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OBJECTIVE@#High-fat diet (HFD) and inflammation are two key contributors to nonalcoholic fatty liver disease (NAFLD). Shenling Baizhu powder (SLBZP), a classical herbal compound, has been successfully used to alleviate NAFLD. However, its specific mechanisms are not fully understood. In this study, we assessed the anti-NAFLD effect of SLBZP in vivo.@*METHODS@#Rats were fed an HFD with or without SLBZP or with probiotics. At the end of week 16, an echo magnetic resonance imaging (EchoMRI) body composition analyser was used to quantitatively analyse body composition; a micro-computed tomography (micro-CT) imaging system was used to evaluate whole body and liver fat; and the Moor full-field laser perfusion imager 2 was used to assess liver microcirculation, after which, all rats were sacrificed. Then, biochemical indicators in the blood and the ultrastructure of rat livers were evaluated. Protein expression related to the liver Toll-like receptor 4 (TLR4)/Nod-like receptor family pyrin domain-containing 3 (NLRP3) signalling pathway was assessed using Western blot analysis. Further, high-throughput screening of 29 related inflammatory factors in liver tissue was performed using a cytokine array.@*RESULTS@#SLBZP supplementation reduced body weight, serum free fatty acid, and insulin resistance index (P < 0.05). It also ameliorated liver microcirculation and ultrastructural abnormalities. EchoMRI and micro-CT quantitative analyses showed that treatment with SLBZP reduced fat mass and visceral fat (P < 0.05 and P < 0.01, respectively). In addition, SLBZP decreased the expression of lipopolysaccharide (LPS)-activated TLR4/NLRP3 signalling pathway-related proteins and altered the expression levels of some inflammatory cytokines in liver tissues.@*CONCLUSION@#SLBZP can inhibit NLRP3 inflammasome activation and interleukin-1β release by suppressing LPS-induced TLR4 expression in rats with HFD-induced NAFLD. Thus, SLBZP may be beneficial for the prevention and treatment of inflammatory damage and associated diseases.
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Animals , Rats , Liver , NLR Family, Pyrin Domain-Containing 3 Protein , Non-alcoholic Fatty Liver Disease/drug therapy , Powders , Toll-Like Receptor 4 , X-Ray MicrotomographyABSTRACT
Objective::To observe the effect of Shenling Baizhusan(SBS)on the mammalian target of rapamycin complex 1 (mTORC1)/signal transducers and activators of transcription 3 (STAT3) pathway in liver hepatocyte of nonalcoholic fatty liver disease(NAFLD)rats induced by high fat diet, in order to reveal the mechanism of SBS against rat NAFLD from the perspective of inflammation. Method::Totally 80 SD rats were randomly divided into 4 groups, normal control group, model group, high-dose SBP group(30 g·kg-1), and low-dose SBS group(10 g·kg-1), with 20 rats in each group. The rats of NAFLD model were established by being fed with high-fat diets for 8 weeks, and the treatment groups were fed with high or low dose of SBS respectively. After treatment for 8 weeks, blood and liver samples of rats were collected. Alanine aminotransferase (ALT), aspartate aminotransferase(AST), total cholesterol (TC), triglyceride(TG), high-density lipoprotein cholesterol(HDL-C)and low-density lipoprotein cholesterol(LDL-C)levels in blood serum were detected with automatic biochemical analyzer. The liver tissues were observed by oil red O and hematoxylin-eosin (HE) staining. Hepatocytes were isolated by type Ⅳ collagenase perfusion in vitro. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-5 and IL-6 in hepatocytes were detected by enzyme-linked immunosorbent assay (ELISA), and the relevant gene and proteins expressions of mTORC1 and STAT3 in hepatocytes were detected by Real-time fluorescent quantitative polymerase chain reaction (Real-time PCR) and Western blot detection respectively. Result::Compared with the normal control group, the serum levels of TG, TC, AST, ALT and LDL-C were increased significantly, the levels of TNF-α, IL-1β, IL-5 and IL-6 in hepatocytes were increased significantly, and the expression levels of mTORC1, STAT3 mRNA and proteins in hepatocytes were increased significantly(P<0.01). Compared with the model group, the hepatic lipid accumulation of the medicine intervention group was relieved significantly, the serum levels of AST, ALT, TG and LDL-C were decreased significantly, the expression levels of TNF-α, IL-1β, IL-5 and IL-6 of hepatocytes were decreased significantly, and the expressions of mTORC1, STAT3 mRNA and proteins in hepatocytes were decreased significantly(P<0.05, P<0.01). In the high-dose SBS group, the effects in improving the lipid accumulation and inhibiting the inflammatory reaction were better than those of the low-dose SBS group, and the expressions of mTORC1 and STAT3 genes and proteins in hepatocytes were significantly decreased (P<0.05, P<0.01). Conclusion::SBS can improve the fat metabolism disorder and reduce liver lipid accumulation and inflammatory reaction in NAFLD rats induced by high-fat diet. The mechanism may be correlated with the inhibition of mTORC1/STAT3 pathway relating to genes and protein expression in hepatocytes.
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Objective To investigate the involvement of sirtuin 1 (SIRT1)-uncoupling protein 2 (UCP2) pathway in the development of non-alcoholic fatty liver disease and whether berberine exerts its effects by regulating this pathway. Methods Male SD rats were divided into three groups: normal control group, high-fat diet group, and berberine supplement group. The rats in the normal control group were given normal diet while the rats in the other two groups were fed with high-fat diet. Rats in the berberine supplement group were concurrently given berberine (100 mg/kg body weight) once daily. After 16 weeks, the levels of serum, liver lipids, and serum aminotransferase were measured using an automatic biochemical analyzer. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in the liver were measured using commercial kits. Histopathological changes of liver tissues were observed by hematoxylin and eosin (HE) staining and Oil Red O staining. The hepatic mRNA and protein levels of SIRT1 and UCP2 were assayed by reverse transcription polymerase chain reaction (RT-PCR) or Western blotting. Results Berberine supplement could significantly decrease the serum and liver lipid contents in rats fed with high-fat diet. Meanwhile, SOD level was significantly elevated, but MDA level was reduced in the liver. The results of HE and Oil Red O staining showed that the hepatic steatosis was alleviated in berberine supplement group. Furthermore, berberine induced an increase in SIRT1 expression but a decrease in UCP2 expression. Conclusion The regulation of hepatic SIRT1-UCP2 pathway may be an important mechanism by which berberine exerts the beneficial effects in NAFLD rats.
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<p><b>OBJECTIVE</b>To explore a new method of establishing HepG2 cell model of steatosis and observe the expression and significance of nuclear factor erythroid-2p45-related factor 2(Nrf2)/antioxidative response element (ARE) pathway related factors in HepG2 cells of steatosis.</p><p><b>METHODS</b>HepG2 cells were induced with DMEM containing 25% fetal bovine serum, 0.1% MCT/LCT Fat Emulsion and 0.1 mmol/L free fatty acid (FFA) at different stages and the control group cells were cultured with normal DMEM medium. After the cell models were successfully established, lipid droplets in cytoplasm were observed with Oil Red 0 staining, and the triglyceride (TG) accumulation in HepG2 cells were tested by biochemical assay. Intracellular reactive oxygen species (ROS) concentration were detected by flow cytometry. Nitric oxide (NO), superoxide dismutase(SOD), malonyldialdehyde(MDA) and glutathione peroxidase(GSH-Px) were tested by biological reagent kit, while the protein expression of nuclear factor erythroid-2p45-related factor 2(Nrf2), heme oxygenase-1 (HO-1) and</p><p><b>NAD(P)H</b>quinone oxidoreductase-1(NQO1) were analyzed by Western blot.</p><p><b>RESULTS</b>Compared with that in the control group, red cytoplasmic lipid droplets were visible in model group; TG,ROS, NO, MDA concentration (P < 0.05, P < 0.01) and the protein expression of Nrf2, HO-1 and NQO1 (P < 0.05, P < 0.01)were significantly higher in model group, while SOD, GSH-Px concentration reduced significantly (P < 0.01).</p><p><b>CONCLUSION</b>The in vitro cell model of steatosis and oxidative stress was successfully established. The activation of Nrf2/ARE pathway related factors maybe relevant to the overreaction of oxidative stress in HepG2 cells of steatosis.</p>