Molecular and Biochemical Effects of Thyme (Thymus vulgaris) Extract on Carbon Tetrachloride (CCl₄)-Induced Hepatic Injury in Rats

Abstract

Background: Thyme (Thymus vulgaris) is a common plant with anti-inflammatory, antioxidant, and antimicrobial properties, and it is used in the treatment of respiratory diseases. Despite its widespread use, its therapeutic targets and mechanisms of action are still not fully understood. The carbon tetrachloride (CCl₄)-induced liver injury model is widely used as a non-viral hepatitis model. This study aimed to evaluate the effect of thyme extract in alleviating liver damage caused by CCl₄ in rats by examining liver enzymes, oxidative stress indicators, inflammatory cytokines, and the lipid profile. Materials and Methods: Adult male rats were randomly divided into six groups, including the control group, the CCl₄ group (rats treated with CCl₄ only), the silymarin group (rats treated with CCl₄ and then with silymarin at a dose of 100 mg/kg body weight/day), the thyme group (rats treated with CCl₄ and then with thyme extract). Low-dose thyme group: Rats were treated with CCl₄ and then with thyme extract at a dose of (200 mg/kg body weight/day). The high-dose thyme group of rats were treated with CCl₄ and then treated with thyme extract at a dose of (400 mg/kg body weight/day). For 4 weeks. Liver enzymes (ALT, AST), oxidative stress indicators (ROS, MDA), lipid profile (HDL, LDL), inflammatory cytokines (TNF-α, IL-6, IL-10, TGF-β), and antioxidant status (GSH and uric acid levels) were measured. Results: Treatment with thyme extract led to a significant decrease in ALT and AST levels in the injured group compared to the uninjured group, with the effect increasing with higher doses. Thyme also contributed to reducing oxidative stress indicators (ROS and MDA) and improving the lipid profile by increasing HDL and decreasing LDL. The levels of inflammatory cytokines, including TNF-α, IL-6, IL-10, and TGF-β, were regulated. Thyme also restored antioxidant levels, with GSH increasing and uric acid decreasing, and the effects were more pronounced at the high dose. Conclusions: Thyme extract, especially at the high dose, showed a clear protective effect on the liver by reducing oxidative stress, inflammation, and lipid disorder. Its efficacy was similar to that of interferon, suggesting the possibility of considering it a safe natural alternative for treating liver injuries. However, additional clinical studies are needed to confirm its safety and efficacy