AMELIORATIVE EFFECTS OF ERYTHROPOIETIN AND THYMOQUINONE ON VINCRISTINE-INDUCED BRAIN TOXICITY IN ALBINO RATS

Vincristine (VCR) is a powerful anticancer medication, but one of its most serious adverse effects is neurotoxicity. The current experiment investigated the adverse effect of VCR on the brain and the potential neuroprotective effect of Erythropoietin (EPO) and Thymoquinone (TQ) or their combination against VCR toxicity in a rat model. The adverse effects were monitored by estimation of brain oxidative stress markers and neurotransmitters and by histopathological observation. Intraperitoneal injection of VCR (150 μg/kg) three times weekly for five consecutive weeks, significantly decreased both the level of glutathione (GSH) and the activity of acetylcholinesterase (AChE) and significantly increased the lipid peroxidation (LPO), nitric oxide (NO) and glutamate levels. Moreover, VCR caused marked histopathological changes such as neuronal degeneration, demyelination, sub-meningeal edema, hemorrhage, dilatation of brain ventricles and hyperplasia of the choroid plexus. Co-treatment of rats with EPO (80μg/kg) and their combination with TQ (10 mg/kg) improved all VCR-induced changes, however, TQ alone improved almost all changes except neurotransmitters alterations. These results suggested that the combination of EPO and TQ had an obvious neuroprotective ef fect aga inst VCR neurotoxicity on oxidative stress markers, brain neurotransmitters levels and the histopathological findings in comparison with each one alone.