Olive leaf extract reverses the behavioral disruption and oxidative stress induced by intrastriatal injection of 6-hydroxydopamine in rats

Introduction: Oxidative stress seems to play a critical role in the degeneration of dopaminergic neurons in Parkinson’s disease (PD). Antioxidant compounds can deactivate and scavenge free radical. Olive leaves are considered as a useful source of phenolic compounds. Therefore, this study was designed to investigate the effects of methanolic olive leaf extract (OLE) on neurobehavioral activity and antioxidant enzyme activity, malondialdehyde (MDA) and glutathione (GSH) levels in striatum of rats in an experimental model of PD. Methods: The PD was induced in animals by intrastriatal injection of 6-hydroxydopamin unilaterally. Animals were pretreated with the OLE (50, 100 and 150 mg/kg body weight) for 7 weeks, and then behavioral activity (narrow beam and grip testes) and antioxidant parameters were evaluated. Results: In our study behavioral testes showed improvement in motor coordination and balance behavior in rats pretreated with OLE. Furthermore the extract of olive leaf restored the activity of antioxidant enzymes (superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase) and decreased MDA and increased GSH levels in the brain of rats. Conclusion: Our results suggest that OLE shows a neuroprotective effect in animal models of Parkinson's disease.