Metabolic dysfunction-associated fatty liver disease (MAFLD), characterized by fatty acid overload, secondary chronic inflammation, and fibrosis, has become the most prevalent chronic liver disease globally. While no effective pharmacotherapy exists for MAFLD, mitigating inflammatory responses represents a promising approach to preventing the progression from steatosis to severe steatohepatitis. The NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, which detects endogenous danger and stress signals, has emerged as a significant target for inflammatory disease treatment, as transcriptional inactivation of its components demonstrates the therapeutic potential for MAFLD. Natural products targeting NLRP3 inflammasome activation have shown promising efficacy in MAFLD therapy. This review synthesizes the current understanding of NLRP3 inflammasome activation and therapeutic targets for NLRP3 homeostasis. Additionally, natural products reported to inhibit NLRP3 inflammasome for MAFLD improvement are categorized according to their mechanisms of action. The review also addresses limitations and future directions regarding natural products targeting NLRP3 inflammasome in MAFLD treatment. Enhanced understanding of NLRP3 inflammasome activation mechanisms in MAFLD and the identification of novel natural products supported by mechanistic research will significantly advance MAFLD treatment.
Humans ; NLR Family, Pyrin Domain-Containing 3 Protein/immunology* ; Inflammasomes/metabolism* ; Biological Products/therapeutic use* ; Animals ; Fatty Liver/immunology*

This study aimed to investigate the involved immunologic mechanism of pure total flavonoids from Citrus (PTFC) on the development of non-alcoholic steatohepatitis (NASH). C57BL/6 mice were fed with high .fat diet for 16 weeks to induce the NASH model, and from the 7th week three dosages (25, 50 and 100 mg x kg(-1) x d(-1)) of PTFC were administrated intragastric for 10 weeks respectively. Serum TG, CHOL, ALT, AST were determined by biochemical assay, histopathological changes of the liver tissue were observed by HE staining, expression of RORyt and Foxp3 mRNA of the liver tissue was detected by Real-time PCR, and serum IL-17, IL-6, IL-10 and IL-4 were determined by.Cytometric Beads Array. As a result, we find that after the administration of PTFC, the in- flammation of the liver tissue of NASH mice was attenuated, liver function was improved, and the expression of RORgammat mRNA was higher in the liver tissue while which was lower of Foxp3 mRNA, the level of proinflammatory cytokines IL-17 and IL-6 decreased and the level of suppressive cytokines IL-10 and IL-4 increased. These data show that PTFC protects the development of NASH through regulating the Th17/Treg balance and attenuating inflammation.
Animals ; Citrus ; chemistry ; Cytokines ; blood ; Flavonoids ; pharmacology ; Male ; Mice ; Mice, Inbred C57BL ; Non-alcoholic Fatty Liver Disease ; immunology ; prevention & control ; T-Lymphocytes, Regulatory ; drug effects ; Th17 Cells ; drug effects

Nonalcoholic steatohepatitis (NASH) can progress into liver cirrhosis; however, no definite treatment is available. Omega-3 polyunsaturated fatty acid (omega-3) has been reported to alleviate experimental NASH, although its beneficial effect was not evident when tested clinically. Thus, this study aimed to investigate the additive effect of omega-3 and ursodeoxycholic acid (UDCA) on diet-induced NASH in mice. C57BL/6 mice were given a high-fat diet (HFD) for 24 weeks, at which point the mice were divided into three groups and fed HFD alone, HFD with omega-3 or HFD with omega-3 in combination with UDCA for another 24 weeks. Feeding mice an HFD and administering omega-3 improved histologically assessed liver fibrosis, and UDCA in combination with omega-3 further attenuated this disease. The assessment of collagen alpha1(I) expression agreed with the histological evaluation. Omega-3 in combination with UDCA resulted in a significant attenuation of inflammation whereas administering omega-3 alone failed to improve histologically assessed liver inflammation. Quantitative analysis of tumor necrosis factor alpha showed an additive effect of omega-3 and UDCA on liver inflammation. HFD-induced hepatic triglyceride accumulation was attenuated by omega-3 and adding UDCA accentuated this effect. In accordance with this result, the expression of sterol regulatory binding protein-1c decreased after omega-3 administration and adding UDCA further diminished SREBP-1c expression. The expression of inducible nitric oxide synthase (iNOS), which may reflect oxidative stress-induced tissue damage, was suppressed by omega-3 administration and adding UDCA further attenuated iNOS expression. These results demonstrated an additive effect of omega-3 and UDCA for alleviating fibrosis, inflammation and steatosis in diet-induced NASH.
Animals ; Cholagogues and Choleretics/pharmacology/*therapeutic use ; Diet, High-Fat/adverse effects ; Drug Synergism ; Fatty Acids, Omega-3/pharmacology/*therapeutic use ; Fibrosis/drug therapy/etiology/immunology/pathology ; Inflammation/drug therapy/etiology/immunology/pathology ; Liver/*drug effects/immunology/pathology ; Male ; Mice, Inbred C57BL ; Non-alcoholic Fatty Liver Disease/*drug therapy/etiology/immunology/pathology ; Ursodeoxycholic Acid/pharmacology/*therapeutic use

BACKGROUNDNonalcoholic fatty liver disease (NAFLD) has emerged as the major cause of chronic liver injury. Intestinal barrier plays an important role in the pathogenis of NAFLD. The aim of this article was to assess intestinal immune barrier function during the development of NAFLD.

METHODSTotally 60 male Sprague-Dawley (SD) rats were divided into 2 groups: normal diet (ND) group and high-fat diet (HFD) group. NAFLD rat model was established in the HFD rat group. Portal blood endotoxin level was assessed by limulus test. The percentage of CD4+ cells and CD8+ cells in peripheral blood mononuclear cells (PBMC) and lymphocytes in Peyer's patches (PP) were analysed by flow cytometry. Intestinal secretory immunoglobulin A (SIgA) level was evaluated by enzyme-linked immunosorbent assay. Paired Student's t test was used for the statistic analysis.

RESULTSHFD rats presented with simple steatosis at the 4th and 8th week and progressed to nonalcoholic steatohepatitis at the 12th week. Elevated lipopolysaccharides (LPS) level in HFD rats was observed at the 8th week ((1.54 ± 0.30) times of ND group, P < 0.01). CD4/CD8 ratios in PBMC and PP of HFD rats were increased at the 4th week ((1.50 ± 0.47) and (1.63 ± 0.34) times of ND group, P < 0.05) and decreased at the 8th week ((0.50 ± 0.16) and (0.61 ± 0.26) times of ND group, P < 0.05). At the 12th week, CD4/CD8 ratio ((1.47 ± 0.46) times, P < 0.05) in PP increased to levels observed in the 4th week. Intestinal SIgA expression of HFD rats was remarkably up-regulated at 12th week ((2.70 ± 1.65) times, P < 0.05).

CONCLUSIONLiver-gut axis in rats with NAFLD may mediate and improve intestinal immune function by increased CD4/CD8 ratio in PP and increased production of SIgA.

Animals ; CD4-Positive T-Lymphocytes ; immunology ; CD8-Positive T-Lymphocytes ; immunology ; Diet, High-Fat ; adverse effects ; Disease Models, Animal ; Fatty Liver ; chemically induced ; etiology ; immunology ; Immunoglobulin A, Secretory ; immunology ; Intestines ; immunology ; Male ; Non-alcoholic Fatty Liver Disease ; Rats ; Rats, Sprague-Dawley

Although peroxisome proliferator receptor (PPAR)-alpha and PPAR-gamma agonist have been developed as chemical tools to uncover biological roles for the PPARs such as lipid and carbohydrate metabolism, PPAR-delta has not been fully investigated. In this study, we examined the effects of the PPAR-delta agonist GW0742 on fatty liver changes and inflammatory markers. We investigated the effects of PPAR-delta agonist GW0742 on fatty liver changes in OLETF rats. Intrahepatic triglyceride contents and expression of inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and monocyte chemo-attractant protein-1 (MCP-1) and also, PPAR-gamma coactivator (PGC)-1alpha gene were evaluated in liver tissues of OLETF rats and HepG2 cells after GW0742 treatment. The level of TNF-alpha and MCP-1 was also examined in supernatant of Raw264. 7 cell culture. To address the effects of GW0742 on insulin signaling, we performed in vitro study with AML12 mouse hepatocytes. Rats treated with GW0742 (10 mg/kg/day) from 26 to 36 weeks showed improvement in fatty infiltration of the liver. In liver tissues, mRNA expressions of TNF-alpha, MCP-1, and PGC-1alpha were significantly decreased in diabetic rats treated with GW0742 compared to diabetic control rats. We also observed that GW0742 had inhibitory effects on palmitic acid-induced fatty accumulation and inflammatory markers in HepG2 and Raw264.7 cells. The expression level of Akt and IRS-1 was significantly increased by treatment with GW0742. The PPAR-delta agonist may attenuate hepatic fat accumulation through anti-inflammatory mechanism, reducing hepatic PGC-1alpha gene expression, and improvement of insulin signaling.
Animals ; Anti-Inflammatory Agents/*pharmacology/therapeutic use ; Blood Glucose ; Cytokines/genetics/metabolism ; Diabetes Mellitus/blood/immunology/metabolism ; Fatty Liver/blood/*drug therapy/immunology ; Glucose Tolerance Test ; Hep G2 Cells ; Humans ; Insulin Resistance ; Liver/metabolism ; Male ; PPAR delta/*agonists/metabolism ; Rats ; Rats, Long-Evans ; Thiazoles/*pharmacology/therapeutic use ; Triglycerides/metabolism

Animals ; Fatty Liver ; immunology ; pathology ; Male ; Natural Killer T-Cells ; drug effects ; Non-alcoholic Fatty Liver Disease ; Probiotics ; pharmacology ; Rats ; Rats, Wistar

Adult ; Biopsy ; Fatty Liver ; complications ; immunology ; pathology ; Female ; Hepatitis B, Chronic ; complications ; immunology ; pathology ; Humans ; Male ; T-Lymphocytes, Regulatory ; immunology

Animals ; Cytokines ; metabolism ; Fatty Liver ; immunology ; metabolism ; Humans ; Immune Tolerance ; Killer Cells, Natural ; immunology ; Liver ; immunology ; Liver Diseases ; immunology ; metabolism ; Liver Failure ; immunology ; metabolism ; T-Lymphocytes ; immunology ; United States

Fatty Liver ; immunology ; Immune Tolerance ; Liver ; immunology

BACKGROUND/AIMS: Exclusion of liver disease from other causes such as autoimmune hepatitis is necessary for diagnosis of nonalcoholic fatty liver disease (NAFLD). However, there has been no study on the prevalence and significance of autoantibodies in the patients with clinically suspected NAFLD in Korea, where hepatitis B is endemic and autoimmune hepatitis is relatively uncommon. METHODS: We prospectively tested for anti-nuclear antibody (ANA), anti-smooth muscle antibody (ASMA), and anti-mitochondrial antibody (AMA) in 135 serially enrolled patients with suspected NAFLD. We compared the clinical characteristics and biochemical indices of the ANA-positive or ASMA-positive group with those of the autoantibody-negative group. RESULTS: Sixteen patients (11.8%) had serum autoantibodies; there was ANA in 8 patients (5.9%), ASMA in 7 (5.1%), and AMA in 2 (1.5%). Both ANA and AMA were positive in one patient. The ANA-positive or ASMA-positive group showed an older age (49.5+/-13.0 vs. 42.0+/-10.9 years, respectively, P=0.018) and higher levels of serum globulin (3.1+/-0.4 vs. 2.9+/-0.4 g/dL, respectively, P=0.037), compared with the autoantibody-negative group. Two cases with positive ANA or ASMA fulfilled the diagnostic criteria for probable autoimmune hepatitis and two cases with positive AMA were suspected as primary biliary cirrhosis. CONCLUSIONS: These findings suggest that autoantibodies could be found in some patients with suspected NAFLD in Korea, AMA-positivity or ASMA-positivity could be associated with old age and high serum globulin, and some of the autoantibody-positive cases could be diagnosed as autoimmune hepatitis or primary biliary cirrhosis. Further studies are necessary to clarify the clinical significance of autoantibody positivity in those patients.
Adult ; Aged ; Antibodies, Antinuclear/analysis ; Autoantibodies/*blood ; English Abstract ; Fatty Liver/*immunology ; Female ; Humans ; Male ; Middle Aged ; Muscle, Smooth/immunology