Effects of methyl viologen on the antioxidant system in cultured Salvia miltiorrhiza cells

Aims We studied the effects of the methyl viologen (MV) in the culture medium on the antioxidant enzyme system in Salvia miltiorrhiza cells and investigated changes in the contents of H₂O₂, malonaldehyde (MDA), glutathione (GSH), and antioxidant enzyme. The differential expressions of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were discussed. Our objective was to explore if the MV could significantly affect the antioxidant system in the cultured S. miltiorrhiza cells.
Methods We treated the S. miltiorrhiza cells in suspension cultures with MV as an elicitor on the accumulation of H₂O₂, and used the diuron (DCMU) as an electron transporting antagonist. The biosynthesis of H₂O₂, MDA, and GSH, and the activities of SOD, CAT, and POD were determined by ultraviolet spectrophotometry. The specific isoenzymes bands of SOD, CAT, and POD were examined by acrylamide gel electrophoresis technique.
Important findings We found that MV significantly increased the accumulation of H₂O₂, MDA, and GSH, along with increased activities of CAT and POD as well as enhanced expressions and increased number of isoenzymes bands of CAT and POD; whereas DCMU inhibited the effects of MV. Results in this study suggest that MV could significantly enhance H₂O₂ accumulation in chloroplasts and regulate the antioxidant system in S. miltiorrhiza cells in suspension cultures, in order to maintain normal physiological conditions.