Hepatoprotective Effect of Cannabidiol on the Progression of Experimental Hepatic Cirrhosis in Rats

Introduction: Liver cirrhosis is a condition characterized by the gradual replacement of normal liver tissue with scar tissue, ultimately leading to liver failure. This slow and progressive disease begins with a chronic inflammatory process induced by a noxious agent. In its advanced stages, the disease lacks effective therapies. Research has demonstrated the significant involvement of the endocannabinoid system in the pathogenesis of this disease. This study evaluated the hepatoprotective effect of cannabidiol (CBD) in the progression of experimental hepatic cirrhosis induced by thioacetamide (TAA) in rats.

Methods: A randomized experimental design was employed using Holtzman rats. Hepatic cirrhosis was induced by intraperitoneal administration of TAA at a dose of 150 mg/kg for 6 weeks, with treatment initiated additionally. The groups were as follows: Group 1: TAA + vehicle; Group 2: TAA + CBD 2 mg/kg; Group 3: TAA + CBD 9 mg/kg; Group 4: TAA + CBD 18 mg/kg; Group 5: TAA + silymarin 50 mg/kg; and Group 6: Healthy control. Serum biochemical analysis (total bilirubin, direct bilirubin, ALT, AST, alkaline phosphatase, and albumin) and hepatic histopathological study were performed. The Knodell histological activity index (HAI) was determined, considering periportal necrosis, intralobular degeneration, portal inflammation, fibrosis, and focal necrosis.

Results: All groups receiving TAA exhibited an elevation in AST levels; however, only those treated with CBD at doses of 2 mg/kg and 18 mg/kg did not experience significant changes compared to their baseline values (152.8 and 135.7 IU/L, respectively). Moreover, ALT levels in animals treated with CBD showed no significant variation compared to baseline. The HAI of hepatic tissue was notably lower in animals treated with CBD at doses of 9 and 18 mg/kg, scoring 3.0 and 3.25, respectively, in contrast to the TAA + vehicle group, which recorded a score of 7.00. Animals treated with CBD at 18 mg/kg showed a reduced degree of fibrosis and necrosis compared to those receiving TAA alone (p ≤ 0.05).

Conclusion: Our findings demonstrate that cannabidiol exerts a hepatoprotective effect in the development of experimental hepatic cirrhosis induced in rats.