Quercetin as the Active Principle of Hypericum hircinum Exerts a Selective Inhibitory Activityagainst MAO-A: Extraction, Biological Analysis, and Computational Study
The methanol extract from Hypericum hircinum leaves exhibited in vitro inhibition of monoamine oxidases (MAO).Bioassay-guided fractionation led to the isolation of quercetin and five compounds identified for the first time from H.hircinum. Quercetin was the only compound with a selective inhibitory activity against MAO-A, with an IC50 value of0.010 μM. To explain MAO selective inhibition at the molecular level, a computational study was carried out byconformational search and docking techniques using recently determined crystallographic models of both enzymaticisoforms. An in vivo study in mice was carried out using the forced swimming test in order to elucidate the behavioraleffects of quercetin.
