Pomegranate (Punica granatum L.) consumption is an ancient medical treatment for a variety of ailments.1 It contains a unique combination of antioxidants, including polyphenols and anthocyanins. The anthocyanins in pomegranate have greater antioxidant activity than those in red wine or green tea.
Pomegranate and its constituents have been shown to affect cell signaling and pathways involved in inflammation, proliferation, tumorigenesis, and angiogenesis in multiple in vitro studies. Several studies demonstrated that pomegranate extract and juice has anticancer activity in breast cancer cell lines, though no in-human studies have been conducted to specifically evaluate pomegranate as a breast cancer treatment or preventative.
In Vitro Results
Treatment of human breast cancer cells with pomegranate extract resulted in dose-dependent growth inhibition and cytotoxicity.2 This is consistent with findings from another study, which found that pomegranate seed extract reduced human breast cancer cell viability and inhibited growth.3 A subsequent study found that pomegranate extract inhibited human breast cancer cell growth through cell cycle arrest at the G2/M checkpoint, which resulted in apoptosis.4
Other studies evaluated extracts from different parts of the pomegranate fruit. One study, for example, found that fermented pomegranate juice or aqueous pericarp (outer covering of the pomegranate fruit) extract inhibited human breast cancer cell growth, particularly in cells dependent on estrogen.5 Pomegranate seed oil also reduced human breast cancer cell proliferation. Another study found that pomegranate peel extract resulted in cytotoxicity, growth inhibition, and reduced cell viability of human breast cancer cells.6
Results from several studies suggest that pomegranate extract may reduce cancer cell invasion and motility, both of which are required for metastasis. One study demonstrated that pomegranate fruit extract resulted in dose-dependent inhibition of estrogen and progesterone receptor–negative human breast cancer cell proliferation, invasion, and motility.7 Another study demonstrated that pomegranate juice inhibited breast cancer cell growth, but also increased cell adhesion and reduced cell migration and inhibited chemotaxis.8 Pomegranate juice also inhibited genes important for inducing the epithelial-to-mesenchymal transition.