In silico guided in vitro study of traditionally used medicinal plants reveal the alleviation of post-menopausal symptoms through ERβ binding and MAO-A inhibition

Abstract

The slumping level of estrogen and serotonin in menopausal women is directly associated with the occurrence of menopausal symptoms where, estrogen receptor-β (ERβ) and monoamine oxidase-A (MAO-A) are directly involved. The present investigation aimed for validation of promising plants traditionally used to alleviate menopausal symptoms with ERβ mediated MAO-A inhibition potential through in silico disease-target network construction using Cytoscape plugins followed by molecular docking of phytomolecules through AutoDock vina. ADMET parameters of identified bioactive phytomolecules were analysed through swissADME and ProTox II. The efficacy of promising plant leads was further established through in vitro ERβ competitive binding, MAO-A inhibition, enzyme kinetics and free radical quenching assays. In silico analysis suggested glabrene (ΔG = −9.7 Kcal/mol) as most promising against ERβ in comparison to 17β-estradiol (ΔG = −11.4 Kcal/mol) whereas liquiritigenin (ΔG = −9.4 Kcal/mol) showed potential binding with MAO-A in comparison to standard harmine (ΔG = −8.8 Kcal/mol). In vitro analysis of promising plants segregated Glycyrrhiza glabra (IC50 = 0.052 ± 0.007 μg/ml) as most promising, followed by Hypericum perforatum (IC50 = 0.084 ± 0.01 μg/ml), Trifolium pratense (IC50 = 0.514 ± 0.01 μg/ml) and Rumex nepalensis (IC50 = 2.568 ± 0.11 μg/ml). The enzyme kinetics of promising plant leads showed reversible and competitive nature of inhibition against MAO-A. The potency of plant extracts in quenching free radicals was at par with ascorbic acid. The identified four potent medicinal plants with ERβ selective, MAO-A inhibitory and free radical quenching abilities could be used against menopausal symptoms however, finding needs to be validated further for menopausal symptoms in in vivo conditions for drug development. Communicated by Ramaswamy H. Sarma