Protective effects of paeoniflorin on dopaminergic neurons in brain slice of substantia nigra treated with 1-methyl-4-phenylpytidinium / 中国药理学通报

ABSTRACT

Aim To study the protective effects of Paeoniflorin (PF) on dopaminergic neurons in brain slice of substantia nigra treated with MPP~+ and to investigate the transcription of alpha-synuclei (α-syn) mRNA.Methods The organatypic brain slice culture of substantia nigra prepared from neonatal SD rats was placed on Millicell-CM porous membranes and cultured to day-10.Then the cultrues of slice were treated with different concentrations (0.1,0.5,1.0 mmol·L~(-1)) of MPP~+ for 24 h.Some of the cultrues treated with 0.5 mmol·L~(-1) MPP~+ also received PF (1 or 10 μmol·L~(-1)).Slices cultured in normal medium were used as vehicle control.The tyrosine hydroxylase (TH) immunohistochemical staining with the cell counting was used to determine the dopaminergic neruons.The transcription of α-syn mRNA was examined by real-time quantitative RT-PCR.Results MPP~+(0.1,0.5,1.0 mmol·L~(-1)) exposure markedly decreased the number of TH~+ cells in a dose-dependent manner (P<0.05 or P<0.01) and sharply induced the transcription of α-syn mRNA (P<0.01) in slices treated with 0.5 mmol·L~(-1) MPP~+.The addition of PF (10 μmol·L~(-1)) to MPP~+-treated slices significantly increased dopaminergic neurons survival (P<0.01) and downregulated the transcription of α-syn mRNA significantly (P<0.05).Conclusion PF can effectively inhibit the injury of dopaminergic neurons induced by MPP~+ on brain slice of substantia nigra and downregulate the transcription of alpha-synuclein.