Anti-Diabetic Potential of the Leaves of Anisomeles malabarica in Streptozotocin Induced Diabetic Rats

Abstract

Background/Aims: Diabetes mellitus is a pandemic metabolic disorder that is affecting a majority of populations in recent years. There is a requirement for new drugs that are safer and cheaper due to the side effects associated with the available medications. Methods: We investigated the anti-diabetic activity of leaves of Anisomeles malabarica following bioactivity guided fractionation. The different solvent (hexane, ethyl acetate, methanol and water) extracts of A. malabarica leaves were used in acute treatment studies to evaluate and identify the active fraction. The ethyl acetate extract was subjected to further fractionation using silica gel column chromatography and the compounds were identified by LC-SRM/MS and GC-MS. Additional chronic treatment studies were carried out using this active fraction (AMAF) for 30 days in experimental diabetic rats. Fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), plasma insulin levels and glucose tolerance were measured along with insulin resistance/sensitivity indicators (HOMA-IR, HOMA-β and QUICKI) to assess the beneficial effects of A. malabarica in the management of diabetes mellitus. Results: Among the different solvent extracts tested, ethyl acetate extract showed maximum (66%) anti-hyperglycemic activity. The hexane and ethyl acetate (1: 1) fraction that has maximum anti-diabetic activity was identified as active fraction of A. malabarica (AMAF). The FBG, HbA1c, plasma insulin levels and insulin sensitivity/resistance indicators such as glucose tolerance, HOMA-IR, HOMA-β and QUICKI were significantly improved to near normal in diabetic rats treated with AMAF. Further, we identified key flavonoids and fatty acids as the anti-diabetic active principles from the AMAF of A. malabarica leaves. Conclusion: The results of our study suggest that Anisomeles malabarica has potential anti-diabetic activity in STZ induced diabetic rats.