The In Vitro Antioxidant and Anti-Proliferative Effect and Induction of Phase II Enzymes by a Mistletoe (Viscum Album ) Extract

Abstract

The increasing interest for phytochemical antioxidants, found in many medicinal plants, is demonstrated experimentally by epidemiological and in vitro studies which show their positive effects on human health. Mistletoe contains therapeutically active ingredients which incubated with several human cancer cell lines revealed cytotoxicity for the cancer cells, but no evidence is available for their chemoprotective properties. We investigated in vitro the potential of extracts from Viscum album growing on Mallus domestica (VAM) to modulate the activity of phase II detoxifying enzymes using the gluthatione S-transferase (GST) and quinone oxidoreductase (QR) assays and to inhibition of adherent epithelial human ovarian tumor cells A2780 proliferation using the MTT assay. We found that different concentrations of VaM extract had inhibitory effects on the growth of adherent epithelial human ovarian tumor cells A2780 (IC50 = 120.62 µg/ml, after 48 h treatment). Also, this extract is a good antioxidant source (total phenol content of 91.51 mg gallic acid equivalents /g dry weight), having a radical scavenging ability and a reducing potential proportional to the dose used (from 0.312 to 5 mg/ml) in vitro. At 120 µg/ml, this extract increased, significantly, the activity of GST and QR, as well the level of GSH.