Leptin improves fatty liver independently of insulin sensitization and appetite suppression in hepatocyte-specific Pten-deficient mice with insulin hypersensitivity

Hepatic Fat Content Is Associated with Fasting-Induced Fibroblast Growth Factor 21 Secretion in Mice Fed Soy Proteins

Previous studies suggest that circulating fibroblast growth factor 21 (FGF21) levels are elevated in patients with fatty liver, while fasting-induced secretion of FGF21 is lower in obese patients. It has been reported that soy protein prevents hepatic fat accumulation and induces FGF21 secretion. The present study was designed to evaluate the response of circulating FGF21 levels to feeding and fasting in mice fed soy protein-rich diets. For this, C57BL/6J mice were distributed into control, high-fat high-sucrose (HFHS)-casein protein, HFHS-soy protein, and HFHS-β-conglycinin diet groups. Plasma samples were collected after 10 and 11 wk either in dark periods with feeding conditions or light periods under fasting conditions using a crossover design. After a 12-wk period of feeding, HFHS-induced hepatic fat accumulation was significantly reduced in the groups fed HFHS-soy protein and HFHS-β-conglycinin as compared to that in the HFHS-casein-fed group (p<0.05). Plasma FGF21 concentration was significantly higher in the dark/feeding periods in the HFHS-casein group (p<0.05), while in the HFHS-β-conglycinin group it was higher in the light/fasting periods (p<0.05). The amount of mesenteric fat was significantly lower in the HFHS-β-conglycinin group than in the HFHS-casein and HFHS-soy protein groups (p<0.01). The fasting-induced FGF21 secretion was significantly and negatively correlated with hepatic fat content (p<0.05). The present study revealed that hepatic fat accumulation was associated with lower fasting-induced FGF21 secretion, which was regulated better by dietary intake of soy protein. These results support the preventive effects of soy protein on central obesity.

Effects of probiotics on nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has become prevalent in recent decades, especially in developed countries, and approaches for the prevention and treatment of NAFLD are not clear. The aim of this research was to analyze and summarize randomized controlled trials that investigated the effects of probiotics on NAFLD.

METHODS

Seven databases (PubMed, Embase, the Web of Science, the Cochrane Library, China National Knowledge Infrastructure, Wan Fang Data, and VIP Database) were searched. Then, eligible studies were identified. Finally, proper data extraction, synthesis and analysis were performed by trained researchers.

RESULTS

Anthropometric parameters: with use of probiotics weight was reduced by 2.31 kg, and body mass index (BMI) was reduced by 1.08 kg/m². Liver function: probiotic treatment reduced the alanine aminotransferase level by 7.22 U/l, the aspartate aminotransferase level by 7.22 U/l, the alkaline phosphatase level by 25.87 U/l, and the glutamyl transpeptidase level by -5.76 U/l. Lipid profiles: total cholesterol, low-density lipoprotein cholesterol, and triglycerides were significantly decreased after probiotic treatment. Their overall effects (shown as standard mean difference) were -0.73, -0.54, and -0.36, respectively. Plasma glucose: probiotics reduced the plasma glucose level by 4.45 mg/dl and the insulin level by 0.63. Cytokines: probiotic treatment decreased tumor necrosis factor alpha by 0.62 and leptin by 1.14. Degree of liver fat infiltration (DFI): the related risk of probiotics for restoring DFI was 2.47 (95% confidence interval, 1.61-3.81, p < 0.001).

CONCLUSION

Probiotic treatment or supplementation is a promising therapeutic method for NAFLD.

Modified lingguizhugan decoction incorporated with dietary restriction and exercise ameliorates hyperglycemia, hyperlipidemia and hypertension in a rat model of the metabolic syndrome

Background

Modified Lingguizhugan Decoction (MLD) came from famous Chinese medicine Linggui Zhugan Decoction. The MLD is used for the treatment of metabolic syndrome in the clinical setting. Our study focuses on the comprehensive treatment of MLD incorporated with dietary restriction and exercise in a rat model of the metabolic syndrome (MS).

Methods

Rats were divided into five groups: control group (Cont), high-fat diet group (HFD), high-fat diet incorporated with dietary restriction group (HFD-DR), exercise incorporated with dietary restriction group (HFD-DR-Ex) and MLD incorporated with dietary restriction and exercise group (HFD-DR-Ex-MLD). Treatments were conducted for 1 week after feeding high-fat diet for 12 weeks. The effects of treatments on high fat diet-induced obesity, hyperglycemia, hyperlipidemia, hypertension, hepatic injury and insulin resistance in rats of MS were examined. In addition, the tumor necrosis factor-α (TNF-α), leptin and protein kinase B (PKB) in rats serum and liver were also examined by enzyme-linked immunosorbent assay (ELISA).

Results

After a week’s intervention by dietary restriction, dietary restriction incorporated with exercise or MLD, compared with HFD rats, the relative weight of liver and fat, levels of triglyceride, total cholesterol, low-density lipoprotein, free fatty acid, aspartate aminotransferase, glutamic-pyruvic transaminase and alkaline phosphatase, insulin, were significantly decreased (p < 0.05 or 0.01). This treatment also inhibited abnormal increases of TNF-α, leptin and PKB in serum and liver.

Conclusion

MLD incorporated with dietary restriction and exercise treatment exhibit effects in alleviating high-fat diet-induced obesity, hyperglycemia, hyperlipidemia, hypertension, hepatic injury and insulin resistance, which are possibly due to the down-regulation of TNF-α, leptin and PKB.