NEUROPROTECTIVE EFECT OF POLYGALA MYRTIFOLIA ON PARKINSONS DISEASE IN MALE SPRAGUE DAWLEY RATS

Chlorpromazine (CPZ), a widely used antipsychotic, is associated with neurotoxicity characterized by oxidative stress, mitochondrial dysfunction, and dopaminergic depletion, leading to motor deficits and neurochemical imbalances. This study evaluated the neuroprotective effects of Polygala extract against CPZ-induced toxicity in rats. Four groups were treated: vehicle control, CPZ alone, and CPZ combined with Polygala extract at 100 mg/kg and 200 mg/kg doses for 21 days. Results demonstrated that CPZ significantly increased lipid peroxidation, midbrain calcium levels, and dopamine metabolites while decreasing antioxidant enzyme activities (catalase, SOD, glutathione reductase), mitochondrial Complex I activity, and dopamine levels. Co-treatment with Polygala extract dose-dependently reversed these changes, restoring antioxidant defenses, mitochondrial function, calcium homeostasis, and dopaminergic balance. Behavioral assessments, including rotarod and catalepsy tests, showed improved motor coordination and reduced neurotoxicity with Polygala treatment. The findings suggest that Polygala extract exerts potent neuroprotective effects by mitigating oxidative stress, preserving mitochondrial integrity, and supporting dopaminergic neurotransmission. These results highlight its potential as a natural adjunct therapy to prevent or reduce antipsychotic-induced neurotoxicity. Keywords: Polygala extract, Chlorpromazine, lipid peroxidation, midbrain calcium levels