Neuroprotective Effects Of Bak Foong Pill Extracts On Dopamine Neurons In MPTP-Treated Mouse Model Of Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disorder, characterized by the selective loss of dopamninergic neurons in the substantia nigra pars compacta (SNc). Up to now, the reason for the degeneration of dopamine (DA) neurons in the SNc of PD has not been identified. It may be due to the free radical damage, the glutamate-mediated excitotoxicity, as well as the mitochondria dysfunction. Among these toxic effects, apoptosis might involve in these processes. Apoptosis induced the degeneration of DA neurons might be one of the reasons for PD. Therefore, anti-apoptotic and neuroprotective strategies seem to be one of the effective treatments for PD. It is well known that the gonadal steroid hormones, especially estrogen, have neuroprotective effect in the neurodegenerative disorder. It can prevent 1-methyl-4-phenyM,2,3,6-tetrahydropyridine (MPTP) induced DA depletion. Bak Foong Pill (BFP), a well known gynaecological tonic in China, has the estrogen-like activities. It has been reported that it can exert beneficial effects on various functional systems including central nervous system. Based on our previous study, using immunohistochemistry for TH and Bax and high performance liquid chromatography electrochemical detection (HPLC-ECD) for DA and its metabolites, we investigated the neuroprotective effect of MPTP Bak Foong Pill extracts on dopamine neurons in MPTP-treated mouse model of Parkinson's disease. The results were as follows:1. In MPTP treated mice, the numbers of TH-immunoreactive (TH-ir) neurons in the SN markedly decreased compared to the Control (P<0.01). When pretreated with BFP, the numbers of TH-ir neurons in the SN remained at control values.2. In MPTP treated mice, the numbers of Bax-positive neurons in the SN increased significantly compared to the Control (P<0.01). When pretreated with BFP, the numbers of Bax-positive neurons in the SN remained at almost normal levels.3. In MPTP treated mice, the contents of DA and its metabolites dihydroxy-phenylacetic acid (DOPAC) and homovanillic (HVA) significantly decreased compared to theControl (P