Metabolic and oxidative stress markers in Wistar rats after 2 months on a high-fat diet

Oat protein modulates cholesterol metabolism and improves cardiac systolic function in high fat, high sucrose fed rats

Oats are recognized to provide many health benefits that are mainly associated with its dietary fibre, β-glucan. However, the protein derived from oats is largely understudied with respect to its ability to maintain health and attenuate risk factors of chronic diseases. The goal of the current study was to investigate the metabolic effects of oat protein consumption in lieu of casein as the protein source in high fat, high sucrose (HF/HS) fed Wistar rats. Four-week-old rats were divided into three groups and were fed three different experimental diets: a control diet with casein as the protein source, an HF/HS diet with casein, or an HF/HS diet with oat protein for 16 weeks. Heart structure and function were determined by echocardiography. Blood pressure measurements, an oral glucose tolerance test, and markers of cholesterol metabolism, oxidative stress, inflammation, and liver and kidney damage were also performed. Our study results show that incorporation of oat protein in the diet was effective in preserving systolic heart function in HF/HS fed rats. Oat protein significantly reduced serum total and low-density lipoprotein cholesterol levels. Furthermore, oat protein normalized liver HMG-CoAR activity, which, to our knowledge, is the first time this has been reported in the literature. Therefore, our research suggests that oat protein can provide hypocholesterolemic and cardioprotective benefits in a diet-induced model of metabolic syndrome.

A role and mechanism for redox sensing by SENP1 in β-cell responses to high fat feeding

Pancreatic β-cells respond to metabolic stress by upregulating insulin secretion, however the underlying mechanisms remain unclear. Here we show, in β-cells from overweight humans without diabetes and mice fed a high-fat diet for 2 days, insulin exocytosis and secretion are enhanced without increased Ca2+ influx. RNA-seq of sorted β-cells suggests altered metabolic pathways early following high fat diet, where we find increased basal oxygen consumption and proton leak, but a more reduced cytosolic redox state. Increased β-cell exocytosis after 2-day high fat diet is dependent on this reduced intracellular redox state and requires the sentrin-specific SUMO-protease-1. Mice with either pancreas- or β-cell-specific deletion of this fail to up-regulate exocytosis and become rapidly glucose intolerant after 2-day high fat diet. Mechanistically, redox-sensing by the SUMO-protease requires a thiol group at C535 which together with Zn+-binding suppresses basal protease activity and unrestrained β-cell exocytosis, and increases enzyme sensitivity to regulation by redox signals.

"Golden" Tomato Consumption Ameliorates Metabolic Syndrome: A Focus on the Redox Balance in the High-Fat-Diet-Fed Rat

Tomato fruits defined as "golden" refer to a food product harvested at an incomplete ripening stage with respect to red tomatoes at full maturation. The aim of this study is to explore the putative influence of "golden tomato" (GT) on Metabolic Syndrome (MetS), especially focusing on the effects on redox homeostasis. Firstly, the differential chemical properties of the GT food matrix were characterized in terms of phytonutrient composition and antioxidant capacities with respect to red tomato (RT). Later, we assessed the biochemical, nutraceutical and eventually disease-modifying potential of GT in vivo in the high-fat-diet rat model of MetS. Our data revealed that GT oral supplementation is able to counterbalance MetS-induced biometric and metabolic modifications. Noteworthy is that this nutritional supplementation proved to reduce plasma oxidant status and improve the endogenous antioxidant barriers, assessed by strong systemic biomarkers. Furthermore, consistently with the reduction of hepatic reactive oxygen and nitrogen species (RONS) levels, treatment with GT markedly reduced the HFD-induced increase in hepatic lipid peroxidation and hepatic steatosis. This research elucidates the importance of food supplementation with GT in the prevention and management of MetS.

NMN Alleviates NP-Induced Learning and Memory Impairment Through SIRT1 Pathway in PC-12 Cell

Nonylphenol (NP) is widely used in the chemical industry; it accumulates in organisms through environmental contamination and causes learning memory impairment. Nicotinamide mononucleotide (NMN) has been found to have a positive effect on the treatment of central nervous-related diseases. This study aimed to investigate the protective effect of NMN on NP-induced learning memory-related impairment in vitro and to further identify the underlying mechanisms. The results showed that NP induced oxidative stress and impaired the cholinergic system, 5-HT system in PC-12 cells. NMN alleviated NP-induced learning and memory impairment at the molecular level through alleviating oxidative stress and protective effects on the 5-HT system and cholinergic system. The 50 μM NP group significantly reduced the NAD⁺ content, and the relative expression of SIRT1, PGC-1α, Nrf2, MAOA, BDNF, and p-TrkB were significantly downregulated. Co-treatment of NMN with NP significantly reduced oxidative stress, improved the homeostasis of 5-HT and cholinergic system, enhanced the intracellular NAD⁺ content, and significantly upregulated the expression of SIRT1 pathway proteins. SIRT1 inhibitors reduced the expression of SIRT1 pathway-related proteins, which implied the impairment of learning and memory by NP and the protective effect of NMN might be achieved through the SIRT1-mediated PGC-1α/MAOA/BDNF signaling pathway. Overall, this study not only help us to understand the toxic mechanism of NP on learning memory impairment in vitro, but also have important reference significance to further explore the health care value of NMN and promote the development of related functional foods.

A Review of Medicinal Plants with Renoprotective Activity in Diabetic Nephropathy Animal Models

Diabetic nephropathy (DN), also recognized as diabetic kidney disease, is a kidney malfunction caused by diabetes mellitus. A possible contributing factor to the onset of DN is hyperglycemia. Poorly regulated hyperglycemia can damage blood vessel clusters in the kidneys, leading to kidney damage. Its treatment is difficult and expensive because its causes are extremely complex and poorly understood. Extracts from medicinal plants can be an alternative treatment for DN. The bioactive content in medicinal plants inhibits the progression of DN. This work explores the renoprotective activity and possible mechanisms of various medicinal plant extracts administered to diabetic animal models. Research articles published from 2011 to 2022 were gathered from several databases including PubMed, Scopus, ProQuest, and ScienceDirect to ensure up-to-date findings. Results showed that medicinal plant extracts ameliorated the progression of DN via the reduction in oxidative stress and suppression of inflammation, advanced glycation end-product formation, cell apoptosis, and tissue injury-related protein expression.

Correlation of Metabolic Syndrome with Redox Homeostasis Biomarkers: Evidence from High-Fat Diet Model in Wistar Rats

Metabolic Syndrome (MetS) is an extremely complex disease. A non-balanced diet such as high-fat diet (HFD) induces metabolic dysfunction that could modify redox homeostasis. We here aimed at exploring redox homeostasis in male Wistar rats, following 8 weeks of HFD, correlating the eventual modification of selected biomarkers that could be associated with the clinical manifestations of MetS. Therefore, we selected parameters relative to both the glucose tolerance and lipid altered metabolism, but also oxidative pattern. We assessed some biomarkers of oxidative stress i.e., thiols balance, lipid peroxidation and antioxidant barriers, via the use of specific biochemical assays, individuating eventual cross correlation with parameters relative to MetS through a Principal Component Analysis (PCA). The present study shows that 8 weeks of HFD induce MetS in rats, altering glucose and lipid homeostasis and increasing visceral adipose tissue, but also impairing the physiological antioxidant responses that could not counteract the oxidative stress condition. Crucially, cross-correlation analysis suggested that the assessment of specific oxidative stress parameters reported here can provide information comparable to the more widely acquired biomarkers of Mets such as glucose tolerance. Lastly, hepatic steatosis in association with the oxidative stress condition was also highlighted by histological analysis. This research will elucidate the fundamental impact of these oxidative stress parameters on MetS induced in the HFD rat model, tracing paths for developing prevention approaches.

Pancreas fat content, insulin homeostasis and circulating endothelial microparticles in male essential hypertensive patients

The pancreas fat content has been poorly investigated in essential hypertension. The authors aim to relate pancreas and liver fat content with parameters measuring insulin resistance, beta-cell function and also with markers of endothelial dysfunction and platelet or endothelial cell destruction. The authors studied a group of 40 male hypertensive patients with well-controlled blood pressure, maintaining a stable weight, and having not changed their medication during the last year. Pancreas fat content was correlated with HOMA-IR (r = .616, p < .001), HOMA-S (r = -.439, p < .005), beta cell function parameter (r = .457, p < .005), and QUICKI (r = .412, p < .01), whereas liver fat was not patients in the highest quartile of pancreas fat content had more circulating endothelial microparticles than patients in the other quartiles (median 129 [94.3-200] vs. 60.9 [49.4-88.8], p = .002). However, patients in the highest quartile of the pancreas fat content distribution did not differ from the lowest in hyperemic response after ischemia nor circulating platelet microparticles count. Liver fat content was not related to any of the parameters studied. In a multivariate stepwise binary logistic regression analysis (Wald Method) circulating endothelial microparticles remain significantly associated with pancreas fat content after adjusting for confounding factors, such as tobacco, diabetes mellitus, hypercholesterolemia, or metabolic syndrome. Our results reflect that in essential hypertension, pancreas fat content is superior to liver fat to study beta-cell functionality and insulin resistance. Moreover, the authors described for the first time that pancreas fat content is related to endothelial cell destruction. Further studies are needed to confirm this point.

Duodenojejunal Omega Switch Surgery Reduces Oxidative Stress Induced by Cafeteria Diet in Sprague-Dawley Rats

Over-nutrition with cafeteria diet leads to glycemic control failure and subsequent obesity. Bariatric surgery remains the ultimate treatment option, and when complemented with specific dietary protocol, it may mitigate the effects of oxidative stress induced by a cafeteria diet. The study measured antioxidant marker activity: superoxidase dismutase (SOD) and ceruloplasmin (CER), total antioxidant capacity (TAC), and lipid peroxidation marker concentrations: lipofuscin (LS) and malondialdehyde (MDA), in the plasma of 56 Sprague-Dawley rats fed with a cafeteria (HFS) or a control (CD) diet and subjected to duodenojejunal omega switch (DJOS) or control (SHAM) surgery. The diet change after the surgery (CD/HFS or HFS/CD) strongly influenced SOD activity in DJOS- and SHAM-operated rats, but SOD activity was always higher in SHAM-operated rats. Every dietary protocol used in the study increased CER activity, except for the CD/CD combination. Cafeteria diet consumed before or after either of surgeries led to decrease in TAC levels. DJOS and no change in diet reduced MDA levels. DJOS reduced LS levels, but its beneficial effect was deteriorated by selected dietary protocols. The cafeteria diet negatively affected the positive impact of DJOS surgery, but SOD, CER, MDA, and LS were significantly lower in rats that underwent DJOS, suggesting that eight weeks of dietary treatment before and after the surgery did not totally dilapidate the effects of the bariatric treatment.

Resistance to Obesity in SOD1 Deficient Mice with a High-Fat/High-Sucrose Diet

Metabolic syndrome (Mets) is an important condition because it may cause stroke and heart disease in the future. Reactive oxygen species (ROSs) influence the pathogenesis of Mets; however, the types of ROSs and their localization remain largely unknown. In this study, we investigated the effects of SOD1, which localize to the cytoplasm and mitochondrial intermembrane space and metabolize superoxide anion, on Mets using SOD1 deficient mice (SOD1^−/−). SOD1^−/− fed on a high-fat/high-sucrose diet (HFHSD) for 24 weeks showed reduced body weight gain and adipose tissue size compared to wild-type mice (WT). Insulin secretion was dramatically decreased in SOD1^−/− fed on HFHSD even though blood glucose levels were similar to WT. Ambulatory oxygen consumption was accelerated in SOD1^−/− with HFHSD; however, ATP levels of skeletal muscle were somewhat reduced compared to WT. Reflecting the reduced ATP, the expression of phosphorylated AMPK (Thr 172) was more robust in SOD1^−/−. SOD1 is involved in the ATP production mechanism in mitochondria and may contribute to visceral fat accumulation by causing insulin secretion and insulin resistance.

Salvia hispanica L. (chia) seed ameliorates liver injury and oxidative stress by modulating NrF2 and NFκB expression in sucrose-rich diet-fed rats

The aim of this study was to analyze the liver injury and oxidative stress in an experimental model of Metabolic Syndrome (MS) induced by chronic administration of a sucrose-rich diet (SRD) and to evaluate the effects of chia seed as a therapeutic strategy. Male Wistar rats were fed with a reference diet (RD) -6 months- or a SRD -3 months. Then, the latter group was randomly divided into two subgroups. One subgroup continued receiving the SRD for up to 6 months and the other was fed with a SRD where whole chia seed was incorporated as a source of dietary fat for the next 3 months (SRD+CHIA). The results showed that rats fed with a SRD for a long period of time developed dyslipidemia, hyperglycemia, hepatic lipid accumulation, liver injury, hepatic lipid peroxidation and oxidative stress. Hepatic NrF2 expression was significantly decreased. In addition, a significant increase in hepatic NFκB p65 expression and a positive correlation of this with plasma TNFα levels were found. The administration of chia seed for 3 months reversed dyslipidemia, hyperglycemia, lipid accumulation, liver injury, lipid peroxidation and oxidative stress. In the liver tissue, NrF2 expression was normalized and NFκB p65 expression was decreased, the latter was associated with a decrease in plasma TNFα levels. The present study showed new aspects of liver damage, lipid peroxidation and oxidative stress in dyslipidemic insulin resistant rats chronically fed with a sucrose-rich diet. However, we demonstrated new properties and molecular mechanisms associated with the beneficial anti-oxidant effects of chia seed consumption.

Acetate-mediated-obestatin modulation attenuates adipose-hepatic dysmetabolism in high fat diet-induced obese rat model

PURPOSE

Approximately 650 million of world adult population is affected by obesity, which is characterized by adipose and hepatic metabolic dysfunction. Short chain fatty acids (SCFAs) have been linked to improved metabolic profile. However, the effect of SCFAs, particularly acetate on adipose-hepatic dysfunction is unclear. Therefore, the present study investigated the role of acetate on adipose-hepatic metabolic dysfunction and the possible involvement of obestatin in high fat diet-induced obese Wistar rats.

METHODS

Adult male Wistar rats (160-190 g) were allotted into groups (n = 6/group): Control, acetate-treated, obese and obese + acetate-treated groups received vehicle (distilled water), sodium acetate (200 mg/kg), 40% HFD and 40% HFD plus sodium acetate respectively. The administration lasted for 12 weeks.

RESULTS

HFD caused increased body weight gain and visceral adiposity, insulin resistance, hyperinsulinemia and increased pancreatic-β cell function and plasma/hepatic triglyceride and total cholesterol as well as decreased adipose triglyceride and total cholesterol, increased plasma, adipose, and hepatic malondialdehyde, TNF-α, uric acid, lactate production and plasma/adipose but not gamma-glutamyl transferase and decreased plasma, adipose, and hepatic nitric oxide, glucose-6-phosphate dehydrogenase (G6PD), glutathione (GSH) and obestatin concentration compared to the control group. Notwithstanding, treatment with acetate attenuated the alterations.

CONCLUSIONS

The results demonstrate that high fat diet-induced obesity is characterized with adipose and hepatic lipid dysmetabolism, which is associated with obestatin suppression. Findings also suggest that acetate provide protection against adipose and hepatic metabolic perturbations by restoring obestatin as well as G6PD/GSH-dependent antioxidant system.

Alterations of Liver Functions and Morphology in a Rat Model of Prediabetes After a Short-term Treatment of a High-fat High-glucose and Low-dose Streptozotocin

BACKGROUND: The administration of high-fat and high-glucose in diet followed by a low-dose streptozotocin injection in rats could mimic hyperglycemia, prediabetic, or diabetic conditions in humans. However, whether the rat model may lead to early liver impairment was still unclear. AIM: This study was aimed to investigate the possible changes in liver functions and morphology in the rat model of prediabetes after a short-term administration of a high-fat and high-glucose diet followed by low-dose streptozotocin injection. METHODS: Eighteen male Wistar rats were divided into nine rats in the control group and nine in the prediabetic group. To induce prediabetic rats, high-fat high-glucose in daily diets for 3 weeks continued with once to twice low-dose streptozotocin was given. Rats in control groups were fed with a standard diet for 2 months. Afterward, we analyzed glucose control parameters, liver functions, and liver histology of the rats. RESULTS: High-fat, high-glucose diet combined with a low dose of streptozotocin successfully caused prediabetics in the rats. There was a significant increase in several liver enzymes, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT). However, no significant changes were found in the serum lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) levels. The histological changes in the liver confirmed the increase in liver enzymes. CONCLUSION: Short-term administration of high-fat high-glucose in combination with low-dose streptozotocin triggers alterations in liver functions marker and liver morphology.

B Vitamins Supplementation Can Improve Cognitive Functions and May Relate to the Enhancement of Transketolase Activity in A Rat Model of Cognitive Impairment Associated with High-fat Diets

OBJECTIVE

To determine whether B vitamin treatment was sufficient to reduce cognitive impairment associated with high-fat diets in rats and to modulate transketolase (TK) expression and activity.

METHODS

To test this, we separated 50 rats into five groups that were either fed a standard chow diet (controls) or a high-fat diet (experimental groups H0, H1, H2, and H3). H0 group animals received no additional dietary supplementation, while H1 group animals were administered 100 mg/kg body weight (BW) thiamine, 100 mg/kg BW riboflavin, and 250 mg/kg BW niacin each day, and group H2 animals received daily doses of 100 mg/kg BW pyridoxine, 100 mg/kg BW cobalamin, and 5 mg/kg BW folate. Animals in the H3 group received the B vitamin regimens administered to both H1 and H2 each day.

RESULTS

Over time, group H0 exhibited greater increases in BW and fat mass relative to other groups. When spatial and memory capabilities in these animals were evaluated via conditioned taste aversion (CTA) and Morris Water Maze (MWM), we found B vitamin treatment was associated with significant improvements relative to untreated H0 controls. Similarly, B vitamin supplementation was associated with elevated TK expression in erythrocytes and hypothalamus of treated animals relative to those in H0 (P<0.05).

CONCLUSION

Together, these findings suggest B vitamin can modulate hypothalamic TK activity to reduce the severity of cognitive deficits in a rat model of obesity. As such, B vitamin supplementation may be a beneficial method for reducing cognitive dysfunction in clinical settings associated with high-fat diets.

Black raspberry (Rubus occidentalis) attenuates inflammatory markers and vascular endothelial dysfunction in Wistar rats fed a high-fat diet with fructose solution

A continuous high-fat/high-fructose diet induces inflammation and lowers vascular endothelial function in the body. This research examined the effects of black raspberry (BR) powder consumption on the inflammatory response and endothelial dysfunction in rats fed with a high-fat diet and fructose solution. Wistar rats were randomly divided into two groups as control (AIN-93G diet + distilled water) and HFF (high-fat diet + 20% fructose solution) groups, for 16 weeks. At 8 weeks, the HFF was further divided into three subgroups: HFF, HFFBR2.5 (2.5% BR in high-fat diet), and HFFBR5 (5% BR in high-fat diet). The BR-fed groups showed significantly higher high-density lipoprotein-cholesterol and lower triglycerides than the HFF group. Rats supplemented with BR showed decreased mRNA and protein expressions of inflammatory cytokines and adhesion molecules in the liver and aorta tissues. Furthermore, the aortic protein expression of endothelial nitroxide synthase was significantly greater in the HFFBR2.5 and HFFBR5 than HFF. PRACTICAL APPLICATIONS: Black raspberry (BR: Rubus occidentalis) is abundant in flavonoids and anthocyanins. BR displays various biological activities and has been used to alleviate inflammatory conditions. In our study, BR supplementation showed promising effects against high-fat/high-fructose diet-induced inflammation and endothelial dysfunction in rats by decreasing markers of inflammation and improving vascular endothelial function. These findings suggest that BR consumption could have beneficial effects on the risk factors of cardiovascular disease.

Effects of Micronutrient Supplementation on Glucose and Hepatic Lipid Metabolism in a Rat Model of Diet Induced Obesity

Obesity increases the risk of metabolic disorders, partly through increased oxidative stress. Here, we examined the effects of a dietary micronutrient supplement (consisting of folate, vitamin B6, choline, betaine, and zinc) with antioxidant and methyl donor activities. Male Sprague Dawley rats (3 weeks old, 17/group) were weaned onto control (C) or high-fat diet (HFD) or same diets with added micronutrient supplement (CS; HS). At 14.5 weeks of age, body composition was measured by magnetic resonance imaging. At 21 weeks of age, respiratory quotient and energy expenditure was measured using Comprehensive Lab Animal Monitoring System. At 22 weeks of age, an oral glucose tolerance test (OGTT) was performed, and using fasting glucose and insulin values, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was calculated as a surrogate measure of insulin resistance. At 30.5 weeks of age, blood and liver tissues were harvested. Liver antioxidant capacity, lipids and expression of genes involved in lipid metabolism (Cd36, Fabp1, Acaca, Fasn, Cpt1a, Srebf1) were measured. HFD increased adiposity (p < 0.001) and body weight (p < 0.001), both of which did not occur in the HS group. The animals fed HFD developed impaired fasting glucose, impaired glucose tolerance, and fasting hyperinsulinemia compared to control fed animals. Interestingly, HS animals demonstrated an improvement in fasting glucose and fasting insulin. Based on insulin release during OGTT and HOMA-IR, the supplement appeared to reduce the insulin resistance developed by HFD feeding. Supplementation increased hepatic glutathione content (p < 0.05) and reduced hepatic triglyceride accumulation (p < 0.001) regardless of diet; this was accompanied by altered gene expression (particularly of CPT-1). Our findings show that dietary micronutrient supplementation can reduce weight gain and adiposity, improve glucose metabolism, and improve hepatic antioxidant capacity and lipid metabolism in response to HFD intake.

Scolymus hispanicus (Golden Thistle) Ameliorates Hepatic Steatosis and Metabolic Syndrome by Reducing Lipid Accumulation, Oxidative Stress, and Inflammation in Rats under Hyperfatty Diet

Background

Lipotoxicity is characterized by a metabolic disturbance leading to the development of nonalcoholic fatty liver disease (NAFLD). Some medicinal plant extracts exert hepatoprotective activity by modulating oxidative stress, inflammation, and metabolic disorders. Scolymus hispanicus or the golden thistle can be considered an important natural source of antioxidants. In traditional medicine, the consumption of this plant is recommended for diseases of the liver and intestines.

Objective

In this study, we aimed to determine the effects of Scolymus hispanicus on a hyperfatty diet- (HFD-) induced metabolic disorders, oxidative stress, and inflammation.

Materials and Methods

Our experiment focused on the administration of an HFD (40%) in Rattus norvegicus for 2 months and treatment with the aqueous extract of Scolymus hispanicus at a rate of 100 mg/kg during the last eight days of experimentation. In this context, several aspects were studied: the evaluation of blood biochemical parameters, liver function such as lipids and glycogen, markers of oxidative stress (TBARS, carbonyl proteins, advanced oxidation proteins, catalase, and SOD) and inflammation (NO and NFkB), morphological study of hepatocytes in primary culture, and histological study of the liver.

Results

Lipotoxicity induced metabolic disorders, both serum and tissue. HFD induced an increase in the total lipids and a decrease in glycogen reserve and an alteration in the oxidant-antioxidant balance. HFD induced an increase in markers of liver damage, which resulted in NAFLD, confirmed by histological study and hepatocytes cell culture. Scolymus appears to have lipid-lowering, hypoglycemic, anti-inflammatory and antioxidant properties. It improved glucose tolerance and the condition of fatty liver disease.

Conclusion

Golden thistle improves glucose tolerance and hyperlipidemia and ameliorates hepatic steatosis by reducing oxidative stress, inflammation, and lipid accumulation. Its incorporation into a dietary program or as an aliment supplement would prevent hepatic complications associated with an HFD.

Therapeutic doses of acetaminophen with co-administration of cysteine and mannitol during early development result in long term behavioral changes in laboratory rats

Based on several lines of evidence, numerous investigators have suggested that acetaminophen exposure during early development can induce neurological disorders. We had previously postulated that acetaminophen exposure early in life, if combined with antioxidants that prevent accumulation of NAPQI, the toxic metabolite of acetaminophen, might be innocuous. In this study, we administered acetaminophen at or below the currently recommended therapeutic dose to male laboratory rat pups aged 4-10 days. The antioxidants cysteine and mannitol were included to prevent accumulation of NAPQI. In addition, animals were exposed to a cassette of common stress factors: an inflammatory diet, psychological stress, antibiotics, and mock infections using killed bacteria. At age 37-49 days, observation during introduction to a novel conspecific revealed increased rearing behavior, an asocial activity, in animals treated with acetaminophen plus antioxidants, regardless of their exposure to oxidative stress factors (2-way ANOVA; P < 0.0001). This observation would suggest that the initial hypothesis is incorrect, and that oxidative stress mediators do not entirely eliminate the effects of acetaminophen on neurodevelopment. This study provides additional cause for caution when considering the use of acetaminophen in the pediatric population, and provides evidence that the effects of acetaminophen on neurodevelopment need to be considered both in the presence and in the absence of oxidative stress.

Hypolipidemic effects of Hypericum Scabrum extract on the serum lipid profile and obesity in high-fat diet fed rats

Diets included high-fat (HFD) and high calories intake is correlated with greater risk of obesity and oxidative stress, which lead to increase the risk of related diseases such as cardiovascular and metabolic disease. In the present study, we have examined the hypolipidemic activity of Hypericum Scabrum extract on HFD fed rats. Fifty-four male Wistar rats divided into six groups: 1) control, 2) H. Scabrum extract (100 mg/kg gavage per day), 3) H. Scabrum extract (300 mg/kg), 4) HFD, 5) HFD and H. Scabrum extract (100 mg/kg), 6) HFD and H. Scabrum extract (300 mg/kg). The groups were fed their diet and treatment for 3 months. Biochemical analysis showed elevated lipid serum profile in HFD rats compared to control group. H. Scabrum extract supplementation significantly ameliorated triglyceride, total cholesterol and LDL-cholesterol. H. Scabrum extract supplementation leading to increase HDL-cholesterol in HFD treated groups. This experiment showed that H. Scabrum extract decreased HFD complications and might be beneficial herbal drug for treatment of hyperlipidemia and obesity.

Comprehensive lipidomic profiling in serum and multiple tissues from a mouse model of diabetes

INTRODUCTION

Diabetes mellitus is a serious metabolic disorder causing multiple organ damage in human. However, the lipidomic profiles in different organs and their associations are rarely studied in either diabetic patients or animals.

OBJECTIVES

To evaluate and compare the characteristics of lipid species in serum and multiple tissues in a diabetic mouse model.

METHODS

Semi-quantitative profiling analyses of intact and oxidized lipids were performed in serum and multiple tissues from a diabetic mouse model fed a high fat diet and treated with streptozotocin by using LC/HRMS and MS/MS. The total content of each lipid class, and the tissue-specific lipid species in all tissue samples were determined and compared by multivariate analyses.

RESULTS

The diabetic mouse model displayed characteristic differences in serum and multiple organs: the brain and heart showed the largest reduction in cardiolipin, while the kidney had more alterations in triacylglycerol. Interestingly, the lipidomic differences also existed between different regions of the same organ: cardiolipin species with highly polyunsaturated fatty acyls decreased only in atrium but not in ventricle, while renal cortex showed longer fatty acyl chains for both increased and decreased triacylglycerol species than renal medulla. Importantly, diabetes caused an accumulation of lipid hydroperoxides, suggesting that oxidative stress was induced in all organs except for the brain during the development of diabetes.

CONCLUSIONS

These findings provided novel insight into the organ-specific relationship between diabetes and lipid metabolism, which might be useful for evaluating not only diabetic tissue injury but also the effectiveness of diabetic treatments.

The effect of high-fat diet and 13-cis retinoic acid application on lipid profile, glycemic response and oxidative stress in female Lewis rats

Vitamin A and its metabolites are key regulators of the development of adipose tissue and associated metabolic complications. The aim of this study was to determine the effect of high fat diet and 13-cis retinoic acid (13 cRA) application on metabolic parameters, adipogenic and inflammatory indicators in female Lewis rats. Female rats of Lewis strain were fed standard laboratory diet (STD) and high fat diet (HFD, 45% of saturated fatty acids) during 30 days. The groups were divided into additional 3 groups (6 rats each): two experimental groups that received 13 cRA orally on a daily basis during 30 days (7.5 mg/kg and 15 mg/kg, respectively) and the control group that was given sunflower oil. Animals were sacrificed after 60 days. Feeding of Lewis rats with chronic HFD diet with 13 cRA supplementation increased weight gain, adiposity index, dyslipidaemia, hyperleptinaemia, insulin resistance, VLDL concentrations, oxidative stress and atherogenic indices. Administration of 13 cRA in Lewis rats fed STD did not change the weight of the animals, but it slightly increased the atherogenic parameters. 13 cRA and HFD affect metabolic parameters, glucose and lipid metabolism in Lewis rats and its administration has a completely different effect on metabolism in rats fed STD, highlighting the complex role of vitamin A supplementation in obesity. Other factors, such as genetics, age, sex, adipose tissue distribution, also must be taken into consideration.

Anorexic and metabolic effect of jojoba: potential treatment against metabolic syndrome and hepatic complications

Background

Evaluation of the action of various traditional plants to treat metabolic syndrome are strongly studied. In our study, we investigated the effect of the Tunisian jojoba seed on a metabolic syndrome induced in rat by the High Fat diet and High Fructose (HFHF) and its renal and hepatic complications.

Methods

The rats were fed with HFHF or Normal Diet (ND) for a period of 8 weeks. After that, a switch from HFHF to ND or Normal Diet Jojoba (NDJ),(jojoba diet approach) or High Fat and High Fructose and Jojoba diet (HFHFJ) (nutraceutical approach) has been done. Metabolic disorder was evaluated by measuring the fasting body weight, glycemia and C-peptide and leptin. Oxidative stress parameters like ThioBarbituric Acid Reactive Substances (TBARS) and Total Antioxidant Capacity (TAOC) were analyzed in the plasma and renal and hepatic function were determined by the measure of creatinine and alanine transferase (ALT) respectively. Histological analysis was performed on the liver, kidney and pancreas.

Results

HFHF diet exhibited characteristics of metabolic syndrome presented by insulin resistance, hyperinsulinemia, hyperleptinemia, fat mass with hepatic steatosis and renal disorder. HFHF diet was associated with oxidative stress (OS) presented by an increase in TBARS and a decrease in TAOC. Adding jojoba seeds to HFHF rat group diet induced a decrease in body weight, fat mass (58 and 41%), insulin resistance (59 and 56%), oxidative stress (60 and 41%), liver steatosis (from a score = 3 to a score = 0) and renal complications (25 and 42%). This effect was emphasized with diet approach.

Conclusion

The results demonstrated the beneficial effect of jojoba against metabolic syndrome and oxidative stress, suggesting that jojoba could be used in the prevention and treatment of metabolic syndrome.

Graphical abstract

The Oxidative Stress Markers in the Erythrocytes and Heart Muscle of Obese Rats: Relate to a High-Fat Diet but Not to DJOS Bariatric Surgery

Obesity and high-fat diet (HF) are prevalent causes of oxidative stress (OS). Duodenal-jejunal omega switch (DJOS) is a bariatric procedure used for body mass reduction, extensively tested in animal models. We studied the long-term impact of bariatric surgery and an HF diet on the oxidative stress markers in erythrocytes and heart muscles of rats. We analyzed superoxide dismutase (SOD), catalase (CAT), glutathione transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx) activity and malondialdehyde (MDA) concentration in DJOS or SHAM (control) operated rats fed with different dietary protocols (control diet (CD) and high-fat diet (HF)), before and after the surgery (CD/CD, HF/HF, CD/HF, and HF/CD). We observed higher erythrocytes CAT, GST and GPx activity in DJOS-operated (vs. SHAM) rats fed with an HF/HF diet. For DJOS-operated rats, erythrocytes CAT and GPx activity and MDA concentration were significantly lower in CD/CD group. We observed increased heart muscle GR activity in SHAM-operated rats (vs. DJOS bariatric surgery) fed with an HF/HF diet. Change from HF to CD diet increased heart muscle GPx activity after DJOS bariatric surgery. Heart muscle SOD activity was lower in HF/HF and CD/CD groups after DJOS bariatric surgery (vs. SHAM). DJOS surgery significantly reduced heart muscle MDA concentration in HF/HF and HF/CD groups (vs. SHAM). We conclude that the selected dietary patterns had a stronger impact on oxidative stress markers in erythrocytes and heart muscle than DJOS bariatric surgery.

A novel organic mineral complex prevented high fat diet-induced hyperglycemia, endotoxemia, liver injury and endothelial dysfunction in young male Sprague-Dawley rats

The prevalence of metabolic syndrome (MetSyn) has risen 35% since 2012 and over two-thirds of Americans exhibit features characterizing this condition (obesity, dyslipidemia, hyperglycemia, insulin resistance and/or endothelial dysfunction). The aim of this study was to evaluate the effects of a novel dietary supplemental organic mineral complex (OMC) on these risk factors in a rodent model of MetSyn. Six-week old male Sprague-Dawley rats were fed either standard chow or a high-fat diet (HFD) composed of 60% kcal from fat for 10 weeks. Rats were also treated with OMC in their drinking water at either 0 mg/mL (control), 0.6 mg/mL, or 3.0 mg/mL. The HFD-treated rats exhibited significantly increased body mass (p<0.05), epididymal fat pad mass (p<0.001), waist circumference (p = 0.010), in addition to elevations in plasma endotoxins (p<0.001), ALT activity (p<0.001), fasting serum glucose (p = 0.025) and insulin concentrations (p = 0.009). OMC did not affect body weight or adiposity induced by the HFD. At the higher dose OMC significantly blunted HFD-induced hyperglycemia (p = 0.021), whereas both low and high doses of OMC prevented HFD-induced endotoxemia (p = 0.002 and <0.001, respectively) and hepatocyte injury (ALT activity, p<0.01). Despite evidence of oxidative stress (elevated urinary H₂O₂p = 0.032) in HFD-fed rats, OMC exhibited no demonstrable antioxidative effect. Consistent with prior studies, mesenteric arteries from HFD rats had more uncoupled eNOS (p = 0.006) and iNOS protein expression (p = 0.027) in addition to impaired endothelium-dependent vasodilation that was abrogated by the high dose of OMC (p<0.05). This effect of OMC may be attributed to the high nitrate content of the supplement. These findings suggest that the OMC supplement, particularly at the higher dose, ameliorated several risk factors associated with MetSyn via a non-antioxidant-dependent mechanism.

A Short-Term High-Fat Diet Alters Glutathione Levels and IL-6 Gene Expression in Oxidative Skeletal Muscles of Young Rats

Obesity and ensuing disorders are increasingly prevalent worldwide. High-fat diets (HFD) and diet-induced obesity have been shown to induce oxidative stress and inflammation while altering metabolic homeostasis in many organs, including the skeletal muscle. We previously observed that 14 days of HFD impairs contractile functions of the soleus (SOL) oxidative skeletal muscle. However, the mechanisms underlying these effects are not clarified. In order to determine the effects of a short-term HFD on skeletal muscle glutathione metabolism, young male Wistar rats (100–125 g) were fed HFD or a regular chow diet (RCD) for 14 days. Reduced (GSH) and disulfide (GSSG) glutathione levels were measured in the SOL. The expression of genes involved in the regulation of glutathione metabolism, oxidative stress, antioxidant defense and inflammation were measured by RNA-Seq. We observed a significant 25% decrease of GSH levels in the SOL muscle. Levels of GSSG and the GSH:GSSG ratio were similar in both groups. Further, we observed a 4.5 fold increase in the expression of pro-inflammatory cytokine interleukin 6 (IL-6) but not of other cytokines or markers of inflammation and oxidative stress. We hereby demonstrate that a short-term HFD significantly lowers SOL muscle GSH levels. This effect could be mediated through the increased expression of IL-6. Further, the skeletal muscle antioxidant defense could be impaired under cellular stress. We surmise that these early alterations could contribute to HFD-induced insulin resistance observed in longer protocols.

Six-Week High-Fat Diet Alters the Gut Microbiome and Promotes Cecal Inflammation, Endotoxin Production, and Simple Steatosis without Obesity in Male Rats

Energy-dense foods can alter gut microbial diversity. However, the physiological effects of diet-induced microbial changes on the development of nonalcoholic fatty liver disease (NAFLD) remain debatable. We hypothesized that high-fat intake for 6 weeks would promote intestinal dysbiosis by increasing gram-positive bacteria, inducing the intestinal production of proinflammatory cytokines and subsequent hepatic lipid infiltration in young male rats. Six-week old male Sprague-Dawley rats were divided into two groups and fed either a standard rodent chow or a 60% high-fat diet (HFD) for 6 weeks. Chromogenic endotoxin quantification assays indicate an increase in lipopolysaccharide concentration in the plasma of HFD rats (p = 0.032). Additionally, Western blot analyses of the cecum showed significantly greater protein expression of the transcription factor, nuclear factor kappa B (NF-kB), (p = 0.037) and the proinflammatory cytokine, interleukin-1β (IL-1β), (p = 0.042) in rats fed HFD. Linear discriminate analysis of effect size (LEfSe) showed greater abundance of Firmicutes and Actinobacteria in the samples collected from the cecum of HFD rats compared to chow. Consistent with the development of steatosis, the Oil-Red-O-stained area was increased in liver sections from HFD rats. Hepatic triacylglycerol concentrations (p < 0.001) and plasma alanine aminotransferase (p < 0.001) were significantly increased in HFD-fed animals compared to chow. These findings show that a short duration of high-fat consumption can have profound deleterious effects on gastrointestinal health and the inflammatory state of these young male Sprague-Dawley rats.

Fractionated whole body gamma irradiation modulates the hepatic response in type II diabetes of high fat diet model rats

HFD animals were exposed to a low rate of different fractionated whole body gamma irradiation doses (0.5, 1 and 2 Gy, three fractions per week for two consecutive months) and the expression of certain genes involved in type 2 diabetes mellitus (T2DM) in livers and brains of HFD Wistar rats was investigated. Additionally, levels of diabetes-related proteins encoded by the studied genes were analyzed. Results indicated that mRNA level of incretin glucagon like peptite-1 receptor (GLP-1R) was augmented in livers and brains exposed to 1 and 2 Gy doses. Moreover, the mitochondrial uncoupling proteins 2 and 3 (UCP2/3) expressions in animals fed on HFD compared to those fed on normal chow diet were significantly increased at all applied doses. GLP-1R and UCP3 protein levels were up regulated in livers. Total protein content increased at 0.5 and 1 Gy gamma irradiation exposure and returned to its normal level at 2 Gy dose. Results could be an indicator of type 2 diabetes delayed development during irradiation exposure and support the importance of GLP-1R as a target gene in radiotherapy against T2DM and its chronic complications. A new hypothesis of brain-liver and intestine interface is speculated by which an increase in the hepatic GLP-1R is influenced by the effect of fractionated whole body gamma irradiation.

Standardized Aronia melanocarpa Extract as Novel Supplement against Metabolic Syndrome: A Rat Model

The aim of our study was to examine the effects of different dietary strategies, high-fat (HFd) or standard diet (Sd) alone or in combination with standardized oral supplementation (0.45 mL/kg/day) of Aronia melanocarpa extract (SAE) in rats with metabolic syndrome (MetS). SAE is an official product of pharmaceutical company Pharmanova (Belgrade, Serbia); however, the procedure for extraction was done by EU-Chem company (Belgrade, Serbia). Rats were divided randomly into six groups: control with Sd, control with Sd and SAE, MetS with HFd, MetS with HFd and SAE, MetS with Sd and MetS with Sd and SAE during 4 weeks. At the end of the 4-week protocol, cardiac function and liver morphology were assessed, while in the blood samples glucose, insulin, iron levels and systemic redox state were determined. Our results demonstrated that SAE had the ability to lower blood pressure and exert benefits on in vivo and ex vivo heart function. Moreover, SAE improved glucose tolerance, attenuated pathological liver alterations and oxidative stress present in MetS. Obtained beneficial effects of SAE were more prominent in combination with changing dietary habits. Promising potential of SAE supplementation alone or in combination with different dietary protocols in triggering cardioprotection should be further examined in future.

Impact of obesity as an independent risk factor for the development of renal injury: implications from rat models of obesity

Diabetes and hypertension are the major causes of chronic kidney disease (CKD). Epidemiological studies within the last few decades have revealed that obesity-associated renal disease is an emerging epidemic and that the increasing prevalence of obesity parallels the increased rate of CKD. This has led to the inclusion of obesity as an independent risk factor for CKD. A major complication when studying the relationship between obesity and renal injury is that cardiovascular and metabolic disorders that may result from obesity including hyperglycemia, hypertension, and dyslipidemia, or the cluster of these disorders [defined as the metabolic syndrome, (MetS)] also contribute to the development and progression of renal disease. The associations between hyperglycemia and hypertension with renal disease have been reported extensively in patients suffering from obesity. Currently, there are several obese rodent models (high-fat diet-induced obesity and leptin signaling dysfunction) that exhibit characteristics of MetS. However, the available obese rodent models currently have not been used to investigate the impact of obesity alone on the development of renal injury before hypertension and/or hyperglycemia. Therefore, the aim of this review is to describe the incidence and severity of renal disease in these rodent models of obesity and determine which models are suitable to study the independent effects obesity on the development and progression of renal disease.

Adalimumab mitigates ovarian ischemia-reperfusion injury in rats by regulating oxidative stress, apoptosis and resolution of inflammation

AIM

Ovarian torsion is a rare but an important reason of acute lower abdominal pain in women and associated with serious morbidity and mortality, if not treated promptly. The aim of this study was to evaluate the effects of an antitumor necrosis factor-α antibody on ovarian torsion in a rat model of ischemia-reperfusion (I/R) injury.

METHODS

Forty female Wistar Albino rats were used in the present study. The rats were randomly divided into four groups: group I (sham), group II (I/R), group III (I/R + isotonic saline) and group IV (I/R + adalimumab). The I/R model was induced by torsion of both ovaries. Immunohistochemical staining for interleukin-1β (IL-1β), nuclear factor-κB (NF-κB), and inducible nitric oxide synthase was performed. Tissue and serum oxidative stress markers in conjunction with apoptotic index (AI) with the terminal deoxynucleotidyl transferase dUTP nick end labeling method were also calculated.

RESULTS

Tissue total oxidant status, oxidative stress index and nitric oxide values were significantly decreased, and tissue total antioxidant status was found to be increased in group IV. Inflammation, vascular congestion and hemorrhagia were significantly lower in adalimumab-treated group. Serum oxidative stress markers and tissue malondialdehyde levels did not differ in study groups. The AI was significantly increased in groups 2 and 3. Adalimumab treatment significantly decreased the AI.

CONCLUSION

Adalimumab therapy in rats attenuated I/R induced ovarian injury, possibly suppressing inflammation, inhibiting oxidative stress, and altering apoptotic pathways.

Antioxidant Status in the Soleus Muscle of Sprague-Dawley Rats in Relation to Duodenal-Jejunal Omega Switch and Different Dietary Patterns

Background

Obesity and chronic ingestion of lipid-rich meals are related to an enhanced oxidative stress (OS).

Aims

To examine the influence of duodenal-jejunal omega switch surgery in combination with different diets on the antioxidative status in the soleus muscle of rats.

Methods

After 8 weeks on a high-fat diet (HF) or control diet (CD), rats underwent duodenal-jejunal omega switch (DJOS) or SHAM (control) surgery. After surgery, for the next 8 weeks, half of DJOS/SHAM animals were kept on the same diet as before, and half had a changed diet. The total superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione reductase (GR) activity as well as malondialdehyde (MDA) concentration were measured in the soleus of rats.

Results

CAT and GPx activity were significantly lower after DJOS surgery versus SHAM, regardless of the type of diet. The activity of CAT, SOD, GR, CuZnSOD, and GPx was altered in the CD/HF or HF/CD groups. After DJOS, the lowest muscle concentration of MDA was observed in the CD/CD group and the highest in CD/HF.

Conclusions

DJOS surgery significantly decreases the antioxidative system in soleus muscles of rats. CD/HF and HF/CD dietary patterns lead to an increase in antioxidative activity, while remaining on unchanged diet (CD or HF) is associated with a reduced oxidative stress.

[Sardine purified proteins improve blood pressure, glycemic control, anti-atherogenic metabolic pathways and antioxidant capacity in obese rats]

AIM OF THE STUDY

The effects of sardine by-products (SBy-P) and fillet proteins (SF-P) were compared to casein (Cas) ; these effects were assessed on blood pressure, glycemic control, reverse cholesterol transport, lipid peroxidation and total antioxidant capacity in obese rats.

MATERIALS AND METHODS

Eighteen male Wistar rats were subjected for three months, to a high-fat diet. The obese rats were divided into three groups and consumed the same high-fat diet for 28 days after addition of either, 20% SBy-P, SF-P or Cas.

RESULTS

The sardine proteins (SBy-P and SF-P) compared respectively to Cas, reduced diastolic (-14%, -11% P<0.05) and systolic pressures (-12%, -8% P<0.05), blood glucose (-24%, -21% P<0.05), glycated hemoglobin (-28%, -21% P<0.05), insulinemia (-29%, -18% P<0.05) and HOMA-IR index (-29%, -18% P<0.05). They improve the reverse cholesterol transport by increasing the lecithin: cholesterol acyltransferase (LCAT) activity (+43%, +30% P<0.05) and high-density lipoproteins in cholesterol esters (+108%, +88% P<0.05), and decreasing the atherogenicity ratios and membrane fluidity (P<0.05). Furthermore, SBy-P and SF-P induced a reduction of reactive thiobarbituric acid substances concentrations in heart (-45%, -25% P<0.05), aorta (-62%, -41% P<0.05), liver (-40%, -21% P<0.05) and adipose tissue (-50%, -37% P<0.05) with an improvement in antioxidant capacity.

CONCLUSION

Sardine proteins, in particular those extracted from by-products, because of their hypotensive, hypoglycemic, anti-atherogenic and antioxidant properties, may have protective effects against the cardiovascular risk associated with obesity.

miRNA Long-Term Response to Early Metabolic Environmental Challenge in Hypothalamic Arcuate Nucleus

Epidemiological reports and studies using rodent models indicate that early exposure to nutrient and/or hormonal challenges can reprogram metabolism at adulthood. Hypothalamic arcuate nucleus (ARC) integrates peripheral and central signals to adequately regulate energy homeostasis. microRNAs (miRNAs) participate in the control of gene expression of large regulatory networks including many signaling pathways involved in epigenetics regulations. Here, we have characterized and compared the miRNA population of ARC of adult male rats continuously exposed to a balanced metabolic environment to the one of adult male rats exposed to an unbalanced high-fat/high-carbohydrate/moderate-protein metabolic environment during the perinatal period and/or at adulthood that consequently displayed hyperinsulinemia and/or hyperleptinemia. We identified more than 400 miRNA species in ARC of adult male rats. By comparing the miRNA content of six biological replicates in each of the four perinatal/adult environments/rat groups, we identified the 10 miRNAs specified by clusters miR-96/182/183, miR-141/200c, and miR-200a/200b/429 as miRNAs of systematic and uncommonly high variation of expression. This uncommon variation of expression may underlie high individual differences in aging disease susceptibilities. By comparing the miRNA content of the adult ARC between the rat groups, we showed that the miRNA population was not affected by the unbalanced adult environment while, in contrast, the expression of 11 miRNAs was repeatedly impacted by the perinatal unbalanced environment. Our data revealed a miRNA response of adult ARC to early metabolic environmental challenge.

Sirt3 Deficiency Increased the Vulnerability of Pancreatic Beta Cells to Oxidative Stress-Induced Dysfunction

AIMS

Hyperlipidemia-induced oxidative stress is considered to be one of the main pathogenic factors that contribute to pancreatic beta cell dysfunction in the development of type 2 diabetes (T2D). Sirtuin 3 (Sirt3) is abundantly expressed in the mitochondria as an NAD⁺-dependent deacetylase and regulates mitochondrial adaptive responses to oxidative stress. We examined the antioxidant defense mechanism of Sirt3 in pancreatic beta cells in the context of hyperlipidemia.

RESULTS

Chronic high-fat diet (HFD) feeding caused elevated oxidative stress accompanied by reduced Sirt3 expression in the pancreatic beta cells of wild-type mice. Primary pancreatic islets of Sirt3 knockout (KO) mice and murine pancreatic MIN6 cells with downregulated Sirt3 expression showed increased superoxide dismutase 2 (SOD2) acetylation and reduced glucose-stimulated insulin secretion and glucose-stimulated adenosine triphosphate (ATP) generation. Moreover, Sirt3 deficiency sensitized the pancreatic islets and MIN6 cells to palmitate- and H₂O₂-induced beta cell dysfunction linked with aggravated c-Jun N-terminal kinase phosphorylation and cleaved caspase-3 expression. These negative effects were reversed by antioxidant chemical treatment or restoration of Sirt3 in KO islets. Finally, overexpression of Sirt3 in MIN6 cells partially rescued palmitate-induced reactive oxygen species generation, pancreatic and duodenal homeobox-1 (Pdx-1) nucleo-cytoplasmic translocation, and beta cell dysfunction.

INNOVATION

We present that Sirt3 expression protected pancreatic beta cells from lipotoxicity by antagonizing oxidative stress-induced cell damage.

CONCLUSION

These results suggest that Sirt3 may be a target for amelioration of beta cell dysfunction due to obesity and T2D. Antioxid. Redox Signal. 27, 962-976.

Supplementation of Syzygium cumini seed powder prevented obesity, glucose intolerance, hyperlipidemia and oxidative stress in high carbohydrate high fat diet induced obese rats

Background

Obesity and related complications have now became epidemic both in developed and developing countries. Cafeteria type diet mainly composed of high fat high carbohydrate components which plays a significant role in the development of obesity and metabolic syndrome.

This study investigated the effect of Syzygium cumini seed powder on fat accumulation and dyslipidemia in high carbohydrate high fat diet (HCHF) induced obese rats.

Method

Male Wistar rats were fed with HCHF diet ad libitum, and the rats on HCHF diet were supplemented with Syzygium cumini seed powder for 56 days (2.5% w/w of diet). Oral glucose tolerance test, lipid parameters, liver marker enzymes (AST, ALT and ALP) and lipid peroxidation products were analyzed at the end of 56 days. Moreover, antioxidant enzyme activities were also measured in all groups of rats.

Results

Supplementation with Syzygium cumini seed powder significantly reduced body weight gain, white adipose tissue (WAT) weights, blood glucose, serum insulin, and plasma lipids such as total cholesterol, triglyceride, LDL and HDL concentration. Syzygium cumini seed powder supplementation in HCHF rats improved serum aspartate amino transferase (AST), alanine amino transferase (ALT), and alkaline phosphatase (ALP) activities. Syzygium cumini seed powder supplementation also reduced the hepatic thiobarbituric acid reactive substances (TBARS) and elevated the antioxidant enzyme superoxide dismutase (SOD) and catalase (CAT) activities as well as increased glutathione (GSH) concentration. In addition, histological assessment showed that Syzygium cumini seed powder supplementation prevented inflammatory cell infiltration; fatty droplet deposition and fibrosis in liver of HCHFD fed rats.

Conclusion

Our investigation suggests that Syzygium cumini seed powder supplementation prevents oxidative stress and showed anti-inflammatory and antifibrotic activity in liver of HCHF diet fed rats. In addition, Syzygium cumini seed powder may be beneficial in ameliorating insulin resistance and dyslipidemia probably by increasing lipid metabolism in liver of HCHF diet fed rats.

Beneficial effects of a red wine polyphenol extract on high-fat diet-induced metabolic syndrome in rats

PURPOSE

Individuals with metabolic syndrome (MS) show several metabolic abnormalities including insulin resistance, dyslipidaemia, and oxidative stress (OS). Diet is one of the factors influencing the development of MS, and current nutritional advice emphasises the benefits of fruit and vegetable consumption. Here, we assessed the effects of naturally occurring antioxidants, red wine polyphenols (RWPs), on MS and OS.

METHODS

Wistar rats (n = 20) weighing 200-220 g received a high-fat diet (HFD) for 2 months before they were divided into two groups that received either HFD only or HFD plus 50 mg/kg RWPs in their drinking water for an additional 2 months. A control group (n = 10) received a normal diet (ND) for 4 months.

RESULTS

Rats receiving HFD increased body weight over 20 % throughout the duration of the study. They also showed increased blood levels of C-peptide, glucose, lipid peroxides, and oxidised proteins. In addition, the HFD increased OS in hepatic, pancreatic, and vascular tissues, as well as induced pancreatic islet cell hyperplasia and hepatic steatosis. Addition of RWPs to the HFD attenuated these effects on plasma and tissue OS and on islet cell hyperplasia. However, RWPs had no effect on blood glucose levels or hepatic steatosis.

CONCLUSIONS

RWPs showed an antioxidant mechanism of action against MS. This result will inform future animal studies exploring the metabolic effects of RWPs in more detail. In addition, these findings support the use of antioxidants as adjunctive nutritional treatments for patients with diabetes.

High-fructose and high-fat diet-induced disorders in rats: impact on diabetes risk, hepatic and vascular complications

BACKGROUND

As a result of the increased consumption of sugar-rich and fatty-products, and the increase in preference for such products, metabolic disorders are becoming more common at a younger age. Fructose is particularly used in prepared foods and carbonated beverages. We investigated the impact of regular consumption of fructose, in combination or not with fatty food, on the onset of metabolic syndrome and type 2 diabetes (T2D). We evaluated the metabolic, oxidative, and functional effects on the liver and blood vessels, both related to diabetes complications.

METHODS

High-fat diet (HFD), high-fructose beverages (HF) or both (HFHF) were compared to rats fed with normal diet (ND) for 8 months to induce T2D and its metabolic, oxidative, and functional complications. Metabolic control was determined by measuring body weight, fasting blood glucose, C-peptide, HOMA2-IR, leptin, and cholesterol; oxidative parameters were studied by lipid peroxidation and total antioxidant capacity in plasma and the use of ROS labelling on tissue. Histological analysis was performed on the liver and endothelial function was performed in main mesenteric artery using organ-baths.

RESULTS

After 2 months, HFHF and HFD increased body weight, leptin, HOMA2-IR associated to steatosis, oxidative stress in plasma and tissues, whereas HF had only a transient increase of leptin and c-peptide. Only HFHF induced fasting hyperglycaemia after 6 months and persistent hyperinsulinaemia and fasting hyperglycaemia with complicated steatosis (inflammation and fibrosis) after 8 months. HFHF and HFD induced endothelial dysfunction at 8 months of diet.

CONCLUSIONS

Six months, high fat and high carbohydrate induced T2D with widespread tissues effects. We demonstrated the role of oxidative stress in pathogenesis as well as in complications (hepatic and vascular), reinforcing interest in the use of antioxidants in the prevention and treatment of metabolic diseases, including T2D.