Influence of NF-κB on iNOS expression in substantia nigra of mouse models of Parkinson's disease induced by MPTP

Objective To investigate effection of NF-κB in modulating the expression of iNOS in the substantia nigra(SN) of mice with1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP) induced Parkinson's disease(PD),and investigate the effect of ginsenoside Rg1 on NF-κB to further explore the possible mechanism of the dopaminergic(DA) neuron death in PD.Methods C57BL/6N mice were treated with MPTP to produce the subacute PD model,and the behavioral changes were observed.Immunohistochemistry and Western blot for tyrosine hydroxylase(TH),NF-κB and iNOS were used to observe the changes of positive cell number in the midbrain after treatment with ginsenoside Rg1.Results Compared with the control mice,the mice with PD presented with typical symptoms of PD.The number of NF-κB,and iNOS positive cells significantly increased in the SN area(P0.01).The number of TH-positive neurons in the PD model group was substantially reduced(P0.01 vs control group).In mice with ginsenoside Rg1 treatment,the number of NF-κB and iNOS positive cells was reduced obviously as compared with that in the model group(P0.01).The number of TH-positive neurons in the SN was decreased by only 25%(P0.01 vs control group).Conclusion NF-κB may play an important role in mediating iNOS expression in SN in the early stage of the MPTP-induced subacute PD,and ginsenoside Rg1 may influence the expression of NF-κB and protect the DA neurons in PD.