Department of Clinical Biochemistry, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Mol Nutr Food Res. 2012 Feb;56(2):259-69. doi: 10.1002/mnfr.201100311. Epub 2011 Nov 21.
The basis for the vivid color of carotenoids and their antioxidant activity is the multiple conjugated double bonds, which are characteristic for these phytonutrients. Moreover, the cleavage of these oxidation-prone double bonds leads to the formation of apocarotenoids. A large number of carbonyl-containing oxidation products are expected to be produced as a result of carotenoid oxidation and these can be further metabolized into the corresponding acids and alcohols. As discussed in this review, many, but not all, of these potential products have been detected and identified in plants as well as in human and animal plasma and tissues. Some of these compounds were found to be biologically active as anticancer agents. In addition to the inhibition of cancer cell proliferation, several carotenoid metabolites were shown to modulate the activity of various transcription systems. These include ligand-activated nuclear receptors, such as the retinoic acid receptor, retinoid X receptor, peroxisome proliferator-activated receptor and estrogen receptor, as well as other transcription systems that have an important role in cancer, such as the electrophile/antioxidant response element pathway and nuclear factor-κB. Therefore, apocarotenoids can be considered as natural compounds with multifunctional, rather than monofunctional, activity and, thus, can be useful in the prevention of cancer and other degenerative diseases.
类胡萝卜素的鲜艳颜色和抗氧化活性的基础是其多重共轭双键，这是这些植物营养素的特征。此外，这些易氧化双键的断裂会导致类胡萝卜素的断裂产物的形成。由于类胡萝卜素的氧化，预计会产生大量含有羰基的氧化产物，这些产物可以进一步代谢为相应的酸和醇。正如本综述中所讨论的，许多（但不是全部）这些潜在的产物已经在植物以及人和动物的血浆和组织中被检测和鉴定。其中一些化合物被发现具有抗癌活性。除了抑制癌细胞增殖外，几种类胡萝卜素代谢物还被证明可以调节各种转录系统的活性。这些包括配体激活的核受体，如视黄酸受体、视黄醇 X 受体、过氧化物酶体增殖物激活受体和雌激素受体，以及在癌症中具有重要作用的其他转录系统，如亲电体/抗氧化剂反应元件途径和核因子-κB。因此，断裂产物可以被认为是具有多功能而非单一功能的天然化合物，因此可用于预防癌症和其他退行性疾病。
