potent antiprolifrative effects of combination of atra with gallic acid on human mcf-7 breast cancer cells

Breast cancer is the most common malignancy in women worldwide (1) and is one of the main causes of cancer-dependent death among women in developed and developing countries (2). in recent decades, plants, fruits and natural food have been recognized as a valuable resource in developing new and advanced cancer treatments (3). recent studies have demonstrated the pro-oxidant and anticancer activities of two natural compounds, gallic acid and all-trans-retinoic acid (atra) in human cancer cells. in the present study, we evaluated the effects of combined gallic acid and atra treatment in mcf-7 cells by mtt assay after 48 hr. our data showed an additive cytotoxic effect in the concurrent treatment of 200 μm atra and 80 μm gallic acid in mcf-7 cells. however, it was found that the sequential treatment of cells with gallic acid (80 μm) for 1 hr followed by atra (200 μm), exhibited increased effectiveness with a combined index below 1. in conclusion, the findings of our study proposed that combined atra and gallic acid treatment could have a significant impact in clinical settings as a chemotherapeutic strategy for breast cancer.