Screening for antidiabetic activity and phytochemical constituents of common bean (Phaseolus vulgaris L.) seeds

Seeds of Phaseolus vulgaris were given individually at different doses to different batches of rats (both normal and hyperglicemic rats) after an overnight fast. Seeds contain the bioactive components – alkaloids, flavonoids, fiber, proteins, tannins, terpenoids, saponins, quercetin, anthocyanin and catechin. The blood glucose levels were measured at 0, 1, 2, 3, 4, 5 and 6 h after the treatment. Most active doses were further studied to dose-dependent (300, 200 and 100 g/kg bw) antihyperglycemic effects alone and in combination with glibenclamide (0.20, 0.10 and 0.05 g/kg bw). Seeds of P. vulgaris at a dosage of 300 g/kg bw is showing maximal blood glucose lowering effect in diabetic rats after third hour. The antihyperglycemic activity of P. vulgaris seeds was compared with the treatment of glibenclamide, an oral hypoglycemic agent. The combination of seeds of most dose (300 mg/kg bw) and higher dose of glibenclamide (0.20 g/kg bw) showed safer and potent hypoglycemic as well as antihyperglycemic activities without creating severe hypoglycemia in normal rats.   Key words: Phaseolus vulgaris, seeds, diabetes mellitus, antihyperglycemic activity, glucose-infused diabetes, glibenclamide.