Thymoquinone exerts neuroprotective effect in animal model of Parkinson’s disease

Oxidative stress plays an important role in both the initiation and progression of Parkinson's disease (PD). Rotenone, an environmental toxin, induces oxidative stress and impact mitochondrial dynamics, including fission and fusion. Thymoquinone (TQ) has been reported to have antioxidant and anti-inflammatory characteristics in vitro and in vivo. TQ scavenges free radicals so prevents cell damage against oxidative agents. To evaluate the efficacy of TQ in the management of PD, male Wistar rats (8-10 months) received rotenone. Pre-treatment with TQ (7.5 and 15mg/kg/day, po) one hour prior to the rotenone injection, changed motor tests results (rotarod, rearing and bar tests). Dopamine levels of dopaminergic areas in the substantia nigra (SN) and striatum (ST) measured using high-performance liquid chromatography. Western blot analysis employed to determine the protein contents of Parkin and Drp1 (dynamin-related protein-1) in these areas and in order to identify tyrosine hydroxylase positive cells, Immunohistochemical assays performed. The results indicated that TQ significantly prevented rotenone-induced motor defects and changes in the Parkin, Drp1, dopamine and TH levels in both studied areas. These findings show that TQ effects on ameliorating the PD symptoms induced by rotenone might be associated with the neuroprotective and antioxidant effects of this compound.