Effect of Tectona grandis Linn. on dexamethasone-induced insulin resistance in mice

Ethnopharmacological relevance: The bark of Tectona grandis Linn. is traditionally used in the treatment of diabetes. Aim: The present study was undertaken to investigate the effect of ethanolic extract of bark of Tectona grandis Linn. (TG) in dexamethasone-induced insulin resistance in mice. Materials and methods: Mice were treated with prestandardised dose of dexamethasone for 22 days and effect of TG at the doses of 50, 100 and 200 mg/kg, p.o. on plasma blood glucose level, serum triglyceride level, glucose uptake in skeletal muscle, levels of hepatic antioxidant enzymes (GSH, SOD, catalase and LPO), and body weight were observed. Results: TG showed significant decrease in plasma glucose and serum triglyceride levels (p < 0.01) at the dose of 100 and 200 mg/kg, p.o. and also stimulated glucose uptake in skeletal muscle. The levels of antioxidant enzymes GSH, SOD, and catalase were significantly increased (p < 0.01) and there was significant decrease (p < 0.01) in level of LPO. Conclusion: Hence it can be concluded that Tectona grandis may prove to be effective in the treatment of Type-II Diabetes mellitus owing to its ability to decrease insulin resistance. (C) 2009 Elsevier Ireland Ltd. All rights reserved.