MUCUNA PRURIENS SHOWS NEUROPROTECTIVE EFFECT BY INHIBITING APOPTOTIC PATHWAYS OF DOPAMINERGIC NEURONS IN THE PARAQUAT MOUSE MODEL OF PARKINSONISM

Satyndra Kumar Yadav, Sachchida Nand Rai and Surya Pratap Singh

ABSTRACT

The neuroprotective effects of an ethanolic extract of Mucuna pruriens (Mp) seeds were evaluated in a Parkinsonian mice model induced by the pesticide paraquat (PQ). PQ induces classical symptoms of Parkinson’s disease (PD) including motor deficits, cellular loss in the substantia nigra (SN) and depletion of dopamine levels. The present study investigates the mechanisms of neuroprotection elicited by Mp, a herb traditionally recognized by the Indian system of medicine, Ayurveda. Co-treatment of PQ-treated mice with Mp significantly enhanced antioxidant activity and decreased oxidant levels. Mp also improved the motor abnormalities observed in PD mice, effectively rescued the levels of dopamine and its metabolites in the SN. HPTLC analysis of the Mp seed extract identified that a large proportion of the extract consisted of L-DOPA and also identified a novel constituent, ursolic acid, present in significant quantity. Mp also facilitated neuroprotection by creating an anti-apoptotic environment indicated by reduced apoptotic (Bax and caspase-3) and increased levels the anti-apoptotic (Bcl2) protein expression, respectively. Altogether, the present study suggests that Mp treatment provides nigrostriatal dopaminergic neuroprotection against PQ induced Parkinsonism by the modulation of oxidative stress and apoptotic machinery possibly accounting for the behavioural effects.

Keywords: Mucuna pruriens, ursolic acid, Parkinson’s disease, Bax, Bcl2, caspase-3.