Humans depend on a dietary intake of lipids to maintain optimal health. Among various classes of dietary lipids, the physiological importance of carotenoids is still controversially discussed. On one hand, it is well established that carotenoids, such as β,β-carotene, are a major source for vitamin A that plays critical roles for vision and many aspects of cell physiology. On the other hand, large clinical trials have failed to show clear health benefits of carotenoids supplementation and even suggest adverse health effects in individuals at risk of disease. In recent years, key molecular players for carotenoid metabolism have been identified, including an evolutionarily well conserved family of carotenoid-oxygenases. Studies in knockout mouse models for these enzymes revealed that carotenoid metabolism is a highly regulated process and that this regulation already takes place at the level of intestinal absorption. These studies also provided evidence that β,β-carotene conversion can influence retinoid-dependent processes in the mouse embryo and in adult tissues. Moreover, these analyses provide an explanation for adverse health effects of carotenoids by showing that a pathological accumulation of these compounds can induce oxidative stress in mitochondria and cell signaling pathways related to disease. Advancing knowledge about carotenoid metabolism will contribute to a better understanding of the biochemical and physiological roles of these important micronutrients in health and disease. This article is part of a Special Issue entitled Retinoid and Lipid Metabolism.
|Original language||English (US)|
|Number of pages||10|
|Journal||Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids|
|State||Published - Jan 2012|
Bibliographical noteFunding Information:
The authors would like to thank Drs. Ouliana Ziouzenkova and Earl Harrison for the invitation to contribute this article to this special issue of BBA. This work was supported by the National Institute of Health grant EY019641 . Darwin Babino was supported by a visual science training grant (NIH T32-EY07157).
- Oxidative stress