| 摘要 |
<p>beta -Carotene and canthaxanthin, as representative carotenoids, and to a lesser extent, retinoic acid, a representative retinoid, undergo extensive oxidation to yield substances, insofar as oxidized beta -carotene is a model, which have properties useful as non-toxic agents active against cell proliferation, tumors, and tumorigenic viruses, and useful as promoters of cell differentiation. It is evident from chemical analysis of the highly oxidized beta -carotene product mixture that none of the various forms of vitamin A are present or are present only in minor amounts. Furthermore, the biological activities of oxidized canthaxanthin and retinoic acid, which cannot form, vitamin A, indicate the presence of active substances that are different from vitamin A. Although the anti-proliferative and differentiation promotion activities of oxidized beta -carotene resemble those of vitamin A itself, generally the effects are more powerful for oxidized beta -carotene in a wide variety of circumstances. Unlike vitamin A, the oxidized beta -carotene of the invention is non-toxic.</p> |
