Effects of Vitamin E on Doxorubicin Cytotoxicity in Human Breast Cancer Cells in Vitro

OBJECTIVE: This study aimed to evaluate in vitro synergistic anticancer effect of doxorubicin combined with Vitamin E. METHODS: The MTT assay was utilized to assess the cytotoxicity of Vitamin E and vitamin E combined with doxorubicin and vital activities of SKBR3, MDA-MB-231, and HFF cells over a 24-hour incubation period. In addition, the antioxidant properties of these interventions and the decrease of reactive oxygen species (ROS) content caused by the treatment were evaluated. RESULTS: The antiproliferative effect of doxorubicin increased significantly in combination with vitamin E (Doxcorobicin 2µM vs. Vitamin E 120µM, P=0.000). Despite reducing cell ROS content due to vitamin E treatment, the combination of vitamin E and doxorubicin showed no significant synergistic effect (Doxcorobicin 2µM vs. Vitamin E 120µM, P=0.998). CONCLUSION: This study indicated that the doxorubicin–vitamin E treatment reduced the viability of breast cancer cells with the minimum side effects on normal cells. In addition, the high dosage of vitamin E intensified the cytotoxicity of doxorubicin.