Di Mascio P, Murphy M E, Sies H
Institut für Physiologische Chemie I, Universität Düsseldorf, FRG.
Am J Clin Nutr. 1991 Jan;53(1 Suppl):194S-200S.
Reactive oxygen species occur in tissues and can damage DNA, proteins, carbohydrates, and lipids. These potentially deleterious reactions are controlled by a system of enzymatic and nonenzymatic antioxidants which eliminate prooxidants and scavenge free radicals. The ability of the lipid-soluble carotenoids to quench singlet molecular oxygen may explain some anticancer properties of the carotenoids, independent of their provitamin A activity. Tocopherols are the most abundant and efficient scavengers of hydroperoxyl radicals in biological membranes. Water-soluble antioxidants include ascorbate and cellular thiols. Glutathione is an important substrate for enzymatic antioxidant functions and is capable of nonenzymatic radical scavenging. Thiols associated with membrane proteins may also be important to the antioxidant systems. Interactions between the thiols, tocopherols, and other compounds enhance the effectiveness of cellular antioxidant defense.
活性氧存在于组织中，会损害DNA、蛋白质、碳水化合物和脂质。这些潜在的有害反应由酶促和非酶促抗氧化剂系统控制，该系统可消除促氧化剂并清除自由基。脂溶性类胡萝卜素淬灭单线态分子氧的能力可能解释了类胡萝卜素的一些抗癌特性，这与其维生素A原活性无关。生育酚是生物膜中最丰富、最有效的氢过氧自由基清除剂。水溶性抗氧化剂包括抗坏血酸和细胞硫醇。谷胱甘肽是酶促抗氧化功能的重要底物，能够进行非酶促自由基清除。与膜蛋白相关的硫醇对抗氧化系统也可能很重要。硫醇、生育酚和其他化合物之间的相互作用增强了细胞抗氧化防御的有效性。
