Antidiabetic activity of extracts and fraction of Zizyphus mauritiana

Various extracts, petroleum ether, chloroform, acetone, ethanol, aqueous, and crude aqueous, of fruits of Zizyphus mauritiana Lam. (Rhamnaceae) and the fractions of petroleum ether and aqueous extracts were tested for antihyperglycemic activity in glucose overloaded hyperglycemic rats. The effective antihyperglycemic extracts and fraction were tested for their hypoglycemic activity at two dose levels, 200 and 400 mg/kg, respectively. To confirm their utility in a higher model, the effective extracts and fraction of Z. mauritiana were also subjected to an antidiabetic study in the alloxan-induced diabetic model at two dose levels, 200 and 400 mg/kg. The aqueous extract and the non-polysaccharide fraction of the aqueous extract of Z mauritiana were found to exhibit significant antihyperglycemic and hypoglycemic activities. The petroleum ether extract was found to exhibit only an antihyperglycemic effect. Treatment of diabetic rats with petroleum ether extract, aqueous extract, and non-polysaccharide fraction of this plant restored the elevated biochemical parameters, glucose, urea, creatinine, serum cholesterol, serum triglyceride, HDL, LDL, hemoglobin, and glycosylated hemoglobin significantly to the near normal level. Comparatively, the non-polysaccharide fraction of the aqueous extract was found to be more effective, followed by the aqueous extract, and the petroleum ether extract. The activity of the non-polysaccharide fraction was comparable to that of the standard drug glibenclamide.