Chemoprevention of Skin Cancer with Dietary Phytochemicals

Cancer is responsible for a major cause of death in human. It is calculated that more than 11 million people are diagnosed with cancer worldwide (Jemal et al., 2009). Cancer arises through accumulation of multiple genetic alterations. In skin, UV radiation-induced gene mutations have been considered as a driving force of the skin carcinogenesis. Over the past 30 years, ozone depletion has induced increase in the level of UV-B radiation at the earth’s surface. As a result, incidence of the skin cancer has been significantly increased, and it is recognized as a serious public health issue. Many researchers have studied mechanisms of UV-B radiation-induced skin cancer and strategies for skin cancer prevention and treatment. Among the various cancer therapies, chemoprevention is a pharmacological approach using natural, synthetic or biological agents that can prevent, inhibit and reverse the carcinogenic progression. Especially, dietary natural products in chemoprevention have been appreciated as credible components for the management of cancer. Epidemiological studies including more than 250 populations indicated that people who take five different kinds of fruits and vegetables a day showed about 50% decrease in cancer incidence and development than not or less eating plant foods. Based on accumulated researches, dietary plants have been believed to outstanding sources of the cancer preventive substances, and received considerable attention due to their various biological effects – anti-oxidant, antiinflammatory and anti-carcinogenic functions. Therefore, chemoprevention by dietary phytochemicals has been regarded as a new, safety and efficiency strategy for cancer treatment. This chapter gives a useful overview of recent studies in chemoprevention of skin cancer with dietary phytochemicals, and especially, focuses on UV-B radiation as a major factor of skin cancer and summarizes the UV-B radiation-induced skin carcinogenic mechanism.