γ-oryzanol ameliorates the oxidative stress and inflammatory response in a mice model of LPS-induced liver injury

Background: γ-Oryzanol (ORY) is a main component of rice bran oil and consists of a mixture of phytosteryl ferulates with antioxidant and anti-inflammatory properties. The purpose of this study was to evaluate the protective effects of ORY on hepatic oxidative damage and inflammatory response induced by lipopolysaccharide (LPS) in adult male mice. Materials and Methods: Adult male BALB/c mice (n=24) were intraperitoneally administered either LPS (0.75 mg/kg/d) or saline for a week. Meanwhile, mice were supplemented with ORY (100 mg/kg/d, gavage) or vehicle for 2 weeks. After treatment, animals were sacrificed and the markers of liver injury including aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were evaluated in blood. In addition, we measured the oxidative stress and inflammatory markers including lipid peroxidation (TBARS), total free thiol, catalase activity, tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), and nuclear factor kappa B (NF-κB) expression levels in hepatic tissue. Results: Systemic LPS injections induced oxidative stress in the liver of treated animals, characterized by increased TBARS, with significantly decreased catalase activity and total free thiol content. Besides, the serum levels of ALT and AST increased in all experimental groups compared with the control group. These findings were accompanied by the increased hepatic expression levels of IL-6, IL-1β, TNF-α, and NF-κB. Furthermore, pathological evaluation of tissues showed LPS-induced microvesicular steatosis, which was ameliorated by ORY supplementation for two weeks. Conclusion: In summary, our results demonstrate that LPS-induced hepatic damage is mitigated by ORY supplementation in adult mice. These findings support the idea that natural products can protect against hepatotoxicity.