ABSTRACTObjective: This study was undertaken to evaluate the preventive effect of heartwood of P. marsupium in dexamethasone-induced hyperinsulinemiaand hyperglycemia and compare it with that of pioglitazone.Methods: Male albino wistar rats were divided into five groups (n=6). Plain control group received gum acacia (2%) orally from d 1 to d 12. Dexacontrol group received gum acacia (2%) orally for d 1 to d 12 and Dexa (8 mg/kg) intraperitoneal (i.p.) from d 7 to d 12, during the study period.Two test groups received ethanolic extract of Pterocarpus marsupium heartwood (PME) (1 and 2 g/kg/) per oral (PO), and standard control groupreceived pioglitazone (60 mg/kg/PO) from d 1 to d 12. During the 12-d study period, the two test groups and standard control group received Dexa(8 mg/kg/i.p.) from d 7 to d 12. On last day of the study, the blood samples were collected by retro-orbital sinus punctureand used for estimation ofserum insulin and glucose levels. Homeostatic Model Assessment (HOMA) method was employed to calculate the degree of insulin resistance(IR).Results were analyzed by using one-way analysis of variance followed by Scheffe's multiple comparison test (p<0.05).Results: Treatment with ethanolic extract of P. marsupium and pioglitazone significantly (p<0.05) reduced the elevated insulin and glucose levels aswell as HOMA-IR and HOMA-IS values in dexa treated animals.Conclusion: Ethanolic extract of P. marsupium heartwood effectively countered dexamethasone-induced hyperinsulinemia and hyperglycemia.Insulin-sensitizing activity of P. marsupium heartwood was found to be more effective than pioglitazone.Keywords: Pterocarpus marsupium, Insulin resistance, Hyperinsulinemia, Hyperglycemia
