Faculty of Medicine, Tokushima University, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan.
Food Funct. 2023 Aug 29;14(17):7799-7824. doi: 10.1039/d3fo02330c.
Humans are unique indiscriminate carotenoid accumulators, so the human body accumulates a wide range of dietary carotenoids of different types and to varying concentrations. Carotenoids were once recognized as physiological antioxidants because of their ability to quench singlet molecular oxygen (O). In the 1990s, large-scale intervention studies failed to demonstrate that supplementary β-carotene intake reduces the incidence of lung cancer, although its antioxidant activity was supposed to contribute to the prevention of oxidative stress-induced carcinogenesis. Nevertheless, the antioxidant activity of carotenoids has attracted renewed attention as the pathophysiological role of O has emerged, and as the ability of dietary carotenoids to induce antioxidant enzymes has been revealed. This review focuses on six major carotenoids from fruit and vegetables and revisits their physiological functions as biological antioxidants from the standpoint of health promotion and disease prevention. β-Carotene 9',10'-oxygenase-derived oxidative metabolites trigger increases in the activities of antioxidant enzymes. Lutein and zeaxanthin selectively accumulate in human macular cells to protect against light-induced macular impairment by acting as antioxidants. Lycopene accumulates exclusively and to high concentrations in the testis, where its antioxidant activity may help to eliminate oxidative damage. Dietary carotenoids appear to exert their antioxidant activity in photo-irradiated skin after their persistent deposition in the skin. An acceptable level of dietary carotenoids for disease prevention should be established because they can have deleterious effects as prooxidants if they accumulate to excess levels. Finally, it is expected that the reason why humans are indiscriminate carotenoid accumulators will be understood soon.
人类是独特的不分种类的类胡萝卜素积累者，因此人体能积累广泛的不同类型和不同浓度的膳食类胡萝卜素。类胡萝卜素曾经因其能淬灭单线态氧（O）而被认为具有生理抗氧化活性。在 20 世纪 90 年代，大规模的干预研究未能证明补充β-胡萝卜素摄入可降低肺癌的发病率，尽管其抗氧化活性被认为有助于预防氧化应激诱导的致癌作用。然而，随着 O 的病理生理作用的出现，以及膳食类胡萝卜素诱导抗氧化酶的能力被揭示，类胡萝卜素的抗氧化活性再次引起了人们的关注。这篇综述集中讨论了来自水果和蔬菜的六种主要类胡萝卜素，并从促进健康和预防疾病的角度重新审视了它们作为生物抗氧化剂的生理功能。β-胡萝卜素 9'，10'-加氧酶衍生的氧化代谢物触发抗氧化酶活性的增加。叶黄素和玉米黄质选择性地在人眼黄斑细胞中积累，通过充当抗氧化剂来防止光诱导的黄斑损伤。番茄红素仅在睾丸中特异性地积累到高浓度，其抗氧化活性可能有助于消除氧化损伤。膳食类胡萝卜素在经光照的皮肤中似乎在其持续沉积后发挥其抗氧化活性。应该确定预防疾病的可接受的膳食类胡萝卜素水平，因为如果它们积累到过量水平，它们可能作为促氧化剂产生有害影响。最后，预计人类是不分种类的类胡萝卜素积累者的原因很快就会被理解。
