| Popis: |
Complex bioflavonoid phytochemicals produced by certain plants, including the anthocyanin pigments, the proanthocyanidins, and other compounds in the same biosynthetic pathway, are now recognized as potent chemopreventive agents for disease prevention. Anticancer activity can in part be attributed to their role as blocking agents (Bomser et al., 1996; Kelloff et al., 1994) which can act to inhibit carcinogen uptake, activation of carcinogens, or carcinogen binding to DNA. Blocking agents can be inhibitory to enzymes that activate the cancer process, but they may also stimulate activity of enzymes that enhance DNA repair, or accomplish carcinogen detoxification. The bioflavonoids may act as antiproliferative agents, which can modulate signal transduction, inhibit polyamine metabolism and abnormal oncogene function, enhance intercellular communication, or restore tumor suppressor gene function. For example, an antiproliferative agent may inhibit stages of inflammation during carcinogenesis. The best known property of the bioflavonoids, however, is their well-recognized strong antioxidant activity in metabolic reactions; the ability to scavenge oxygen radicals and other reactive electrophiles, which have direct impact on aging, cancer incidence, and human health in general. Patterns of hydroxylation and glycosylation in anthocyanins appear to modulate their antioxidant capacity (Wang et al. 1997). Anthocyanin pigments demonstrated strong antioxidant capacity in a liposomal system recently (Tsuda et al. 1996), and in an oxygen radical absorbance capacity assay (Wang et al. 1997). |
