Cytotoxicity of benalaxyl, metalaxyl, and triadimefon on Chinese hamster ovary cells

Abstract

The cytotoxicity of the fungicides benalaxyl, metalaxyl, and triadimefon was evaluated in vitro using the Chinese hamster ovary (CHO-K1) cell line. The midpoint cytotoxicity values of neutral red (NR) incorporation (NRI<inf>50</inf>), total cellular protein content (TCP<inf>50</inf>), and the methyl tetrazolium assay (MTT<inf>50</inf>) were estimated. Benalaxyl was the most cytotoxic fungicide, followed by metalaxyl and triadimefon. Fetal calf serum (10%) caused a reduction in benalaxyl, metalaxyl, and triadimefon cytotoxicity by factors of 1.8, 1.3, and 1.3. The effects of sublethal concentrations (NRI<inf>25</inf>) of the three fungicides on the glutathione redox cycle components glutathione S-transferase, glutathione reductase, glutathione peroxidase, and total glutathione content were studied. The ameliorative effects of extracellular glutathione (1 mmol L⁻¹), vitamin C (70 µmol L⁻¹), and vitamin E (30 µmol L⁻¹) were also investigated. The three antioxidants led to significant effects on the glutathione redox cycle components.