In vivo protection of a water-soluble derivative of vitamin E, Trolox, against methylmercury-intoxication in the rat.

Methylmercury (MeHg) is a well-known neurotoxicant. MeHg-intoxication causes a disturbance in mitochondrial energy metabolism in skeletal muscle and apoptosis in cerebellum. We report the first in vivo effectiveness of antioxidant Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carhoxylic acid), a water soluble vitamin E analog, against the MeHg-induced cellular responses. Treatment with Trolox (6-hydroxy-2.5,7,8-tetramethylchroman-2-carboxylic acid) clearly protects MeHg-treated rat skeletal muscle against the decrease in mitochondrial electron transport system enzyme activities despite the retention of MeHg. Tdt-mediated dUTP nick-end-labeling method clarified that Trolox is effective for protecting cerebellum from MeHg-induced apoptosis. These data indicate that MeHg-mediated oxidative stress plays an important role in the in vivo pathological process of MeHg intoxication. Trolox may prevent some of clinical manifestations of MeHg-intoxication in humans.