DNA damage and NF-κB inactivation implicate glycyrrhizic acid-induced G1 phase arrest in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the most frequently occurring liver malignancy in Asia. Glycyrrhizic acid is known to reduce the risk of HCC formation in patients with chronic hepatitis C. To identify whether glycyrrhizic acid may play a role in anti-HCC therapy as an adjuvant is important. However, the inhibitory effect of glycyrrhizic acid on cell cycle progression in HCC cells and the mechanism of such have not been fully elucidated. This study used the comet assay, cell cycle analysis, immunofluorescence staining, the TUNEL assay, and Western blotting to identify the anti-HCC role of glycyrrhizic acid. Glycyrrhizic acid may induce DNA damage, apoptosis, activation of ATM, and expression of p21, and p27 in HCC cells. In addition, glycyrrhizic acid may also induce G(1) phase arrest and suppress NF-kappa B-mediated Cyclin D1 expression. DNA damage and NF-kappa B inactivation may be associated with glycyrrhizic acid-induced G(1) phase arrest in HCC cells.