Role of Dietary Ceramide 2-Aminoethylphosphonate on Aberrant Crypt Foci Formation and Colon Inflammation in 1,2-Dimethylhydrazine-Treated Mice: A Comparison with the Role of Sphingomyelin.

Abstract

Background: Ceramide 2-aminoethylphosphonate (CAEP), a major sphingolipid class in mollusks, possesses unique structures that are not observed in other sphingolipids. CAEP has a carbon-phosphorus bond and unusual long-chain bases (LCBs). CAEP has been reported to exhibit nutritional functions, such as improving skin conditions and promoting cholesterol metabolism. Objectives: In this study, we investigated the role of dietary CAEP in the formation of aberrant crypt foci (ACF) and colon inflammation induced by 1,2-dimethylhydrazine (DMH) in mice. Methods: Five-week-old female Bagg Albino/c mice were divided into four groups (n = 11), which were treated with the respective experimental diet and DMH intraperitoneal injection nine times for ten weeks. The results obtained after administering CAEP were compared with those obtained after administering sphingomyelin (SPM), which is a major sphingolipid in mammal-derived foods. Results: The predominant LCB in the octopus-extracted CAEP was determined as hexadeca-4-sphingenine. Dietary CAEP suppressed the formation of ACF, and egg yolk-derived dietary SPM exerted a higher suppressive effect on the formation of ACF. Additionally, dietary CAEP suppressed the DMH-decreased expressions of two inflammation-related cytokines in the colon mucosa, whereas dietary SPM normalized the expressions of two cytokines different from those suppressed by CAEP. Conclusions: CAEP provides intestinal protection, with effects that differ from those of SPM. The polar head groups or LCBs in sphingolipids are important for determining their nutritional function in the intestine. The study findings contribute toward the understanding of the nutritional benefits of sphingolipids in daily diets or supplements in maintaining intestinal health.