Mango polyphenols reduce inflammation in MDA‐MB231 breast cancer cell and targets MicroRNA‐21

Mango polyphenols have received some attention based on their antioxidant, anticarcinogenic and anti‐inflammatory properties. Our objective was to determine the anti‐inflammatory and cytotoxic properties of mango polyphenols (MP) in MCF12A non‐cancer breast fibroblasts and MDA‐MB231 breast cancer cells. mRNA, miRNA and protein expression of MDA‐MB231 and MCF12A cells were analyzed by real time PCR and Western blotting. Results show that MP (5mg of gallic acid equivalents/L (GAE/L)) decreased the proliferation of MB‐231 breast cancer cells by 90%; but not of MCF‐12A cells. In MB‐231 breast cancer cells, MP downregulated the expression of NF‐□B (to 0.6‐fold of the control), VEGF (0.5‐fold), TNF‐α (0.8‐fold), survivin (0.5‐fold) and Bcl2 (0.5‐fold). In MCF‐12A breast cells, MP downregulated TNF‐α‐induced expression of IL‐6 (0.8‐fold), IL‐1β (0.6‐fold) and NFKb (0.4‐ fold). miRNA 21 is up‐regulated in breast cancer and targets Bcl2 which is involved in apoptosis. MP reduced the expression the miR‐21 in a dose dependent manner and these findings were confirmed using the specific antagomir for miR‐21, where it reversed the effect of the polyphenolic treatment in MB‐231 cells. These results indicate that the cytotoxic effects of mango polyphenols are specific to cancer cells where inflammation was reduced in both, cancer and non‐cancer cells, seemingly through the involvement of miR‐21. Grant Funding Source : Research Assistanship