The Potential of Flavonoids and Tannins from Medicinal Plants as Anticancer Agents.

: The tendency of using herbs extracts or natural compounds extracted from herbs for preventing or treating different illness, including cancer, continues to be an alternative to drug use. Many studies of plants compounds are aimed to find substances with selective cytotoxicity on abnormal cells. Phenolic compounds, as important secondary metabolites from plants are between them. In this review, the recent literature data from past five years about anticancer/antitumor effect of flavonoids and tannins extracted from medicinal plants are surveyed. The cytostatic/antitumor effect of the individual compounds extracted from plants and/or of the plants polyphenolic extracts are considered, in order to point out the most significant constituents or plants with anticancer potential. The most important results concerning these compounds and their derivatives in cancer prevention and treatment, the importance of their chemical structure, their mechanism of action in vitro and in vivo, and some bioavailability aspects are discussed.