MDR-involved human glutathione transferases (hGSTs) are targets for inhibition by 2,2'-dihydroxybenzophenones and N-carbonyl analogues

Abstract

Over expression of human GSTA1-1 in tumour cells is part of MDR mechanisms. Substituted 2-hydroxybenzophenones are ubiquitous in naturally occurring and synthetic compounds, exhibiting important biological activities. 2,2’-Dihydroxybenzophenones and N-carbonyl analogues, structurally, are ringopened forms of xanthone analogues which we reported recently as hGSTA1-1 inhibitors. The present study combined GST inhibition screening, in silico molecular docking and enzyme inhibition kinetics, revealing four analogues with strong inhibitory potency (IC50 = 0.18-1.8 μM) and modest cytotoxic activity for Caco2 cell line (LC50 = 35 to > 400 μM), thus being useful as lead structures for the design of new inhibitors against hGSTs.