LC-MS Based Metabolomics, In vitro and In silico Approaches to Characterize Possible Inhibitors of Alpha-glucosidase and Protein Glycation from Premna serratifolia L: Implications in Controlling Diabetes

Ethnobotanically, Premna serratifolia has been used in folk medicine to treat a number of aliments including diabetes. However, there is no data on its antiglycation activity. The present study evaluated the alpha-glucosidase inhibition potential, antiglycation, cell protective and antioxidant potential of crude total methanol and fractionated hexane, ethyl acetate and methanol extracts prepared from leaves and stem bark of P. serratifolia. The stem ethyl acetate extract (S-EA) had the highest alpha-glucosidase inhibition potential, total phenolic and flavonoid content. The S-EA extract also displayed highest total antioxidant activity and highest reducing power. The total methanol extract of leaves (L-TM) displayed maximum free radical scavenging activity evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS). All aqueous extracts of leaves and stem exerted noticeable antiglycation potential evaluated using multistage glycation markers (fructosamines, protein carbonyls, thiols and β aggregation) with reduction in carbonyl levels and increase in free thiol groups (R=0.890; p