Effect of Natural Polyphenols on Breast Cancer Chemoprevention and Treatment.

Breast cancer is the most common type of malignancy among women worldwide. Significant achievements have been made in diagnostic tools and cancer treatments in the past decade; however, the complexity and heterogeneity of certain breast cancer subtypes often lead to drug resistance and metastatic progression. Owing to their low toxicity and high variety, natural products and their derivatives are becoming increasingly valuable sources for small-molecule anticancer drugs. Polyphenols are becoming more widely known for their role in breast cancer prevention and as adjuvants in conventional treatment strategies. Therefore, this review focuses on the antitumor effects of curcumin, resveratrol, and polydatin on breast cancer. According to the main databases, only in vitro and preclinical studies with solid scientific backgrounds and reports of protective effects on breast cancer treatment were included. Curcumin, resveratrol, and polydatin have antioxidant, anti-inflammatory, and anticancer effects; indeed, they improve drug efficacy; reduce chemoresistance, angiogenesis, and tumor growth; and induce apoptosis, autophagy, and cell cycle arrest in breast cancer through multiple molecular pathways, including the suppression of epithelial-mesenchymal transition (EMT), NF-κB, PI3K/Akt/mTOR, c-Jun N-terminal kinase (JNK), MAPK, ERK1/2, and STAT signaling pathways; the inhibition of cyclins and matrix metalloproteinase (MMP)-2 and MMP-9; and the activation of p53 and microtubule-associated protein light chain 3 (LC3).