise have been proposed to exert cardioprotection in the I/R heart in obese-insulin resistant animals, some interventions including ischemic post-conditioning failed to protect the heart from I/R injury. In this comprehensive review, reports from both genetic deletion and dietary-induced obese-insulin resistant animal models regarding the effects of obese-insulin resistance on metabolic parameters, cardiac function, infarct size, and molecular mechanisms under I/R injury are summarized. Moreover, the effects of anti-diabetic drugs and other pharmacological interventions on these parameters in an obese-insulin resistant model under I/R injury are also comprehensively summarized and discussed.
    Cardiovascular drugs and therapy / sponsored by the International Society of Cardiovascular Pharmacotherapy. 10/2014;
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    ABSTRACT: Background and Aims Obesity induced by high-fat diet (HFD) impaired brain insulin receptor function, caused cognitive decline well as reduced dendritic spine density. Previous studies suggested that dipeptidyl peptidase IV (DPP-4) inhibitor and peroxisome proliferator-activated receptor-gamma (PPARγ) agonist exerted the neuroprotective effects in obese insulin-resistant rats. However, the effects of these drugs on dendritic spines in obese insulin-resistant rats have not yet been investigated. In the present study, we determined the effects of DPP-4 inhibitor and PPARγ agonist on dendritic spines density of obese insulin-resistant rats caused by HFD. Methods Male Wistar Rats were divided into two groups. Animals in each group were fed with normal diet (ND) or HFD for 12 weeks. After then, rats in each group were subdivided into three subgroups to receive either vehicle or vildagliptin (3 mg/kg/day) or pioglitazone (10 mg/kg/day) for 3–4 weeks. At the end of the experiment, the metabolic parameters and density of dendritic spines in CA1 hippocampus were determined. Results We found that HFD-fed rats caused peripheral insulin resistance as well as the reduction of the density of dendritic spines in CA1 hippocampus. Treatment with both DPP-4 inhibitor and PPARγ agonist in HFD-fed rats improved insulin sensitivity as well as increased the number of dendritic spines in CA1 hippocampus. Moreover, both drugs have equally improved this deterioration. Conclusion Our findings indicate that DPP-4 inhibitor and PPARγ agonist restored the reduction of dendritic spines caused by HFD, suggesting the beneficial roles of DPP-4 inhibitors and PPARγ agonists in neurodegenerative disorders.
    Archives of Medical Research. 09/2014;
  • International journal of cardiology. 08/2014;
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    ABSTRACT: We previously reported that vagus nerve stimulation (VNS) applied immediately at the onset of cardiac ischemia provides cardioprotection against cardiac ischemia-reperfusion (I/R) injury.
    Heart rhythm: the official journal of the Heart Rhythm Society 08/2014; · 4.56 Impact Factor
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    ABSTRACT: Oxidative stress has been shown to play an important role in the pathogenesis of diabetic-induced cardiac dysfunction. Protocatechuic acid (PCA) is a phenolic compound, a main metabolite of anthocyanin, which has been reported to exert various pharmacological properties. We hypothesized that PCA exerts cardioprotection in type-1 diabetic rats (T1DM). Male Sprague-Dawley rats were induced to be T1DM by a single intraperitoneal injection of 50mg/kg streptozotocin, and received the following treatments for 12 weeks: (1) oral administration of vehicle, (2) PCA at 50mg/kg/day, (3) PCA 100mg/kg/day, (4) subcutaneous injection of insulin 4U/kg/day, (5) a combination of PCA 100mg/kg/day and insulin 4U/kg/day. The metabolic parameters, echocardiography, heart rate variability were monitored every four weeks and the glycated hemoglobin (HbA1C), cardiac malondialdehyde (MDA), cardiac mitochondrial function and cardiac Bax/Bcl-2 expression were evaluated at the end of treatment. The PCA, insulin and combined drug treatments significantly improved metabolic parameters, cardiac function as shown by increased %fractional shortening and %left ventricular ejection fraction, and decreased LF/HF ratio in T1DM rats. Moreover, all treatments significantly decreased plasma HbA1C, cardiac MDA, improved cardiac mitochondrial function and increased Bcl-2 expression. Our results demonstrated for the first time the efficacy of PCA in improving cardiac function and cardiac autonomic balance, preventing cardiac mitochondrial dysfunction and increasing anti-apoptotic protein in STZ-induced T1DM rats. Thus, PCA possesses a potential cardioprotective effect and could restore cardiac function when combined with insulin treatment. These findings suggested that the supplement of PCA might be helpful for the prevention and alleviation of cardiovascular complications in T1DM.
    The Journal of endocrinology. 07/2014;
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    ABSTRACT: Objective: This review article summarizes in vitro, in vivo, and clinical evidence pertaining to temozolomide (TMZ) and bevacizumab (BEV) efficacy and mechanism of action in gliomas. Methods: Relevant publications published before June 2013 in PubMed database were reviewed. Results: Temozolomide and BEV are current chemotherapeutic agents treating patients with high-grade glioma, including glioblastoma. In vitro and in vivo studies have proposed discordant cell death pathways for TMZ as either apoptosis or autophagy using different experimental setting details or cell lines. In addition, BEV may cause cell death through hypoxia-induced autophagy or unspecific indirect effects on cancer cells. The complexity of cancer cells in glioma has contributed to their resistance of both chemotherapies. In clinical trials, overall survival duration in glioma patients with recurrence (8-9 months) is lower than that in newly diagnosed patients (12-15 months). Conclusion: Our collected data support the addition of radiotherapy, BEV, and other targeted agents to TMZ treatment, indicating prolonged survival duration in newly diagnosed patients. However, the optimal regimen for treating high-grade glioma cannot be concluded without more clinical trials.
    Neurological Research 07/2014; · 1.18 Impact Factor
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    ABSTRACT: Cilostazol is a type 3 phosphodiesterase inhibitor which has been previously demonstrated to prevent the occurrence of tachyarrhythmia and improve defibrillation efficacy. However, the mechanism for this beneficial effect is still unclear. Since cardiac mitochondria have been shown to play a crucial role in fatal cardiac arrhythmias and that oxidative stress is one of the main contributors to arrhythmia generation, we tested the effects of cilostazol on cardiac mitochondria under severe oxidative stress.
    Journal of geriatric cardiology : JGC. 06/2014; 11(2):151-7.
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    ABSTRACT: Abstract Insulin and its downstream signaling pathway are indispensable for postnatal bone growth and turnover by having influence on both osteoblast and osteoclast development. Insulin signaling regulates both bone formation by osteoblasts and bone resorption by osteoclasts; however, the regulation occurs mainly through the insulin signaling pathway within osteoblasts. An impairment of osteoblastic insulin signaling leads to an impaired bone quality by affecting osteoblast proliferation, differentiation and survival. The insulin signaling pathway and MAPK and PI3K/Akt pathways play pivotal roles in the differentiation, function and survival of bone cells. Current evidence suggests that osteoblastic insulin signaling not only modulates bone growth and turnover but is also required for energy metabolism. Several mice models with impaired insulin signaling exhibited both bone and metabolic phenotypes, including symptoms of low bone mass, obesity, glucose intolerance and insulin resistance. In this review, we discuss the key findings that suggest a pivotal role of osteoblastic insulin signaling in both bone and energy metabolism.
    Endocrine Research 03/2014; · 1.03 Impact Factor
  • Wasana Pratchayasakul, Nipon Chattipakorn, Siriporn C Chattipakorn
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    ABSTRACT: We previously demonstrated that obesity caused the reduction of peripheral and brain insulin sensitivity and that estrogen therapy improved these defects. However, the beneficial effect of estrogen on brain insulin sensitivity and oxidative stress in either ovariectomy alone or ovariectomy with obesity models has not been determined. We hypothesized that ovariectomy alone or ovariectomy with obesity reduces brain insulin sensitivity and increases brain oxidative stress, which are reversed by estrogen treatment. Thirty female rats were assigned as either sham-operated or ovariectomized. After the surgery, each group was fed either a normal diet or high-fat diet for 12weeks. At week 13, rats in each group received either the vehicle or estradiol for 30days. At week 16, blood and brain were collected for determining the peripheral and brain insulin sensitivity as well as brain oxidative stress. We found that ovariectomized rats and high-fat diet fed rats incurred obesity, reduced peripheral and brain insulin sensitivity, and increased brain oxidative stress. Estrogen ameliorated peripheral insulin sensitivity in these rats. However, the beneficial effect of estrogen on brain insulin sensitivity and brain oxidative stress was observed only in ovariectomized normal diet-fed rats, but not in ovariectomized high fat diet-fed rats. Our results suggested that reduced brain insulin sensitivity and increased brain oxidative stress occurred after either ovariectomy or obesity. However, the reduced brain insulin sensitivity and the increased brain oxidative stress in ovariectomy with obesity could not be ameliorated by estrogen treatment.
    Metabolism: clinical and experimental 03/2014; · 3.10 Impact Factor
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    ABSTRACT: Excessive iron accumulation leads to iron toxicity in the brain; however the underlying mechanism is unclear. We investigated the effects of iron overload induced by high iron-diet consumption on brain mitochondrial function, brain synaptic plasticity and learning and memory. Iron chelator (deferiprone) and antioxidant (n-acetyl cysteine) effects on iron-overload brains were also studied. Male Wistar rats were fed either normal diet or high iron-diet consumption for 12 weeks, after which rats in each diet group were treated with vehicle or deferiprone (50 mg/kg) or n-acetyl cysteine (100 mg/kg) or both for another 4 weeks. High iron-diet consumption caused brain iron accumulation, brain mitochondrial dysfunction, impaired brain synaptic plasticity and cognition, blood-brain-barrier breakdown, and brain apoptosis. Although both iron chelator and antioxidant attenuated these deleterious effects, combined therapy provided more robust results. In conclusion, this is the first study demonstrating that combined iron chelator and anti-oxidant therapy completely restored brain function impaired by iron overload.
    PLoS ONE 01/2014; 9(1):e85115. · 3.53 Impact Factor
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    ABSTRACT: Obese-insulin resistance caused by long-term high-fat diet (HFD) consumption is associated with left ventricular (LV) dysfunction and increased risk of myocardial infarction. Metformin and vildagliptin have been shown to exert cardioprotective effects. However, the effect of these drugs on the hearts under obese-insulin resistance with ischemia-reperfusion (I/R) injury is unclear. We hypothesized that combined vildagliptin and metformin provide better protective effects against I/R injury than monotherapy in obese-insulin resistant rats.
    PLoS ONE 01/2014; 9(7):e102374. · 3.53 Impact Factor
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    ABSTRACT: Aim:We hypothesized that dipeptidyl peptidase (DPP)-4 inhibitor (vildagliptin) reduces fatal arrhythmias, cardiac dysfunction and infarct size caused by ischaemia-reperfusion (I/R) injury via its attenuation of cardiac mitochondrial dysfunction.Methods:In total, 26 rats were randomized to receive either 1 mL normal saline solution or 2.0 mg/kg vildagliptin intravenously (n = 13/group) 30 min prior to a 30-min left anterior descending coronary artery occlusion, followed by a 120-min reperfusion. Arrhythmia scores, cardiac functions, infarct size and mitochondrial function were evaluated.Results:Vildagliptin reduced the infarct size by 44% and mitigated cardiac dysfunction by preserving cardiac function without altering the incidence of cardiac arrhythmias. Vildagliptin increased expression of Bcl-2 and pro-caspase3 in the ischaemic area, whereas Bax and phosphorylated-connexin43/total-connexin43 were not altered. Vildagliptin attenuated cardiac mitochondrial dysfunction by reducing the reactive oxygen species level and mitochondrial swelling.Conclusions:DPP-4 inhibitor provides cardioprotection by reducing the infarct size and ameliorating cardiac dysfunction in I/R hearts by attenuating cardiac mitochondrial dysfunction and cardiomyocyte apoptosis.
    Diabetes & Vascular Disease Research 12/2013; · 2.59 Impact Factor
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    ABSTRACT: Garlic has been shown to exhibit antioxidant effects and cardioprotective properties. However, the effects of garlic extract on the heart in insulin resistance induced by long-term high-fat-diet consumption are not well defined. Therefore, we sought to determine the effects of garlic extract in the obese insulin-resistant rats. Male Wistar rats (180-200 g) were divided into two groups: normal-diet or high-fat-diet (n = 24/group) fed for 12 weeks. Rats in each groups were divided into three subgroups (n = 8 each): vehicle or garlic extract (250 or 500 mg/kg/day, respectively) treated for 28 days. At the end of the treatment, the metabolic parameters, heart rate variability (HRV), cardiac function, and cardiac mitochondrial function were determined. Rats that received a high-fat-diet for 12 weeks had increased body weight, visceral fat, plasma insulin levels, total cholesterol, oxidative stress levels, depressed HRV, and cardiac mitochondrial dysfunction. Garlic extract at both concentrations significantly decreased the plasma insulin, total cholesterol, homeostasis model assessment index, and oxidative stress levels. Furthermore, garlic extract at both doses restored the HRV, cardiac function, and cardiac mitochondrial function. We concluded that garlic extract at both concentrations exerted cardioprotective effects against cardiac dysfunction and mitochondrial dysfunction in obese insulin-resistant rats.
    European Journal of Nutrition 10/2013; · 3.13 Impact Factor
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    ABSTRACT: Iron overload in the heart can lead to iron overload cardiomyopathy and cardiac arrhythmia. In past decades, growing evidence has suggested that cardiac mitochondrial dysfunction is associated with development of cardiac dysfunction and lethal arrhythmias. Despite these facts, the effect of iron overload on cardiac mitochondrial function is still unclear. In this study, we determined the effects of iron overload on the cardiac mitochondrial function and the routes of cardiac mitochondrial iron uptake. We tested the hypothesis that iron overload can lead to cardiac mitochondrial dysfunction, and that mitochondrial calcium uniporter (MCU) plays a major role for cardiac mitochondrial iron uptake under iron overload condition. Cardiac mitochondrial function was assessed via the determination of mitochondrial swelling, mitochondrial reactive oxygen species (ROS) production, and mitochondrial membrane potential changes. Isolated cardiac mitochondria from male Wistar rats were used in this study. To determine the routes for cardiac mitochondrial iron uptake, isolated mitochondria were exposed to MCU blocker (Ru360), mitochondrial permeability transition pore (mPTP) blocker (Cyclosporin A) and an iron chelator (Deferoxamine). We found that 1) iron overload caused cardiac mitochondrial dysfunction, indicated by increased ROS production, mitochondrial membrane depolarization and mitochondrial swelling, 2) only MCU blocker completely protected cardiac mitochondrial dysfunction caused by iron overload. These findings strongly suggest that MCU could be the major route for iron uptake into cardiac mitochondria. The inhibition of MCU could be the novel pharmacological intervention for preventing iron overload cardiomyopathy. This article is protected by copyright. All rights reserved.
    Acta Physiologica 09/2013; · 4.38 Impact Factor
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    ABSTRACT: Myocardial siderosis is known as the major cause of death in thalassemia major (TM) patients since it can lead to iron overload cardiomyopathy. Although this condition can be prevented if timely effective intensive chelation is given to patients, the mortality rate of iron overload cardiomyopathy still remains high due to late detection of this condition. Various direct and indirect methods of iron assessment, including serum ferritin level, echocardiogram, non-transferrin-bound iron, cardiac magnetic resonance T2*, heart rate variability, and liver biopsy and myocardial biopsy, have been proposed for early detection of cardiac iron overload in TM patients. However, controversial evidence and limitations of their use in clinical practice exist. In this review article, all of these iron assessment methods that have been proposed or used to directly or indirectly determine the cardiac iron status in TM reported from both basic and clinical studies are comprehensively summarized and presented. Since there has been growing evidence in the past decades that cardiac magnetic resonance imaging as well as cardiac autonomic status known as the heart rate variability can provide early detection of cardiac involvement in TM patients, these two methods are also presented and discussed. The existing controversy regarding the assessment of cardiac involvement in thalassemia is also discussed.
    World Journal of Cardiology (WJC) 08/2013; 5(8):270-279. · 2.06 Impact Factor
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    ABSTRACT: Right cervical VNS provides cardioprotective effects against acute ischemia-reperfusion injury in small animals. However, inconsistent findings have been reported. The purpose of this study was to determine whether low-amplitude, left cervical vagus nerve stimulation (VNS) applied either intermittently or continuously imparts cardioprotection against acute ischemia-reperfusion injury. Thirty-two isoflurane-anesthetized swine (25-30 kg) were randomized into 4 groups: Control (sham operated, no VNS), Continuous-VNS (C-VNS, 3.5mA, 20Hz), Intermittent-VNS (I-VNS, continuously recurring cycles of 21-s ON, 30-s OFF), and I-VNS+Atropine (1mg/kg). Left cervical VNS was applied immediately after left anterior ascending artery (LAD) occlusion (60 min), and continued until the end of reperfusion (120 min). The ischemic and non-ischemic myocardium was harvested for cardiac mitochondrial function assessment. VNS significantly reduced infarct size, improved ventricular function, decreased VF episodes, and attenuated cardiac mitochondrial reactive oxygen species (ROS) production, depolarization and swelling, compared to Control. However, I-VNS produced the most profound cardioprotective effects, particularly infarct size reduction and decreased ventricular fibrillation episodes, compared to Control and C-VNS. These beneficial effects of VNS were abolished by atropine. During ischemia-reperfusion injury, both C-VNS and I-VNS provide significant cardioprotective effects compared to Control. These beneficial effects were abolished by muscarinic blockade, suggesting the importance of muscarinic receptor modulation during VNS. The protective effects of VNS could be due to its protection of mitochondrial function during ischemia-reperfusion.
    Heart rhythm: the official journal of the Heart Rhythm Society 08/2013; · 4.56 Impact Factor
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    ABSTRACT: INTRODUCTION: A 3-antibiotic combination (3Mix) is widely used in endodontics for root canal disinfection, particularly in pulp revascularization procedures. However, the cytotoxicity of 3Mix has not been evaluated. The purpose of this study was to determine the cytotoxicity and antibacterial efficacy of 3Mix and each single antibiotic component of 3Mix. METHODS: For the cytotoxicity test, human dental pulp cells and apical papilla cells were exposed to either 3Mix or to each single antibiotic component of 3Mix using concentrations of 0.024, 0.097, 0.39, 1.56, 6.25, and 25.00 μg/mL for 1, 3, 5, and 7 days. Cell viability was determined using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. For the antibacterial test, 25.00 μg/mL and 0.39 μg/mL 3Mix or single antibiotic were tested on bacteria isolated from necrotic teeth by measuring bacterial recovery on blood agar. RESULTS: The 0.024-μg/mL concentration of all experimental groups generated the highest dental pulp cell or apical pulp cell viability at all time periods. On day 7, 0.39 μg/mL 3Mix produced more than 90% cell viability; 25.00 μg/mL 3Mix completely eliminated isolated bacteria, whereas 0.39 μg/mL was unable to eradicate all bacteria. However, the overall bacterial reduction was significantly different compared with the control group (P < .01). CONCLUSIONS: All drugs except metronidazole induced cytotoxicity on cultured cells. 3Mix generated higher cytotoxicity compared with a single drug. The cytotoxicity increased in a concentration- and time-dependent manner; 0.39 μg/mL 3Mix had less cytotoxicity and was able to significantly reduce bacteria isolated from necrotic teeth.
    Journal of endodontics 06/2013; 39(6):813-819. · 2.95 Impact Factor
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    ABSTRACT: Recent evidence has demonstrated that insulin resistance is related to the development of Type 2 Diabetes Mellitus. Our previous study found that high-fat diet consumption caused not only peripheral and brain insulin resistance, but also brain mitochondrial dysfunction and cognitive impairment. Vildagliptin and sitagliptin, dipeptidyl-peptidase-4 inhibitors, are recently developed anti-diabetic drugs. However, the effects of both drugs on cognitive behaviors and brain mitochondrial function in high-fat diet induced insulin resistant rats have not yet been investigated. Sixty male Wistar rats were divided into 2 groups to receive either normal diet or high-fat diet for 12 weeks. Rats in each group were then further divided into 3 treatment groups to receive either vehicle, vildagliptin (3 mg/kg/day) or sitagliptin (30 mg/kg/day) for 21 days. The cognitive behaviors of the rats were tested using the Morris Water Maze test. Blood samples were collected to determine metabolic parameters and plasma oxidative stress levels. Upon completion of the study, animals were euthanized and the brains removed to investigate brain and hippocampal mitochondrial function as well as oxidative stress levels. We demonstrated that both drugs significantly improved the metabolic parameters and decreased circulating and brain oxidative stress levels in high-fat diet induced insulin resistant rats. In addition, both drugs completely prevented brain and hippocampal mitochondrial dysfunction and equally improved the learning behaviors impaired by high-fat diet. Our findings suggest that the inhibition of dipeptidyl-peptidase-4 enzymes with vildagliptin or sitagliptin in insulin-resistant rats not only increases peripheral insulin sensitivity but also decreases brain dysfunction.
    Journal of Endocrinology 04/2013; · 4.06 Impact Factor

Publication Stats

568 Citations
223.11 Total Impact Points


  • 2004–2014
    • Chiang Mai University
      • • Department of Physiology
      • • Faculty of Medicine
      • • Department of Pathology
      Amphoe Muang Chiang Mai, Chiang Mai, Thailand
  • 2011–2012
    • Naresuan University
      • Department of Medical Technology
      Amphoe Muang Phitsanulok, Phitsanulok, Thailand
  • 2002–2006
    • University of Alabama at Birmingham
      • Department of Cell, Developmental and Integrative Biology (CDIB)
      Birmingham, AL, United States