Antidiabetic activity of plumeria alba linn (Apocynaceae) root extract and fractions in Streptozotocin-Induced diabetic rats

Abstract

Purpose: To investigate the effect of total hydroalcohol root extract of Plumeria alba (Apocynaceae) and its active fraction on diabetes in rats. Methods: The effect of total hydroalcohol extract at 250 mg/kg and different fractions was evaluated on oral glucose tolerance test (OGTT) in mice. The effect of the active fractions on OGTT was measured on a model of diabetic rats (fructose-enriched fat diet and streptozotocin-induced). Results: The results show that the total extract (250 mg/kg), ethyl acetate fraction and supernatant fraction (obtained after centrifugation of total extract) at a dose of 100 mg/kg significantly (p < 0.01) reduced hyperglycemia induced by glucose overload in mice. Fructose-enriched fat diet increased blood cholesterol, triglycerides and high density lipoprotein (HDL) levels in hyperlipidemic untreated rats compared to normal control rats. Administration of total extract (250 mg/kg/day) and supernatant fraction of P. alba (100 mg/kg/day) during 14 days significantly reduced lipid parameters (total cholesterol, p < 0.001; triglycerides, p < 0.01; HDL, p < 0.05). Analysis of oxidative stress markers shows that the supernatant fraction and total extract significantly increased serum glutathione level (p < 0.01) but significantly lowered malondialdehyde (MDA) concentration in liver (p < 0.05). Conclusion: These results suggest that the total extract and fractions of P. alba exhibit significant antidiabetic and hypolipidemic properties in streptozotocin-induced diabetic animals. The supernatant fraction (which is free of organic solvent) was the most biologically active.