Therapeutic potential of Leea asiatica: Chemical isolation and validation of ethnomedicinal claims through in vitro and in silico assessment of antioxidant and anti-inflammatory properties

Leea asiatica (L.) Ridsdale has been used by different ethnic communities to manage diseased conditions that can be traced to oxidative stress and cellular inflammations but scientific evidences to support the claim are scanty. The objective of this study was to isolate and identify the antioxidants present in the aerial parts of Leea asiatica, perform their molecular docking against proteins to inspect whether the traditional uses of the plant can be validated by an in-silico approach. Quercetin (1), gallic acid (2), kaempferol (3), methyl gallate (4), myricetin 3-O-α-L-rhamnopyranoside (5), (−)-epicatechin-3-O-gallate (6) and (−)-epigallocatechin-3-O-gallate (7) were isolated from the 70 % methanolic extract of the aerial parts. Compounds 2, 4, 6, and 7 are reported for the first time from Leea asiatica. Quercetin (1), gallic acid (2), (−)-epicatechin-3-O-gallate (6) and (−)-epigallocatechin-3-O-gallate (7) showed potent antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Molecular docking with NADPH oxidase and TNF-α revealed that epicatechin-3-O-gallate, epigallocatechin-3-O-gallate and quercetin bound with the least binding energy amongst the isolated compounds as well as standard (Trolox and Prednisolone). By molecular dynamics analysis, epicatechin-3-O-gallate maintained stable conformation with NADPH oxidase and TNF-α and was found to possess good ADMET profile thereby validating the ethnic use of the plant as a medicine in the management of inflammatory conditions by an in vitro and in silico approach.