Abstract: AIM: To explore the role of ginsenoside Rg1 as an antioxidant in preventing against 1-methyl-4- phenyl-1, 2, 3, 6- tetrahydropyridine (MPTP)-induced apoptosis of substantia nigra neurons in Parkinson' s disease (PD)mice models. METHODS: C57BL mice were administrated (sc)withMPTP to produce PD mice models.Different doses (5.0, 10.0, and 20.0 mg·kg ^-1)of Rg1 were given (ip)MPTP prior 3 days in the pretreatment groups.Nissl staining, tyrosinehydroxythase (TH) immunostaining, cleaved caspase 3 immunostaining, and TUNEL staining were used to observe the changes of nigra neurons.Meanwhile, biochemical technique was used to detect the concentration of GSH and the vitality of SOD in substantia nigra. RESULTS: Pretreatment with Rg1 could increase the concentration of GSH and descent the vitality of SOD in substantia nigra, prevent the loss of Nissl staining neurons and TH-positive neurons, and decrease the percent of cleaved caspase 3 and TUNEL-positive cells. CONCLUSION: Down-regulation of oxidative stress is the possible mechanism of ginsenoside Rg1 protecting the substantia nigra neurons in PD mice.

Key words: pharmacodynamics, ginsenoside Rg1, apoptosis, substantia nigra neuron, oxidative stress