scholarly journals Ameliorative Effects of Oral Glucosamine on Insulin Resistance and Pancreatic Tissue Damage in Experimental Wistar rats on a High-fat Diet

2021 ◽  
Author(s):  
Cornelio Barrientos ◽  
Angélica Pérez ◽  
Jorge Vázquez
Keyword(s):  
Insulin Resistance ◽  
High Fat Diet ◽  
Wistar Rats ◽  
Fatty Infiltration ◽  
Pancreatic Tissue ◽  
Protein Glycosylation ◽  
Control Group ◽  
Chow Diet ◽  
High Fat ◽  
Nuclear Pyknosis

Hyperlipidemia due to a high-fat diet (HFD) is a risk factor for inducing insulin resistance (IR) and adverse effects onpancreatic β-cells in obesity and type 2 diabetes mellitus. This relationship may be due to activation of the hexosaminebiosynthesis pathway. Administration of exogenous glucosamine (GlcN) can increase the end product of this pathway(uridine-5′-diphosphate-N-acetyl-glucosamine), which can mediate IR and protein glycosylation. The objective of this study was to evaluate the effects of oral GlcN and HFD on IR and pancreatic histologic damage in a 22 wk study of 4 groups of male Wistar rats: control group with normal chow diet, HFD group (24%. g/g lard), GlcN group (500 mg/kg−1 per day of glucosamine hydrochloride in drinking water) and HFD plus oral GlcN. Metabolic variables related to IR that were measured included triglycerides (TG), free fatty acids (FFAs) and malondialdehyde (MDA). Histopathologic evaluation of the pancreas was also performed. The results showed IR in the HFD group, which had increased pancreatic nuclear pyknosis and vacuolization, with fatty infiltration and structural alteration of the islets of Langerhans. TG, FFAs and MDA were higher in serum and pancreatic tissue as compared with the control group. The GlcN group did not develop IR and had only mild nuclear pyknosis with no significant change in the pancreatic content of TG, FFAs and MDA. However, the combined administration of GlcN and HFD attenuated IR and improved TG, FFAs and MDA levels in serum and pancreatic tissue and the pancreatic histopathologic changes, with no significant differences as compared with the control group. These findings suggest that the oral GlcN at a dose of 500 mg/kg−1 is protective against IR and the pancreatic histologic damage caused by HFD.

scholarly journals Protective role of melatonin against adipose-hepatic metabolic comorbidities in experimentally induced obese rat model

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260546
Author(s):  
Mary J. Obayemi ◽  
Christopher O. Akintayo ◽  
Adesola A. Oniyide ◽  
Ayodeji Aturamu ◽  
Olabimpe C. Badejogbin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Food Intake ◽  
High Fat Diet ◽  
Wistar Rats ◽  
Liver Lipid ◽  
Control Group ◽  
Metabolic Dysfunction ◽  
High Fat ◽  
Male Wistar Rats

Background Adipose and hepatic metabolic dysfunctions are critical comorbidities that also aggravate insulin resistance in obese individuals. Melatonin is a low-cost agent and previous studies suggest that its use may promote metabolic health. However, its effects on some comorbidities associated with obesity are unknown. Herein, we investigated the hypothesis that melatonin supplementation would attenuate adipose-hepatic metabolic dysfunction in high fat diet (HFD)-induced obesity in male Wistar rats. Materials and methods Twenty-four adult male Wistar rats (n = 6/group) were used: Control group received vehicle (normal saline), obese group received 40% high fat diet, melatonin-treated group received 4 mg/kg of melatonin, and obese plus melatonin group received 40% HFD and melatonin. The treatment lasted for 12 weeks. Results HFD caused increased food intake, body weight, insulin level, insulin resistance and plasma and liver lipid but decreased adipose lipid. In addition, HFD also increased plasma, adipose and liver malondialdehyde, IL-6, uric acid and decreased Glucose-6-phosphate dehydrogenase, glutathione, nitric oxide and circulating obestatin concentration. However, these deleterious effects except food intake were attenuated when supplemented with melatonin. Conclusion Taken together, the present results indicate that HFD exposure causes adipose-hepatic metabolic disturbance in obese animals, which are accompanied by oxidative stress and inflammation. In addition, the present results suggest that melatonin supplementation attenuates adipose-hepatic metabolic dysfunction, accompanying obesity by suppression of oxidative stress/inflammation-dependent mechanism and increasing circulating obestatin.

scholarly journals Fenofibrate Alleviates Insulin Resistance and Hepatic Steatosis via Modulation of let-7/ SERCA2b Axis

2020 ◽  
Author(s):  
Dan Zhang ◽  
Shan-zhuang Niu ◽  
Yi-cheng Ma ◽  
Bo Zhou ◽  
Yi Deng ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Hepatic Steatosis ◽  
High Fat Diet ◽  
Luciferase Reporter ◽  
Control Group ◽  
Chow Diet ◽  
High Fat ◽  
Alcoholic Fatty Liver

Abstract Background: Fenofibrate is a peroxisome proliferator-activated receptor alpha agonist, which is widely used in clinical practice to effectively ameliorates the development of NAFLD. However, the molecular mechanism remains largely unknown, the present study aimed to investigate the role and specific mechanism of fenofibrate on lipid metabolism disorders associated diseases.Methods: The male C57BL6/J mice were divided into 3 groups, the mice in control group (n=10) were fed with normal chow diet, and the mice in HFD-fed group (n =10) were fed with a high fat diet (HFD) for 14 weeks. For the fenofibrate +HFD-fed group (n =10), the mice fed HFD were orally gavaged with fenofibrate (40 mg/kg) daily for the last 4 weeks. Body weight and hip width were measured. Macrosteatosis and fat deposition in the liver were measured by H&E staining and Oil red O staining individually. The levels of serum and hepatic triglyceride were measured, and HOMA-IR, HOMA-ISI were analyzed. The levels of SCD-1, Bip, CHOP and SERCA2b were measured by western blotting. The expression of let-7 were analyzed by qPCR, and the complementarity between the 3′-UTR of SERCA2b gene and let-7 was measured by luciferase reporter assay.Results: Fenofibrate reduces hepatic steatosis and insulin resistance in HFD-fed mice. Fnofibrate alleviates endoplasmic reticulum stress (ER stress) of mice fed a high fat diet (HFD). Fenofibrate increases the levels of Sarco-endoplasmic reticulum Ca2+-ATPase 2b (SERCA2b) which serves as a regulator of ER stress. Further, the levels of let-7 microRNA is also regulated by fenofibrate, and let-7 directly targets 3’-UTR of SERCA2b. Conclusion: The present data suggests that fenofibrate alleviates ER stress through the let-7/SERCA2b axis to protect against excessive lipid accumulation in the liver of Non-alcoholic fatty liver disease (NAFLD) mice.

scholarly journals d-Allulose Ameliorates Skeletal Muscle Insulin Resistance in High-Fat Diet-Fed Rats

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6310
Author(s):  
Yang Gou ◽  
Bingyang Liu ◽  
Mengyao Cheng ◽  
Takako Yamada ◽  
Tetsuo Iida ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
High Fat Diet ◽  
Wistar Rats ◽  
Tolerance Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Chow Diet ◽  
High Fat ◽  
Glut 4 ◽  
Tnf Α

Background: d-Allulose is a rare sugar with antiobesity and antidiabetic activities. However, its direct effect on insulin sensitivity and the underlying mechanism involved are unknown. Objective: This study aimed to investigate the effect of d-allulose on high-fat diet (HFD)-induced insulin resistance using the hyperinsulinemic–euglycemic (HE)-clamp method and intramuscular signaling analysis. Methods: Wistar rats were randomly divided into three dietary groups: chow diet, HFD with 5% cellulose (HFC), and HFD with 5% d-allulose (HFA). After four weeks of feeding, the insulin tolerance test (ITT), intraperitoneal glucose tolerance test (IPGTT), and HE-clamp study were performed. The levels of plasma leptin, adiponectin, and tumor necrosis factor (TNF)-α were measured using the enzyme-linked immunosorbent assay. We analyzed the levels of cell signaling pathway components in the skeletal muscle using Western blotting. Results: d-allulose alleviated the increase in HFD-induced body weight and visceral fat and reduced the area under the curve as per ITT and IPGTT. d-Allulose increased the glucose infusion rate in the two-step HE-clamp test. Consistently, the insulin-induced phosphorylation of serine 307 in the insulin receptor substrate-1 and Akt and expression of glucose transporter 4 (Glut-4) in the muscle were higher in the HFA group than HFC group. Furthermore, d-allulose decreased plasma TNF-α concentration and insulin-induced phosphorylation of stress-activated protein kinase/Jun N-terminal kinase in the muscle and inhibited adiponectin secretion in HFD-fed rats. Conclusions: d-allulose improved HFD-induced insulin resistance in Wistar rats. The reduction of the proinflammatory cytokine production, amelioration of adiponectin secretion, and increase in insulin signaling and Glut-4 expression in the muscle contributed to this effect.

scholarly journals Estrogens Protect against High-Fat Diet-Induced Insulin Resistance and Glucose Intolerance in Mice

Endocrinology ◽  
2009 ◽  
Vol 150 (5) ◽  
pp. 2109-2117 ◽  
Author(s):  
Elodie Riant ◽  
Aurélie Waget ◽  
Haude Cogo ◽  
Jean-François Arnal ◽  
Rémy Burcelin ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Glucose Intolerance ◽  
High Fat Diet ◽  
Chow Diet ◽  
High Fat ◽  
Normal Chow ◽  
Visceral Adipose ◽  
Deficient Mice ◽  
Normal Chow Diet

Although corroborating data indicate that estrogens influence glucose metabolism through the activation of the estrogen receptor α (ERα), it has not been established whether this pathway could represent an effective therapeutic target to fight against metabolic disturbances induced by a high-fat diet (HFD). To this end, we first evaluated the influence of chronic 17β-estradiol (E2) administration in wild-type ovariectomized mice submitted to either a normal chow diet or a HFD. Whereas only a modest effect was observed in normal chow diet-fed mice, E2 administration exerted a protective effect against HFD-induced glucose intolerance, and this beneficial action was abolished in ERα-deficient mice. Furthermore, E2 treatment reduced HFD-induced insulin resistance by 50% during hyperinsulinemic euglycemic clamp studies and improved insulin signaling (Akt phosphorylation) in insulin-stimulated skeletal muscles. Unexpectedly, we found that E2 treatment enhanced cytokine (IL-6, TNF-α) and plasminogen activator inhibitor-1 mRNA expression induced by HFD in the liver and visceral adipose tissue. Interestingly, although the proinflammatory effect of E2 was abolished in visceral adipose tissue from chimeric mice grafted with bone marrow cells from ERα-deficient mice, the beneficial effect of the hormone on glucose tolerance was not altered, suggesting that the metabolic and inflammatory effects of estrogens can be dissociated. Eventually comparison of sham-operated with ovariectomized HFD-fed mice demonstrated that endogenous estrogens levels are sufficient to exert a full protective effect against insulin resistance and glucose intolerance. In conclusion, the regulation of the ERα pathway could represent an effective strategy to reduce the impact of high-fat diet-induced type 2 diabetes.

Particular Matter of Motor Vehicle Exposure and High-Fat Diet Effects on Kidney Histopathology, Creatinine, and Malondialdehyde (MDA) Levels in Wistar Rats

2021 ◽  
Vol 5 (3) ◽  
pp. 124-128
Author(s):  
Rizka Veni ◽  
Awal Prasetyo ◽  
Muflihatul Muniroh
Keyword(s):  
High Fat Diet ◽  
Wistar Rats ◽  
Motor Vehicle ◽  
Histopathological Change ◽  
Normal Diet ◽  
Control Group ◽  
High Fat ◽  
Control Group Design ◽  
Treatment Groups ◽  
Significant Difference

This study aims to analyze the effect of combination of motor vehicle particular matter exposure and high-fat diet in kidney histopathology, creatinine levels, and MDA levels in Wistar rats. This study used a posttest-only control group design. Eighteen healthy male Wistar rats were divided into three groups. The intervention groups received motor vehicle fume exposure for 100 s with normal diet (X1) or high-fat diet (X2), and the control group received no exposure (C). Data analysis was processed with a SPSS 25.0 computer program by using the one-way ANOVA test followed by post hoc LSD. The degree of kidney histopathological damage showed significant differences between the X1 and X2 groups when compared with the control group (p < 0.05). The results of the creatinine level examination found a significant difference between the X2 and C groups (p < 0.05) and the treatment groups X1 and X2 (p < 0.05). The results of kidney MDA level examination showed a significant difference between the treatment groups (X1 and X2) and the control group (p < 0.05). The combination of particular matter of motor vehicle fumes exposure and high-fat diet could induce kidney damage through histopathological change and increased creatinine levels and kidney MDA levels in Wistar rats.

scholarly journals Histologi Lumen Dan Endotelium Arteri Dorsal Penis Tikus Wistar (Rattus Novergicus) Yang Diinduksi Pakan Tinggi Lemak

2020 ◽  
Vol 7 (1) ◽  
pp. 73
Author(s):  
I Wayan Rosiana ◽  
I Gede Widhiantara
Keyword(s):  
Treatment Group ◽  
High Fat Diet ◽  
Wistar Rats ◽  
Wistar Rat ◽  
Lumen Diameter ◽  
Control Group ◽  
High Fat ◽  
Arterial Lumen ◽  
Male Wistar Rats ◽  
The Difference

This study aims to look at the histopathological picture of the dorsal arteries of the penis of the hiperlipidemic wistar rats (Rattus novergicus) induction by high-fat diet that seen in terms of lumen diameter and thickness of the arterial endotelium wall. Hyperlipidemia is a risk factor for ateriosclerosis in the penile arteries causing erectile dysfunction in men. This study is an experimental study with a randomized posttest only control goup design. The sample are  10 individuals adult male wistar rats aged 3-4 months with a range of body weight 150-200 grams. Before treatment, adaptation was carried out for 7 days. After that the sample rats in the treatment group were made hyperlidemic by feeding lard for 50 days. Then surgery is performed for histopathological preparations at the posttest. To determine the differences in endotelium thickness and arterial lumen diameter in the two groups, an independent t-test was used. Thick diameter data of the endotelium and dorsal arteries of the penis of the wistar rat between the lower treatment group and the control group. The difference that occurred was statistically significant (p <0.05). So it can be concluded that the provision of high-fat diet (hyperlipidemia) decreases the lumen diameter and endotelium thickness of dorsal arteries penis. Keywords: Dorsal arteries, high-fat diet, Wistar rats

Abstract 686: Intervention with Naringenin Enhances Weight Loss, Potentiates Improvements in Metabolic Dysregulation and Halts Progression of Atherosclerosis Induced by a High-Fat Diet in LDLr-/- Mice.

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Amy C Burke ◽  
Brian G Sutherland ◽  
Julia M Assini ◽  
Murray W Huff
Keyword(s):  
Insulin Resistance ◽  
Weight Loss ◽  
Plasma Glucose ◽  
High Fat Diet ◽  
Lesion Size ◽  
Chow Diet ◽  
High Fat ◽  
Metabolic Dysregulation ◽  
The Metabolic Syndrome ◽  
Progression Of Atherosclerosis

Previous studies demonstrate that the addition of naringenin, a grapefruit flavonoid, to a high-fat diet prevents the development of many disorders of the metabolic syndrome and atherosclerosis in Ldlr-/- mice. Furthermore, in intervention studies, the addition of naringenin to a high-fat, high cholesterol (HFHC) diet reversed pre-established obesity, hyperlipidemia, hepatic steatosis, insulin resistance and improved atherosclerotic lesion pathology, but not lesion size. In the present intervention study, we tested the hypothesis that addition of naringenin to a chow diet would further improve pre-established metabolic dysregulation and attenuate lesion development, compared to chow alone. Ldlr-/- mice were fed a HFHC diet for 12 weeks to induce metabolic dysregulation. Subsequently, mice received one of 3 diets for another 12 weeks: 1) continuation of the HFHC diet, 2) an isoflavone-free chow diet or 3) isoflavone-free chow with 3% naringenin. At 12 weeks, the HFHC diet induced significant weight gain and increased adiposity. Intervention with chow alone reduced the weight gained during induction by 22%, whereas the addition of naringenin to chow induced a weight loss of 71%. Specifically, the reduction in adiposity was 2.75-times greater in naringenin-treated mice, compared to chow alone. The HFHC diet increased VLDL cholesterol 20-fold and LDL cholesterol 5-fold, which were reduced by intervention with both chow (>60%) and chow supplemented with naringenin (>80%). The HFHC diet induced insulin resistance and glucose intolerance. Naringenin improved insulin tolerance (plasma glucose AUC -38%) and glucose tolerance (plasma glucose AUC -58%), which was accompanied by normalization of plasma insulin and glucose. HFHC-induction promoted the development of intermediate atherosclerotic lesions. Continuation of the HFHC diet doubled lesion size. Intervention with chow alone attenuated lesion size progression by 65%. The addition of naringenin to chow slowed lesion progression by 90%, resulting in smaller lesions compared to chow intervention alone (P=0.042). We conclude that intervention with naringenin-supplemented chow enhances weight loss, improves metabolic dysregulation and halts the progression of atherosclerosis.

scholarly journals CD44 contributes to hyaluronan-mediated insulin resistance in skeletal muscle of high-fat-fed C57BL/6 mice

2019 ◽  
Vol 317 (6) ◽  
pp. E973-E983 ◽  
Author(s):  
Annie Hasib ◽  
Chandani K. Hennayake ◽  
Deanna P. Bracy ◽  
Aimée R. Bugler-Lamb ◽  
Louise Lantier ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
High Fat Diet ◽  
Critical Role ◽  
Chow Diet ◽  
Wild Type ◽  
High Fat ◽  
Insulin Resistant ◽  
Beneficial Effects

Extracellular matrix hyaluronan is increased in skeletal muscle of high-fat-fed insulin-resistant mice, and reduction of hyaluronan by PEGPH20 hyaluronidase ameliorates diet-induced insulin resistance (IR). CD44, the main hyaluronan receptor, is positively correlated with type 2 diabetes. This study determines the role of CD44 in skeletal muscle IR. Global CD44-deficient ( cd44−/−) mice and wild-type littermates ( cd44+/+) were fed a chow diet or 60% high-fat diet for 16 wk. High-fat-fed cd44−/− mice were also treated with PEGPH20 to evaluate its CD44-dependent action. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp (ICv). High-fat feeding increased muscle CD44 protein expression. In the absence of differences in body weight and composition, despite lower clamp insulin during ICv, the cd44−/− mice had sustained glucose infusion rate (GIR) regardless of diet. High-fat diet-induced muscle IR as evidenced by decreased muscle glucose uptake (Rg) was exhibited in cd44+/+ mice but absent in cd44−/− mice. Moreover, gastrocnemius Rg remained unchanged between genotypes on chow diet but was increased in high-fat-fed cd44−/− compared with cd44+/+ when normalized to clamp insulin concentrations. Ameliorated muscle IR in high-fat-fed cd44−/− mice was associated with increased vascularization. In contrast to previously observed increases in wild-type mice, PEGPH20 treatment in high-fat-fed cd44−/− mice did not change GIR or muscle Rg during ICv, suggesting a CD44-dependent action. In conclusion, genetic CD44 deletion improves muscle IR, and the beneficial effects of PEGPH20 are CD44-dependent. These results suggest a critical role of CD44 in promoting hyaluronan-mediated muscle IR, therefore representing a potential therapeutic target for diabetes.

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.

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