[제 4 주제] 전통식품 및 소재의 암예방활성

In spite of immense efforts to improve treatment for cancer, overall mortality rates for most forms of cancer has not declined in the past 30 years. Relatively low efficacy in cancer treatment regimen stimulated interest in cancer prevention. Chemoprevention is the use of pharmacologic and natural agents that inhibit the development of invasive cancer either by blocking the DNA damage that initiates carcinogenesis or by arresting or reversing the progression of premalignant cells in which such damage has already occurred. As many natural compounds have been reported to have cancer protective effect, screening possible chemopreventive agents from foodstuffs and natural resources are being performed extensively. Recently several traditional foods such as kimchi, soy products and green tea have been reported to exert cancer preventive effect. Typical kimchi is prepared by mixing pre-salted cabbage with spice vegetables including red pepper, garlic, and green onion followed by fermentation. Kimchi ingredients seem to be associated with chemopreventive effect of kimchi rather than kimchi itself. Especially garlic and cabbage were reported to have a strong anticarcinogenic effect by activating detoxifying enzymes and rapidly removing carcinogens from the body. We undertook a study directed to reveal the mechanism of chemopreventive activities of soy and its products and found that isoflavones are responsible for inhibition of benzo(a)pyrene-induced tumorgenesis in mice and induction of quinone reductase, an anticarcinogenic enzyme. Feeding rats with soy isoflavones also caused the appreciable reduction in serum dihydrotestosterone level which is closely related to the development of prostate cancer, suggesting the potential usefulness of soy or isoflavones as chemopreventive agents. Currently available data indicate that human can get health benefit by consuming one-milligram isoflavones per kg body weight or equivalent soy product without any known toxic effect.