Neuroprotective effect of thymoquinone in acrylamide-induced neurotoxicity in Wistar rats

Acrylamide (ACR) has broad applications in different industries. It also forms in food during heating process. Oxidative stress has a critical role in ACR-induced neurotoxicity in both in vitro and in vivo models; therefore, the aim of the current study was the evaluation of effects of thymoquinone, the main constituent of volatile oil from Nigella sativa seeds in ACR-induced neurotoxicity. Male Wistar rats were treated with ACR (50 mg/kg IP) alone or with thymoquinone (TQ) (2.5, 5, 10 mg/kg IP) for 11 days. Two protocols were used in this study, A: in this one TQ and ACR were used simultaneously, B: Administration of TQ was started 1 week before ACR treatment and continued during exposure to ACR. At the end of the treatment, behavioral index (gait score) was examined for rats. After that, rats were sacrificed and molondialdehyde (MDA) as a marker of lipid peroxidation and glutathione (GSH) content were determined in cerebral cortex. Exposure to ACR led to severe gait abnormalities and treatment with TQ significantly decreased abnormalities. Level of MDA was elevated in cerebral cortex after exposure to ACR while TQ treatment significantly and in a dose-dependent manner reduced lipid peroxidation. Results clearly showed that there is no significant difference between two protocols of administration of TQ. It suggests the neuroprotective effect of TQ in this model in part, may be because of due the antioxidant activity of this natural compound.