Effects Of Icariin Combined With Levodopa On 6-hydroxydopamine-induced Parkinson's Rats Model

Objective: The research aimed to observe the effect of Icariin(ICA)combined with L-3,4-Dihydroxyphenylalanine(L-DOPA)on 6-hydroxydopamine(6-OHDA)-induced Parkinson's disease(PD)rats model.Methods: PC12 cells induced by 6-OHDA were used to simulate PD model.The experiment was randomly divided into control,6-OHDA(100 ?M)alone,6-OHDA +ICA group(0.1 ?M),6-OHDA + L-DOPA(50 ?M),6-OHDA + L-DOPA(100 ?M),6-OHDA + ICA + L-DOPA(50 ?M),6-OHDA + ICA + L-DOPA(100 ?M)groups.Cell activity was determined by MTT assay.Photocolorimetric method was applied to detect LDH activity.The expression of related apoptosis genes BAX and Bcl2 were detected by Western blotting.Cell apoptosis rate was detected by flow cytometry.In addition,the model of Parkinson's disease was established by injection of 6-OHDA(8?g)into the midbrain of rats.Male Sprague-Dawley were randomly divided into control,ICA(20 mg/kg)alone,6-OHDA(8 ?g),6-OHDA + ICA(20 mg/kg),6-OHDA + L-DOPA(25 mg/kg),6-OHDA + ICA(20 mg/kg)+ L-DOPA(25 mg/kg)groups.Rats were injected intraperitoneally with L-DOPA and oral ICA,once a day for 21 days.Immunohistochemical staining was used to evaluate the dopamine(DA)neuronal damage with anti-tyrosine hydroxylase(TH)antibody on the seventh and the twenty-first day.The content of DA,dihydroxyphenylacetic acid(DOPAC),homovanillic acid(HVA)were detected by HPLC.Abnormal involuntary movement(AIM),forelimb motor function test(step test)and rotarod test were performed.Western blotting assay was applied to detect the protein expressions of COX-2,IL-1?and TNF-?.Results: In the PC12 cells culture,compared with the control culture,6-OHDA induced PC12 cells damage,the intracellular levels of LDH were increased,the ratio of Bax/Bcl-2 was increased.PC12 cells was increased after ICA treatment,LDH were decreased.After treatment with ICA and L-DOPA,PC12 cells was significantly increased,the ratio of LDH,Bax/Bcl-2 were significantly decreased.For in vivo experiment,compared with the control group,the DA neurons was decreased in the model group,the DA and its metabolites were decreased,the motor coordination ability was decreased,the expression of COX-2,IL-1? and TNF-? protein were increased in the model group.After treatment with ICA and L-DOPA,DA neurons was significantly increased,motor coordination ability was significantly increased,AIM score was significantly decreased,forelimb motor function was increased,the expression of COX-2,IL-1? and TNF-? protein cut back.Conclusion: ICA combined with L-DOPA has a protective effect on6-OHDA-induced PD rats and improves the dyskinesia caused by long-term administration of L-DOPA.