Antidiabetic Activity of Plumeria Alba Linn (Apocynaceae) Root Extract and Fractions in Streptozotocin-Induced Diabetic Rats

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 activeKeywords: Diabetes, Hyperlipidermia, Plumeria alba, Fructose-enriched fat diet, Oxidative stress markers, Streptozotocin