Puerarin improves hepatic glucose and lipid homeostasis in vitro and in vivo by regulating the AMPK pathway

2021 ◽  
Vol 12 (6) ◽  
pp. 2726-2740
Author(s):  
Dong-Xue Xu ◽  
Xiao-Xuan Guo ◽  
Zhu Zeng ◽  
Yong Wang ◽  
Jing Qiu
Keyword(s):  
Insulin Resistance ◽  
Hepatic Insulin Resistance ◽  
Lipid Homeostasis ◽  
Therapeutic Effects ◽  
Ampk Pathway ◽  
Hepatic Glucose ◽  
Glucose And Lipid Homeostasis

Identification of potential therapeutic effects of puerarin for the prevention of hepatic insulin resistance and steatosis in vivo and in vitro.

scholarly journals Erchen Decoction and Linguizhugan Decoction Ameliorate Hepatic Insulin Resistance by Inhibiting IRS-1Ser307 Phosphorylation In Vivo and In Vitro

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Huicun Zhang ◽  
Na Ta ◽  
Pengmin Chen ◽  
Hongbing Wang
Keyword(s):  
Insulin Resistance ◽  
Histopathological Examination ◽  
Hepatic Insulin Resistance ◽  
Hepatocyte Proliferation ◽  
Therapeutic Effects ◽  
Protective Effects ◽  
Serum Aminotransferase ◽  
Nonalcoholic Fatty Liver

Erchen decoction (ECD) and Linguizhugan decoction (LGZGD), both are Chinese herbal formula, have been used clinically for the treatment of nonalcoholic fatty liver disease (NAFLD). However, their therapeutic mechanisms are still unclear. Because insulin resistance (IR) is a key etiological factor in the pathology of high-fat diet- (HFD-) induced NAFLD, in this study, the protective effects of ECD and LGZGD on HFD-induced insulin resistance in rats were evaluated and their mechanisms were investigated by OGTT and Western blot. The results showed that treatment with ECD and LGZGD significantly improved insulin resistance and liver damage in rats, evidenced by supported serum aminotransferase levels and the histopathological examination. ECD and LGZGD also showed significant protective effects against HFD-induced hyperlipidemia and the inhibition of the hepatocyte proliferation by palmitate. Furthermore, supplementation of ECD and LGZGD decreased TNF-α, NF-κB, and IRS-1Ser307 phosphorylation expressions in vivo and in vitro. These results indicated that ECD and LGZGD have protective effects against HFD-induced liver IR and their underlying mechanisms involve the TNF-αand insulin pathway. These findings would be beneficial for understanding of the therapeutic effects of ECD and LGZGD in treatment of NAFLD.

scholarly journals Interleukin-6 Depletion Selectively Improves Hepatic Insulin Action in Obesity

Endocrinology ◽  
2005 ◽  
Vol 146 (8) ◽  
pp. 3417-3427 ◽  
Author(s):  
Peter J. Klover ◽  
Alicia H. Clementi ◽  
Robert A. Mooney
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Receptor ◽  
Endogenous Glucose Production ◽  
Hepatic Insulin Resistance ◽  
Stat3 Phosphorylation ◽  
Insulin Dependent ◽  
Significant Change

Abstract Obesity and insulin resistance are considered chronic inflammatory states, in part because circulating IL-6 is elevated. Exogenous IL-6 can induce hepatic insulin resistance in vitro and in vivo. The importance of endogenous IL-6, however, to insulin resistance of obesity is unresolved. To test the hypothesis that IL-6 contributes to the inflammation and insulin resistance of obesity, IL-6 was depleted in Lepob mice by injection of IL-6-neutralizing antibody. In untreated Lepob mice, signal transducer and activator of transcription-3 (STAT3) activation was increased compared with that in lean controls, consistent with an inflammatory state. With IL-6 depletion, activation of STAT3 in liver and adipose tissue and expression of haptoglobin were reduced. Expression of the IL-6-dependent, hepatic acute phase protein fibrinogen was also decreased. Using the hyperinsulinemic-euglycemic clamp technique, insulin-dependent suppression of endogenous glucose production was 89% in IL-6-depleted Lepob mice, in contrast to only 32% in Lepob controls, indicating a marked increase in hepatic insulin sensitivity. A significant change in glucose uptake in skeletal muscle after IL-6 neutralization was not observed. In a direct comparison of hepatic insulin signaling in Lepob mice treated with anti-IL-6 vs. IgG-treated controls, insulin-dependent insulin receptor autophosphorylation and activation of Akt (pSer473) were increased by nearly 50% with IL-6 depletion. In adipose tissue, insulin receptor signaling showed no significant change despite major reductions in STAT3 phosphorylation and haptoglobin expression. In diet-induced obese mice, depletion of IL-6 improved insulin responsiveness in 2-h insulin tolerance tests. In conclusion, these results indicate that IL-6 plays an important and selective role in hepatic insulin resistance of obesity.

Perturbation of glucose flux in the liver by decreasing F26P2 levels causes hepatic insulin resistance and hyperglycemia

2006 ◽  
Vol 291 (3) ◽  
pp. E536-E543 ◽  
Author(s):  
Chaodong Wu ◽  
Salmaan A. Khan ◽  
Li-Jen Peng ◽  
Honggui Li ◽  
Steven G. Carmella ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Hepatic Insulin Resistance ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Peroxisome Proliferator Activated Receptor ◽  
Glucose Flux ◽  
Hepatic Glucose

Hepatic insulin resistance is one of the characteristics of type 2 diabetes and contributes to the development of hyperglycemia. How changes in hepatic glucose flux lead to insulin resistance is not clearly defined. We determined the effects of decreasing the levels of hepatic fructose 2,6-bisphosphate (F26P2), a key regulator of glucose metabolism, on hepatic glucose flux in the normal 129J mice. Upon adenoviral overexpression of a kinase activity-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase, the enzyme that determines F26P2 level, hepatic F26P2 levels were decreased twofold compared with those of control virus-treated mice in basal state. In addition, under hyperinsulinemic conditions, hepatic F26P2 levels were much lower than those of the control. The decrease in F26P2 leads to the elevation of basal and insulin-suppressed hepatic glucose production. Also, the efficiency of insulin to suppress hepatic glucose production was decreased (63.3 vs. 95.5% suppression of the control). At the molecular level, a decrease in insulin-stimulated Akt phosphorylation was consistent with hepatic insulin resistance. In the low hepatic F26P2 states, increases in both gluconeogenesis and glycogenolysis in the liver are responsible for elevations of hepatic glucose production and thereby contribute to the development of hyperglycemia. Additionally, the increased hepatic gluconeogenesis was associated with the elevated mRNA levels of peroxisome proliferator-activated receptor-γ coactivator-1α and phospho enolpyruvate carboxykinase. This study provides the first in vivo demonstration showing that decreasing hepatic F26P2 levels leads to increased gluconeogenesis in the liver. Taken together, the present study demonstrates that perturbation of glucose flux in the liver plays a predominant role in the development of a diabetic phenotype, as characterized by hepatic insulin resistance.

scholarly journals Cichoric acid regulates the hepatic glucose homeostasis via AMPK pathway and activates the antioxidant response in high glucose-induced hepatocyte injury

RSC Advances ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 1363-1375 ◽  
Author(s):  
Di Zhu ◽  
Ni Zhang ◽  
Xuelian Zhou ◽  
Mengying Zhang ◽  
Zhigang Liu ◽  
...  
Keyword(s):  
Glucose Homeostasis ◽  
High Glucose ◽  
Antioxidant Response ◽  
Cichoric Acid ◽  
Ampk Pathway ◽  
Hepatocyte Injury ◽  
Hepatic Glucose

CA regulates hepatic glucose homeostasisviathe AMPK pathway and improves hepatocyte injuryviaantioxidant responsein vitroandin vivo.

scholarly journals New insight into the mechanisms of ectopic fat deposition improvement after bariatric surgery

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Giulia Angelini ◽  
Lidia Castagneto Gissey ◽  
Giulia Del Corpo ◽  
Carla Giordano ◽  
Bruna Cerbelli ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Bariatric Surgery ◽  
Insulin Sensitivity ◽  
Hepatic Insulin Resistance ◽  
Alcoholic Fatty Liver ◽  
Fat Accumulation ◽  
Impaired Liver ◽  
Ectopic Fat Deposition

AbstractNon-alcoholic fatty-liver disease (NAFLD) is frequent in obese patients and represents a major risk factor for the development of diabetes and its complications. Bariatric surgery reverses the hepatic features of NAFLD. However, its mechanism of action remains elusive. We performed a comprehensive analysis of the mechanism leading to the improvement of NAFLD and insulin resistance in both obese rodents and humans following sleeve-gastrectomy (SG). SG improved insulin sensitivity and reduced hepatic and monocyte fat accumulation. Importantly, fat accumulation in monocytes was well comparable to that in hepatocytes, suggesting that Plin2 levels in monocytes might be a non-invasive marker for the diagnosis of NAFLD. Both in vitro and in vivo studies demonstrated an effective metabolic regeneration of liver function and insulin sensitivity. Specifically, SG improved NAFLD significantly by enhancing AMP-activated protein kinase (AMPK) phosphorylation and chaperone-mediated autophagy (CMA) that translate into the removal of Plin2 coating lipid droplets. This led to an increase in lipolysis and specific amelioration of hepatic insulin resistance. Elucidating the mechanism of impaired liver metabolism in obese subjects will help to design new strategies for the prevention and treatment of NAFLD.

Free fatty acids increase basal hepatic glucose production and induce hepatic insulin resistance at different sites

2003 ◽  
Vol 284 (2) ◽  
pp. E281-E290 ◽  
Author(s):  
Tony K. T. Lam ◽  
Gérald Van de Werve ◽  
Adria Giacca
Keyword(s):  
Insulin Resistance ◽  
Phosphatase Activity ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Fatty Acyl ◽  
Hepatic Insulin Resistance ◽  
P Content ◽  
Hepatic Glucose ◽  
Fasted Rats

To investigate the sites of the free fatty acid (FFA) effects to increase basal hepatic glucose production and to impair hepatic insulin action, we performed 2-h and 7-h Intralipid + heparin (IH) and saline infusions in the basal fasting state and during hyperinsulinemic clamps in overnight-fasted rats. We measured endogenous glucose production (EGP), total glucose output (TGO, the flux through glucose-6-phosphatase), glucose cycling (GC, index of flux through glucokinase = TGO − EGP), hepatic glucose 6-phosphate (G-6- P) content, and hepatic glucose-6-phosphatase and glucokinase activities. Plasma FFA levels were elevated about threefold by IH. In the basal state, IH increased TGO, in vivo glucose-6-phosphatase activity (TGO/G-6- P), and EGP ( P < 0.001). During the clamp compared with the basal experiments, 2-h insulin infusion increased GC and in vivo glucokinase activity (GC/TGO; P < 0.05) and suppressed EGP ( P< 0.05) but failed to significantly affect TGO and in vivo glucose-6-phosphatase activity. IH decreased the ability of insulin to increase GC and in vivo glucokinase activity ( P < 0.01), and at 7 h, it also decreased the ability of insulin to suppress EGP ( P < 0.001). G-6- P content was comparable in all groups. In vivo glucose-6-phosphatase and glucokinase activities did not correspond to their in vitro activities as determined in liver tissue, suggesting that stable changes in enzyme activity were not responsible for the FFA effects. The data suggest that, in overnight-fasted rats, FFA increased basal EGP and induced hepatic insulin resistance at different sites. 1) FFA increased basal EGP through an increase in TGO and in vivo glucose-6-phosphatase activity, presumably due to a stimulatory allosteric effect of fatty acyl-CoA on glucose-6-phosphatase. 2) FFA induced hepatic insulin resistance (decreased the ability of insulin to suppress EGP) through an impairment of insulin's ability to increase GC and in vivo glucokinase activity, presumably due to an inhibitory allosteric effect of fatty acyl-CoA on glucokinase and/or an impairment in glucokinase translocation.

scholarly journals Berberine improves hepatic insulin resistance by activating the SIRT1/Opa1 pathway: An in vitro and in vivo study

2021 ◽  
Author(s):  
Jia Xu ◽  
Yining Zhang ◽  
Zhiyi Yu ◽  
Yueqi Guan ◽  
Yuqian Lv ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Animal Models ◽  
Hepg2 Cells ◽  
Insulin Signalling ◽  
Morphological Changes ◽  
Mitochondrial Fusion ◽  
Hepatic Insulin Resistance ◽  
Inner Mitochondrial Membrane

Abstract Aim: This study explored whether abnormality in the inner mitochondrial membrane fusion protein optic atrophy 1 (Opa1) causes hepatic insulin resistance and whether berberine (BBR) can prevent hepatic insulin resistance through the SIRT1/Opa1 pathway. Method: High-fat diet (HFD)-fed mice and db/db mice were used as animal models to study hepatic insulin resistance in vivo . Insulin resistance, morphological changes, and mitochondrial injury of the liver were examined to explore the effects of BBR. SIRT1/Opa1 protein expressions were determined to confirm whether the signalling pathway was damaged in the model animals and involved in BBR treatment. A palmitate (PA)-induced hepatocyte insulin resistance model was established in HepG2 cells in vitro . Opa1 silencing and SIRT1 overexpression were induced to verify whether Opa1 abnormality causes hepatocyte insulin resistance and whether SIRT1 could improve this dysfunction. BBR treatment and SIRT1 silencing were employed to prove that BBR can prevent hepatic insulin resistance by activating the SIRT1/Opa1 pathway. Results: We found that Opa1 deficiency caused imbalance in mitochondrial fusion/fission and impaired insulin signalling in the HepG2 cells. SIRT1 and BBR overexpression ameliorated PA-induced insulin resistance, increased Opa1, and improved mitochondrial function. SIRT1 silencing could partly reverse the effects of BBR in the HepG2 cells. SIRT1 and Opa1 were downregulated in the animal models. BBR attenuated hepatic insulin resistance and enhanced SIRT1/Opa1 signalling in the the db/db mice. Conclusion: Opa1 silencing-mediated mitochondrial fusion/fission imbalance could lead to hepatocyte insulin resistance. BBR may improve hepatic insulin resistance by regulating the SIRT1/Opa1 pathway, and thus, it may be used to treat type 2 diabetes.

scholarly journals Neonatal exendin-4 treatment reduces oxidative stress and prevents hepatic insulin resistance in intrauterine growth-retarded rats

2009 ◽  
Vol 297 (6) ◽  
pp. R1785-R1794 ◽  
Author(s):  
Elisabeth L. Raab ◽  
Patricia M. Vuguin ◽  
Doris A. Stoffers ◽  
Rebecca A. Simmons
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Hepatic Insulin Resistance ◽  
Glucose Disposal ◽  
Intrauterine Growth ◽  
Hepatic Glucose ◽  
Neonatal Hepatocytes

Intrauterine growth retardation (IUGR) has been linked to the development of Type 2 diabetes in adulthood. We have developed an IUGR model in the rat whereby the animals develop diabetes later in life. Previous studies demonstrate that administration of the long-acting glucagon-like-peptide-1 agonist, Exendin-4, during the neonatal period prevents the development of diabetes in IUGR rats. IUGR animals exhibit hepatic insulin resistance early in life (prior to the onset of hyperglycemia), characterized by blunted suppression of hepatic glucose production (HGP) in response to insulin. Basal HGP is also significantly higher in IUGR rats. We hypothesized that neonatal administration of Exendin-4 would prevent the development of hepatic insulin resistance. IUGR and control rats were given Exendin-4 on days 1–6 of life. Hyperinsulinemic-euglycemic clamp studies showed that Ex-4 significantly reduced basal HGP by 20% and normalized insulin suppression of HGP in IUGR rats. While Ex-4 decreased body weight and fat content in both Control and IUGR animals, these differences were only statistically significant in Controls. Exendin-4 prevented development of oxidative stress in liver and reversed insulin-signaling defects in vivo, thereby preventing the development of hepatic insulin resistance. Defects in glucose disposal and suppression of hepatic glucose production in response to insulin were reversed. Similar results were obtained in isolated Ex-4-treated neonatal hepatocytes. These results indicate that exposure to Exendin-4 in the newborn period reverses the adverse consequences of fetal programming and prevents the development of hepatic insulin resistance.

Clinical Trials in Thrombosis: Secondary Prevention of Myocardial Infarction

1976 ◽  
Vol 35 (01) ◽  
pp. 049-056 ◽  
Author(s):  
Christian R Klimt ◽  
P. H Doub ◽  
Nancy H Doub
Keyword(s):  
Myocardial Infarction ◽  
Secondary Prevention ◽  
Case Control ◽  
Therapeutic Effects ◽  
Case Control Studies ◽  
Definitive Answer ◽  
Inhibition Of Platelet Aggregation ◽  
Prospective Trials

SummaryNumerous in vivo and in vitro experiments, investigating the inhibition of platelet aggregation and the prevention of experimentally-induced thrombosis, suggest that anti-platelet drugs, such as aspirin or the combination of aspirin and dipyridamole or sulfinpyrazone, may be effective anti-thrombotic agents in man. Since 1971, seven randomized prospective trials and two case-control studies have been referenced in the literature or are currently being conducted, which evaluate the effects of aspirin, sulfinpyrazone, or dipyridamole in combination with aspirin in the secondary prevention of myocardial infarction. A critical review of these trials indicates a range of evidence from no difference to a favorable trend that antiplatelet drugs may serve as anti-thrombotic agents in man. To date, a definitive answer concerning the therapeutic effects of these drugs in the secondary prevention of coronary heart disease is not available.

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