In Silico and In Vivo Anti-Diabetic Studies of Pterocarpus Milbreadii Extract Using Molecular Docking Against Dipeptidyl Peptidase-4 and Alloxan-Induced Hyperglycemic Rats

Diabetes mellitus is a disease of both man and animal especially dogs. This present study evaluated the possible anti-diabetic effects of Pterocarpus milbreadii (PM), a culinary vegetable using computer-aided technique and in alloxan-induced hyperglycemia in rats. AutoDock Vina was used for molecular docking of three most abundant compounds (ascorbic acid, phytol and octadecanoic acid) obtained by gas chromatography-mass spectrometry analysis of the methanol leaf extract of PM against Dipeptidyl peptidase-4 (DPP-4). The in vivo anti-diabetic experiment was evaluated using 20 male albino wistar rats assigned into four groups (A–D) of five rats per group. A single intraperitoneal injection of alloxan monohydrate (160 mg/kg) was used to induce diabetes in groups B–D rats while rats in group A served as normal control. Rats in groups A and B received distilled water whereas groups C and D rats were respectively treated with 200 mg/kg and 400 mg/kg of the extract. Fasting blood glucose (FBG) values were evaluated post treatment. Results showed that ascorbic acid showed a binding energy (in Kcal/mol) of -5.3 compared to phytol (–5.2) and octadecanoic acid (–4.8) while Sitagliptin, the standard drug, produced a binding energy of –8.3 when docked against DPP-4 enzyme. The extract, at 400 mg/kg reduced by 51.96 %, the FBG levels of the diabetic rats 24 hours post treatment compared to that of the diabetic untreated (5.16%). It was concluded that the methanol leaf extract of PM has in vivo hypoglycemic potentials and in silico ability to inhibit DPP-4 enzyme.