The objective of this study was to determine if
astaxanthin (ASTX), a xanthophyll
carotenoid, can prevent
obesity-associated metabolic abnormalities,
inflammation and
fibrosis in diet-induced
obesity (DIO) and
nonalcoholic steatohepatitis (NASH) mouse models. Male C57BL/6J mice were fed a low-fat (6% fat, w/w), a high-fat/high-
sucrose control (HF/HS; 35% fat, 35%
sucrose, w/w), or a HF/HS containing ASTX (AHF/HS; 0.03% ASTX, w/w) for 30 weeks. To induce NASH, another set of mice was fed a HF/HS diet containing 2%
cholesterol (HF/HS/HC) a HF/HS/HC with 0.015% ASTX (AHF/HS/HC) for 18 weeks. Compared to LF, HF/HS significantly increased plasma total
cholesterol,
triglyceride and
glucose, which were lowered by ASTX. ASTX decreased hepatic
mRNA levels of markers of macrophages and
fibrosis in both models. The effect of ASTX was more prominent in NASH than DIO mice. In epididymal fat, ASTX also decreased macrophage infiltration and M1 macrophage marker expression, and inhibited
hypoxia-inducible factor 1-α and its downstream fibrogenic genes in both mouse models. ASTX significantly decreased
tumor necrosis factor α
mRNA in the splenocytes from DIO mice upon
lipopolysaccharides stimulation compared with those from control mice fed an HF/HS diet. Additionally, ASTX significantly elevated the levels of genes that regulate
fatty acid β-oxidation and mitochondrial biogenesis in the skeletal muscle compared with control obese mice, whereas no differences were noted in adipose lipogenic genes. Our results indicate that ASTX inhibits
inflammation and
fibrosis in the liver and adipose tissue and enhances the skeletal muscle's capacity for mitochondrial
fatty acid oxidation in obese mice.