Chemopreventive effects of some popular phytochemicals on human colon cancer: a review.

Colon cancer is one of the major causes of morbidity and mortality worldwide. Dietary phytochemicals have been drawing increasing attention for colon cancer prevention and treatment due to their chemical diversity, biological activity, easy availability, lack of toxic effects, and ability to modulate various signal transduction pathways and cell processes. The chemoprotective effects elicited by phytochemicals include antioxidative and anti-inflammatory activities, induction of phase II enzymes, cell cycle arrest, apoptosis, autophagy, and changes in gut microbiota. The present review summarizes the main chemopreventive properties of selected phytochemicals (carotenoids, flavonoids, flavonolignan, proanthocyanidin, isothiocyanates, terpenoids, peptides, and medicinal plant extracts) against colon cancer. It is found that these phytochemicals exhibit their anti-colon cancer activity through the modulation of various signaling pathways involved in the regulation of chronic inflammation, cell cycle, autophagy, apoptosis, metastasis, and angiogenesis. These phytochemicals could be helpful starting points in the design and development of novel colon cancer chemopreventive agents.