Association between serum β-carotene-to-retinol ratio and severity of hepatic steatosis in non-alcoholic fatty liver disease in Japan: A cross-sectional study

Integrated strategy of RNA-sequencing and network pharmacology for exploring the protective mechanism of Shen-Shi-Jiang-Zhuo formula in rat with non-alcoholic fatty liver disease

CONTEXT

Shen-Shi-Jiang-Zhuo formula (SSJZF) exhibits a definite curative effect in the clinical treatment of non-alcoholic fatty liver disease (NAFLD).

OBJECTIVE

To explore the therapeutic effect and mechanism of SSJZF on NAFLD.

MATERIALS AND METHODS

Sprague Dawley rats were randomly divided into control, NAFLD, positive drug (12 mg/kg/day), SSJZF high-dose (200 mg/kg/day), SSJZF middle-dose (100 mg/kg/day), and SSJZF low-dose (50 mg/kg/day) groups. After daily intragastric administration of NAFLD rats for 8 weeks, lipid metabolism and hepatic fibrosis were evaluated by biochemical indices and histopathology. Then we uncovered the main active compounds and mechanism of SSJZF against NAFLD by integrating RNA-sequencing and network pharmacology, and PI3K/AKT pathway activity was verified by western blot.

RESULTS

High dose SSJZF had the best inhibitory effect on hepatic lipid accumulation and fibrosis in rats with NAFLD, which significantly down-regulated total triglycerides (58%), cholesterol (62%), aspartate aminotransferase (57%), alanine aminotransferase (41%) andγ-glutamyl transpeptidase (36%), as well as the expression of ACC (5.3-fold), FAS (12.1-fold), SREBP1C (2.3-fold), and CD36 (4.4-fold), and significantly reduced collagen deposition (67%). Then we identified 23 compounds of SSJZF that acted on 25 key therapeutic targets of NAFLD by integrating RNA-sequencing and network pharmacology. Finally, we also confirmed that high dose SSJZF increased p-PI3K/PI3K (1.6-fold) and p-AKT/AKT (1.6-fold) in NAFLD rats.

DISCUSSION AND CONCLUSION

We found for first time that SSJZF improved NAFLD in rats by activating the PI3K/Akt pathway. These findings provide scientific support for SSJZF in the clinical treatment of NAFLD and contribute to the development of new NAFLD drugs.

Higher serum vitamin A is associated with a worsened progression of non-alcoholic fatty liver disease in adults: a prospective study

Background: The association between serum vitamin A and non-alcoholic fatty liver disease (NAFLD) remains uncertain due to inconsistent results and scarce longitudinal data. We examined the prospective associations between serum vitamin A and the evolution of the NAFLD severity score as well as the potential mediating effects in middle-aged and older Chinese adults. Method: A total of 2658 adults (between 40-75 years of age) were included in the analysis. We determined the serum concentrations of vitamin A at the onset of the study (the baseline), and the degree of NAFLD after years 3 and 6. Results: Subjects were classified into stable, progressed, and improved groups according to the changes in their severity score (0-3) of NAFLD between two visits. Analyses of covariance showed that the serum VA concentrations were positively associated with NAFLD progression (all p-trend < 0.05). After adjusting for potential confounders, the mean differences in the serum vitamin A were 7.7% lower in the improved group than those in the progressed group among the total population. Path analyses showed that vitamin A was positively associated with the serum retinol-binding protein 4, triglycerides, insulin resistance, and body mass index (standardized β 0.065-0.304, all p < 0.001), and all of these factors positively correlated with the prevalence and progression of NAFLD (standardized β 0.045-0.384, all p < 0.01). Conclusions: A higher serum vitamin A concentration was associated with NAFLD progression, which might be mediated by increases in the serum retinol-binding protein 4, triglycerides, insulin resistance, and body mass index.

Associations of Dietary Lipid-Soluble Micronutrients with Hepatic Steatosis among Adults in the United States

Lipid-soluble micronutrients may be beneficial to non-alcoholic fatty liver disease due to their important roles in metabolism and maintaining tissue functions. Utilizing 2017-2018 National Health and Nutrition Examination Survey, this study examined the potential overall and race/ethnicity-specific (black, Hispanic and white) associations of dietary lipid-soluble micronutrients (α-tocopherol, retinol, vitamin D, β-carotene and total carotenoids) with hepatic steatosis. The analysis included 4376 adults (1037 blacks, 981 Hispanics, 1549 whites) aged ≥20 years who completed the transient elastography examination with dietary data available. Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated using logistic regressions. The age-adjusted prevalence of steatosis was 20.9% for blacks, 34.0% for Hispanics and 28.7% for whites. Overall, dietary α-tocopherol was inversely associated with steatosis (highest vs. lowest quartile: OR = 0.51, 95%CI = 0.35-0.74, P_trend = 0.0003). The associations remained significant among blacks (highest vs. lowest tertile: OR = 0.45, 95%CI = 0.26-0.77, P_trend = 0.002) and whites (highest vs. lowest tertile: OR = 0.56, 95%CI = 0.33-0.94, P_trend = 0.02). Higher α-tocopherol intake was associated with lower odds of steatosis among all (P_trend = 0.016) and black participants (P_trend = 0.003) classified as never/rare/occasional alcohol drinkers. There was a trend suggesting higher β-carotene intake with lower odds of steatosis (P_trend = 0.01). Our results suggest potential protective effects of dietary vitamin E as α-tocopherol on steatosis particularly among blacks.