Comparative evaluation of extract of Bacopa monnieri and Mucuna pruriens as neuroprotectant in MPTP model of Parkinson’s disease

Parkinson’s disease (PD) results primarily from the death of dopaminergic neurons in substantia nigra. Treatment of PD has been shifted recently towards herbal medicines. Bacopa monnieri (L.) Wettst. (BM) and Mucuna pruriens (L.) DC (MP) are traditional herbal plants known to have neuroprotective effects due to the presence of bacosides in whole plant extract of Bacopa monnieri (BME) and L-DOPA in MP seed extract (MPE). In this study, the comparative effect of BME and MPE in Parkinsonian mice induced by chronic exposure to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was evaluated. Twenty four Swiss albino mice (35-45 g) were grouped into Control, MPTP, MPTP+BME and MPTP+MPE (6 mice in each). Experimental mice were given 40 mg/kg body wt. BME, 48 mg/kg body wt. MPE treatment was given orally for one month with prior use of 15 mg/kg body wt. of MPTP for 2 wk. After the treatment period, behavioral study was performed and assessment of neuroprotective effect was done via neurochemical analysis, Immunohistochemical parameters studied included functional viability of dopaminergic neurons in substantia nigra by Tyrosine hydroxylase (TH) using monoclonal antibody against TH and apoptotic study through caspase-3 and m-RNA expression of neurogenic gene in substantia nigra region of brain. Treatment with BME or MPE for one month significantly decreased the elevated levels of oxidative stress found in Parkinsonian mice. In behavioral tests, comparative analysis of BME and MPE showed a significant increase in spontaneous locomotor activity and grip strength test. Moreover, it was found that the use of BME considerably improved the tyrosine hydroxylase activity, caspase-3 and expression of neurogenic gene in the substantia nigra region of the brain. The results suggest that BME may provide a better platform for future drug discoveries and novel treatment strategies for PD as compared to MPE.