Role of Natural Phenolic Compounds in Cancer Chemoprevention via Regulation of the Cell Cycle

Natural phenolic compounds have been considered as one of the interesting secondary metabolites for their chemopreventive and chemotherapeutic effects in cancer for a long time. These are a large and diverse family of phytochemicals classified into several subgroups such as simple phenols, lignans, phenylpropanoids, flavonoids, coumarins, etc. The antioxidant potential of phenolic compounds is almost bolded in the treatment and prevention of cancer. Due to the concerns on the diverse effects of antioxidants in cancer, differentiation and clarification of their anti-neoplastic mechanisms are necessary. An important mechanism for phenolic compounds is related to their direct effect on the cell cycle progression, which has not been discussed in detail so far. This study aims to criticize the evidence on regulatory mechanisms of phenolic compounds in the cell cycle. Recent studies indicate that phenolic compounds from several subgroups significantly inhibit the proliferation of different cancer cells. The structural diversity of these compounds influences various components involved in cell cycle regulation. Forming active metabolites and sensitizing cancerous cells to chemotherapeutic medicines are additional values of these compounds. In the recent years, many studies on neoplastic cell cultures have been carried out to investigate the mechanisms of action of these compounds but dissimilarity of in vitro systems in comparison with human body in terms of metabolism and bioavailability is a major concern. Therefore, further studies are still needed.