Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801, USA.
J Nutr. 2010 Dec;140(12):2134-8. doi: 10.3945/jn.110.128033. Epub 2010 Oct 20.
Two enzymes have been identified for the oxidative metabolism of carotenoids in mammals. Carotene-15,15'-monooxygenase (CMO-I) primarily centrally cleaves β,β-carotene to form vitamin A. We hypothesize that carotene-9',10'-monooxygenase (CMO-II) plays a key role in metabolism of acyclic nonprovitamin A carotenoids such as lycopene. We investigated carotenoid bioaccumulation in young adult, male, wild-type (WT) mice or mice lacking CMO-II (CMO-II KO). Mice were fed an AIN-93G diet or identical diets supplemented with 10% tomato powder, 130 mg lycopene/kg diet (10% lycopene beadlets), or placebo beadlets for 4 or 30 d. Lycopene preferentially accumulated in CMO-II KO mouse tissues and serum compared with WT mouse tissues. β-Carotene preferentially accumulated in some CMO-II KO mouse tissues compared with WT mouse tissues. Relative tissue mRNA expression of CMO-I and CMO-II was differentially expressed in mouse tissues, and CMO-II, but not CMO-I, was expressed in mouse prostate. In conclusion, the loss of CMO-II expression leads to increased serum and tissue concentrations of lycopene in tomato-fed mice.
两种酶已被鉴定为哺乳动物类胡萝卜素的氧化代谢酶。β，β-胡萝卜素-15,15'-单加氧酶（CMO-I）主要在中枢部位裂解β，β-胡萝卜素形成维生素 A。我们假设类胡萝卜素-9'，10'-单加氧酶（CMO-II）在非环非维生素 A 类胡萝卜素（如番茄红素）的代谢中起关键作用。我们研究了年轻成年雄性野生型（WT）小鼠或缺乏 CMO-II 的小鼠（CMO-II KO）中类胡萝卜素的生物积累。小鼠喂食 AIN-93G 饮食或相同饮食，补充 10%番茄粉、130mg 番茄红素/千克饮食（10%番茄红素微丸）或安慰剂微丸，持续 4 或 30 天。与 WT 小鼠组织相比，番茄红素更优先在 CMO-II KO 小鼠组织和血清中积累。与 WT 小鼠组织相比，β-胡萝卜素在一些 CMO-II KO 小鼠组织中更优先积累。在小鼠组织中，CMO-I 和 CMO-II 的相对组织 mRNA 表达存在差异，并且在小鼠前列腺中表达 CMO-II，但不表达 CMO-I。总之，CMO-II 表达的缺失导致喂食番茄的小鼠血清和组织中番茄红素浓度增加。
