Thymoquinone restores liver fibrosis and improves oxidative stress status in a lipopolysaccharide-induced inflammation model in rats

Objective Liver fibrosis is the primary sign of chronic liver injury induced by various causes. Thymoquinone (TQ) is the major ingredient of Nigella sativa with several beneficial effects on the body. In the present study, we aimed to investigate the effect of TQ on liver fibrosis in a lipopolysaccharide (LPS)-induced inflammation in male rats. Materials and methods Fifty male Wistar rats were randomly divided into five groups (n=10 in each group) as follow: (1) control; (2) LPS (1 mg/kg/day; i.p); (3) LPS+TQ 2 mg/kg/day (i.p) (LPs+TQ2); (4) LPS+TQ 5 mg/kg/day (LPS+TQ5); (5) LPS+ TQ 10 mg/kg/day (LPS+ TQ10). After three weeks, blood samples were taken for evaluation of liver function tests. Then, the livers were harvested for histological evaluation of fibrosis and collagen content and measurement of oxidative stress markers including malondialdehyde (MDA), total thiol groups, superoxide dismutase (SOD) and catalase activity in tissue homogenates. Results LPS group showed higher levels of fibrosis and collagen content stained by Masson's trichrome in liver tissue with impaired liver function test and increased oxidative stress markers (p<0.05). Treatment by TQ restored liver fibrosis, improved liver function tests and increased the levels of anti-oxidative enzymes (SOD and catalase), while reduced MDA concentration (p<0.05). Conclusion Treatment by TQ restores inflammation-induced liver fibrosis possibly through affecting oxidative stress status. It seems that administration of TQ can be considered as a part of liver fibrosis management.