In this study, we investigated the neuroprotective effects of madecassoside, isolated from the Chinese medicinal herb Centella asiatica, in the rat model of early phase of parkinsonism. During intragastric administrations of madecassoside for 7 days, the rats were injected with MPTP on the 7th day. And for the following 14 days, madecassoside were also administered. On the 14th day, the behavioral tests were assessed after 1h of administration. And then, the rats were sacrificed, substantia nigra and striatum were dissected. The content of DA, MDA, GSH, and Bcl-2/Bax gene expression levels and BDNF protein level was determined. Treatment with madecassoside was found to improve locomotor dysfunction and to protect dopaminergic neuron by antagonizing MPTP induced neurotoxicity. Madecassoside significantly attenuated the MPTP-induced reduction of dopamine in the striatum. The MDA contents were significantly decreased while the GSH levels, Bcl-2/Bax ratio and protein expression of BDNF were significantly increased in madecassoside treated groups. These results indicated that madecassoside was effective in recovering MPTP-induced early signs of parkinsonism via its neuroprotective effects including reversing the depletion of DA, antioxidant activity, increasing ratio of Bcl-2/Bax, increasing protein expression of BDNF.
Keywords: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; 3 4-dihydroxybenzylamine; 3 4-dihydroxyphenylacetic acid; BDNF; Bcl-2/Bax ratio; DA; DHBA; DOPAC; GSH; HPLC; HVA; LPO; MDA; MPTP; Madecassoside; PD; Parkinson's disease; Redox balance; SN; TBA; TBARS; brain derived neurophic factor; dopamine; high-performance liquid chromatography; homovanillic acid; lipid peroxidation; malonyldialdehyde; qRT-PCR; quantitative real-time polymerase chain reaction; reduced glutathione; substantia nigra; thiobarbituric acid; thiobarbituric acid reactive substances.