Preventive effect of Tinospora cordifolia against high-fructose diet-induced insulin resistance and oxidative stress in male Wistar rats

High intake of dietary fructose exerts a number of adverse metabolic effects. The aim of the present study was to investigate whether aqueous extract of Tinospora cordifolia stem (TCAE) alleviates high-fructose diet-induced insulin resistance and oxidative stress in rats. High-fructose diet (66% of fructose) and TCAE (400 mg/kg/day) were given simultaneously for a period of 60 days. Fructose fed rats showed hyperglycemia, hyperinsulinemia. hypertriglyceridemia, impaired glucose tolerance and impaired insulin sensitivity (P<0.05). TCAE treatment prevented the rise in glucose levels by 21.3%, insulin by 51.5%, triglycerides by 54.12% and glucose-insulin index by 59.8% of the fructose fed rats. Regarding liver anti-oxidant status, fructose fed rats showed higher values of lipid peroxidation (91.3%), protein carbonyl groups (44%) and lowered GSH levels (42.1%) and, lowered activities of enzymatic antioxidants, while TCAE treatment prevented all these observed abnormalities. In conclusion, our data indicate the preventive role of T. cordifolia against fructose-induced insulin resistance and oxidative stress; hence this plant could be used as an adjuvant therapy for the prevention and/or management of chronic diseases characterized by hyperinsulinemia, hypertriglyceridemia, insulin resistance and aggravated antioxidant status. (C) 2009 Elsevier Ltd. All rights reserved.