Effect of Bromocriptine on 6-Hydroxydopamine-induced Lipid Peroxidation and Cytotoxicity <I>in vitro</I> and <I>in vivo</I>

Effect of Bromocriptine on 6-Hydroxydopamine-induced Lipid Peroxidation and Cytotoxicity <I>in vitro</I> and <I>in vivo</I>

<P> The present study was to evaluate the protective effects of bromocriptine, which is known as D<SUB>2</SUB> dopamine receptor agonist and used for the treatment of patients with Parkinson s disease (PD), on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity <I>in vitro</I> and <I>in vivo</I>. Lipid peroxidation product (malondialdehyde; MDA) produced by the administration of 6-OHDA was profoundly reduced following the treatment of bromocriptine in a dose-dependent manner in rabbit brain homogenate. Quinone formation by 6-OHDA autoxidation was also attenuated, and its effect was as potent as other antioxidants. Pretreatment of bromocriptine reduced the cytotoxicity of 6-OHDA on SH-SY5Y neuroblastoma cell lines dose-dependently. The loss of striatal dopamine and its metabolite, DOPAC (dihydroxyphenylacetic acid) as well as increase of MDA production caused by intrastriatal injection of 6-OHDA was significantly recovered following the treatment of bromocriptine. The present study clearly showed that bromocriptine had a protective action against 6-OHDA-induced neurotoxicity. These results suggest that bromocriptine has the antioxidant properties, which could be another advantage for delaying the progress of Parkinson s disease.