Mechanism of Action of Flavonoids in Prevention of Inflammation- Associated Skin Cancer.

Skin cancer in humans represents about 30% of all new cancers and is by far the most common malignancy in the Caucasian population. Exposure to radiations especially ultraviolet-B (UV-B) radiation is the major cause for development of skin cancers along with other chemical or biological factors. The growing incidence rates of skin cancer around the world, demand the need for new treatment options. Understanding the etiology and pathogenesis of skin cancer is therefore crucial for developing an effective drug against this prevailing disease. Medicinal plants are rich with numerous secondary metabolites such as flavonoids, which are now known to treat various chronic diseases, including inflammations and cancers. Flavonoids are sub-classified in to flavones, flavonols, iosflavones, flavanones, flavanols and anthocyanidins. They act on different targets including scavenging reactive oxygen species (ROS), regulation of the cell cycle, and initiation of DNA repair mechanisms, apoptotic induction and inhibition of metastasis. Innumerable evidence suggested that an increased consumption of flavonoid-rich fruits and vegetables rendered DNA protection to normal skin exposed to carcinogens such as UV-B radiation. Flavonoids also showed the potential to induce cell death mechanisms in melanoma, the most dreadful form of skin cancer. This comprehensive review presents flavonoids and their mechanism of action in relation to inflammation and skin cancer management.