ß-carotene genetically-enriched lyophilized orange juice increases antioxidant capacity and reduces ß-amyloid proteotoxicity and fat accumulation in Caenorhabditis elegans.

Citrus sinensis orange juice is an excellent dietary source of ß-carotene, a well-known antioxidant. However, ß-carotene concentrations are relatively low in most cultivars. We developed a new orange through metabolic engineering strategy (GS) with 33.72-fold increase in ß-carotene content compared to its conventional counterpart (CV). Using Caenorhabditis elegans, we found that animals treated with GS showed a greater reduction in intracellular reactive oxygen species (ROS) which is associated with a greater resistance to oxidative stress and induction of the expression of antioxidant genes. Moreover, animals treated with GS orange showed a more effective protection against ß-amyloid proteotoxicity and greater hypolipidemic effect under high glucose diet compared to animals treated with CV. These data demonstrate that the increased amount of ß-carotene in orange actually provides a greater beneficial effect in C. elegans and a valuable proof of principle to support further studies in mammals and humans.