A neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is known to induce parkinsonism in rodents and human via dopaminergic cell death by a common oxidative mechanism. To find whether a neurotoxin-induced neurotoxicity is prevented by the treatment with an antioxidant, we investigated the effects of ginsenoside Rb1, a major saponin from Panax ginseng, on lipid peroxidaton and neurotoxicity induced by MPTP in mice using chemiluminescense-HPLC. Levels of lipid hydroperoxides in plasma and liver were increased by MPTP treatment, but the increased levels of this were not observed in mice pretreated with ginsenoside Rb1. Activities of protein kinase C and NADPH-cytochrome c reductase in the pretreated group with ginsenoside Rb1 were lower than in MPTP groups. Treatment with ginsenoside Rb1 was, however, less effective in suppressing the influence of MPTP on the levels of dopamine and its metabolite, homovanillic acid in the striatum of mice brain. These results indicate that ginsenoside Rb1 has an antioxidant effect and may not have the ability enough to suppress the neurotoxicity induced by MPTP.
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