Effect of Thymoquinone on Hippocampal Oxidative Stress and Neuronal Density Following Aacrylamide in Male Rat

Acrylamide is a neurotoxic agent that increases oxidative stress by creating an imbalance between the production and removal of free radicals, which in turn contributes to the pathogenesis of some neurodegenerative disorders. Thymoquinone extracted from Nigella satvia has prominent antioxidant effects. The objective of this study was to evaluate the effects of thymoquinone on hippocampal oxidative stress and neuronal density following acrylamide administration in male rats.

In this experimental study, 28 male Wistar rats aged 10-12 weeks and weighing 180-200 g were randomly divided into 4 groups of 7 rats: control, acrylamide, acrylamide + thymoquinone treatment (1 mg/kg), and acrylamide + thymoquinone treatment (5 mg/kg). For induction of brain injury, 50 mg/kg of acrylamide was injected intraperitoneally. Two days after the acrylamide injection, the rats were sacrificed, and malondialdehyde (MDA), glutathione (GSH), and catalase levels were measured in hippocampal homogenate. Evaluation of neuronal density in hippocampal CA1 region was also performed by Nissl staining.

Acrylamide injection significantly increased MDA level and reduced GSH content and catalase activity in comparison with the control group (P<0.05). Administration of 5 mg/kg thymoquinone significantly reduced MDA level (P<0.05) but improved GSH and catalase activity in comparison with the acrylamide group (P<0.05). In addition, neuron density of hippocampal CA1 region did not differ significantly between the groups.

Thymoquinone can attenuate oxidative stress markers in a dose-dependent manner.