Phenolics are broadly distributed in the plant kingdom and are the most abundant
secondary metabolites of plants. Plant polyphenols have drawn increasing attention due to
their potent antioxidant properties and their marked effects in the prevention of various
oxidative stress associated diseases such as cancer. In the last few years, the identification
and development of phenolic compounds or extracts from different plants has become a
major area of health- and medical-related research. This review provides an updated and
comprehensive overview on phenolic extraction, purification, analysis and quantification as
well as their antioxidant properties. Furthermore, the anticancer effects of phenolics in-vitro
and in-vivo animal models are viewed, including recent human intervention studies. Finally,
possible mechanisms of action involving antioxidant and pro-oxidant activity as well as
interference with cellular functions are discussed.