Bendich A
Clinical Nutrition, Hoffmann-LaRoche Inc., Nutley, NJ 07110.
J Nutr. 1989 Jan;119(1):112-5. doi: 10.1093/jn/119.1.112.
There is growing evidence from in vitro and in vivo laboratory animal studies that beta-carotene can protect phagocytic cells from autooxidative damage, enhance T and B lymphocyte proliferative responses, stimulate effector T cell functions, and enhance macrophage, cytotoxic T cell and natural killer cell tumoricidal capacities, as well as increase the production of certain interleukins. Many of these effects have also been seen with carotenoids lacking provitamin A activity but having the antioxidant and singlet oxygen quenching capacities of beta-carotene. The association of immunoenhancement with decreased tumor burden in animals given carotenoids suggests a potential explanation for the epidemiological data linking lower carotenoid status with higher incidences of certain cancers. Since vitamin A is a relatively poor antioxidant and cannot quench singlet oxygen, beta-carotene may have more importance as a nutrient than simply serving as a precursor of vitamin A.
越来越多来自体外和体内实验室动物研究的证据表明，β-胡萝卜素可以保护吞噬细胞免受自身氧化损伤，增强T和B淋巴细胞的增殖反应，刺激效应T细胞功能，增强巨噬细胞、细胞毒性T细胞和自然杀伤细胞的杀肿瘤能力，以及增加某些白细胞介素的产生。许多缺乏维生素A原活性但具有β-胡萝卜素抗氧化和单线态氧淬灭能力的类胡萝卜素也有这些作用。在给予类胡萝卜素的动物中，免疫增强与肿瘤负担减轻之间的关联为将较低类胡萝卜素水平与某些癌症较高发病率联系起来的流行病学数据提供了一个潜在解释。由于维生素A是一种相对较差的抗氧化剂，不能淬灭单线态氧，β-胡萝卜素作为一种营养素可能比仅仅作为维生素A的前体更重要。
