Extraction solvent polarity affects the antidiabetic activity of Dioscorea bulbifera L. (Dioscoreaceae) Tuber

Abstract

This study investigated the antidiabetic activities of different methanolic concentrations of D. bulbifera extract. The pulverized dried tubers of D. bulbifera were cold macerated with different concentrations of methanol in water 30, 50, 70 % v/v. Hyperglycermia was induced by the administration of a single intraperitoneal dose of alloxan (120 mg/kg). Hyperglycermic mice were treated with various extracts at 50 and 200 mg/kg for 10 days. The trend of activity for the extracts was 70>50>30% methanol extract. Comparism within treatments revealed that 70% methanol extract exhibited significant difference compared to other concentrations at 50 mg/kg on Day 10 and with the 30% extract from days 6-10. At 200 mg/kg, 70% methanol extract showed higher antihyperglycermic activity than the standard (metformine) from day 3-10. The methanol concentration (70%) extracted more saponins compared to other concentrations of methanol. Abundance of saponins may therefore explain higher antidiabetic activity recorded by this extract.