Background: Thymoquinone (TQ) is a potent cytoprotective, antioxidant and anti-inflammatory agent. We aimed to investigate the possible protective effects of TQ on survival, mesenteric artery blood flow (MABF), vascular reactivity, oxidative and inflammatory injuries in a murine sepsis model induced by cecal ligation and puncture (CLP).Methods: Wistar rats were divided into the following four groups: Sham, CLP, Sham + TQand CLP + TQ. TQ (1 mg/kg/day) or vehicle (dimethyl sulfoxide, 1 mL/kg/day) was intraperitoneally injected for 3 days. At 4th day Sham or CLP operation was applied. 20 h after the operations, MABF and contractile responses of isolated aortic rings to phenylephrine were measured. Tissue samples were obtained for histopathological and biochemical examinations. Also, survival rates were recorded throughout 96 h.Results: TQ ameliorated mesenteric hypoperfusion and partially attenuated aortic dysfunction induced by CLP. Survival rate was %0 at 42nd h in CLP group, but in CLP + TQ group it was 33.4% at the end of 96 h. Serum levels of AST, ALT, LDH, BUN, Cr and inflammatory cytokines (tumor necrosis factor-alpha, interleukin-1 beta and interleukin-6) increased in CLP group that were prevented by TQ. The decreases in liver, spleen and kidney glutathione levels and the increases in liver, lung, kidney and spleen malondialdehyde levels induced by CLP were inhibited by TQ. The histopathological protective effects of TQ on multiple organ damage due to CLP were also observed.Conclusion: TQ has ameliorative effects on sepsis due to its protective effects on mesenteric perfusion, contractile function of aorta and its anti-inflammatory and antioxidative effects. (C) 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Sp. z o.o. All rights reserved.