Telmisartan Protects against Insulin Resistance by Attenuating Inflammatory Response in Rats

This study investigated the effects of telmisartan on insulin resistance in high-fat diet-treated rats and the possible mechanism.A total of 40 male Sprague-Dawley rats enrolled in the study were divided into 4 groups at random：ND group（n=10） and HD group（n=10）,in which the rats were given a normal chow diet or a high-fat diet for 20 weeks following a one-week adaptation;ND＋telmisartan（n=10） group and HD＋telmisartan group（n=10）,in which the rats were initially administered in the same way as the ND or HD group,and then they were orally gavaged with telmisartan（5 mg/kg daily） additionally for 5 weeks.Related inflammatory factors were measured by ELISA.Monocyte chemotactic protein 1（MCP-1）,phosphorylated JNK and IκB-α expressions in both adipose and liver were detected by Western blotting.CRP and angiotensin Ⅱ receptor 1（AT1） mRNA expressions in both adipose and liver were determined by RT-PCR.The results showed that telmisartan administration in vivo reversed insulin resistance as evidenced by a decrease in plasma fasting glucose levels,plasma fasting insulin levels and homeostasis model of assessment-insulin resistance（HOMA-IR）.Furthermore,telmisartan administration significantly reduced serum CRP,TNF-α and IL-1β levels,and elevated serum IL-10 levels.It was also found to hamper the high-fat diet-induced increase in CRP mRNA,AT1 mRNA and MCP-1,and decrease in IκB-α in both adipose and liver.It was concluded that telmisartan administration in vivo may improve insulin resistance through attenuated inflammatory response pathways.