Stilbenes and Xanthones from Medicinal Plants as Potential Antitumor Agents

There is an emerging interest in plant polyphenols as dietary ingredients, particularly for digestive disorders and/or as antitumor agents. The plant compounds or extracts continue to be an alternative to drug use, and many studies aim to find natural substances with selective cytotoxicity on abnormal cells. Phenolic compounds, as important secondary metabolites from plants, are intensively studied as a substitute for drugs. In this review, the recent literature data from the past five years about the potential anticancer/antitumor effect of some categories of phenolics such as stilbenes and xanthones extracted from medicinal plants were surveyed. The most important results concerning the effectiveness of these active compounds as antitumor/anticancer agents, isolated compounds or as plant extracts, some bioavailability aspects and their mechanism of action in vitro and in vivo, were considered.