Investigation of anti-diabetic ability of bioactive compounds from Euphorbia Hirta Linn, in silico and vitro experiments

Abstract

Euphorbia hirta Linn. (E. hirta) has been proven to have strong anti-hyperglycemic effects on diabetes-induced mice. However, previous studies mainly focused on effectiveness of crude extracts or fractional extracts. This study objects to evaluate whether a relationship exists between various bioactive compounds in E. hirta Linn. and diabetes-related proteins in human. Current study also objects to narrow number of bioactive compounds into the top six lists of promising anti-diabetic candidates from E. hirta which accelerate the process of drug discovery and development on E. hirta. In parallel with this in silico task, extraction, isolation and characterization of potential anti-hyperglycemic compounds were carried out. Isolated compounds were used to test alpha-amylase inhibition to fully confirm the consistency between in silico and in vitro result. In the first step, molecular docking was done to clarify connection between compounds and targeted protein. High binding energies of the receptors to ligands were calculated into absolute value and binding modes of ligand-protein complexes were also illustrated by hydrogen bond donors (red vector), hydrogen bond acceptors (green vector), and hydrophobic interactions (yellow sphere). Friedelin, taraxerone, taraxerol, α-amyrin, β-amyrin, and quercitrin were selected as 6 promising anti-hyperglycemic compounds. Finally, column chromatography was used for isolating compounds. Quercitrin was purified before being used to test alpha-amylase inhibition. With the IC50 value was 175 ug/mL, quercitrin showed strong anti-hyperglycemic activity and a reliable correlation to in silico result.