Kuo S M
Nutrition Program, Department of Physical Therapy, Exercise and Nutrition Sciences, State University of New York at Buffalo, 14214, USA.
Crit Rev Oncog. 1997;8(1):47-69. doi: 10.1615/critrevoncog.v8.i1.30.
Dietary flavonoids represent a family of polyphenol compounds found in common food items derived from plants. Depending on structural features, flavonoids can be further subdivided into flavones, flavonols, isoflavones, flavanes, and flavanols. The biological activities of flavonoids are structure dependent and epidemiological studies support their role in human cancer prevention. Several flavonoids inhibit cancer development in animal models of chemical and UV carcinogenesis. However, at high dose some flavonoids themselves may also increase cancer incidence. Although flavonoids have been shown to inhibit cancer cell growth in vitro, the ability of flavonoids to limit cancer progression is limited in animal studies. A potential application is the possible synergisticaction of flavonoids with chemotherapy agents. Molecularly, flavonoids have antioxidant properties and can further enhance the antioxidant protein activities in cells and in animals. Isoflavones and some other flavonoids have weak affinity for the estrogen receptor. Neonatal exposure of animals to isoflavonoids affects the development of reproductive organs, an observation that opens the possibility of using isoflavonoids in the prevention of cancers of the reproductive system. Some growth-inhibiting flavonoids also bind to the low-affinity type II estrogen binding sites, but the biochemical identity of type II sites is unknown.
膳食类黄酮是一类存在于源自植物的常见食品中的多酚化合物。根据结构特征，类黄酮可进一步细分为黄酮、黄酮醇、异黄酮、黄烷和黄烷醇。类黄酮的生物活性取决于其结构，流行病学研究支持它们在预防人类癌症中的作用。几种类黄酮在化学致癌和紫外线致癌的动物模型中可抑制癌症发展。然而，高剂量时一些类黄酮本身也可能增加癌症发病率。尽管类黄酮已被证明在体外可抑制癌细胞生长，但在动物研究中类黄酮限制癌症进展的能力有限。一个潜在的应用是类黄酮与化疗药物可能的协同作用。在分子层面，类黄酮具有抗氧化特性，可进一步增强细胞和动物体内的抗氧化蛋白活性。异黄酮和其他一些类黄酮对雌激素受体具有弱亲和力。动物在新生期接触异黄酮会影响生殖器官的发育，这一观察结果为使用异黄酮预防生殖系统癌症开辟了可能性。一些具有生长抑制作用的类黄酮也与低亲和力的Ⅱ型雌激素结合位点结合，但Ⅱ型位点的生化特性尚不清楚。
