Ellagic Acid Protects the Brain Against 6-Hydroxydopamine Induced Neuroinflammation in a Rat Model of Parkinson's Disease

Introduction: Neuroinflammation may play as an important risk factor in progressive degeneration of dopaminergic cells. Antioxidants have protective effects against free radicals-induced neural damage in Parkinson's disease (PD). In the present study, we examined the effects of ellagic acid (EA) on locomotion and neuroinflammatory biomarkers in a rat model of PD induced by 6-hydroxidopamine (6-OHDA). Methods: 6-OHDA (16 mu g/2 mu l) was injected into the right medial forebrain bundle (MFB) in MFB-lesioned rat's brain. Sham group received vehicle instead of 6-OHDA. PD-model was confirmed by rotational test using apomorphine injection. EA (50 mg/kg/2 ml, by gavages) was administered in PD+EA group. One group of MFB-lesioned rats received pramipexole (PPX; 2 mg/kg/2 ml, by gavages) as positive control group (PD+PPX group). Motor activity was assessed by stride length and cylinder tests. The levels of TNF-alpha and IL-1 beta were measured in both striatum and hippocampus tissues. Results: MFB lesion caused significant reduction of stride-length (P<0.001) and also increased the contralateral rotations (P<0.001) and score of the cylinder test (P<0.001). Use of 6-OHDA to induce the PD significantly increased the levels of TNF-alpha (P<0.001) and IL-1 beta (P<0.001) in MFB-lesioned rats. EA significantly restored all of the above parameters. Discussion: EA can improve the motor impairments in the MFB-lesioned rats via reducing the neuroinflammatory biomarkers and protect the brain against free radicals-induced neural damage. The results suggest that EA can be helpful in management of PD treatment.