scholarly journals Paeoniflorin Ameliorates Fructose-Induced Insulin Resistance and Hepatic Steatosis by Activating LKB1/AMPK and AKT Pathways

Nutrients ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1024 ◽  
Author(s):  
Yu-Cheng Li ◽  
Jing-Yi Qiao ◽  
Bao-Ying Wang ◽  
Ming Bai ◽  
Ji-Duo Shen ◽  
...  

The present study aimed to evaluate the effects of paeoniflorin on insulin resistance and hepatic steatosis induced by fructose. Male Sprague-Dawley rats were fed 20% fructose drink for eight weeks. The insulin sensitivity, serum lipid profiles, and hepatic lipids contents were measured. The results showed that paeoniflorin significantly decreased serum insulin and glucagon levels, improved insulin sensitivity and serum lipids profiles, and alleviated hepatic steatosis in fructose-fed rats. Moreover, paeoniflorin enhanced the phosphorylation level of AMP-activated protein kinase (AMPK) and protein kinase B (PKB/AKT) and inhibited the phosphorylation of acetyl coenzyme A carboxylase (ACC)1 in liver. Paeoniflorin also increased the hepatic carnitine palmitoyltransferase (CPT)-1 mRNA and protein expression and decreased the mRNA expression of sterol regulatory element-binding protein (SREBP)1c, stearyl coenzyme A decarboxylase (SCD)-1 and fatty acid synthetase (FAS). Furthermore, we found that paeoniflorin significantly increased the heptatic protein expression of tumor suppressor serine/threonine kinase (LKB)1 but not Ca2+/CaM-dependent protein kinase kinase (CaMKK)β. These results suggest that the protective effects of paeoniflorin might be involved in the activation of LKB1/AMPK and insulin signaling, which resulted in the inhibition of lipogenesis, as well as the activation of β-oxidation and glycogenesis, thus ameliorated the insulin resistance and hepatic steatosis. The present study may provide evidence for the beneficial effects of paeoniflorin in the treatment of insulin resistance and non-alcoholic fatty liver.

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Annah Petek Baykal ◽  
Elizabeth J Parks ◽  
Robert Shamburek ◽  
Stephanie Chung ◽  
Majid M Syed-Abdul ◽  
...  

Abstract De novo lipogenesis (DNL) plays a role in the development of hepatic steatosis and non-alcoholic fatty liver disease (NAFLD). In rodent models of both health and lipodystrophy (LD), leptin decreases DNL. In human patients with LD, reduced adipose tissue results in adipokine deficiencies, including lower plasma leptin, which contributes to insulin resistance, dyslipidemia and ectopic accumulation of triglycerides (TG). The mechanisms by which leptin regulates serum and hepatic-TG are not well elucidated. Studying patients with LD before and after leptin therapy provides an important clinical model for understanding leptin’s effect on DNL. We hypothesized that leptin treatment in lipodystrophic patients would decrease DNL by decreasing insulin resistance and glycemia, resulting in reduced circulating and hepatic-TG. Leptin-naïve patients with LD (n=11) were treated with recombinant leptin (metreleptin) for 6 months. All measurements were performed after an 8–12 hr fast. The % of TG in TG-rich lipoproteins (TRLP-TG) derived from DNL (% DNL) was measured using body water labeling (oral D2O) of TG and mass spectrometry analysis. Absolute DNL was calculated as the product of TRLP-TG and % DNL. HbA1c and serum-TG were measured biochemically, hepatic-TG by MRI, and total body and hepatic insulin sensitivity measured during a hyperinsulinemic-euglycemic clamp. DNL decreased after metreleptin: % DNL from 22.8±6.8 to 9.1±5.1% (p=0.0008) and absolute DNL from 54.2±32.1 to 8.6±6.5 mg/dl (p=0.003). TRLP-TG decreased from (median [interquartile range]) 160 [107, 280] to 98 [66, 147] mg/dl (p=0.01). Total body and hepatic insulin sensitivity increased from 3.7 [3.0, 7.3] to 8.4 [5.1,10.6] mg/kgFFM/min (p=0.03) and from 61.0 [48.5, 69.3] to 84.7 [75.2, 107.6] % (p =0.01), respectively. HbA1c decreased from 8.6±1.8 to 7.1±1.4% (p=0.04), hepatic-TG decreased from 17.6±11.9 to 10.3±9.1% (p=0.02), and serum-TG from 386 [216, 686] to 223 [118, 497] mg/dl (p=0.06). DNL correlated negatively with insulin sensitivity both before (r=-0.73, p=0.03) and after (r=-0.85, p=0.004) metreleptin. DNL correlated positively with hepatic-TG before (r=0.70 p=0.03) and tended to correlate after metreleptin (r=0.65, p=0.06). The change in DNL correlated with change in serum-TG (r=0.77, p=0.04) but not the change in hepatic-TG (p=0.80). We show here for the first time that 6 months of metreleptin treatment in humans with LD decreased DNL by 84% and was associated with reductions in glycemia and improved peripheral and hepatic insulin sensitivity. These data indicate a strong link between metreleptin’s effects to increase clearance of blood glucose by peripheral tissues and reduce hepatic carbohydrate flux, resulting in DNL reductions. This led to lowered hepatic steatosis and dyslipidemia and suggests treatments that target multi-organ insulin resistance may lead to decreased NAFLD and cardiovascular risk.


2012 ◽  
Vol 123 (4) ◽  
pp. 259-270 ◽  
Author(s):  
Julio Cesar Fraulob ◽  
Vanessa Souza-Mello ◽  
Marcia Barbosa Aguila ◽  
Carlos Alberto Mandarim-de-Lacerda

The aim of the present study was to evaluate the effects of ST (rosuvastatin) and GZ (rosiglitazone) on IR (insulin resistance) and on liver as well as adipose tissue in mice fed on an HF (high-fat) diet. Our data show that treatment with ST resulted in a marked improvement in insulin sensitivity characterized by enhanced glucose clearance during the insulin tolerance test and a 70% decrease in the HOMA-IR (homoeostasis model assessment of insulin resistance) index level (P=0.0008). The ST-treated mice exhibited lower gains in BM (body mass; −8%; P<0.01) and visceral fat pad thickness (−60%; P<0.01) compared with the untreated HF group. In comparison with HF-diet-fed mice, HF+ST-treated mice showed a significant reduction in hepatomegaly and liver steatosis (−6%, P<0.05; and −21%, P<0.01 respectively). In HF+ST-treated mice, the hepatic TAG (triacylglycerol) levels were reduced by 58% compared with the HF group (P<0.01). In addition, the expression of SREBP-1c (sterol-regulatory-element-binding protein-1c) was decreased by 50% in the livers of HF+ST-treated mice (P<0.01) relative to the HF-diet-fed mice. The levels of resistin were lower in the HF+ST-treated group compared with the HF group (44% less, P< 0.01). In conclusion, we demonstrated that ST treatment improved insulin sensitivity and decreased liver steatosis in mice fed on an HF diet. Furthermore, ST reduced BM gains, improved the circulating levels of plasma cholesterol and TAG, and reduced hepatic TAG, which was concomitant with lower resistin levels.


2012 ◽  
Vol 90 (2) ◽  
pp. 237-242 ◽  
Author(s):  
Sifan Chen ◽  
Jinghua Li ◽  
Zili Zhang ◽  
Wenxue Li ◽  
Yanshuang Sun ◽  
...  

Resveratrol (Res) has attracted great interest regarding its effects related to metabolic syndrome, especially for lipid metabolic disorder or insulin resistance; however, the underlying mechanisms remain elusive. To explore the effects of Res on insulin sensitivity and the underlying mechanism, insulin-resistant KKAy mice were treated with 2 and 4 g/kg diets of Res for 12 weeks. After the treatment, blood glucose, serum insulin, glucose tolerance, and insulin tolerance, as well as other indices such as adiponectin mRNA in epididymal adipose tissues, silent information regulator 1 (Sirt1), AMP-activated protein kinase (AMPK), insulin receptor substrate 1 (IRS1), and phosphorylated protein kinase B (PKB/AKT) proteins in liver and soleus muscles, were investigated. The results indicate that Res intervention reduces blood glucose and serum insulin levels, improves insulin and glucose tolerance, increases serum adiponectin and adiponectin mRNA levels in epididymal adipose tissues, and more importantly, elevates Sirt1, p-AMPK, p-IRS1, and p-AKT levels in liver and soleus muscles. In conclusion, Res could improve insulin sensitivity and ameliorate insulin resistance in KKAy mice, which may be associated with the upregulation of Sirt1 protein in liver and soleus muscles and consequent AMPK activation, as well as insulin-signaling related proteins.


2021 ◽  
Vol 9 (1) ◽  
pp. e001975
Author(s):  
Nicolas Quezada ◽  
Ilse Valencia ◽  
Javiera Torres ◽  
Gregorio Maturana ◽  
Jaime Cerda ◽  
...  

IntroductionSystemic chronic low-grade inflammation has been linked to insulin resistance (IR) and non-alcoholic steatohepatitis (NASH). NOD-like receptor protein 3 (NLRP3) inflammasome and its final product, interleukin (IL)-1β, exert detrimental effects on insulin sensitivity and promote liver inflammation in murine models. Evidence linking hepatic NLRP3 inflammasome, systemic IR and NASH has been scarcely explored in humans. Herein, we correlated the hepatic abundance of NLRP3 inflammasome components and IR and NASH in humans.Research design and methodsMetabolically healthy (MH) (n=11) and metabolically unhealthy (MUH) (metabolic syndrome, n=21, and type 2 diabetes, n=14) subjects were recruited. Insulin sensitivity (homeostatic model assessment of IR (HOMA-IR) and Oral Glucose Sensitivity (OGIS120)), glycemic (glycated hemoglobin), and lipid parameters were determined by standard methods. Plasma cytokines were quantified by Magpix. Hepatic NLRP3 inflammasome components were determined at the mRNA and protein levels by reverse transcription–quantitative PCR and western blot, respectively. Liver damage was assessed by histological analysis (Non-alcoholic Fatty Liver Disease Activity Score (NAS) and Steatosis, Inflammatory Activity, and Fibrosis (SAF) scores). IR and liver histopathology were correlated with NLRP3 inflammasome components as well as with liver and plasma IL-1β levels.ResultsBody Mass Index, waist circumference, and arterial hypertension frequency were significantly higher in MUH subjects. These patients also had increased high-sensitivity C reactive protein levels compared with MH subjects. No differences in the plasma levels of IL-1β nor the hepatic content of Nlrp3, apoptosis-associated speck-like (Asc), Caspase-1, and IL-1β were detected between MUH and MH individuals. MUH subjects had significantly higher NAS and SAF scores, indicating more severe liver damage. However, histological severity did not correlate with the hepatic content of NLRP3 inflammasome components nor IL-1β levels.ConclusionOur results suggest that NLRP3 inflammasome activation is linked neither to IR nor to the inflammatory status of the liver in MUH patients.


2015 ◽  
Vol 7 (2) ◽  
pp. 41-46
Author(s):  
S Sultana ◽  
Z Zeba ◽  
A Hossain ◽  
A Khaleque ◽  
R Zinnat ◽  
...  

Hyperproinsulinemia is commonly present in subjects with impaired glucose tolerance. The present study was undertaken to investigate the proinsulin level in Bangladeshi IGT subjects and to explore its association with insulin resistance. This observational study was conducted under a case-control design with IGT subjects (n=50) and controls (n=44). IGT was diagnosed following the WHO Study Group Criteria. Serum glucose was measured by glucose-oxidase method, serum lipid profile by enzymatic method and serum insulin and serum proinsulin were measured by ELISA method. Insulin secretory capacity (HOMA%B) and insulin sensitivity (HOMA%S) were calculated from fasting serum glucose and fasting serum insulin by homeostasis model assessment. The study subjects were age- and BMI- matched. Mean (±SD) age (yrs) of the control and IGT subjects were 40±6 and 40±5 respectively (p=0.853). Mean (±SD) BMI of the control and IGT subjects were 23±3 and 22±2 respectively (p=0.123). Fasting glucose was not significantly higher in IGT subjects, but serum glucose 2 hours after 75 gm glucose load was significantly higher in IGT subjects. Median (Range) value of fasting serum glucose (mmol/l) of control and IGT subjects were 5.3 (3.8-6) and 5.2 (4-12) respectively; (p=0.297). Median (Range) value of serum glucose (mmol/l) 2 hours after 75 gm glucose load of control and IGT subjects were 6.1 (3-7.8) and 7.9 (5- 21) respectively; (p=0.001). Fasting TG was significantly higher in IGT subjects and LDL-c was significantly lower in IGT subjects. Serum Total cholesterol and HDL-c were not significantly different between the IGT and control subjects. Median (Range) value of fasting serum TG (mg/dl) of control and IGT subjects were 119 (51-474) and 178 (82-540) respectively; (p=0.001). Median (Range) value of fasting serum T chol (mg/dl) of control and IGT subjects were 180 (65-272) and 186 (140-400) respectively; (p=0.191). Median (Range) value of fasting serum HDL-C (mg/dl) of control and IGT subjects were 29 (19-45) and 31 (15-78) respectively; (p=0.914). Median (Range) value of fasting serum LDL-C (mg/dl) of control and IGT subjects were 117(29-201) and 111(41- 320) respectively; (p=0.001). Fasting serum proinsulin was significantly higher in IGT subjects. Median (Range) value of fasting serum proinsulin (pmol/l) of control and IGT subjects were 9.2(1.8-156) and 17(3-51) respectively; (p=0.001). Insulin secretory capacity (HOMA%B) was higher but insulin sensitivity (HOMA%S) was significantly lower in case of IGT subjects. Median (Range) value of HOMA%B of control and IGT subjects were 97(46-498) and 164(17-300) respectively; (p=0.001). Median (Range) value of HOMA%S of control and IGT subjects were 68(19-270) and 39(15-110) respectively (p=0.001). In multiple regression analysis a significant negative association was found between fasting proinsulin and insulin sensitivity (p=0.037). The data led to the following conclusions: a) Insulin resistance is the predominant defect in Bangladeshi IGT subjects. b) Basal proinsulin level is significantly increased in IGT subjects. c) Insulin resistance is negatively associated with serum proinsulin in IGT subjects. DOI: http://dx.doi.org/10.3329/bjmb.v7i2.22411 Bangladesh J Med Biochem 2014; 7(2): 41-46


2013 ◽  
Vol 125 (11) ◽  
pp. 501-511 ◽  
Author(s):  
Valérie Lebrun ◽  
Olivier Molendi-Coste ◽  
Nicolas Lanthier ◽  
Christine Sempoux ◽  
Patrice D. Cani ◽  
...  

Alcohol consumption is a major cause of liver disease. It also associates with increased cardiovascular risk and Type 2 diabetes. ALD (alcoholic liver disease) and NAFLD (non-alcoholic fatty liver disease) share pathological features, pathogenic mechanisms and pattern of disease progression. In NAFLD, steatosis, lipotoxicity and liver inflammation participate to hepatic insulin resistance. The aim of the present study was to verify the effect of alcohol on hepatic insulin sensitivity and to evaluate the role of alcohol-induced steatosis and inflammation on glucose homoeostasis. C57BL/6J mice were fed for 20 days a modified Lieber–DeCarli diet in which the alcohol concentration was gradually increased up to 35% of daily caloric intake. OH (alcohol liquid diet)-fed mice had liver steatosis and inflammatory infiltration. In addition, these mice developed insulin resistance in the liver, but not in muscles, as demonstrated by euglycaemic–hyperinsulinaemic clamp and analysis of the insulin signalling cascade. Treatment with the PPAR-α (peroxisome-proliferator-activated receptor-α) agonist Wy14,643 protected against OH-induced steatosis and KC (Kupffer cell) activation and almost abolished OH-induced insulin resistance. As KC activation may modulate insulin sensitivity, we repeated the clamp studies in mice depleted in KC to decipher the role of macrophages. Depletion of KC using liposomes-encapsuled clodronate in OH-fed mice failed both to improve hepatic steatosis and to restore insulin sensitivity as assessed by clamp. Our study shows that chronic alcohol consumption induces steatosis, KC activation and hepatic insulin resistance in mice. PPAR-α agonist treatment that prevents steatosis and dampens hepatic inflammation also prevents alcohol-induced hepatic insulin resistance. However, KC depletion has little impact on OH-induced metabolic disturbances.


Nutrients ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 3070
Author(s):  
Valentina Cossiga ◽  
Vincenzo Lembo ◽  
Maria Guarino ◽  
Concetta Tuccillo ◽  
Federica Morando ◽  
...  

Non-alcoholic fatty liver disease (NAFLD) is associated with insulin resistance and diabetes. A reduction in insulin receptor (IR) expression has been reported in these patients. The aims of this study were to evaluate the effects of a mixture of plant extracts consisting of Berberis aristata, Elaeis guineensis and decaffeinated green coffee by Coffea canephora on the improvement of glycaemic profile, through the modulation of IR levels, and of hepatic steatosis in NAFLD patients. Forty-nine patients with a grade of steatosis S1-S2 were randomly allocated to the treatment with plant extracts or placebo for six months. Hepatic steatosis was evaluated using transient elastography with CAP (controlled attenuation parameter). Glucose, insulin, and IR levels were measured in serum samples. At the end of the study, patients treated with plant extracts displayed a significant reduction of serum glucose (p < 0.001), insulin levels (p < 0.01), homeostatic model assessment for insulin resistance (HOMA-IR) index (p < 0.001), and CAP value (p < 0.01) compared to placebo. Moreover, the IR expression was increased significantly in the plant extracts group compared to the placebo group (p < 0.05). The combination of plant extracts increases serum IR levels, determining amelioration of glycemic profile and improvement of hepatic steatosis in NAFLD patients.


2019 ◽  
Vol 20 (9) ◽  
pp. 2325 ◽  
Author(s):  
Hua Li ◽  
Wonbeak Yoo ◽  
Hye-Mi Park ◽  
Soo-Youn Lim ◽  
Dong-Ha Shin ◽  
...  

Arazyme, a metalloprotease from the spider Nephila clavata, exerts hepatoprotective activity in CCL4-induced acute hepatic injury. This study investigated the hepatoprotective effects in high-fat diet (HFD)-induced non-alcoholic fatty liver disease-like C57BL/6J mice. The mice were randomly divided into four groups (n = 10/group): the normal diet group, the HFD group, the arazyme group (HFD with 0.025% arazyme), and the milk thistle (MT) group (HFD with 0.1% MT). Dietary supplementation of arazyme for 13 weeks significantly lowered plasma triglyceride (TG) and non-esterified fatty acid levels. Suppression of HFD-induced hepatic steatosis in the arazyme group was caused by the reduced hepatic TG and total cholesterol (TC) contents. Arazyme supplementation decreased hepatic lipogenesis-related gene expression, sterol regulatory element-binding transcription protein 1 (Srebf1), fatty acid synthase (Fas), acetyl-CoA carboxylase 1 (Acc1), stearoyl-CoA desaturase-1 (Scd1), Scd2, glycerol-3-phosphate acyltransferase (Gpam), diacylglycerol O-acyltransferase 1 (Dgat1), and Dgat2. Arazyme directly reduced palmitic acid (PA)-induced TG accumulation in HepG2 cells. Arazyme suppressed macrophage infiltration and tumor necrosis factor α (Tnfa), interleukin-1β (Il1b), and chemokine-ligand-2 (Ccl2) expression in the liver, and inhibited secretion of TNFα and expression of inflammatory mediators, Tnfa, Il1b, Ccl2, Ccl3, Ccl4, and Ccl5, in PA-induced RAW264.7 cells. Arazyme effectively protected hepatic steatosis and steatohepatitis by inhibiting SREBP-1-mediated lipid accumulation and macrophage-mediated inflammation.


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