Evaluation of in silico, in vitro α-amylase inhibition potential and antidiabetic activity of Pterospermum acerifolium bark.

BACKGROUND

Pterospermum acerifolium (L.) Willd (Sterculiaceae) has been traditionally used in the treatment of diabetes mellitus but no scientific data has been published supporting the claimed ethnomedical use.

OBJECTIVE

The present study was designed to estimate the in silico, in vitro α-amylase inhibition potential and anti-diabetic activity of Pterospermum acerifolium bark.

METHODS

In silico studies were performed between human pancreatic α-amylase (HPA) and β-sitosterol by using autodock 4.2 software. In vitro α-amylase inhibition study was carried out with 50% ethanol extract of the bark (PABEE) and its various fractions. The active ethyl acetate fraction (PABEF) was sub-fractionated into three fractions (PABE1, PABE2 and PABE3). Two doses (15 and 30 mg/kg) based on acute toxicity studies, of the above fractions were subjected to antidiabetic screening in vivo by STZ-nicotinamide induced type II diabetic rats.

RESULTS

In silico studies showed the potent inhibition of β-sitosterol on human pancreatic amylase (HPA) with an estimated inhibition constant (Ki) of 269.35 nmol and two hydrogen bond interactions. PABEF showed marked α-amylase inhibition (69.94%) compared to other fractions. Diabetic rats treated with PABE3 (30 mg/kg) reduced the levels of fasting blood glucose, HbA1c, ALT, AST, ALP, triglycerides, total cholesterol, TBARS significantly (p < 0.01) and increased the levels of HDL-C, catalase, GSH, SOD significantly (p < 0.01) as compared to that of diabetic control animals. Histological studies on PABE3 treated group showed remarkable positive changes in β-cells.

CONCLUSIONS

The present study confirmed the antihyperglycemic activity along with its status on hepatic biomarkers, antihyperlipidemic and antioxidant properties of Pterospermum acerifolium bark.