Neuroprotective Effect of Thymoquinone on Repeated Immobilization Stress-Induced Oxidative Stress in Rats

The present study was designed to investigate the effect of Thymoquinone (TQ) in restraint stress-induced biochemical alterations in Wistar albino rats. Restraint stress was applied for 21 days (4 h/day) and 60 min before every stress exposure the rats were treated with two doses of TQ (5 and 10 mg/kg). In serum, Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Interleukin-1β (IL-1β) Interleukin-6 (IL-6), Tumor Necrosis Factor-α (TNF-α) were estimated. Thiobarbituric Acid Reactive Substances (TBARS), reduced Glutathione (GSH), nitrite and nitrate levels and Super Oxide Dismutase (SOD), Catalase (CAT), Glutathione-S-Transferase (GST), Glutathione-Reductase (GR) and Glutathione Peroxidase (GSH-Px) activities were estimated in brain. Interleukins and enzymatic activities in serum significantly elevated by the restraint stress and were ameliorated by both the doses of TQ treatment. In brain TBARS, nitrite and nitrate levels significantly elevated due to restraint stress, the TQ treatment brings back to normal levels. Restraint stress significantly decreased in oxidative enzyme activities as the SOD, CAT, GST, GSH-Px and GR. TQ treatments significantly enhanced the activities compared to untreated stressed rats. Present results revealed that, TQ reduced the restraint stress-induced oxidative process in terms of above mentioned biochemical parameters. Thus, in view of its antioxidative nature, TQ may be developed as an effective therapeutic agent for stress-induced oxidation and CNS depression.