Cytoprotective effects of Morinda officinalis against hydrogen peroxide-induced oxidative stress in Leydig TM3 cells.

AIM To investigate the antioxidant effects of Morinda officinalis (Morindae radix, MR) on H(2)O(2)-induced oxidative stress in cultured mouse TM3 Leydig cells. METHODS We carried out 2,2-diphenyl-1-picrylhydrazyl free radical scavenging, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, lipid peroxidation, testosterone enzyme immunoassay, superoxide dismutase (SOD), and catalase (CAT) assays in Leydig TM3 cells. RESULTS MR showed a 47.8% 2,2-diphenyl-1-picrylhydrazyl radical scavenging effect in TM3 cells with no significant cytotoxicity. Oxidative stress was induced in TM3 cells with 100 micromol H(2)O(2), and treatment of the cells with 250 microg/mL MR showed the most significant protective effect (64%, P < 0.001) in the cell viability assay with a decreased lipid peroxidation level (1.75 nmol/mg protein, P < 0.05), increased testosterone production (43.5 pg/mL), and improvements in SOD activity (7.49 units of SOD/mg protein, P < 0.001) and CAT activity (74.6 units of CAT/mg protein, P < 0.001). CONCLUSION These findings indicate that MR, as an antioxidant, protects functions of cultured mouse TM3 Leydig cells from H(2)O(2)-induced oxidative stress.