Anti-diabetic activity-guided isolation of α-amylase and α-glucosidase inhibitory terpenes from Capsella bursa-pastoris Linn.

The hypoglycaemic and hypolipidemic potential of ethanol extract of C. bursa-pastoris (ECbp) in streptozotocin (STZ)-provoked diabetic rats was evaluated, and compounds with their α-amylase and α-glucosidase inhibitory potential were isolated. Acute oral toxicity was evaluated in rats. Streptozotocin (STZ) (50 mg/kg body weight) was injected intraperitoneally into rats for diabetes induction. In diabetic rats, ECbp (0.2 g/kg b.w, p.o.) was administered orally for 21 days, and its outcome on blood glucose levels and body weight was observed on a weekly basis besides lipid profile. Compound isolation from ECbp was performed using column chromatography. Oral feeding of ECbp did not produce any toxic effects or death at a dose of 2,000 mg/kg body weight. A serum glucose reduction trend was observed in rats fed with glucose pre-treated with 200 mg/kg b.w. ECbp also appreciably (p < 0.001, p < 0.01, and p < 0.05) diminished raised blood glucose with decreased blood cholesterol levels and led to increased serum high-density lipoprotein levels in comparison to diabetic control rats. Body weight levels were considerably higher (p < 0.05) in diabetic rats treated with ECbp than in diabetic control rats. Isolation of two terpene derivatives (ECbp-1 and ECbp-2) was performed using ECbp, which exhibits significant α-amylase and α-glucosidase inhibition.