Anthocyanins and cancer prevention

Anthocyanins are members of a class of flavonoid compounds commonly known as plant polyphenols. They are responsible for the blue, purple, red and intermediate colors of many flowers, leaves, vegetables and fruits, especially berries. The daily intake of anthocyanins in the United States diet is estimated to be about 200 mg or about 9-fold higher than that of other dietary flavonoids. Anthocyanins have been evaluated for chemopreventive potential, both in cell cultures and in animal model tumor systems. Limited information on their chemopreventive effects is also available from epidemiological studies. This chapter summarizes the chemistry, synthesis and bioavailability of anthocyanins and the latest developments regarding their anti-carcinogenic effects in cell cultures and in animal model systems. The chemopreventive activity of protocatechuic acid (PCA), one of the most abundant metabolites of anthocyanins, is also discussed due to its prominent role in the overall inhibitory effects of anthocyanins. We suggest that PCA be further evaluated for chemoprevention in animal model systems and in humans in view of its relatively low toxicity and commercial availability.