Dose-dependent effect of hesperetin on motor asymmetry induced by intrastriatal injection of 6-hydroxydopamine in the rat

Background and Objective: Parkinson's disease is a rather common movement disorder in aged individuals due to degeneration of dopaminergic neurons within the substantia nigra pars compacta. Due to antioxidant, anti-inflammatory and protective effects of the flavanone hesperetin, the present study assessed dose-dependent effect of hesperetin on motor asymmetry induced by intrastriatal injection of 6-hydroxydopamine in the rat.

Materials and Methods: In this experimental study, male rats (n=35) were divided into sham, lesion, and hesperetin-treated lesion groups. Model of Parkinson's disease was induced by injecting 12.5 microgram of 6-hydroxydopamine-ascorbate dissolved in saline-ascorbate solution into the left striatum. Treated lesion groups received hesperetin at doses of 5, 15, and 50 mg/kg/day p.o. one hour after surgery for 1 week. After 1 week, leftward and rightward rotational behavior induced by apomorphine was assessed.

Results: In the lesion group, apomorphine caused contralateral rotational behavior (P < 0.001). Administration of hesperetin only at a dose of 50 mg/kg significantly reduced the number of contralateral rotations (P < 0.05) and it had not such an effect at other doses.

Conclusion: Oral hesperetin treatment at a dose of 50 mg/kg reduces motor asymmetry (attenuation of rotational behavior) in an experimental model of Parkinson's disease.