Abstract
Phytoestrogens are a large group of natural compounds found in more than 300 plants. They have a close structural similarity to estrogens, which allow them to bind to both estrogen receptors (ER), ERα and ERβ, presenting a weak estrogenic activity. Phytoestrogens have been described as antioxidant, anti-inflammatory, anti-thrombotic, anti-allergic, and anti-tumoral agents. Their role in cancer prevention has been well documented, although their impact on treatment efficiency is controversial. Several reports suggest that phytoestrogens may interfere with the effect of anti-cancer drugs through the regulation of oxidative stress and other mechanisms. Furthermore, some phytoestrogens could exert a protective effect on healthy cells, thus reducing the secondary effects of cancer treatment. In this review, we have studied the recent research in this area to find evidence for the role of phytoestrogens in cancer prevention and therapy efficacy.