The effect of p-cymene in amelioration of catalepsy Behavior, memory recovery and hippocampus cell damage in an animal model of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disease characterized by progressive damage of dopaminergic neurons in the substantia nigra and reduction of dopamine in the striatum. Several studies have shown that oxidative stress plays an important role in the pathophysiology of PD, and antioxidant agents can be useful in reducing the rate of neurodegeneration. This study aimed to evaluate the antioxidant and neuroprotective effect of p-Cymene in the reserpine-induced (RES) PD rat model.

40 male Wistar rats were divided into 5 groups, including control, receiving vehicle of p-Cymene + receiving vehicle of reserpine (VP+VR), receiving reserpine (1 mg/5 days/intraperitoneal) + vehicle of p-Cymene (RES+VP), receiving p-Cymene (50 mg/14 days/oral) + vehicle of reserpine (p-Cymene+VR) and receiving reserpine+p-Cymene (RES+p-Cymene) were divided. After the treatment, the animals were subjected to behavioral evaluation (catalepsy test and shuttle box test). At the end, the level of hippocampal catalase (CAT), superoxide dismutase (SOD) by ELISA and malondialdehyde (MDA) by thiobarbituric acid method and the density of apoptotic neurons in different areas of the hippocampus were measured.

The results showed a significant reduction in catalepsy behavior, amelioration of avoidance memory, a significant increase in CAT and SOD, and a decrease in MDA in the RES+p-Cymene group compared to the p-Cymene+VR group. On the other hand, p-Cymene prevented the increase in the density of apoptotic neurons caused by RES in the CA1 and CA3 regions of the hippocampus.

In general, the results showed that p-cymene had a protective effect in the PD model and prevented motor-cognitive disorders and neuronal damage caused by RES.