Inhibition of enzymes associated with obesity by the polyphenol-rich extracts of Hibiscus sabdariffa

Abstract

Obesity is a prominent global public health challenge. This study is aimed to explore the inhibition properties of organic and aqueous extracts of Hibiscus sabdariffa against the major enzymes associated with obesity (α-amylase, α-glucosidase, and pancreatic lipase). Extraction was carried out using water and organic solvents (methanol, ethanol and ethyl acetate) and inhibitory effect of these extracts on above-mentioned enzymes was carried out using in vitro method. All four extracts showed different yet significant potential to inhibit these enzymes. The organic extracts showed much stronger inhibitory effect on the enzymes than aqueous extract as the former were richer in polyphenols. The potassium hydroxycitrate, which is a salt of major organic acid of H. sabdariffa, did not hinhibit any of these enzymes. The combination of polyphenol-rich extract with potassium hydroxycitrate did not bring about additional inhibition indicating that inhibition potential of H. sabdariffa extract against the above-mentioned enzymes is due to the polyphenolic compounds. The molecular docking approach showed that the phenolic compounds of H. Sabdariffa, particularly catechin hydrate and rutin hydrate, have higher affnity to bind at the active sites of these enzymes, generate hydrogen bonds and thus inhibit their enzymatic activity.