Ameliorative Effect of Withaferin A on Ageing-Mediated Impairment in the Dopamine System and Its Associated Behavior of Wistar Albino Rat.

Withaferin A (WA) was evaluated for its neuro-protective efficacy on ageing induced striatal dopamine (DA) and behavioural changes in aged rats. Wistar albino rats were divided into group I - young (3 months), Group II - aged (24 months), Group III - aged rats supplemented with WA (50 mg/kg b.w once in a day for 30 days) and Group IV - young rats supplemented with WA (50 mg/kg b.w). The HPLC assay revealed significant decline in the levels of DA and homovanillic acid (HVA) in substantia nigra (SN) and striatum (ST) of aged rat. A marked decline in motor activity of aged rat was observed through open field, beam walking and grid walking motor experiments. These results indicate that ageing reduces nigro-striatal activity as well as nigro-striatal DA levels. Interestingly, the administration of WA (50 mg\kg b.w) resulted in a substantial resurge of DA and HVA in SN and ST and a significant reversal of motor impairment in aged rats. This study is the first report that evidently determines the neuro-protective efficacy of WA on dopaminergic system of SN and ST in aged rats.