scholarly journals Edible Bird’s Nest Prevents High Fat Diet-Induced Insulin Resistance in Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Zhang Yida ◽  
Mustapha Umar Imam ◽  
Maznah Ismail ◽  
Der-Jiun Ooi ◽  
Nadarajan Sarega ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Transcriptional Regulation ◽  
Insulin Signaling ◽  
High Fat Diet ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Model Assessment ◽  
High Fat ◽  
Edible Bird’S Nest ◽  
Metabolic Indices

Edible bird’s nest (EBN) is used traditionally in many parts of Asia to improve wellbeing, but there are limited studies on its efficacy. We explored the potential use of EBN for prevention of high fat diet- (HFD-) induced insulin resistance in rats. HFD was given to rats with or without simvastatin or EBN for 12 weeks. During the intervention period, weight measurements were recorded weekly. Blood samples were collected at the end of the intervention and oral glucose tolerance test conducted, after which the rats were sacrificed and their liver and adipose tissues collected for further studies. Serum adiponectin, leptin, F2-isoprostane, insulin, and lipid profile were estimated, and homeostatic model assessment of insulin resistance computed. Effects of the different interventions on transcriptional regulation of insulin signaling genes were also evaluated. The results showed that HFD worsened metabolic indices and induced insulin resistance partly through transcriptional regulation of the insulin signaling genes. Additionally, simvastatin was able to prevent hypercholesterolemia but promoted insulin resistance similar to HFD. EBN, on the other hand, prevented the worsening of metabolic indices and transcriptional changes in insulin signaling genes due to HFD. The results suggest that EBN may be used as functional food to prevent insulin resistance.

Improvement on Lipid Metabolic Disorder by 3′-Deoxyadenosine in High-Fat-Diet-Induced Fatty Mice

2010 ◽  
Vol 38 (06) ◽  
pp. 1065-1075 ◽  
Author(s):  
Ya-Jing Niu ◽  
Rong-Ya Tao ◽  
Qian Liu ◽  
Jin-Ying Tian ◽  
Fei Ye ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
High Fat Diet ◽  
Metabolic Disorder ◽  
Tolerance Test ◽  
The Body ◽  
Oral Glucose ◽  
Model Assessment ◽  
High Fat ◽  
Lipid Metabolic Disorder

This study explores the effects of 3′-deoxyadenosine, a compound from Cordyceps militaris, on lipid metabolic disorder induced by a high-fat-diet in C57BL/6 mice. These mice had an obese body, lipid metabolic disorder and insulin resistance and were treated orally with 100 mg/kg/day 3′-deoxyadenosine (DA), 15 mg/kg/day rosiglitazone and 150 mg/kg/day fenofibrate, respectively. Compared to the model mice, the body weight gain in DA-treated mice were decreased by 66.5%, serum triglyceride and total cholesterol levels were decreased by 20.7% and 16.7%, respectively, and the triglyceride content in the skeletal muscle was reduced by 41.2%. This treatment also had a significant effect on insulin resistance. In DA-treated mice, the serum insulin levels and homeostasis model assessment of the insulin resistance index were decreased by 30% and 46%, respectively, and the areas under the glucose-time curve were depressed by 18% in the insulin tolerance test and by 21.5% in the oral glucose tolerance test. Finally, the value of glucose infusion rates and insulin induced-glucose uptake into the skeletal muscle in the hyperinsulinemic-euglycemic clamp test were increased by 18% and 41%, respectively, compared to those in the model mice. This data suggests that the effects of DA on lipid metabolic disorder induced by a high-fat-diet may be linked to its improvement on insulin resistance, especially concerning the increase of insulin sensitivity in the skeletal muscle.

scholarly journals N-Acetylneuraminic Acid Supplementation Prevents High Fat Diet-Induced Insulin Resistance in Rats through Transcriptional and Nontranscriptional Mechanisms

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Zhang Yida ◽  
Mustapha Umar Imam ◽  
Maznah Ismail ◽  
Norsharina Ismail ◽  
Nur Hanisah Azmi ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Signaling ◽  
High Fat Diet ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
High Fat ◽  
Acetylneuraminic Acid ◽  
High Doses

N-Acetylneuraminic acid (Neu5Ac) is a biomarker of cardiometabolic diseases. In the present study, we tested the hypothesis that dietary Neu5Ac may improve cardiometabolic indices. A high fat diet (HFD) + Neu5Ac (50 or 400 mg/kg BW/day) was fed to rats and compared with HFD + simvastatin (10 mg/kg BW/day) or HFD alone for 12 weeks. Weights and serum biochemicals (lipid profile, oral glucose tolerance test, leptin, adiponectin, and insulin) were measured, and mRNA levels of insulin signaling genes were determined. The results indicated that low and high doses of sialic acid (SA) improved metabolic indices, although only the oral glucose tolerance test, serum triglycerides, leptin, and adiponectin were significantly better than those in the HFD and HFD + simvastatin groups (P<0.05). Furthermore, the results showed that only high-dose SA significantly affected the transcription of hepatic and adipose tissue insulin signaling genes. The data suggested that SA prevented HFD-induced insulin resistance in rats after 12 weeks of administration through nontranscriptionally mediated biochemical changes that may have differentially sialylated glycoprotein structures at a low dose. At higher doses, SA induced transcriptional regulation of insulin signaling genes. These effects suggest that low and high doses of SA may produce similar metabolic outcomes in relation to insulin sensitivity through multiple mechanisms. These findings are worth studying further.

scholarly journals Neurodegeneration in an animal model of Parkinson's disease is exacerbated by a high-fat diet

2010 ◽  
Vol 299 (4) ◽  
pp. R1082-R1090 ◽  
Author(s):  
Jill K. Morris ◽  
Gregory L. Bomhoff ◽  
John A. Stanford ◽  
Paige C. Geiger
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Animal Model ◽  
Locomotor Activity ◽  
Substantia Nigra ◽  
High Fat Diet ◽  
Model Assessment ◽  
High Fat

Despite numerous clinical studies supporting a link between type 2 diabetes (T2D) and Parkinson's disease (PD), the clinical literature remains equivocal. We, therefore, sought to address the relationship between insulin resistance and nigrostriatal dopamine (DA) in a preclinical animal model. High-fat feeding in rodents is an established model of insulin resistance, characterized by increased adiposity, systemic oxidative stress, and hyperglycemia. We subjected rats to a normal chow or high-fat diet for 5 wk before infusing 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle. Our goal was to determine whether a high-fat diet and the resulting peripheral insulin resistance would exacerbate 6-OHDA-induced nigrostriatal DA depletion. Prior to 6-OHDA infusion, animals on the high-fat diet exhibited greater body weight, increased adiposity, and impaired glucose tolerance. Two weeks after 6-OHDA, locomotor activity was tested, and brain and muscle tissue was harvested. Locomotor activity did not differ between the groups nor did cholesterol levels or measures of muscle atrophy. High-fat-fed animals exhibited higher homeostatic model assessment of insulin resistance (HOMA-IR) values and attenuated insulin-stimulated glucose uptake in fast-twitch muscle, indicating decreased insulin sensitivity. Animals in the high-fat group also exhibited greater DA depletion in the substantia nigra and the striatum, which correlated with HOMA-IR and adiposity. Decreased phosphorylation of HSP27 and degradation of IκBα in the substantia nigra indicate increased tissue oxidative stress. These findings support the hypothesis that a diet high in fat and the resulting insulin resistance may lower the threshold for developing PD, at least following DA-specific toxin exposure.

scholarly journals Studies of insulin resistance in patients with clinical and subclinical hypothyroidism

2009 ◽  
Vol 160 (5) ◽  
pp. 785-790 ◽  
Author(s):  
Eirini Maratou ◽  
Dimitrios J Hadjidakis ◽  
Anastasios Kollias ◽  
Katerina Tsegka ◽  
Melpomeni Peppa ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Plasma Membrane ◽  
Glucose Transport ◽  
Subclinical Hypothyroidism ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Model Assessment ◽  
Increased Risk

ObjectiveAlthough clinical hypothyroidism (HO) is associated with insulin resistance, there is no information on insulin action in subclinical hypothyroidism (SHO).Design and methodsTo investigate this, we assessed the sensitivity of glucose metabolism to insulin both in vivo (by an oral glucose tolerance test) and in vitro (by measuring insulin-stimulated rates of glucose transport in isolated monocytes with flow cytometry) in 21 euthyroid subjects (EU), 12 patients with HO, and 13 patients with SHO.ResultsAll three groups had comparable plasma glucose levels, with the HO and SHO having higher plasma insulin than the EU (P<0.05). Homeostasis model assessment index was increased in HO (1.97±0.22) and SHO (1.99±0.13) versus EU (1.27±0.16, P<0.05), while Matsuda index was decreased in HO (3.89±0.36) and SHO (4.26±0.48) versus EU (7.76±0.87, P<0.001), suggesting insulin resistance in both fasting and post-glucose state. At 100 μU/ml insulin: i) GLUT4 levels on the monocyte plasma membrane were decreased in both HO (215±19 mean fluorescence intensity, MFI) and SHO (218±24 MFI) versus EU (270±25 MFI, P=0.03 and 0.04 respectively), and ii) glucose transport rates in monocytes from HO (481±30 MFI) and SHO (462±19 MFI) were decreased versus EU (571±15 MFI, P=0.04 and 0.004 respectively).ConclusionsIn patients with HO and SHO: i) insulin resistance was comparable; ii) insulin-stimulated rates of glucose transport in isolated monocytes were decreased due to impaired translocation of GLUT4 glucose transporters on the plasma membrane; iii) these findings could justify the increased risk for insulin resistance-associated disorders, such as cardiovascular disease, observed in patients with HO or SHO.

Ethno-pharmacological insulin signaling induction of aqueous extract of Syzygium paniculatum fruits in a high-fat diet induced hepatic insulin resistance

2020 ◽  
pp. 113576
Author(s):  
Prabhakar Yellanur Konda ◽  
Vidyasagar Chennupati ◽  
Sreenivasulu Dasari ◽  
Nishesh Sharma ◽  
Muthukumaran Muthulingam ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Aqueous Extract ◽  
Insulin Signaling ◽  
High Fat Diet ◽  
Hepatic Insulin Resistance ◽  
High Fat

scholarly journals Hypoglycemic effects and mechanisms of electroacupuncture on insulin resistance

2014 ◽  
Vol 307 (3) ◽  
pp. R332-R339 ◽  
Author(s):  
Jieyun Yin ◽  
Jian Kuang ◽  
Manisha Chandalia ◽  
Demidmaa Tuvdendorj ◽  
Batbayar Tumurbaatar ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Fatty Acid ◽  
Blood Glucose ◽  
Insulin Sensitivity ◽  
Free Fatty Acid ◽  
Glucose Tolerance ◽  
High Fat Diet ◽  
Postprandial Glucose ◽  
Tolerance Test ◽  
High Fat

The aim of this study was to investigate effects and mechanisms of electroacupuncture (EA) on blood glucose and insulin sensitivity in mice fed a high-fat diet. Both wild-type (WT) and adipose ectonucleotide pyrophosphate phosphodiesterase (ENPP1) transgenic (TG) mice were fed a high-fat diet for 12 wk; for each mouse, an intraperitoneal glucose tolerance test (IPGTT) and insulin tolerance test (ITT) were performed with or without EA at abdomen or auricular areas. A high-fat diet-induced insulin resistance in both WT and TG mice. In the WT mice, EA at 3 Hz and 15 Hz, but not at 1 Hz or 100 Hz, via CV4+CV12 significantly reduced postprandial glucose levels; EA at 3 Hz was most potent. The glucose level was reduced by 61.7% at 60 min and 74.5% at 120 min with EA at 3 Hz (all P < 0.001 vs. control). Similar hypoglycemic effect was noted in the TG mice. On the contrary, EA at auricular points increased postprandial glucose level ( P < 0.03). 4). EA at 3 Hz via CV4+CV12 significantly enhanced the decrease of blood glucose after insulin injection, suggesting improvement of insulin sensitivity. Plasma free fatty acid was significantly suppressed by 42.5% at 15 min and 50.8% at 30 min with EA ( P < 0.01) in both WT and TG mice. EA improves glucose tolerance in both WT and TG mice fed a high-fat diet, and the effect is associated with stimulation parameters and acupoints and is probably attributed to the reduction of free fatty acid.

scholarly journals PKCε contributes to lipid-induced insulin resistance through cross talk with p70S6K and through previously unknown regulators of insulin signaling

2018 ◽  
Vol 115 (38) ◽  
pp. E8996-E9005 ◽  
Author(s):  
Brandon M. Gassaway ◽  
Max C. Petersen ◽  
Yulia V. Surovtseva ◽  
Karl W. Barber ◽  
Joshua B. Sheetz ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Protein Phosphorylation ◽  
Cross Talk ◽  
Insulin Signaling ◽  
High Fat Diet ◽  
Large Scale ◽  
Kinase Assay ◽  
Hepatic Insulin Resistance ◽  
High Fat ◽  
The Impact

Insulin resistance drives the development of type 2 diabetes (T2D). In liver, diacylglycerol (DAG) is a key mediator of lipid-induced insulin resistance. DAG activates protein kinase C ε (PKCε), which phosphorylates and inhibits the insulin receptor. In rats, a 3-day high-fat diet produces hepatic insulin resistance through this mechanism, and knockdown of hepatic PKCε protects against high-fat diet-induced hepatic insulin resistance. Here, we employed a systems-level approach to uncover additional signaling pathways involved in high-fat diet-induced hepatic insulin resistance. We used quantitative phosphoproteomics to map global in vivo changes in hepatic protein phosphorylation in chow-fed, high-fat–fed, and high-fat–fed with PKCε knockdown rats to distinguish the impact of lipid- and PKCε-induced protein phosphorylation. This was followed by a functional siRNA-based screen to determine which dynamically regulated phosphoproteins may be involved in canonical insulin signaling. Direct PKCε substrates were identified by motif analysis of phosphoproteomics data and validated using a large-scale in vitro kinase assay. These substrates included the p70S6K substrates RPS6 and IRS1, which suggested cross talk between PKCε and p70S6K in high-fat diet-induced hepatic insulin resistance. These results identify an expanded set of proteins through which PKCε may drive high-fat diet-induced hepatic insulin resistance that may direct new therapeutic approaches for T2D.

Electroacupuncture Mitigates Endothelial Dysfunction via Effects on the Pi3K/Akt Signalling Pathway in High Fat Diet-Induced Insulin-Resistant Rats

2018 ◽  
Vol 36 (3) ◽  
pp. 162-169 ◽  
Author(s):  
Danchun Lan ◽  
Nenggui Xu ◽  
Jian Sun ◽  
Zhixing Li ◽  
Rongzhen Liao ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Endothelial Dysfunction ◽  
Pancreatic Islet ◽  
High Fat Diet ◽  
Negative Impact ◽  
Fasting Blood Glucose ◽  
Signalling Pathway ◽  
Control Group ◽  
Model Assessment ◽  
High Fat

Objective To investigate the effect of electroacupuncture (EA) on endothelial dysfunction related to high fat diet (HFD)-induced insulin resistance through the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) signalling pathway. Methods Twenty-four male Sprague-Dawley rats were fed a regular diet (Control group, n=8) or a HFD (n=16) for 12 weeks to induce an insulin resistance model. HFD-fed rats were divided into two groups that remained untreated (HFD group, n=8) or received electroacupuncture (HFD+EA group, n=8). EA was applied at PC6, ST36, SP6 and BL23. At the end of the experiment, fasting blood glucose (FBG), serum insulin (FINS), serum C-peptide (C-P) and homeostatic model assessment of insulin resistance (HOMA-IR) indices were determined. Pancreatic islet samples were subjected to histopathological examination. The thoracic aorta was immunostained with anti-rat insulin receptor substrate (IRS)-1, Akt and endothelial nitric oxide synthase (eNOS) antibodies. mRNA and protein expression of IRS-1, PI3K, Akt2 and eNOS in the vascular endothelium were determined by real-time PCR and Western blot analysis, respectively. Results The bodyweight increase of the HFD+EA group was smaller than that of the untreated HFD group. Compared with the HFD group, the levels of FBG, FINS, C-P and HOMA-IR in the HFD+EA group decreased significantly (P<0.01). Histopathological evaluation indicated that EA improved pancreatic islet inflammation. The expression of endothelial markers, such as IRS-1, PI3K, Akt2 and eNOS, decreased in the HFD group, while EA treatment appeared to ameliorate the negative impact of diet. Conclusion EA may improve insulin resistance and attenuate endothelial dysfunction, and therefore could play a potential role in the prevention or treatment of diabetic complications and cardiovascular disease through the PI3K/Akt signalling pathway.

scholarly journals Association between Serum Mg2+ Concentrations and Cardiovascular Organ Damage in a Cohort of Adult Subjects

Nutrients ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1264 ◽  
Author(s):  
Elettra Mancuso ◽  
Maria Perticone ◽  
Rosangela Spiga ◽  
Carolina Averta ◽  
Mariangela Rubino ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Intima Media Thickness ◽  
Multivariate Regression Analysis ◽  
Organ Damage ◽  
Tolerance Test ◽  
Cardiovascular Complications ◽  
Left Ventricular ◽  
Oral Glucose ◽  
Model Assessment ◽  
Increased Risk

Magnesium (Mg2+) levels are associated with insulin resistance, hypertension, atherosclerosis, and type 2 diabetes (T2DM). We evaluated the clinical utility of physiological Mg2+ in assessing subclinical cardiovascular organ damage including increased carotid artery intima- media thickness (c-IMT) and left ventricular mass index (LVMI) in a cohort of well-characterized adult non-diabetic individuals. Age- and gender-adjusted correlations between Mg2+ and metabolic parameters showed that Mg2+ circulating levels were correlated negatively with body mass index (BMI), fasting glucose, and 2h-oral glucose tolerance test (OGTT) glucose. Similarly, Mg2+ levels were significantly and negatively related to c-IMT and LVMI. A multivariate regression analysis revealed that age (β = 0.440; p < 0.0001), BMI (β = 0.225; p < 0.0001), and Mg2+ concentration (β = −0.122; p < 0.01) were independently associated with c-IMT. Age (β = 0.244; p = 0.012), Mg2+ (β = −0.177; p = 0.019), and diastolic blood pressure (β = 0.184; p = 0.038) were significantly associated with LVMI in women, while age (β = 0.211; p = 0.019), Mg2+ (β = −0.171; p = 0.038) and the homeostasis model assessment index of insulin resistance (HOMA-IR) (β = −0.211; p = 0.041) were the sole variables associated with LVMI in men. In conclusion, our data support the hypothesis that the assessment of Mg2+ as part of the initial work-up might help unravel the presence of subclinical organ damage in subjects at increased risk of cardiovascular complications.

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