β-Cryptoxanthin Prevents Non-alcoholic Fatty Liver Disease Through Different Mechanisms Depending on the Presence or Absence of Carotenoid Cleavage Enzymes (FS06-03-192)

OBJECTIVES: β-Cryptoxanthin (BCX), a provitamin A carotenoid, is cleaved by carotenoid cleavage enzymes including β-carotene-15, 15′-oxygenase (BCO1) to generate vitamin A, and β-carotene-9′, 10′-oxygenase (BCO2) which yields bioactive apo-carotenoids. Dietary supplementation of BCX can prevent non-alcoholic fatty liver disease (NAFLD), which is the most common chronic liver disease worldwide. This study aimed to investigate whether BCX-mediated protection against NAFLD proceeds through the liver-mesenteric adipose tissue axis depending on the presence or absence of BCO1/BCO2. METHODS: Six-week-old male wild type (WT) mice (n = 30) and congenic BCO1(−/−)/BCO2(−/−) double KO (DKO) mice (n = 30) were randomly fed either a high-refined carbohydrate diet (HRCD, 66.5% CHO) or HRCD with BCX (10 mg/kg diet) for 24 weeks. RESULTS: Hepatic levels of BCX, but not retinol and retinyl palmitate, were significantly (P