Role of chrysin on expression of insulin signaling molecules

BACKGROUND Currently available drugs are unsuccessful for the treatment of tye-2 diabetes due to their adverseside-effects. Hence, a search for novel drugs, especially ofplant origin, continues. Chrysin (5,7-dihydroxyflavone) is a flavonoid, natural component of traditional medicinal herbs, present in honey, propolis and many plant extracts that hasbeen used in traditional medicine around the world to treat numerous ailments. OBJECTIVE The present study was aimed to identify the protective role of chrysin on the expression of insulin-signaling molecules in the skeletal muscle of high fat and sucrose-induced type-2 diabetic adult male rats. MATERIALS AND METHODS The oral effective dose of chrysin (100 mg/kg body weight) was given once a day until the end of the study (30 days post-induction of diabetes) to high fat diet-induced diabetic rats. At the end of the experimental period, fasting blood glucose, oral glucose tolerance, serum lipid profile, lipid peroxidation (LPO) and free radical generation, as well as the levels of insulin signaling molecules and tissue glycogen in the gastrocnemius muscle were assessed. RESULTS Diabetic rats showed impaired glucose tolerance and impairment in insulin signaling molecules (IR, IRS-1, p-IRS-1Tyr(632), p- Akt(Thr308)), glucose transporter subtype 4 [GLUT4] proteins and glycogen concentration. Serum insulin, lipid profile, LPO and free radical generation were found to be increased in diabetic control rats. The treatment with chrysin normalized the altered levels of blood glucose, serum insulin, lipid profile, LPO and insulin signaling molecules as well as GLUT4 proteins. CONCLUSION Our present findings indicate that chrysin improves glycemic control through activation of insulin signal transduction in the gastrocnemius muscle of high fat and sucrose-induced type-2 diabetic male rats.