The Pycnogenol Improves Motor Function and Anxiety Behavior in 6-hydroaydoamine (6-OHDA)-induced Experimental Model of Parkinson’s Disease in NMRI Male Mice

Considering the role of oxidants in the pathogenesis of this disease, in this study, the effect of pycnogenol as an antioxidant on the improvement of motor function and anxiety behavior in the experimental model of Parkinson’s disease were assessed. Forty male NMRI mice were randomly divided into five groups (n=8 in each group): The control (saline) unilaterally received 3 μl of normal saline solution containing 0.1% ascorbic acid, as a solvent of 6-hydroxy dopamine (6-OHDA), into the left strianum. The treatment group received 6-OHDA toxin containing 1% ascorbic acid at a rate of 3 µg/µl in the left striatum and then received the distilled water, as pycnogenol solvent, via gavage for 7 days (the lesion group). The pycnogenol-treated groups received pycnogenol at doses of 10, 20, and 30 mg/kg via gavage for 7 days. The animals were stereotaxically operated to inject 6-OHDA toxin into the left striatum. Seven days after induction of Parkinson’s model, apomorphine was intraperitoneally used at dose of 0.5 mg/kg and the number of rotation of the animals was measured to confirm the damage to neurons in the striatum. Besides, the catalepsy or muscle stiffness by the bar test and the anxiety behavior by the plus maze test (EPM) were measured. The total number of rotations in apomorphine test showed a significant decrease in the groups receiving pycnogenol. Moreover, administration of pycnogenol significantly reduced catalepsy in pycnogenol-treated groups. The result of the anxiety behavior test demonstrated that the percentage of open arm time (OAT) and the number of open and close arm entries, as an indicator of the animal’s locomotor activity, significantly increased in the pycnogenol-treated groups. Pycnogenol with its antioxidant effect ameliorates movement deficit and reduces anxiety behavior in animal model of Parkinson’s disease..