Terpenoids as anti-colon cancer agents - A comprehensive review on its mechanistic perspectives

- Terpenoids (or isoprenoids) - a subclass of the prenyllipids represent the oldest and the largest group of natural compounds.
- Terpenoids as chemopreventive agents with reference to colon cancer and their molecular targets are reviewed.
- Many of the terpenoids exert its anti-colon cancer effect via cell cycle arrest and apoptosis induction.
- Some terpenoids are also shown to interrupt the various stages of adenoma-carcinoma sequence of colon cancer.
- Extensive preclinical research are warranted to achieve the bench to bedside application of terpenoids.

Multistep model of colon carcinogenesis has provided the framework to advance our understanding of the molecular basis of colon cancer. This multistage process of carcinogenesis takes a long period to transform from a normal epithelial cell to invasive carcinoma. Thus, it provides enough time to intervene the process of carcinogenesis especially through dietary modification. In spite of the in-depth understanding of the colon cancer etiology and pathophysiology and its association with diet, colon cancer remains a major cause of cancer mortality worldwide. Phytochemicals and their derivatives are gaining attention in cancer prevention and treatment strategies because of cancer chemotherapy associated adverse effects. Being the largest group of phytochemicals traditionally used for medicinal purpose in India and China, terpenoids are recently being explored as anticancer agents. Anticancer properties of terpenoids are associated with various mechanisms like counteraction of oxidative stress, potentiating endogenous antioxidants, improving detoxification potential, disrupting cell survival pathways and inducing apoptosis. This review gives a comprehensive idea of naturally occurring terpenoids as useful agents for the prevention of colon cancer with reference to their classes, sources and molecular targets. Based on the explored molecular targets further research in colon cancer chemoprevention is warranted.

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