Hepatic retinaldehyde dehydrogenases are modulated by tocopherol supplementation in mice with hepatic steatosis.

OBJECTIVES: An altered retinol metabolism might play a role in the development of nonalcoholic fatty liver disease (NAFLD). Tocopherols (TF) modulate metabolic pathways and have been proposed as a complementary treatment of obesity-induced metabolic alterations. Moreover, there is evidence suggesting that TF may modulate retinol metabolism. The aim of this study was to evaluate whether the dietary supplementation of α- and γ-TF modulates the expression of hepatic retinaldehyde dehydrogenases, RALDH1, RALDH2, and RALDH3 (involved in retinol metabolism) and, lipogenic factors sterol regulatory element binding protein-1c (SREBP-1c) and cluster differentiation 36 (CD36) in an animal model of diet-induced NAFLD. METHODS: Male C57BL/6J mice were divided into four groups: a control diet (CD) group (10% fat, 20% protein, 70% carbohydrates); a CD + TF group (α-tocopherol: 0.7 mg·kg·d-1, γ-tocopherol: 3.5 mg·kg·d-1); a high-fat diet (HFD) group (60% fat, 20% protein, 20% carbohydrates); and a HFD + TF group (0.01 mL·g body weight·d-1), for 12 wk. General parameters (body-adipose tissue weight, glucose-triacylglyceride serum levels), liver steatosis (histology, liver triacylglycerides content), and hepatic RALDH1, RALDH2, RALDH3, SREBP-1c and CD36 (qPCR, quantitative polymerase chain reaction; IHQ, immunohistochemistry) were measured. RESULTS: TF supplementation in HFD-fed mice decreased the presence of lipid vesicles (90%) and total lipid content (75%) and downregulated the expression of RALDH1, RALDH3, SREBP-1c, and CD36. CONCLUSIONS: The present study demonstrated that α- and γ-TF (1:5 ratio) might play a role in modulating retinol metabolism in the prevention of NAFLD induced by a HFD.

Cancer-related gene expression is associated with disease severity and modifiable lifestyle factors in non-alcoholic fatty liver disease.

OBJECTIVE: The aim of this study was to determine whether hepatic gene expression related to hepatocellular carcinoma (HCC) is associated with disease severity and modifiable lifestyle factors in non-alcoholic fatty liver disease (NAFLD). METHODS: In a cross-sectional study, the associations between hepatic gene expression and liver histology, insulin resistance, anthropometrics, diet, and physical activity were assessed in patients with non-alcoholic steatohepatitis (NASH; n = 19) or simple steatosis (SS; n = 20). In a group of patients with NASH, we then conducted a 1-y, single-arm, pilot study using ω-3 polyunsaturated fatty acid (PUFA) supplementation to determine whether changes in hepatic PUFA content would have a modulating effect on hepatic gene expression and would affect liver histology. RESULTS: In the cross-sectional study, histological features of disease severity correlated with AKR1B10, ANXA2, PEG10, SPP1, STMN2, MT1A, and MT1B in NASH and with EEF1A2, PEG10, and SPP1 in SS. In addition, PEG10, SPP1, ANXA2, and STMN2 expression correlated positively with insulin resistance in NASH. SPP1 and UBD correlated strongly with body mass index in SS. Associations between ENPP2, AKR1B10, SPP1, UBD, and waist circumference depended on sex and diagnosis. Several genes correlated with protein, fat, or carbohydrate intake. PEG10 correlated positively with physical activity in NASH and inversely with plasma vitamin C in both groups. Despite increased erythrocyte and hepatic ω-3 PUFA, supplementation did not alter hepatic gene expression and liver histology. CONCLUSIONS: HCC-related gene expression was associated with liver histology, body mass index, waist circumference, diet, and physical activity but was not affected by ω-3 PUFA supplementation.

Role of dietary α- and γ-tocopherol from Rosa mosqueta oil in the prevention of alterations induced by high-fat diet in a murine model.

OBJECTIVE: The aim of this study was to evaluate the contribution of tocopherols present in Rosa mosqueta oil (RM) in the prevention of high-fat diet (HFD)-induced alterations. METHODS: Male C57 BL/6 J mice (n = 9/group) were fed for 12 wk and divided into four groups: control (CD; 10% kcal fat, 20% kcal protein, 70% kcal carbohydrates); HFD (60% as fat, 20% kcal protein, 20% kcal carbohydrates); HFD + RM (0.01 mL/g body weight/d); and HFD + RM- without tocopherols (0.01 mL/g body weight/d). Parameters of obesity, liver steatosis (histology, triacylglycerols content), inflammation (adipose NLRP3 inflammasome, tumor necrosis factor-α and interleukin-1 ß expression, hepatic nuclear factor-κB) and oxidative stress (hepatic Nrf2 activation, carbonylated proteins) were evaluated. RESULTS: Liver steatosis, inflammatory, and oxidative stress parameters were significantly (P < 0.05) increased in the HFD + RM- compared with the HFD + RM, with no differences between HFD and HFD + RM-. CONCLUSION: The present study suggests that α- and γ-tocopherols from RM may have an important role in the prevention of alterations induced by HFD.