Seco-type β-Apocarotenoid Generated by β-Carotene Oxidation Exerts Anti-inflammatory Effects against Activated Macrophages

beta-Apocarotenoids are the cleavage products of beta-carotene. They are found in plants, carotenoid-containing foods, and animal tissues. However, limited information is available regarding the health benefits of beta-apocarotenoids. Here, we prepared seco-type beta-apocarotenoids through the chemical oxidation of beta-carotene and investigated their anti-inflammatory effects against activated macrophages. Oxidation of beta-carotene with potassium permanganate produced seco-beta-apo-8'-carotenal, in which one end-group formed an open beta-ring and the other was cleaved at the C-7',8' position. In lipopolysaccharide-stimulated murine macrophage-like RAW264.7 cells, seco-beta-apo-8'-carotenal inhibited the secretion and mRNA expression of inflammatory mediators such as nitric oxide, interleukin (IL)-6 and IL-1 beta, and monocyte chemoattractant protein-1. Furthermore, seco-beta-apo-8'-carotenal suppressed phosphorylation of c-Jun N-terminal kinase and the inhibitor of nuclear factor (NF)-kappa B as well as the nuclear accumulation of NF-kappa B p65. Notably, since seco-beta-apo-8'-carotenal exhibited remarkable anti-inflammatory activity compared with beta-apo-8'-carotenal, its anti-inflammatory action could depend on the opened beta-ring structure. These results suggest that seco-beta-apo-8'-carotenal has high potential for the prevention of inflammation-related diseases.

Automated summary

beta-Apocarotenoids, cleavage products of beta-carotene, were prepared through chemical oxidation and investigated for their anti-inflammatory effects against activated macrophages. The seco-beta-apo-8'-carotenal showed significant anti-inflammatory activity compared to beta-apo-8'-carotenal, possibly due to its opened beta-ring structure. The results suggest that seco-beta-apo-8'-carotenal has high potential for preventing inflammation-related diseases.