Regulation of Cell Cycle-Related Damage/Repair Mechanism and Oxidative Stress Status by Oroxylin A in Hepatocellular Carcinoma Cells.

Hepatocellular carcinoma is a progressive tumor with an aggressive nature. Despite many treatment options, survival rates remain low. In this study, the effect of Orox A on hepatocellular carcinoma cells was investigated. Hep3B cells were treated with a range of Orox A, and cell viability was assessed by MTT assays. Subsequent analyses using RT-qPCR demonstrated alterations in the expression of DNA damage and repair genes. To determine the damage in cancer cells, the amount of 8-OHdG and NO in the cells was measured by the ELISA method. Additionally, total antioxidant/oxidant status was measured, and the OSI value was calculated. Flow cytometry analysis was conducted to ascertain the specific cell cycle phase. The IC50 dose of Orox A for hepatocellular carcinoma cells was calculated to be 1385 μM at 24 h. According to the gene expression analysis results, NEIL1, OGG1, ATM and ATR gene expressions increased significantly, while APEX1 gene expression decreased significantly. The amount of 8-OHdG dramatically increased in cancer cells treated with Orox A, whereas the level of NO significantly decreased. Total antioxidant status (TAS) and total oxidant status (TOS) were significantly decreased in Orox A-applied cancer cells, and the oxidative stress index (OSI) was significantly increased. Flow cytometry analysis revealed that Orox A treatment caused G2/M phase arrest in the cell cycle. These findings collectively suggest that Orox A exerts cytotoxic effects on Hep3B cells through mechanisms involving DNA damage, oxidative stress, and cell cycle modulation, making it a promising candidate for further anticancer therapy development.