Assessment of Symptomatic and Neuroprotective Efficacy of Mucuna Pruriens Seed Extract in Rodent Model of Parkinson's Disease

Purpose: The present study undertook an extensive evaluation of the antiparkinsonian effects of an extract of Mucuna pruriens (MP) seeds known to contain, among other components, 12.5% L-DOPA. Moreover, the neuroprotective efficacy of MP was evaluated. Methods and Results: Data obtained reveal how acute administration of MP extract at a dose of 16 mg/kg (containing 2 mg/kg of L-DOPA) consistently antagonized the deficit in latency of step initiation, adjusting step and in placement of the forelimb in vibrissae-evoked forelimb placing test induced by a unilateral 6-hydroxydopamine lesion, whereas L-DOPA was equally effective only at doses of 6 mg/kg. Moreover, MP extract acutely induced a significantly higher contralateral turning than L-DOPA (6 mg/kg) when administered at dose of 48 mg/kg (containing 6 mg/kg of L-DOPA), suggested a significant antagonistic activity on both motor and sensory-motor deficits. Subchronic administration of both MP (48 mg/kg) and L-DOPA (6 mg/kg) induced sensitization of contralateral turning; however, L-DOPA induced a concomitant sensitization in AIMs suggesting that the dyskinetic potential of MP is lower than that of L-DOPA. MP (48 mg/kg) was also effective in antagonizing tremulous jaw movements induced by tacrine, a validated test reproducing parkinsonian tremor. Finally, in a subchronic mice model of MPTP-induced dopamine neuron degeneration, MP extract did not prevent either tyrosine hydroxylase decrease induced by MPTP or astroglial or microglial activation supporting the absence of neuroprotective effects by MP. Conclusions: Characterization of MP extract strongly support its antiparkinsonian activity, however, MP does not show neuroprotective properties in MPTP model of PD.