Vitamin E supplementation and caloric restriction promotes regulation of insulin secretion and glycemic homeostasis by different mechanisms in rats

2018 ◽  
Vol 96 (6) ◽  
pp. 777-785
Author(s):  
Paula R. Venturini ◽  
Bruna Fontana Thomazini ◽  
Camila Andréa Oliveira ◽  
Armindo A. Alves ◽  
Thaís Furtado Camargo ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Vitamin E ◽  
Insulin Receptor ◽  
Caloric Restriction ◽  
Glucose Homeostasis ◽  
Control Group ◽  
Insulin Degrading Enzyme ◽  
Degrading Enzyme ◽  
Food Quantity ◽  
Vitamin E Supplementation

Vitamin E and caloric restriction have antioxidant effects in mammals. The aim of this study was to evaluate effects of vitamin E supplementation and caloric restriction upon insulin secretion and glucose homeostasis in rats. Male Wistar rats were distributed among the following groups: C, control group fed ad libitum; R, food quantity reduction of 40%; CV, control group supplemented with vitamin E [30 mg·kg–1·day–1]; and RV, food-restricted group supplemented with vitamin E. The experiments ran for 21 days. Glucose tolerance and insulin sensitivity was higher in the CV, R, and RV groups. Insulin secretion stimulated with different glucose concentrations was lower in the R and RV groups, compared with C and CV. In the presence of glucose and secretagogues, insulin secretion was higher in the CV group and was lower in the R and RV groups. An increase in insulin receptor occurred in the fat pad and muscle tissue of groups CV, R, and RV. Levels of hepatic insulin receptor and phospho-Akt protein were higher in groups R and RV, compared with C and CV, while muscle phospho-Akt was increased in the CV group. There was a reduction in hepatic RNA levels of the hepatocyte growth factor gene and insulin degrading enzyme in the R group, and increased levels of insulin degrading enzyme in the CV and RV groups. Thus, vitamin E supplementation and caloric restriction modulate insulin secretion by different mechanisms to maintain glucose homeostasis.

scholarly journals Reduced insulin clearance and lower insulin-degrading enzyme expression in the liver might contribute to the thrifty phenotype of protein-restricted mice

2014 ◽  
Vol 112 (6) ◽  
pp. 900-907 ◽  
Author(s):  
Luiz F. Rezende ◽  
Rafael L. Camargo ◽  
Renato C. S. Branco ◽  
Ana P. G. Cappelli ◽  
Antonio C. Boschero ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Protein Kinase ◽  
Glucose Tolerance ◽  
Glucose Homeostasis ◽  
Insulin Clearance ◽  
Protein Diet ◽  
Restricted Diet ◽  
Insulin Degrading Enzyme ◽  
Degrading Enzyme ◽  
Thrifty Phenotype

Nutrient restriction during the early stages of life usually leads to alterations in glucose homeostasis, mainly insulin secretion and sensitivity, increasing the risk of metabolic disorders in adulthood. Despite growing evidence regarding the importance of insulin clearance during glucose homeostasis in health and disease, no information exists about this process in malnourished animals. Thus, in the present study, we aimed to determine the effect of a nutrient-restricted diet on insulin clearance using a model in which 30-d-old C57BL/6 mice were exposed to a protein-restricted diet for 14 weeks. After this period, we evaluated many metabolic variables and extracted pancreatic islet, liver, gastrocnemius muscle (GCK) and white adipose tissue samples from the control (normal-protein diet) and restricted (low-protein diet, LP) mice. Insulin concentrations were determined using RIA and protein expression and phosphorylation by Western blot analysis. The LP mice exhibited lower body weight, glycaemia, and insulinaemia, increased glucose tolerance and altered insulin dynamics after the glucose challenge. The improved glucose tolerance could partially be explained by an increase in insulin sensitivity through the phosphorylation of the insulin receptor/protein kinase B and AMP-activated protein kinase/acetyl-CoA carboxylase in the liver, whereas the changes in insulin dynamics could be attributed to reduced insulin secretion coupled with reduced insulin clearance and lower insulin-degrading enzyme (IDE) expression in the liver and GCK. In summary, protein-restricted mice not only produce and secrete less insulin, but also remove and degrade less insulin. This phenomenon has the double benefit of sparing insulin while prolonging and potentiating its effects, probably due to the lower expression of IDE in the liver, possibly with long-term consequences.

scholarly journals Dietary oxidised frying oil causes oxidative damage of pancreatic islets and impairment of insulin secretion, effects associated with vitamin E deficiency

2010 ◽  
Vol 105 (9) ◽  
pp. 1311-1319 ◽  
Author(s):  
Ya-Fan Chiang ◽  
Huey-Mei Shaw ◽  
Mei-Fang Yang ◽  
Chih-Yang Huang ◽  
Cheng-Hsien Hsieh ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Vitamin E ◽  
Oxidative Damage ◽  
Pancreatic Islets ◽  
Glucose Intolerance ◽  
Basal Diet ◽  
Frying Oil ◽  
Glucose Stimulated Insulin Secretion ◽  
High Level ◽  
Vitamin E Supplementation

We previously reported that, in rodents, a diet with a high oxidised frying oil (OFO) content leads to glucose intolerance associated with a reduction in insulin secretion. The present study aimed at investigating the impairment of pancreatic islets caused by dietary OFO. C57BL/6J mice were divided into three groups to receive a low-fat basal diet containing 5 g/100 g of fresh soyabean oil (LF group) or a high-fat diet containing 20 g/100 g of either fresh soyabean oil (HF group) or OFO (HO group). After 8 weeks, mice in the HO group showed glucose intolerance and hypoinsulinaemia, and their islets showed impaired glucose-stimulated insulin secretion (P < 0·05; HO group v. LF and HF groups). Significantly higher oxidative stress and a lower mitochondrial membrane potential were observed in the islets in the HO group compared with the LF and HF groups. Immunoblots showed that the reduction in insulin levels in HO islets was associated with activation of the c-Jun NH2-terminal kinase and a reduction in levels of pancreatic and duodenal homeobox factor-1. In a second study, when dietary OFO-induced tissue vitamin E depletion was prevented by large-dose vitamin E supplementation (500 IU(1·06 mmol all-rac-α-tocopherol acetate)/kg diet; HO+E group), the OFO-mediated reduction in islet size and impairment of glucose tolerance and insulin secretion were significantly attenuated (P < 0·05; HO group v. HO+E group). We conclude that a high level of dietary OFO ingestion impairs glucose metabolism by causing oxidative damage and compromising insulin secretion in pancreatic islets, and that these effects can be prevented by vitamin E supplementation.

scholarly journals Cafeteria diet inhibits insulin clearance by reduced insulin-degrading enzyme expression and mRNA splicing

2013 ◽  
Vol 219 (2) ◽  
pp. 173-182 ◽  
Author(s):  
P Brandimarti ◽  
J M Costa-Júnior ◽  
S M Ferreira ◽  
A O Protzek ◽  
G J Santos ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Insulin Secretion ◽  
Alternative Splicing ◽  
Insulin Sensitivity ◽  
Glucose Homeostasis ◽  
Insulin Clearance ◽  
Cafeteria Diet ◽  
Mrna Levels ◽  
Insulin Degrading Enzyme ◽  
Diet Induced Obesity

Insulin clearance plays a major role in glucose homeostasis and insulin sensitivity in physiological and/or pathological conditions, such as obesity-induced type 2 diabetes as well as diet-induced obesity. The aim of the present work was to evaluate cafeteria diet-induced obesity-induced changes in insulin clearance and to explain the mechanisms underlying these possible changes. Female Swiss mice were fed either a standard chow diet (CTL) or a cafeteria diet (CAF) for 8 weeks, after which we performed glucose tolerance tests, insulin tolerance tests, insulin dynamics, and insulin clearance tests. We then isolated pancreatic islets for ex vivo glucose-stimulated insulin secretion as well as liver, gastrocnemius, visceral adipose tissue, and hypothalamus for subsequent protein analysis by western blot and determination of mRNA levels by real-time RT-PCR. The cafeteria diet induced insulin resistance, glucose intolerance, and increased insulin secretion and total insulin content. More importantly, mice that were fed a cafeteria diet demonstrated reduced insulin clearance and decay rate as well as reduced insulin-degrading enzyme (IDE) protein and mRNA levels in liver and skeletal muscle compared with the control animals. Furthermore, the cafeteria diet reduced IDE expression and alternative splicing in the liver and skeletal muscle of mice. In conclusion, a cafeteria diet impairs glucose homeostasis by reducing insulin sensitivity, but it also reduces insulin clearance by reducing IDE expression and alternative splicing in mouse liver; however, whether this mechanism contributes to the glucose intolerance or helps to ameliorate it remains unclear.

P4-410 Insulin-degrading enzyme as a downstream target of insulin receptor signaling cascade

2004 ◽  
Vol 25 ◽  
pp. S590-S591
Author(s):  
Lixia Zhao ◽  
Bruce Teter ◽  
Takashi Morihara ◽  
Oliver Ubeda ◽  
Sally A. Frautschy ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Signaling Cascade ◽  
Receptor Signaling ◽  
Insulin Degrading Enzyme ◽  
Degrading Enzyme ◽  
Downstream Target ◽  
Insulin Receptor Signaling

scholarly journals Improving the Quality Characteristics and Shelf Life of Meat and Growth Performance in Goose Fed Diets Supplemented with Vitamin E

Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 798
Author(s):  
Zabihollah Nemati ◽  
Kazem Alirezalu ◽  
Maghsoud Besharati ◽  
Saeid Amirdahri ◽  
Daniel Franco ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Vitamin E ◽  
Shelf Life ◽  
Growth Performance ◽  
Saturated Fatty Acids ◽  
Basal Diet ◽  
Fat Content ◽  
Dietary Vitamin ◽  
Control Group ◽  
Vitamin E Supplementation

The present study was carried out to investigate the effect of dietary vitamin E on growth performance, cellular immunity, carcass characteristics, and meat quality in geese. Sixty-four one-day-old male geese were selected from 1200 goose chicks with the same average body weight (92.5 ± 2.5 g) and subjected to two treatments (basal diet or control and basal diet plus 120 mg/kg vitamin E supplement) with 4 replicates (8 geese per replicate) for 8 weeks. After slaughter, goose meat was aerobically packed in polyethylene packages and stored at 4 °C for 9 days. The results showed that vitamin E supplementation improved the growth performance, carcass yield percentage, and immune response of goose (p < 0.05). The addition of vitamin E in the diet significantly increased the protein and fat content of goose meat but decreased the moisture and ash content with respect to those obtained from the control diet. During storage, meat from the vitamin E treatment showed higher phenolic content and lower thiobarbituric acid reactive substances (TBARSs) and total volatile nitrogen (TVB-N) values than those from the control treatment. Vitamin E supplementation increased the saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs) in goose meat. However, goose meat supplemented with vitamin E displayed a significantly (p < 0.05) higher PUFA/SFA ratio than those of the control group. Based on the results, it was concluded that vitamin E could be used to improve the growth performance of goose, the meat composition in terms of the protein and fat content, the nutritional value in terms of the fatty acid composition, and the shelf life.

scholarly journals Hepatic Insulin Clearance: Mechanism and Physiology

Physiology ◽  
2019 ◽  
Vol 34 (3) ◽  
pp. 198-215 ◽  
Author(s):  
Sonia M. Najjar ◽  
Germán Perdomo
Keyword(s):  
Insulin Resistance ◽  
Insulin Secretion ◽  
Insulin Receptor ◽  
Hepatic Steatosis ◽  
Insulin Clearance ◽  
Hepatic Insulin Resistance ◽  
Insulin Degrading Enzyme ◽  
Insulin Receptor Tyrosine Kinase ◽  
Impaired Insulin ◽  
Hepatic Insulin Clearance

Upon its secretion from pancreatic β-cells, insulin reaches the liver through the portal circulation to exert its action and eventually undergo clearance in the hepatocytes. In addition to insulin secretion, hepatic insulin clearance regulates the homeostatic level of insulin that is required to reach peripheral insulin target tissues to elicit proper insulin action. Receptor-mediated insulin uptake followed by its degradation constitutes the basic mechanism of insulin clearance. Upon its phosphorylation by the insulin receptor tyrosine kinase, carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) takes part in the insulin-insulin receptor complex to increase the rate of its endocytosis and targeting to the degradation pathways. This review summarizes how this process is regulated and how it is associated with insulin-degrading enzyme in the liver. It also discusses the physiological implications of impaired hepatic insulin clearance: Whereas reduced insulin clearance cooperates with increased insulin secretion to compensate for insulin resistance, it can also cause hepatic insulin resistance. Because chronic hyperinsulinemia stimulates hepatic de novo lipogenesis, impaired insulin clearance also causes hepatic steatosis. Thus impaired insulin clearance can underlie the link between hepatic insulin resistance and hepatic steatosis. Delineating these regulatory pathways should lead to building more effective therapeutic strategies against metabolic syndrome.

Positive Association of Vitamin E Supplementation with Hemoglobin Levels in Mildly Anemic Healthy Pakistani Adults

2015 ◽  
Vol 85 (1-2) ◽  
pp. 39-49 ◽  
Author(s):  
Tanveer Jilani ◽  
Iqbal Azam ◽  
Bushra Moiz ◽  
Naseema Mehboobali ◽  
Mohammad Perwaiz Iqbal
Keyword(s):  
Vitamin E ◽  
General Population ◽  
Repeated Measures ◽  
Venous Blood ◽  
Plasma Concentrations ◽  
Intervention Group ◽  
Positive Association ◽  
Total Antioxidant Status ◽  
Control Group ◽  
Vitamin E Supplementation

Abstract. Background: Hemoglobin levels slightly below the lower limit of normal are common in adults in the general population in developing countries. A few human studies have suggested the use of antioxidant vitamins in the correction of mild anemia. The objective of the present study was to investigate the association of vitamin E supplementation in mildly anemic healthy adults with post-supplemental blood hemoglobin levels in the general population of Karachi, Pakistan. Method: In a single-blinded and placebo-controlled randomized trial, 124 mildly anemic subjects from the General Practitioners’ Clinics and personnel of the Aga Khan University were randomized into intervention (n = 82) and control (n = 42) group. In the intervention group, each subject was given vitamin E (400 mg) everyday for a period of three months, while control group subjects received a placebo. Eighty six subjects completed the trial. Fasting venous blood was collected at baseline and after three months of supplementation. Hemoglobin levels and serum/plasma concentrations of vitamin E, vitamin B12, folate, ferritin, serum transferrin receptor (sTfR), glucose, total cholesterol, triglycerides, LDL-cholesterol, HDL-cholesterol, creatinine, total-antioxidant-status and erythropoietin were measured and analyzed using repeated measures ANOVA and multiple linear regression. Results: The adjusted regression coefficients (β) and standard error [SE(β)] of the significant predictors of post-supplemental hemoglobin levels were serum concentration of vitamin E (0.983[0.095]), gender (- 0.656[0.244]), sTfR (- 0.06[0.02]) and baseline hemoglobin levels (0.768[0.077]). Conclusion: The study showed a positive association between vitamin E supplementation and enhanced hemoglobin levels in mildly anemic adults.

Physiological responses in pigs on antioxidant supplementation during summer and winter

2017 ◽  
Author(s):  
Arindam Chakraborty ◽  
Anubha Baruah ◽  
B. C. Sarmah ◽  
J. Goswami ◽  
Arundhati Bora ◽  
...  
Keyword(s):  
Vitamin E ◽  
Pulse Rate ◽  
Rectal Temperature ◽  
Group Treatment ◽  
Physiological Responses ◽  
Growing Pigs ◽  
Control Group ◽  
Significant Difference ◽  
The Mean ◽  
Vitamin E Supplementation

The objective of the study was to assess the variability in the physiological responses of growing pigs on melatonin and vitamin E supplementation during summer and winter seasons.36 nos. of weaned crossbred (Hampshire X Assam local) female pigs were selected for the study. Eighteen (18) animals were subjected to treatment separately during summer and winter. The selected animals were divided into three groups, with six pigs in each group, consisting of the control group (Treatment 1), a second group comprising of animals fed with melatonin (Meloset) @3 mg/animal (Treatment 2) and a third group in which the animals were fed Vitamin E (Evion) @100 mg (Treatment 3), for both the seasons. The rectal temperature, respiration and pulse rate differed significantly (P>0.01) between seasons. There was also significant difference (P>0.01) in the mean pulse rate between treatment.

scholarly journals Pancreatic β-cell-specific deletion of insulin-degrading enzyme leads to dysregulated insulin secretion and β-cell functional immaturity

2019 ◽  
Vol 317 (5) ◽  
pp. E805-E819 ◽  
Author(s):  
Cristina M. Fernández-Díaz ◽  
Beatriz Merino ◽  
José F. López-Acosta ◽  
Pilar Cidad ◽  
Miguel A. de la Fuente ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Beta Cell ◽  
Beta Cells ◽  
Insulin Degrading Enzyme ◽  
Β Cell ◽  
Isolated Pancreatic Islets ◽  
C Peptide ◽  
Degrading Enzyme ◽  
Functional Immaturity ◽  
Glucose Stimulated Insulin Secretion

Inhibition of insulin-degrading enzyme (IDE) has been proposed as a possible therapeutic target for type 2 diabetes treatment. However, many aspects of IDE's role in glucose homeostasis need to be clarified. In light of this, new preclinical models are required to elucidate the specific role of this protease in the main tissues related to insulin handling. To address this, here we generated a novel line of mice with selective deletion of the Ide gene within pancreatic beta-cells, B-IDE-KO mice, which have been characterized in terms of multiple metabolic end points, including blood glucose, plasma C-peptide, and intraperitoneal glucose tolerance tests. In addition, glucose-stimulated insulin secretion was quantified in isolated pancreatic islets and beta-cell differentiation markers and insulin secretion machinery were characterized by RT-PCR. Additionally, IDE was genetically and pharmacologically inhibited in INS-1E cells and rodent and human islets, and insulin secretion was assessed. Our results show that, in vivo, life-long deletion of IDE from beta-cells results in increased plasma C-peptide levels. Corroborating these findings, isolated islets from B-IDE-KO mice showed constitutive insulin secretion, a hallmark of beta-cell functional immaturity. Unexpectedly, we found 60% increase in Glut1 (a high-affinity/low- Km glucose transporter), suggesting increased glucose transport into the beta-cell at low glucose levels, which may be related to constitutive insulin secretion. In parallel, IDE inhibition in INS-1E and islet cells resulted in impaired insulin secretion after glucose challenge. We conclude that IDE is required for glucose-stimulated insulin secretion. When IDE is inhibited, insulin secretion machinery is perturbed, causing either inhibition of insulin release at high glucose concentrations or constitutive secretion.

scholarly journals A PROSPECTIVE STUDY ON ROLE OF VITAMIN E SUPPLEMENTATION IN TYPE 2 DIABETES MELLITUS

2018 ◽  
Vol 11 ◽  
Author(s):  
Pavithra D ◽  
Praveen D ◽  
Vijey Aanandhi M
Keyword(s):  
Diabetes Mellitus ◽  
Vitamin E ◽  
Blood Sugar ◽  
Test Group ◽  
Hypoglycemic Agents ◽  
Control Group ◽  
Diabetic Patients ◽  
Type Ii ◽  
Vitamin E Supplementation

Aim and Objective: The aim of the study was to evaluate the role of Vitamin E supplementation in Type II diabetes mellitus (DM), to determines whether people with Type II DM treated with hypoglycemic agents alone, with or without Vitamin E, to determines the drug interaction in such treatment regimen, and to evaluates the Safety of the regimen.Methods: Type II DM patients with or without complications were included in this study along with serum glycated hemoglobin (HbA1c) concentration between 7.5% and 9.5%. They are divided into test group (which received hypoglycemic agent along with Vitamin E 4000 IU) and control group. Body mass index (BMI) status, fasting blood sugar (FBS), and post-prandial blood sugar (PPBS) were noted once in a month, HbA1c percentage, total cholesterol level (TC), and serum Vitamin E level were estimated and noted for every 3 months at total 9 months of this study. Patients with other comorbid conditions were prominent in this study.Results: It is perceptible with the analysis of obtained data that FBS, PPBS, HbA1c percentage, TC level, and BMI status of the patients were declined gradually in test group (patients with Vitamin E supplementation along with their hypoglycemic agents). Thus, antioxidant therapy is highly propitious whereby delaying the onset of complications in patients with DM. This development would be highly helpful for diabetic patients.

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