Synergistic Hepatoprotective Effects of Glycyrrhiza glabra and Silymarin: Modulation of TGF-β/Smad Signaling Pathway in Experimental Liver Fibrosis

• Ali Hussein Mohammed¹, Prof. Dr. Sahib Jumaah Abdulrahman²

  Author

Liver fibrosis is a progressive pathological condition characterized by increased deposition of the extracellular matrix and deterioration of liver functions. The current study aimed to evaluate the hepatoprotective effects of the ethanolic and aqueous extracts of licorice roots (Glycyrrhiza glabra) compared to silymarin in carbon tetrachloride (CCl₄)-induced liver fibrosis in male rats. Twenty-five adult male Sprague–Dawley rats were used and randomly divided into five groups (5 rats per group). Liver fibrosis was induced by administering carbon tetrachloride (CCl₄) intraperitoneally for six weeks. After inducing fibrosis, the animals were orally treated with silymarin, ethanolic extract, or aqueous extract of licorice for 30 days. The levels of transforming growth factor beta (TGF-β), total protein, albumin, globulin, total bilirubin, as well as oxidative stress indicators including superoxide dismutase (SOD) enzyme, were evaluated, along with histological examination of liver tissues.

The CCl₄ group showed a significant increase (P ≤ 0.05) in serum levels of TGF-β and bilirubin, accompanied by a significant decrease in total protein and albumin concentrations compared to the control group. The treatment with silymarin and licorice extracts led to a significant improvement in these biochemical changes. The aqueous extract also showed better efficacy in some indicators, particularly TGF-β levels and serum proteins. Histological examination confirmed these results, showing a decrease in hepatic degeneration, necrosis, inflammatory infiltration, and fibrosis in the treated groups compared to the untreated infected group. The results indicate that Glycyrrhiza glabra extracts possess liver-protective and anti-fibrotic effects, which are likely due to their antioxidant and anti-inflammatory properties thru the regulation of the TGF-β signaling pathway. The aqueous extract also showed relatively higher efficacy in improving liver functions and liver histological structure.

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