Glycyrrhizic acid alleviates gefitinib-induced liver injury by regulating the p53/p21 pathway and releasing cell cycle arrest

Gefitinib, a first-line tyrosine kinase inhibitor (TKI) target to non-small cell lung cancer (NSCLC) treatment, is known to cause hepatotoxicity, which seriously limiting its therapeutic application. This study investigated the underlying mechanisms of gefitinib-induced liver injury and the protective effects of glycyrrhizic acid (GL) in mice and AML12 cells. Sixty mice were randomly divided into six groups: control, gefitinib, glutathione (200 mg/kg), and three doses of GL (50, 100, and 200 mg/kg). Liver injury was induced in mice through daily oral administration of gefitinib (400 mg/kg) for 16 days, with hepatotoxicity was assessed through serum alanine transaminase (ALT) and aspartate transaminase (AST) levels, and hepatic histopathology. Hepatic mRNA profiles were analyzed using RNA sequencing, with differentially expressed genes (DEGs) confirmed by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot. Finally, the effect of GL on the anticancer efficacy of gefitinib was assessed in A549 and Lewis lung carcinoma (LLC) lung cancer cells, as well as in a urethane-induced lung cancer mouse model. GL treatment significantly reduced liver index and serum ALT and AST levels, while also improving hepatic histopathology. Transcriptomic analysis identified 114 DEGs linked to the p53 pathway and cell cycle regulation. Further study indicated that GL inhibited the expression of p53 and p21, thereby upregulated Cyclin D1 expression, thereby alleviating gefitinib-induced cell cycle arrest without impairing its anticancer activity in vivo and in vitro. These findings highlight the potential of GL as a safe adjunct therapy, effectively mitigating gefitinib-induced hepatotoxicity while preserving its anticancer efficacy.