Chromatography Based Metabolomics and In Silico Screening of Gymnema sylvestre Leaf Extract for Its Antidiabetic Potential

Gymnema sylvestre, popularly known as gurmar, is extensively used in traditional systems of medicine for diabetes, stomach ailments, liver diseases, and cardiac disorders. Dried leaf powder of G. sylvestre was extracted through soxhlation using 70% (v/v) alcohol. The hydroalcoholic extract was concentrated to 1/4th of its volume and basified to isolate gymnemic acid enriched extract using chloroform. The isolated extract was checked for its antioxidant potential against 1, 1-diphenyl-2-picryl-hydrazyl (DPPH), which showed scavenging activity of 82.31% at 80 μg/mL of extract. Quality control analysis of the extract was carried out by TLC. Chloroform and methanol (9.5:0.5, v/v) were used as a solvent system and separated compounds were detected at 254 and 366 nm. A total of 13 metabolites were separated. However, major peaks were at R(f) 0.12, 0.69, 0.79, and 0.85. Further, UPLC-MS fingerprinting of the extract was done using acetonitrile and 0.5% formic acid in water as mobile phase in gradient elution mode. A total of 21 metabolites were separated and tentatively identified from the database. Deacyl gymnemic acid and quercetin are the two major metabolites found in the extract. Gymnemic acid, deacyl gymnemic acid, and quercetin were docked with ten different proteins associated with glucose metabolism, transport, and glucose utilization. It has been observed that gymnemic acid was more potent than deacyl gymnemic acid in terms of binding affinity towards proteins and showed a favorable interaction with amino acid residues at the active site. Thus, the present study gives an insight of identified metabolites with protein interaction and a reason for the hypoglycemic potential of deacyl gymnemic acid enriched extract, which can be further explored for in vitro and in vivo studies to establish its phytopharmacological and therapeutic effect.