Anti-cancer effect of estradiol and β-carotene in human colon cancer cells.

BACKGROUND/OBJECTIVES: Colorectal cancer (CRC) is a common malignancy worldwide and continues to account for significant cancer-associated morbidity and mortality. This study aimed to explore the anti-cancer effects of estradiol (E2), a female hormone, and β-carotene (BC), a dietary antioxidant, focusing on their roles in promoting apoptosis and regulating the expression of BC-related metabolic enzymes in human colon cancer cells. MATERIALS/METHODS: E2, BC, and a combination of both were administered to 2 human colon cancer cell lines, HCT116 and HT29. Cell survival was analyzed using the MTT assay. Expression of estrogen receptor beta (ERβ), β,β-carotene-15',15'-monooxygenase 1 (BCMO1), β,β-carotene-9',10'-oxygenase 2 (BCO2), and apoptosis-related markers such as Bcl-2 (anti-apoptotic) and Bax (pro-apoptotic) was analyzed using polymerase chain reaction or Western blotting. RESULTS: E2 treatment decreased cell viability in both cell lines, indicating that E2 promotes anti-cancer effects. BC treatment modestly increased E2 secretion, while the combined E2 and BC treatment enhanced this effect. Treatment with E2, BC, and their combination suppressed Bcl-2 expression and upregulated Bax. The combination treatment was more effective than each treatment administered individually. Furthermore, treatment with E2, BC, and their combination upregulated the expression of ERβ, BCMO1, and BCO2. CONCLUSION: The anti-cancer effects of E2, BC, and their combination are mediated through apoptosis induction. These findings highlight the potential for utilizing dietary antioxidants and hormonal regulation as complementary strategies in CRC treatment.