dose-dependent effect of hypericum perforatum extract on motor imbalance following intrastriatal injection of 6-hydroxydopamine in the rat

Background and objective: parkinson's disease (pd) is a neurodegenerative disease with selective damage of mesencephalic dopaminergic neurons. due to the protective, anti-inflammatory, and antioxidant effect of hypericum perforatum (hp), this study was undertaken to assess dose-dependent effect of hp hydroalcoholic extract on motor imbalance following intrastriatal injection of 6-hydroxydopamine in the rat.materials and methods: in this experimental research, male wistar rats (n=35) were equally divided into sham, 6-hydroxydopamine (ohda)-lesioned, and hp extract-treated lesion groups. model of pd was induced by microinjecting 12.5 microgram of 6-ohda dissolved in saline-ascorbate solution into the left striatum. treated lesion groups received hp extract at doses of 50, 100, and 200 mg/kg/day p.o. started one week before the surgery for 1 week post-surgery. after 1 week, ipsilateral and contralateral rotations induced by apomorphine were counted and net scores were obtained.results: in the 6-ohda-lesioned group, the dopaminergic agonist apomorphine induced contralateral rotational behavior (p < 0.001) as compared to sham. in addition, administration of hp extract at doses of 100 and 200 mg/kg significantly reduced the number of contralateral rotations (p < 0.05) versus 6-ohda group. conclusion: oral administration of hp extract at doses of 100 and 200 mg/kg could reduce motor imbalance and attenuate forced biased rotational behavior in 6-ohda-induced model of pd.