GC–MS Profiling and In Vitro Tyrosinase Inhibitory Activities of Bauhinia racemosa Lamk. and Bauhinia tomentosa Linn.

Abstract

Bauhinia racemosa Lamk. and Bauhinia tomentosa linn. (Ceasalpiniaceae) leaves are used as holistic medicines mainly for inflammations and various skin disorders by the tribal sovereignty in Odisha ecoregion. This research work presents a study on chemical composition and tyrosinase inhibitory property of the methanol extract of leaves of Bauhinia racemosa (MBR) and Bauhinia tomentosa (MBT) with computational approaches. GC–MS technique, in-silico approach and in vitro tyrosinase inhibitory assay models were used for analysis of skin-whitening efficacies of these plant extracts. The major chemotype of the MBR was found to be myo-Inositol 4-C-methyl- (14.50%), whereas 3-O-Methyl-d-glucose (91.89%) was present in MBT as major compound. Tyrosinase inhibition was investigated against monophenolase (l-tyrosine). IC50 values of MBR and MBT were found to be 280 ± 0.9 and 610 ± 1.7 μg/mL, respectively. Molecular docking analysis of the binding of myo-Inositol, 4-C-methyl- and 3-O-Methyl-d-glucose with protein (PDB ID: 1wx2) showed an extensive hydrogen bond network with amino acid residues like ASN 191, ALA 202 and SER 206, THR 203, ASN 191, respectively. Both these compounds showed good binding affinities with target receptors and can be used as lead molecules for inhibition of tyrosinase. MBR and MBT might be suggested as a better source of skin-whitening agents for cosmetic and medicinal applications.