Abstract
Colorectal cancer is the third leading cause of cancer death worldwide. Zinc oxide nanoparticles (ZnO NPs) have garnered attention as potential anticancer agents in cancer therapy research. Synthesis of metal nanoparticles using beneficial bacteria is considered one of the most effective methods for cancer treatment, with minimal side effects. This study is aimed at synthesizing ZnO nanoparticles from Lactiplantibacillus plantarum biofilm and investigate their impact on cell division and apoptosis-related gene expression in colorectal epithelial cancer cells (HT-29) under laboratory conditions. After isolating and validating ZnO nanoparticles in the L. plantarum biofilm, HT-29 cells were cultured with different concentrations of zinc oxide nanoparticles for 24 h, and MTT was used to determine IC(50). Subsequently, the studied cells were cultured with 5 and 10 μg of ZnO NPs for 24 h, and Western blot, real-time PCR, and Annexin V-PI staining were used to evaluate the role of ZnO NPs in inducing apoptosis and cell division in HT-29 cells. The MTT assay results revealed that a 40 μg/L concentration showed the highest cytotoxicity after 24 h. It was also found that cell viability cultured with ZnO NPs was downregulated in a dose-dependent manner. Additionally, ZnO NPs upregulated the expression of BAX, caspase 3, and 9 genes while downregulating the expression of Bcl-2, PKM2, and HK2 genes. The current study demonstrated the potential of the L. plantarum biofilm to produce ZnO nanoparticles. Moreover, ZnO NPs induced apoptosis and downregulated cell division-related genes in HT-29 cells. These findings provide a foundation for further research and the utilization of zinc oxide nanoparticles in the pharmaceutical and colorectal cancer therapy industries.