Highly selective inhibition of α-glucosidase by green synthesised ZnO nanoparticles - In-vitro screening and in-silico docking studies

Diabetic control through the inhibition of carbohydrate hydrolysing enzymes is established as an effective strategy. Many of the inorganic materials have already been investigated as enzyme inhibitors. Present study investigates the in-vitro antidiabetic activity of ZnO nanoparticles assessing their inhibition efficiency on α-glucosidase and α-amylase. The nanoparticles obtained with average dimeson of 11, 32 and 49 nm via green strategy were subjected to in-vitro antidiabetic assays. The samples were particularly selective for α-glucosidase while very mild inhibitors for α-amylase. ZnO sample with particle dimension of 32 nm was found to be the most potent inhibitor capable of preventing 97.86% enzymatic action. The IC50, and CC50 values of the sample were determined as 1.24 μg/mL and 88.89 μg/mL respectively. The selectivity index (SI) value obtained is 71.68 which indicates good selectivity towards enzymes inhibition rather than the host body. Molecular docking models were generated for ZnO association with α-glucosidase and possible binding sites were recognized. •Green synthesised ZnO nanoparticles possess unusual selectivity towards α-Glucosidase.•Green synthesised ZnO nanoparticles calcined at different temperatures show different inhibition trends.•Experimental and theoretical trends agree for the best candidate.•The experimental and theoretical order of inhibition follows Z5 > Z7 > Z3.•Optimum size factor and crystallinity play vital roles in the inhibition efficiency of in-vitro α-glucosidase.