Diabetes, Metabolic Syndrome and Obesity (Dec 2018)
Telmisartan is effective to ameliorate metabolic syndrome in rat model – a preclinical report
Abstract
Kai-Chun Cheng,1,* Yingxiao Li,1,2,* Wei-Ting Chang,2,3 Feng Yu Kuo,4 Zhih-Cherng Chen,3,5 Juei-Tang Cheng2,6 1Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan; 2Department of Medical Research, Chi-Mei Medical Center, Yong Kang, Tainan City 71003, Taiwan; 3Department of Cardiology, Chi-Mei Medical Center, Yong Kang, Tainan City 71003, Taiwan; 4Cardiovascular Center, Kaohsiung Veterans General Hospital, Kaohsiung City 81362, Taiwan; 5Department of Pharmacy, Chia Nan University of Pharmacy and Science, Jean-Tae, Tainan City 71701, Taiwan; 6Institute of Medical Sciences, Chang Jung Christian University, Gueiren, Tainan City 71101, Taiwan *These authors contributed equally to this work Background: Metabolic syndrome (MS) is known to be associated with hypertension, insulin resistance, and dyslipidemia, and it raises the risk for cardiovascular diseases and diabetes mellitus. Telmisartan is used in clinic as an angiotensin II receptor blocker and it is also identified as activating peroxisome proliferator-activated receptors δ (PPARδ). Activation of PPARδ produced beneficial effects on fatty acid metabolism and glucose metabolism. This study aims to investigate the effects of telmisartan on the modulation of MS in rats fed a high-fat/high-sodium diet. Methods: Rats were fed with a high-fat/high-sodium diet and received injections of streptozotocin at low dose to induce MS. Then, rats with MS were treated with telmisartan. The weight, glucose tolerance, and insulin sensitivity were measured. The lipid profiles were also obtained. The weights of retroperitoneal and epididymal fat pads were determined. The role of PPARδ in telmisartan treatment was identified in rats pretreated with the specific antagonist GSK0660. Results: The results showed that telmisartan, but not losartan, significantly reduced plasma glucose and plasma insulin, and improved insulin resistance in rats with MS. Telmisartan also decreased blood pressure and lipids more significantly than losartan. Moreover, GSK0660 effectively reversed the effects of telmisartan in the MS rats. In the MS group, telmisartan activated PPARδ to enhance the levels of phosphorylated GLUT4 in muscle or the expression of phosphoenolpyruvate carboxykinase (PEPCK) in the liver, which was also abolished by GSK0660. Telmisartan is useful to ameliorate hypertension and insulin resistance in rats with MS. Telmisartan improves the insulin resistance through increased expression of GLUT4 and down-regulation of PEPCK via PPARδ-dependent mechanisms. Conclusion: Telmisartan has been proven to ameliorate MS, particularly in the prediabetes state. Therefore, telmisartan is suitable to develop for the management of MS in clinics. Keywords: metabolic syndrome, telmisartan, PPARδ, GSK0660, diet
