scholarly journals Effects of the green tea polyphenol epigallocatechin-3-gallate on high-fat diet-induced insulin resistance and endothelial dysfunction

2013 ◽  
Vol 305 (12) ◽  
pp. E1444-E1451 ◽  
Author(s):  
Hyun-Ju Jang ◽  
Simone D. Ridgeway ◽  
Jeong-a Kim
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Green Tea ◽  
High Fat Diet ◽  
Reciprocal Relationship ◽  
Tea Polyphenol ◽  
High Fat ◽  
Green Tea Polyphenol

Insulin resistance, a hallmark of metabolic disorders, is a risk factor for diabetes and cardiovascular disease. Impairment of insulin responsiveness in vascular endothelium contributes to insulin resistance. The reciprocal relationship between insulin resistance and endothelial dysfunction augments the pathophysiology of metabolism and cardiovascular functions. The most abundant green tea polyphenol, epigallocatechin-3-gallate (EGCG), has been shown to have vasodilator action in vessels by activation of endothelial nitric oxide synthase (eNOS). However, it is not known whether EGCG has a beneficial effect in high-fat diet (HFD)-induced endothelial dysfunction. Male C57BL/6J mice were fed either a normal chow diet (NCD) or HFD with or without EGCG supplement (50 mg·kg−1·day−1) for 10 wk. Mice fed a HFD with EGCG supplement gained less body weight and showed improved insulin sensitivity. In vehicle-treated HFD mice, endothelial function was impaired in response to insulin but not to acetylcholine, whereas the EGCG-treated HFD group showed improved insulin-stimulated vasodilation. Interestingly, EGCG intake reduced macrophage infiltration into aortic tissues in HFD mice. Treatment with EGCG restored the insulin-stimulated phosphorylation of eNOS, insulin receptor substrate-1 (IRS-1), and protein kinase B (Akt), which was inhibited by palmitate (200 μM, 5 h) in primary bovine aortic endothelial cells. From these results, we conclude that supplementation of EGCG improves glucose tolerance, insulin sensitivity, and endothelial function. The results suggest that EGCG may have beneficial health effects in glucose metabolism and endothelial function through modulating HFD-induced inflammatory response.

Green tea polyphenol epigallocatechin-3-gallate alleviates nonalcoholic fatty liver disease and ameliorates intestinal immunity in mice fed a high-fat diet

2020 ◽  
Vol 11 (11) ◽  
pp. 9924-9935
Author(s):  
Jinbao Huang ◽  
Wenjiao Li ◽  
Wenjing Liao ◽  
Qing Hao ◽  
Dong Tang ◽  
...  
Keyword(s):  
Liver Disease ◽  
Green Tea ◽  
High Fat Diet ◽  
Fatty Liver Disease ◽  
Immune Homeostasis ◽  
Intestinal Immunity ◽  
Tea Polyphenol ◽  
High Fat ◽  
Nonalcoholic Fatty Liver ◽  
Green Tea Polyphenol

Dietary EGCG maintains the intestinal immune homeostasis, which might play a role in preventing systemic inflammation and NAFLD.

scholarly journals Green tea polyphenol (epigallocatechin-3-gallate) improves gut dysbiosis and serum bile acids dysregulation in high-fat diet-fed mice

2019 ◽  
Vol 65 (1) ◽  
pp. 34-46 ◽  
Author(s):  
Chihiro Ushiroda ◽  
Yuji Naito ◽  
Tomohisa Takagi ◽  
Kazuhiko Uchiyama ◽  
Katsura Mizushima ◽  
...  
Keyword(s):  
Bile Acids ◽  
Green Tea ◽  
High Fat Diet ◽  
Tea Polyphenol ◽  
High Fat ◽  
Gut Dysbiosis ◽  
Serum Bile Acids ◽  
Green Tea Polyphenol

Magnesium intake, insulin resistance and markers of endothelial function among women

2021 ◽  
pp. 1-9
Author(s):  
Narges Ghorbani Bavani ◽  
Parvane Saneei ◽  
Ammar Hassanzadeh Keshteli ◽  
Ahmadreza Yazdannik ◽  
Ebrahim Falahi ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Adhesion Molecule ◽  
Cell Function ◽  
Intercellular Adhesion Molecule ◽  
Model Assessment ◽  
Serum Concentrations ◽  
Homeostasis Model Assessment

Abstract Objective: We investigated the association of dietary Mg intake with insulin resistance and markers of endothelial function among Iranian women. Design: A cross-sectional study. Setting: Usual dietary intakes were assessed using a validated FFQ. Dietary Mg intake was calculated by summing up the amount of Mg in all foods. A fasting blood sample was taken to measure serum concentrations of glycemic indices (fasting plasma glucose and insulin) and endothelial function markers (E-selectin, soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1). Insulin resistance and sensitivity were estimated using the Homeostasis Model Assessment-Insulin Resistance (HOMA-IR), Homeostasis Model Assessment β-cell function (HOMA-β) and quantitative insulin sensitivity check index (QUICKI). Participants: Iranian female nurses (n 345) selected by a multistage cluster random sampling method. Results: The Mg intake across energy-adjusted quartiles was 205 (se 7), 221·4 (se 8), 254·3 (se 7) and 355·2 (se 9) mg/d, respectively. After adjustments for potential confounders, QUICKI level was significantly different across quartiles of Mg intake (Q1: 0·34 (se 0·02), Q2: 0·36 (se 0·01), Q3: 0·40 (se 0·01), and Q4: 0·39 (se 0·02), P = 0·02); however, this association disappeared after considering markers of endothelial function, indicating that this relation might be mediated through endothelial dysfunction. After controlling for all potential confounders, Mg intake was inversely, but not significantly, associated with serum concentrations of sICAM (Q1: 239 (se 17), Q2: 214 (se 12), Q3: 196 (se 12), and Q4: 195 (se 17), P = 0·29). There was no other significant association between dietary Mg intake and other indicators of glucose homoeostasis or endothelial markers. Conclusions: Higher dietary Mg intake was associated with better insulin sensitivity in Iranian females. This linkage was mediated through reduced endothelial dysfunction.

scholarly journals CaMKIV limits metabolic damage through induction of hepatic autophagy by CREB in obese mice

2020 ◽  
Vol 244 (2) ◽  
pp. 353-367 ◽  
Author(s):  
Jiali Liu ◽  
Yue Li ◽  
Xiaoyan Zhou ◽  
Xi Zhang ◽  
Hao Meng ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Inflammatory Response ◽  
Mitochondrial Dysfunction ◽  
High Fat Diet ◽  
Insulin Action ◽  
Hepatic Insulin Resistance ◽  
Obese Mice ◽  
High Fat ◽  
Impaired Insulin

High-fat diet (HFD) not only induces insulin resistance in liver, but also causes autophagic imbalance and metabolic disorders, increases chronic inflammatory response and induces mitochondrial dysfunction. Calcium/calmodulin-dependent protein kinase IV (CaMKIV) has recently emerged as an important regulator of glucose metabolism and skeletal muscle insulin action. Its activation has been involved in the improvement of hepatic and adipose insulin action. But the underlying mechanism is not fully understood. In the present study, we aimed to address the direct effects of CaMKIV in vivo and to evaluate the potential interaction of impaired insulin sensitivity and autophagic disorders in hepatic insulin resistance. Our results indicated obese mice receiving CaMKIV showed decreased blood glucose and serum insulin and improved insulin sensitivity as well as increased glucose tolerance compared with vehicle injection. Meanwhile, defective hepatic autophagy activity, impaired insulin signaling, increased inflammatory response and mitochondrial dysfunction in liver tissues which are induced by high-fat diet were also effectively alleviated by injection of CaMKIV. Consistent with these results, the addition of CaMKIV to the culture medium of BNL cl.2 hepatocytes markedly restored palmitate-induced hepatic insulin resistance and autophagic imbalance. These effects were nullified by blockade of cyclic AMP response element-binding protein (CREB), indicating the causative role of CREB in action of CaMKIV. Our findings suggested that CaMKIV restores hepatic autophagic imbalance and improves impaired insulin sensitivity via phosphorylated CREB signaling pathway, which may offer novel opportunities for treatment of obesity and diabetes.

scholarly journals Selenoprotein W deficiency does not affect oxidative stress and insulin sensitivity in the skeletal muscle of high-fat diet-fed obese mice

2019 ◽  
Vol 317 (6) ◽  
pp. C1172-C1182 ◽  
Author(s):  
Min-Gyeong Shin ◽  
Hye-Na Cha ◽  
Soyoung Park ◽  
Yong-Woon Kim ◽  
Jong-Yeon Kim ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
High Fat Diet ◽  
Control Diet ◽  
In Vivo Studies ◽  
Selenoprotein W ◽  
Obese Mice ◽  
High Fat

Selenoprotein W (SelW) is a selenium-containing protein with a redox motif found abundantly in the skeletal muscle of rodents. Previous in vitro studies suggest that SelW plays an antioxidant role; however, relatively few in vivo studies have addressed the antioxidant role of SelW. Since oxidative stress is a causative factor for the development of insulin resistance in obese subjects, we hypothesized that if SelW plays a role as an antioxidant, SelW deficiency could aggravate the oxidative stress and insulin resistance caused by a high-fat diet. SelW deficiency did not affect insulin sensitivity and H2O2 levels in the skeletal muscle of control diet-fed mice. SelW levels in the skeletal muscle were decreased by high-fat diet feeding for 12 wk. High-fat diet induced obesity and insulin resistance and increased the levels of H2O2 and oxidative stress makers, which were not affected by SelW deficiency. High-fat diet feeding increased the expression of antioxidant enzymes; however, SelW deficiency did not affect the expression levels of antioxidants. These results suggest that SelW does not play a protective role against oxidative stress and insulin resistance in the skeletal muscle of high-fat diet-fed obese mice.

scholarly journals Liraglutide Increases FGF-21 Activity and Insulin Sensitivity in High Fat Diet and Adiponectin Knockdown Induced Insulin Resistance

PLoS ONE ◽  
2012 ◽  
Vol 7 (11) ◽  
pp. e48392 ◽  
Author(s):  
Mengliu Yang ◽  
Lili Zhang ◽  
Chong Wang ◽  
Hua Liu ◽  
Guenther Boden ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
High Fat Diet ◽  
High Fat
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