Inflammation, oxidative stress, and obesity

Dietary intervention causes redistribution of zinc in obese adolescents

Obese people tend to have low zinc circulation levels; this is not always related to zinc intake but can reflect the distribution of zinc in relation to the proportion of body fat and factors related to the inflammatory processes that cause obesity. The purpose of this study was to assess zinc distribution in 15 obese adolescent girls before and after a nutritional orientation program. Participants ranged from 14 to 18 years old (postpubescent) and had a body fat percent (BF%) of >35 %. Zinc nutritional status and other zinc-dependent parameters, such as superoxide dismutase (SOD) and insulin levels, were assessed by biochemical analysis of plasma and erythrocytes, salivary sediment, and urine. Samples were collected before and after 4 months of dietary intervention. Dual energy X-ray absorptiometry (DXA) was used to verify BF% both at the beginning and at the end of the study. Food consumption was assessed in ten individual food questionnaires throughout the study; food groups were separated on the questionnaires in the same way as suggested by some authors to develop the Healthy Eating Index (HEI) but with the addition of zinc. After 4 months of nutritional orientation, 78 % of the participants showed a decrease in BF%. Intraerythrocytic zinc increased over the study period, while salivary sediment zinc, SOD, insulin, and Zn urinary24 h/creatinine all decreased (p < 0.05). There was no difference in zinc intake throughout the study but participants did increase their consumption of fruits, dairy, and meats during the study (p < 0.05). There were inverse and statistically significant correlations between the increased levels of intraerythrocytic zinc and decreased levels of SOD. There was also a statistically significant correlation between BF% and Zn urinary 24h/creatinine, and SOD. All these parameters were diminished at the end of the study. The dietary intervention for obese adolescent girls is effective with decrease of BF that led to the redistribution of zinc in the body as shown by the changes in erythrocytes, plasma, salivary, urine zinc, as well as the complementary parameters of insulin and SOD. These changes were not affected by zinc intake.

Assessment of inflammatory and oxidative biomarkers in obesity and their associations with body mass index

The aim of this study was to evaluate the inflammatory and oxidative biomarkers' levels in obese subjects and their associations with body mass index (BMI), in order to investigate the role of these biomarkers in obesity. Fasting glucose, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, apolipoprotein A, apolipoprotein B, albumin, urinary albumin, creatinine, glomerular filtration rate, interleukin-6 (IL-6), nitrate/nitrite (NOx), and ischemia-modified albumin (IMA) were measured in 93 subjects divided according to different BMI. IL-6, urinary albumin, and IMA levels were significantly higher in obese subjects. However, the levels of NOx were significantly lower in this population. Significant correlations between BMI and IL-6 (r = 0.326, P = 0.002), NOx (r = -0.249, P = 0.021), urinary albumin (r = 0.270, P = 0.008), and IMA (r = 0.286, P = 0.005) were reported. We have shown an increase of IL-6, urinary albumin, and IMA combined with lower levels of NOx in obese patients and an association between of these biomarkers with BMI, suggesting a possible interplay of oxidative stress, inflammation, and endothelial dysfunction state in obesity.

C-reactive protein is not correlated with endothelial dysfunction in overweight and obese women

Background

Obesity is a complex and multifactorial disease, has an inflammatory pattern and is associated with higher cardiometabolic risk. There are recent reports associating an elevated C-Reactive Protein (CRP) with a microscopic endothelial dysfunction. The objective is to evaluate if there is an association between serum levels of CRP and endothelial function in women with overweight/obesity, as well as the correlation between CRP and anthropometric variables.

Methods

This is a cross-sectional study that analyzed secondary data from patients treated in an institution of tertiary education, as part of the weight excess and cardiometabolic disease survey. The study included patients with overweight/obesity who had CRP and endothelial function tests already made and inserted into the survey database. The endothelial function was evaluated by: reactive hyperemia test (endothelium-dependent vasodilation). All tests were recorded and later analyzed by the same echocardiographer who performed the examination. Statistical analyses were realized in the Statistical Package for the Social Sciences (SPSS) version 14. It was considered statistically significant a P value < 0.05.

Results

This study included 47, nonsmoker women. with a BMI of 32.37 ± 5.06 kg/m², median of CRP of 2.59 mg/L and flow-mediated dilation (FMD) of 8.75% ± 5.22%. There was no correlation between CRP and endothelial dysfunction in this population (r_s = 0.08, P = 0.64). No correlation was observed between CRP and BMI. There were no differences of endothelial dysfunction variables and CRP in groups in use or not of medications (Hypolipidemic, antihypertensives and hypoglycemic agents).

Conclusion

There was no association between CRP and FMD and this can suggest that it is possible that the level of eNOS dysfunction associated with increased CRP is not enough to lead to macroscopic changes and harm vasodilation.

Resveratrol suppresses PAI-1 gene expression in a human in vitro model of inflamed adipose tissue

Increased plasminogen activator inhibitor-1 (PAI-1) levels are associated with a number of pathophysiological complications; among them is obesity. Resveratrol was proposed to improve obesity-related health problems, but the effect of resveratrol on PAI-1 gene expression in obesity is not completely understood. In this study, we used SGBS adipocytes and a model of human adipose tissue inflammation to examine the effects of resveratrol on the production of PAI-1. Treatment of SGBS adipocytes with resveratrol reduced PAI-1 mRNA and protein in a time- and concentration-dependent manner. Further experiments showed that obesity-associated inflammatory conditions lead to the upregulation of PAI-1 gene expression which was antagonized by resveratrol. Although signaling via PI3K, Sirt1, AMPK, ROS, and Nrf2 appeared to play a significant role in the modulation of PAI-1 gene expression under noninflammatory conditions, those signaling components were not involved in mediating the resveratrol effects on PAI-1 production under inflammatory conditions. Instead, we demonstrate that the resveratrol effects on PAI-1 induction under inflammatory conditions were mediated via inhibition of the NF κ B pathway. Together, resveratrol can act as NF κ B inhibitor in adipocytes and thus the subsequently reduced PAI-1 expression in inflamed adipose tissue might provide a new insight towards novel treatment options of obesity.

[Energy restriction reduces oxidative stress in the aorta and heart and corrects the atherogenic risk in obese rat]

AIM OF THE STUDY

The aim was to see if 40% of caloric restriction can improve in rats, the oxidative stress induced by a high fat diet on liver, heart and aorta, and have a positive impact on the lipoproteins-cholesterol contents.

METHODS

Male Wistar rats (n=12) consumed at weaning obesegenic diet. The obese rats were divided into two groups (n=6) each consumed for 4 weeks a normocaloric diet (1,60 MJ) or a calorie restricted diet (40% of energy of the standard diet [0.96 MJ]). A control group (n=6) was fed a standard diet during the experiment.

RESULTS

Caloric restriction decreased cholesterol and low-density lipoproteins-cholesterol, whereas the high-density lipoproteins-cholesterol was elevated. Levels of cholesterol in the aorta and heart were lowered in the group that consumed caloric restriction compared to normocaloric diet. The values of thiobarbituric acid reactive substances and hydroperoxides were lowered in the aorta and the heart. The caloric restriction compared to normocaloric diet increased positively the superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase activities in the heart and those of catalase and superoxide dismutase in aorta.

CONCLUSION

In obese rats, caloric restriction may play a role in the antioxidant defense of cardiovascular system by reducing proatherogenic cholesterol and lipid peroxidation and increasing the antioxidant activity of some enzymes, which was in favor of reduction of cardiometabolic risk associated with obesity.

The role of chronic inflammation in obesity-associated cancers

There is a strong relationship between metabolism and immunity, which can become deleterious under conditions of metabolic stress. Obesity, considered a chronic inflammatory disease, is one example of this link. Chronic inflammation is increasingly being recognized as an etiology in several cancers, particularly those of epithelial origin, and therefore a potential link between obesity and cancer. In this review, the connection between the different factors that can lead to the chronic inflammatory state in the obese individual, as well as their effect in tumorigenesis, is addressed. Furthermore, the association between obesity, inflammation, and esophageal, liver, colon, postmenopausal breast, and endometrial cancers is discussed.

Obesity-associated oxidative stress: strategies finalized to improve redox state

Obesity represents a major risk factor for a plethora of severe diseases, including diabetes, cardiovascular disease, non-alcoholic fatty liver disease, and cancer. It is often accompanied by an increased risk of mortality and, in the case of non-fatal health problems, the quality of life is impaired because of associated conditions, including sleep apnea, respiratory problems, osteoarthritis, and infertility. Recent evidence suggests that oxidative stress may be the mechanistic link between obesity and related complications. In obese patients, antioxidant defenses are lower than normal weight counterparts and their levels inversely correlate with central adiposity; obesity is also characterized by enhanced levels of reactive oxygen or nitrogen species. Inadequacy of antioxidant defenses probably relies on different factors: obese individuals may have a lower intake of antioxidant- and phytochemical-rich foods, such as fruits, vegetables, and legumes; otherwise, consumption of antioxidant nutrients is normal, but obese individuals may have an increased utilization of these molecules, likewise to that reported in diabetic patients and smokers. Also inadequate physical activity may account for a decreased antioxidant state. In this review, we describe current concepts in the meaning of obesity as a state of chronic oxidative stress and the potential interventions to improve redox balance.

Capillary electrophoretic analysis of hydroxyl radicals produced by respiring mitochondria

Here, we report the use of a capillary electrophoretic method with laser-induced fluorescence detection to evaluate hydroxyl radicals produced by respiring mitochondria. The probe, hydroxyphenylfluorescein (HPF), is separated from the product, fluorescein, in under 5 min with zeptomole and attomole limits of detection for fluorescein and HPF, respectively. Purification of the probe with a C-18 SPE column is necessary to reduce the fluorescein impurity in the probe stock solution from 0.4% to less than 0.001%. HPF was responsive to hydroxyl radicals produced by isolated mitochondria from L6 cells, and this signal was blunted when DMSO was added to scavenge hydroxyl radicals and when carbonyl cyanide m-chlorophenylhydrazone was added to depolarize the mitochondria. The method was used to compare hydroxyl radical levels in mitochondria isolated from brown adipose tissue of lean and obese mice. Mitochondria from obese mice produced significantly more hydroxyl radicals than those from lean mice.

Relationship between obesity and serum reactive oxygen metabolites in adolescents

OBJECTIVES

Various cross-sectional studies have revealed a significant positive relationship between systemic oxidative stress and obesity-related indices such as body mass index (BMI, kg/m²). However, little is known of the role of oxidative stress during adolescence. The aim of this study was to determine the association between obesity and serum reactive oxygen metabolites (ROM) in adolescents.

METHOD

A total of 595 healthy junior high school students from northern Japan were enrolled in the study. Oxidative stress was evaluated by measuring serum levels of ROM. Obesity indices included BMI and percentage body fat (PBF). The analyses were stratified by sex and controlled for age and menarche. Partial correlation coefficients and analysis of covariance were also analyzed.

RESULTS

In female students, ROM levels increased with increasing BMI and PBF. Therefore, ROM levels were significantly higher in the underweight group than in the BMI-classified overweight-obese (P < 0.001) and normal weight groups (P < 0.05). ROM levels were significantly higher in the high PBF group than in the underweight (P < 0.05) and normal groups (P < 0.001).

CONCLUSION

The results of this study show that, regardless of menarche, obesity indicators such as BMI and PBF are correlated with the level of oxidative stress in female adolescents.

[Metabolic alteration in healthy men with first degree type 2 diabetic relatives]

INTRODUCTION

The recognition of prediabetic patients with the genetic risk of type 2 diabetes is very important as prediabetes is the last stage when manifestation of diabetes could be prevented by life style modification or drug intervention. This suggests the need for diagnostic processes to trace the risk of patients in time.

AIMS

The authors looked for metabolic differences between age and BMI in adjusted healthy men with or without first degree type 2 diabetic relatives.

METHODS

The study included 73 healthy men (21 with and 52 without) first-degree relatives with type 2 diabetes.

RESULTS

Total body and muscle tissue glucose utilization, glucose tolerance did not differ between the two groups, but free fatty acid levels were not suppressed by glucose load in subjects with diabetic relatives. In addition the body fat content, leptin and IL-6 levels were higher, while adiponectin and the free fatty acid/adiponectin ratio were significantly lover in healthy men with diabetic relatives. In this group HDL cholesterol, and the large buoyant LDL fraction were lower whereas the high density LDL - small molecular lipid fraction was higher than those measured in subjects without diabetic relatives.

CONCLUSIONS

These data suggest that deteriorations of insulin sensitivity and glucose tolerance is preceded by disturbances of fatty acid metabolism. The observed alteration in free fatty acid/adiponectin ratio, and/or the absence of free fatty acid suppression during glucose tolerance tests could be a screening tool for diabetes risk among men.

Oxidative stress and protein carbonylation in adipose tissue - implications for insulin resistance and diabetes mellitus

While historically considered simply as a depot for excess energy, white adipose tissue is a dynamically active endocrine organ capable of responding to a variety of efferent stimuli resulting in the synthesis and secretion of peptides, proteins and metabolites that serve as signal transducers to the peripheral and central circulation. Such regulation controls a variety of physiological processes including energy expenditure, food intake, reproductive capacity and responsiveness to insulin. Indeed, the accumulation of inflammatory cells in white adipose tissue is considered to be causative in the development of insulin resistance and eventually type 2 diabetes mellitus. A large body of evidence suggests that oxidative stress in adipose tissue not only correlates with insulin resistance but is also causative in its development. Moreover, using the available plasma oxidative stress biomarkers, many clinical studies have shown the presence of systemic oxidative stress in obese insulin resistant subjects, and its decrease after the successful treatment of obesity. In this review we emphasize the role of protein carbonylation in dysfunctional obese white adipose tissue and its metabolic implications. We focus on glutathione S-transferase A4 as the key enzyme for trans-4-hydroxy-2-nonenal and trans-4-oxo-2-nonenal removal from the cell, thus preventing protein carbonylation. This article is part of a Special Issue entitled: Posttranslational Protein modifications in biology and Medicine.

Supplementation with L-arginine favorably influences plasminogen activator inhibitor type 1 concentration in obese patients. A randomized, double blind trial

BACKGROUND

Elevated plasminogen activator inhibitor type 1 (PAI 1) plays an important role in the pathogenesis of excess blood coagulability in obese patients. L-arginine supplementation has shown to be associated with enhanced cardiovascular and metabolic health. The aim of the study was to assess the effect of L-arginine supplementation on PAI 1 concentration and to evaluate the relation to changes in nitric oxide (NO) plasma level, insulin sensitivity (M value), and total antioxidant status (TAS) in obese patients.

MATERIAL/SUBJECTS AND METHODS

A randomized, double-blind, placebo-controlled study was conducted from March 2010 to June 2011. Eightyeight obese patients were randomly assigned to receive either 9 g of L-arginine or placebo daily for 6 months. At baseline and after 6 months, selected anthropometrical measurements and blood biochemical analyses were performed, and PAI 1, NO, TAS levels were assessed. Insulin sensitivity was evaluated using the hyperinsulinemic euglycemic clamp technique.

RESULTS

We found that 6-month L-arginine supplementation resulted in significant decrease of PAI 1. Significant increase of NO, TAS, and insulin sensitivity level were noticed. In a group of patients treated with L-arginine, negative correlation between a change of insulin sensitivity value and a change of PAI 1 concentration was found.

CONCLUSIONS

The present findings demonstrate favorable influence of L-arginine supplementation on PAI 1 concentration in obese patients. Beneficial influence is related to insulin sensitivity improvement. The potential therapeutic role of L-arginine administration in patients with obesity needs further investigation.

Beneficial effects of the RESMENA dietary pattern on oxidative stress in patients suffering from metabolic syndrome with hyperglycemia are associated to dietary TAC and fruit consumption

Hyperglycemia and oxidative stress are conditions directly related to the metabolic syndrome (MetS), whose prevalence is increasing worldwide. This study aimed to evaluate the effectiveness of a new weight-loss dietary pattern on improving the oxidative stress status on patients suffering MetS with hyperglycemia. Seventy-nine volunteers were randomly assigned to two low-calorie diets (−30% Energy): the control diet based on the American Health Association criteria and the RESMENA diet based on a different macronutrient distribution (30% proteins, 30% lipids, 40% carbohydrates), which was characterized by an increase of the meal frequency (seven-times/day), low glycemic load, high antioxidant capacity (TAC) and high n-3 fatty acids content. Dietary records, anthropometrical measurements, biochemical parameters and oxidative stress biomarkers were analyzed before and after the six-month-long study. The RESMENA (Metabolic Syndrome Reduction in Navarra) diet specifically reduced the android fat mass and demonstrated more effectiveness on improving general oxidative stress through a greater decrease of oxidized LDL (oxLDL) values and protection against arylesterase depletion. Interestingly, oxLDL values were associated with dietary TAC and fruit consumption and with changes on body mass index (BMI), waist circumference, fat mass and triacilglyceride (TG) levels. In conclusion, the antioxidant properties of the RESMENA diet provide further benefits to those attributable to weight loss on patients suffering Mets with hyperglycemia.

Clozapine-induced mitochondria alterations and inflammation in brain and insulin-responsive cells

Background

Metabolic syndrome (MetS) is a constellation of factors including abdominal obesity, hyperglycemia, dyslipidemias, and hypertension that increase morbidity and mortality from diabetes and cardiovascular diseases and affects more than a third of the population in the US. Clozapine, an atypical antipsychotic used for the treatment of schizophrenia, has been found to cause drug-induced metabolic syndrome (DIMS) and may be a useful tool for studying cellular and molecular changes associated with MetS and DIMS. Mitochondria dysfunction, oxidative stress and inflammation are mechanisms proposed for the development of clozapine-related DIMS. In this study, the effects of clozapine on mitochondrial function and inflammation in insulin responsive and obesity-associated cultured cell lines were examined.

Methodology/Principal Findings

Cultured mouse myoblasts (C2C12), adipocytes (3T3-L1), hepatocytes (FL-83B), and monocytes (RAW 264.7) were treated with 0, 25, 50 and 75 µM clozapine for 24 hours. The mitochondrial selective probe TMRM was used to assess membrane potential and morphology. ATP levels from cell lysates were determined by bioluminescence assay. Cytokine levels in cell supernatants were assessed using a multiplex array. Clozapine was found to alter mitochondria morphology, membrane potential, and volume, and reduce ATP levels in all cell lines. Clozapine also significantly induced the production of proinflammatory cytokines IL-6, GM-CSF and IL12-p70, and this response was particularly robust in the monocyte cell line.

Conclusions/Significance

Clozapine damages mitochondria and promotes inflammation in insulin responsive cells and obesity-associated cell types. These phenomena are closely associated with changes observed in human and animal studies of MetS, obesity, insulin resistance, and diabetes. Therefore, the use of clozapine in DIMS may be an important and relevant tool for investigating cellular and molecular changes associated with the development of these diseases in the general population.

Why it is necessary to translate curcumin into clinical practice for the prevention and treatment of metabolic syndrome?

Curcumin (diferuloylmethane) is the yellow-orange pigment of dried Curcuma longa L. rhizomes (turmeric). During the past two decades, there has been a large volume of published studies describing the biological and pharmacological properties of this phytochemical including anticancer, anti-inflammatory, antioxidant, antithrombotic, antiatherosclerotic, cardioprotective, neuroprotective, memory enhancing, antiparkinsonism, antirheumatic, anti-infectious, antiaging, antipsoriatic, and anticonvulsant activities. In addition, curcumin has been shown to be extremely safe and interact with multiple molecular targets that are involved in the pathogenesis of metabolic syndrome. Curcumin could favorably affect all leading components of metabolic syndrome including insulin resistance, obesity, hypertriglyceridemia, decreased HDL-C and hypertension, and prevent the deleterious complications of MetS including diabetes and cardiovascular disease. Owing to its antioxidant and anti-inflammatory properties, curcumin can also exert several pleiotropic effects and improve endothelial dysfunction, adipokine imbalances, and hyperuricemia which usually accompany MetS. Despite the potential tremendous benefit of this multifaceted phytopharmaceutical, no trial result has yet been publicized on this issue. This review seeks to briefly summarize the ample scientific evidence that supports the therapeutic efficacy of curcumin, at least as an adjunctive treatment, in patients with MetS.

Oxidative stress associated to dysfunctional adipose tissue: a potential link between obesity, type 2 diabetes mellitus and breast cancer

Diabetes mellitus and breast cancer are two important health problems. Type 2 diabetes (T2DM) and obesity are closely linked with both being associated with breast cancer. Despite abundant epidemiological data, there is no definitive evidence regarding the mechanisms responsible for this association. The proposed mechanisms by which diabetes affects breast cancer risk and prognosis are the same as the mechanisms hypothesised for the contribution of obesity to breast cancer risk. The obesity-induced inflammation promoted by adipose tissue dysfunction is a key feature, which is thought to be an important link between obesity and cancer. Inflammation induces an increase in free radicals and subsequently promotes oxidative stress, which may create a microenvironment favourable to the tumor development in obese persons. Oxidative stress is also proposed as the link between obesity and diabetes mellitus. Therefore, obesity-related oxidative stress could be a direct cause of neoplastic transformation associated with obesity and T2DM in breast cancer cells. This review is focused on the role of obesity-related oxidative stress in the context of chronic inflammation, on the time of breast cancer onset and progression, which provide targets for preventive and therapeutic strategies in the fields of diabetes and obesity-related breast cancer.

Agrimonia eupatoria tea consumption in relation to markers of inflammation, oxidative status and lipid metabolism in healthy subjects

Phytotherapy reports strong anti-oxidative and anti-inflammatory potential of agrimony (Agrimonia eupatoria L.). However the effects of agrimony tea consumption are not scientifically proven in humans. We investigated the effects of one month's consumption of agrimony tea in healthy volunteers. Significant elevation of plasma total antioxidant capacity was observed and interleukin 6 levels were significantly lowered at the end of the intervention. An improved lipid profile as estimated by increased high density lipoprotein (HDL) cholesterol was established upon agrimony tea supplementation and HDL cholesterol correlated with adiponectin levels. The results presented in this first human intervention study with agrimony tea indicate that the plant has potential in improving markers of lipid metabolism, oxidative status and inflammation in healthy adults.

The Antiobesity Effect of Polygonum aviculare L. Ethanol Extract in High-Fat Diet-Induced Obese Mice

The antiobesity effects of a P. aviculare ethanol extract (PAE) in high-fat diet- (HFD-) induced obese mice were investigated. The mice were fed an HFD or an HFD supplemented with PAE (400 mg/kg/day) for 6.5 weeks. The increased body weights, adipose tissue weight, and adipocyte area as well as serum total triglyceride, leptin, and malondialdehyde concentrations were decreased in PAE-treated HFD-induced obese mice relative to the same measurements in untreated obese mice. Furthermore, PAE significantly suppressed the elevated mRNA expression levels of sterol regulatory element-binding protein-1c, peroxisome proliferator-activated receptor γ, fatty acid synthase, and adipocyte protein 2 in the white adipose tissue of obese mice. In addition, PAE treatment of 3T3-L1 cells inhibited adipocyte differentiation and fat accumulation in a dose-dependent manner. These results suggest that PAE exerts antiobesity effects in HFD-induced obese mice through the suppression of lipogenesis in adipose tissue and increased antioxidant activity.

Increase in maternal adiposity and poor lipid profile is associated with oxidative stress markers during pregnancy

OBJECTIVE

This study aimed to evaluate changes in maternal adiposity and lipid profile and to correlate these parameters with Deoxyribonucleic acid (DNA) damage and total antioxidant capacity (TAC) levels among pregnant women.

METHOD

This was a longitudinal study which took place in Kelantan state, Malaysia. Fasting blood samples of 159 healthy pregnant women were collected in second and third trimesters from April 2010 until October 2011. Maternal total body fat was assessed using bioimpedance analysis method.

RESULTS

When compared to data in second trimester, pregnant women in third trimester showed significantly higher levels of total body fat (p<0.001), total cholesterol (p<0.001), triglyceride (p<0.001), LDL-C (p=0.001), DNA damage (p<0.001) and TAC (p<0.001) but a lower level of HDL-C (p<0.001). Maternal adiposity and lipid profile were positively and consistently correlated with DNA damage in second and third trimesters. Significant and positive correlations of triglyceride with TAC levels were noted in both periods indicating compensatory action against increased oxidative stress.

CONCLUSION

Normal pregnancy is associated with marked changes in lipid metabolism, prooxidant and antioxidant status. Dyslipidemia-associated oxidative stress was demonstrated with advancing gestational age. Appropriate preventive and compensatory measures should be practiced to minimize the effect of oxidative stress throughout pregnancy.

High dietary fat selectively increases catalase expression within cardiac mitochondria

Obesity is a predictor of diabetes and cardiovascular disease. One consequence of obesity is dyslipidemia characterized by high blood triglycerides. It has been proposed that oxidative stress, driven by utilization of lipids for energy, contributes to these diseases. The effects of oxidative stress are mitigated by an endogenous antioxidant enzyme network, but little is known about its response to high fat utilization. Our experiments used a multiplexed quantitative proteomics method to measure antioxidant enzyme expression in heart tissue in a mouse model of diet-induced obesity. This experiment showed a rapid and specific up-regulation of catalase protein, with subsequent assays showing increases in activity and mRNA. Catalase, traditionally considered a peroxisomal protein, was found to be present in cardiac mitochondria and significantly increased in content and activity during high fat feeding. These data, coupled with the fact that fatty acid oxidation enhances mitochondrial H(2)O(2) production, suggest that a localized catalase increase is needed to consume excessive mitochondrial H(2)O(2) produced by increased fat metabolism. To determine whether the catalase-specific response is a common feature of physiological conditions that increase blood triglycerides and fatty acid oxidation, we measured changes in antioxidant expression in fasted versus fed mice. Indeed, a similar specific catalase increase was observed in mice fasted for 24 h. Our findings suggest a fundamental metabolic process in which catalase expression is regulated to prevent damage while preserving an H(2)O(2)-mediated sensing of diet composition that appropriately adjusts insulin sensitivity in the short term as needed to prioritize lipid metabolism for complete utilization.

Indirubin-3'-(2,3 dihydroxypropyl)-oximether (E804) is a potent modulator of LPS-stimulated macrophage functions

Indirubin is a deep-red bis-indole isomer of indigo blue, both of which are biologically active ingredients in Danggui Longhui Wan, an ancient Chinese herbal tea mixture used to treat neoplasia and chronic inflammation and to enhance detoxification of xenobiotics. Multiple indirubin derivatives have been synthesized and shown to inhibit cyclin-dependent kinases (CDKs) and glycogen-synthase kinase (GSK-3β) with varying degrees of potency. Several indirubins are also aryl hydrocarbon receptor (AhR) agonists, with AhR-associated activities covering a wide range of potencies, depending on molecular structure. This study examined the effects of indirubin-3'-(2,3 dihydroxypropyl)-oximether (E804), a novel indirubin with potent STAT3 inhibitory properties, on basal and LPS-inducible activities in murine RAW264.7 macrophages. Using a focused commercial qRT-PCR array platform (SuperArray®), the effects of E804 on expression of a suite of genes associated with stress and toxicity were determined. Most genes up-regulated by LPS treatment were suppressed by E804; including LPS-induced expression of pro-inflammatory cytokines and receptors, apoptosis control genes, and oxidative stress response genes. Using qRT-PCR as a follow up to the commercial arrays, E804 treatment suppressed LPS-induced COX-2, iNOS, IL-6 and IL-10 gene expression, though the effects on iNOS and COX-2 protein expression were less dramatic. E804 also inhibited LPS-induced secretion of IL-6 and IL-10. Functional endpoints, including iNOS and lysozyme enzymatic activity, phagocytosis of fluorescent latex beads, and intracellular killing of bacteria, were also examined, and in each experimental condition E804 suppressed activities. Collectively, these results indicate that E804 is a potent modulator of pro-inflammatory profiles in LPS-treated macrophages.

Protein feeding pattern, casein feeding, or milk-soluble protein feeding did not change the evolution of body composition during a short-term weight loss program

Studies have shown that timing of protein intake, leucine content, and speed of digestion significantly affect postprandial protein utilization. Our aim was to determine if one can spare lean body mass during energy restriction by varying the quality and the timing of protein intake. Obese volunteers followed a 6-wk restricted energy diet. Four groups were compared: casein pulse, casein spread, milk-soluble protein (MSP, = whey) pulse, and MSP spread (n = 10-11 per group). In casein groups, caseins were the only protein source; it was MSP in MSP groups. Proteins were distributed in four meals per day in the proportion 8:80:4:8% in the pulse groups; it was 25:25:25:25% in the spread groups. We measured weight, body composition, nitrogen balance, 3-methylhistidine excretion, perception of hunger, plasma parameters, adipose tissue metabolism, and whole body protein metabolism. Volunteers lost 7.5 ± 0.4 kg of weight, 5.1 ± 0.2 kg of fat, and 2.2 ± 0.2 kg of lean mass, with no difference between groups. In adipose tissue, cell size and mRNA expression of various genes were reduced with no difference between groups. Hunger perception was also never different between groups. In the last week, due to a higher inhibition of protein degradation and despite a lower stimulation of protein synthesis, postprandial balance between whole body protein synthesis and degradation was better with caseins than with MSP. It seems likely that the positive effect of caseins on protein balance occurred only at the end of the experiment.

Leptin triggers Ca(2+) imbalance in monocytes of overweight subjects

Obesity is a major risk factor in numerous diseases, in which elevated intracellular Ca(2+) plays a major role in increased adiposity. We examined the difference between Ca(2+) signals in monocytes of lean and overweight subjects and the relationship between leptin induced NADPH oxidase activation and intracellular calcium concentration [Ca(2+)](i) homeostasis. Our results are as follows: (1) The basal level of [Ca(2+)](i) in resting monocytes of overweight subjects (OW monocytes) was higher than that in control cells, whereas the leptin-induced peak of the Ca(2+) signal was lower and the return to basal level was delayed. (2) Ca(2+) signals were more pronounced in OW monocytes than in control cells. (3) Using different inhibitors of cellular signaling, we found that in control cells the Ca(2+) signals originated from intracellular pools, whereas in OW cells they were generated predominantly by Ca(2+)-influx from medium. Finally, we found correlation between leptin induced superoxide anion generation and Ca(2+) signals. The disturbed [Ca(2+)](i) homeostasis in OW monocytes was fully restored in the presence of fluvastatin. Statins have pleiotropic effects involving the inhibition of free radical generation that may account for its beneficial effect on elevated [Ca(2+)](i) and consequently on the pathomechanism of obesity.

Influence of hypertension, obesity and nicotine abuse on quantitative and qualitative changes in acute-phase proteins in patients with essential hypertension

Background

Hypertension is a powerful risk factor for cardiovascular disease and frequently occurs in conjunction with obesity. Accumulative evidence suggests a link between inflammation and hypertension. The aim of study was to evaluate whether blood pressure, obesity and smoking may influence acute-phase response.

Material/Methods

Ninety-two patients with essential hypertension and 75 healthy volunteers as a control group were studied. In all subjects assessment of hsCRP, α1-acid glycoprotein (AGP), α1-antichymotrypsin, transferrin, α1-antitrypsin, and C3 and C4 complement were performed. Evaluation of glycosylation profile and reactivity coefficient (RC) for AGP was done by means of affinity immunoelectrophoresis with concanavalin A as a ligand.

Results

When compared to the controls, hypertensive subjects presented significantly higher hsCRP concentrations and lower transferrin level. Hypertensive patients had elevated AGP-AC. The intensification of the inflammatory reaction was greater in the subgroup of hypertensive patients smoking cigarettes. In obese hypertensives, elevated serum C3 complement level was found.

Conclusions

We conclude that arterial hypertension may evoke the acute-phase response in humans. Markers of acute-phase response are particularly strongly expressed in smokers. Serum C 3 complement, but not other APPs, is elevated in hypertension coexisting with obesity.

Silymarin decreases connective tissue growth factor to improve liver fibrosis in rats treated with carbon tetrachloride

Silymarin is an herbal product showing potential as protection against hepatic disorders. In an attempt to develop the agent for the treatment of hepatic fibrosis, we screened the effects of silymarin on a rat model of hepatic fibrosis induced by carbon tetrachloride (CCl₄). Intraperitoneal administration of CCl₄ to rats for 8 weeks not only increased the plasma levels of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) but also induced a marked increase in the formation of hepatic fibrosis. Moreover, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were also reduced in the liver of rats treated with CCl₄. Oral administration of silymarin (200 mg/kg, three times daily), in parallel, decreased the plasma levels of GOT and GPT. Furthermore, in addition to the improvement of hepatic fibrosis, the hepatic levels of hydroxyproline and connective tissue growth factor (CTGF) were both markedly decreased by silymarin. Silymarin also elevated the activities of SOD and GPx in liver isolated from CCl₄-treated rats. The results suggest that oral administration of silymarin protects against CCl₄-induced hepatic fibrosis in rats, likely due to the decrease in fibrotic parameters such as CTGF.

The role of T-bet in obesity: lack of T-bet causes obesity in male mice

The association of T helper (Th) 1 cells with obesity is well documented in both animals and humans. The T-box transcription factor (T-bet) is known as the transcription factor that is responsible for the development of Th1 cells. However, the role of T-bet in obesity has never been elucidated. The present study aimed to investigate the regulatory function of T-bet on obesity in mice. Th1 cytokine levels were decreased, whereas Th2 cytokine level and GATA-3 messenger RNA (mRNA) expression were increased in T-bet knockout (KO) mice. T-bet KO male mice induced obesity as a result of increased body weight and food efficiency despite the fact that they feed a control diet. T-bet KO mice have an increase in weight of white adipose tissue and levels of triacylglyceride and low-density lipoprotein cholesterol. Interestingly, the expression levels of energy expenditure-related genes were decreased in T-bet KO mice. Both T-bet KO male and female mice had impaired glucose tolerance. In white adipose tissue, leptin, the increase in peroxisome proliferator receptor-γ and CAAT/enhancer-binding protein α mRNA expressions in T-bet KO mice was more than that in wild-type mice. Furthermore, we found that the level of interleukin (IL)-6 mRNA expression in white adipose tissue was elevated in T-bet KO mice but not IL-1β and tumor necrosis factor-α. IL-6 mRNA expression was increased in adipocyte fraction and stromal vascular fraction in white adipose tissue of T-bet KO mice. Taken together, our results reveal that T-bet may affect obesity through the regulation of IL-6 expression in adipocytes of white adipose tissue.

AMP-activated protein kinase: an emerging drug target to regulate imbalances in lipid and carbohydrate metabolism to treat cardio-metabolic diseases

The adenosine monophosphate-activated protein kinase (AMPK) is a metabolic sensor of energy metabolism at the cellular as well as whole-body level. It is activated by low energy status that triggers a switch from ATP-consuming anabolic pathways to ATP-producing catabolic pathways. AMPK is involved in a wide range of biological activities that normalizes lipid, glucose, and energy imbalances. These pathways are dysregulated in patients with metabolic syndrome (MetS), which represents a clustering of major cardiovascular risk factors including diabetes, lipid abnormalities, and energy imbalances. Clearly, there is an unmet medical need to find a molecule to treat alarming number of patients with MetS. AMPK, with multifaceted activities in various tissues, has emerged as an attractive drug target to manage lipid and glucose abnormalities and maintain energy homeostasis. A number of AMPK activators have been tested in preclinical models, but many of them have yet to reach to the clinic. This review focuses on the structure-function and role of AMPK in lipid, carbohydrate, and energy metabolism. The mode of action of AMPK activators, mechanism of anti-inflammatory activities, and preclinical and clinical findings as well as future prospects of AMPK as a drug target in treating cardio-metabolic disease are discussed.

Dahl salt-sensitive rats are protected against vascular defects related to diet-induced obesity

Obesity increases plasma renin activity and angiotensin II levels, leading to vascular damage, elevated blood pressure, diabetes mellitus, and renal damage. Because genetic deletion of crucial parts of the renin-angiotensin system protect against obesity-related cardiovascular defects, we hypothesized that Dahl salt-sensitive (SS) rats, a model of chronically low plasma renin activity and angiotensin II levels, would be protected against vascular defects during diet-induced obesity compared with SS.13(BN) consomic rats showing normal renin-angiotensin system regulation. We evaluated vascular function in middle cerebral arteries of SS or SS.13(BN) rats fed high-fat (45% kcal from fat) versus normal-fat diet for 15 to 20 weeks from weaning. Endothelium-dependent relaxation in response to acetylcholine (10(-8) to 10(-4) mol/L) was restored in middle cerebral arteries of high-fat SS rats versus normal-fat diet controls, whereas vasodilation to acetylcholine was dramatically reduced in high-fat SS 13(BN) rats versus normal-fat diet controls. These findings support the hypothesis that physiological levels of angiotensin II play an important role in maintaining normal vascular relaxation in cerebral arteries and suggest that the cerebral vasculature of the SS rat model is genetically protected against endothelial dysfunction in diet-induced obesity.

Protection of the extracts of Lentinus edodes mycelia against carbon-tetrachloride-induced hepatic injury in rats

Lentinus edodes is the medicinal macrofungus showing potential for therapeutic applications in infectious disorders including hepatitis. In an attempt to develop the agent for handling hepatic injury, we used the extracts of Lentinus edodes mycelia (LEM) to screen the effect on hepatic injury in rats induced by carbon tetrachloride (CCl₄). Intraperitoneal administration of CCl₄ not only increased plasma glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) but also decreased hepatic superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels in rats. Similar to the positive control silymarin, oral administration (three times daily) of this product (LEM) for 8 weeks significantly reduced plasma GOT and GPT. Also, the activities of antioxidant enzymes of SOD and GPx were elevated by LEM. in liver from CCl₄-treated rats, indicating that mycelium can increase antioxidant-like activity. Moreover, the hepatic mRNA and protein levels of SOD and GPx were both markedly raised by LEM. The obtained results suggest that oral administration of the extracts of Lentinus edodes mycelia (LEM) has the protective effect against CCl₄-induced hepatic injury in rats, mainly due to an increase in antioxidant-like action.

Association of systemic inflammation with marked changes in particulate air pollution in Beijing in 2008

Many studies have linked ambient fine particulate matter (aerodynamic diameters less than 2.5 μm, PM₂.₅) air pollution to increased morbidity and mortality of cardiovascular diseases in the general population, but the biologic mechanisms of these associations are yet to be elucidated. In this study, we aimed to evaluate the relationship between daily variations in exposure to PM₂.₅ and inflammatory responses in mice during and for 2 months after the Beijing Olympic Games. Male C57BL/6 mice were exposed to Beijing PM₂.₅ or filtered air (FA) in 2008 during the 2 months of Beijing Olympic and Paralympic Games, and for 2 months after the end of the Games. During the Games, circulating monocyte chemoattractant protein 1 and interleukin 6 were increased significantly in the PM₂.₅ exposure group, when compared with the FA control group, although there were no significant inter-group differences in tumor necrosis factor-α or interferon-γ, or in macrophages, neutrophils or lymphocytes in the spleen or thymus between these 2 groups. However, macrophages were significantly increased in the lung and visceral fat with increasing PM₂.₅. After the Olympic Games, there were no significant PM₂.₅-associated differences for macrophages, neutrophils or lymphocytes in the thymus, but macrophages were significantly elevated in the lung, spleen, subcutaneous and visceral fat with increasing PM₂.₅, and the numbers of macrophages were even higher after than those during the Games. Moreover, the number of neutrophils was markedly higher in the spleen for the PM₂.₅-exposed- than the FA-group. These data suggest that short-term increases in exposure to ambient PM₂.₅ leads to increased systemic inflammatory responses, primarily macrophages and neutrophils in the lung, spleen, and visceral adipose tissue. Short-term air quality improvements were significantly associated with reduced overall inflammatory responses.

Nutritional care for aging cats and dogs

Veterinarians need to be prepared to provide nutritional advice for healthy pets as well as for pets that are ill. Before instituting a dietary change in any patient, especially an older dog or cat, a nutritional evaluation should be completed. This should include an evaluation of the patient, the current diet, and feeding management. Diets should be appropriate to the unique needs of the individual patient. Many diseases in senior pets are “diet-sensitive” meaning that diet can play a role in managing the effects of the disease. Common examples discussed include cognitive dysfunction of aging, osteoarthritis, and obesity.

Diets rich in fruits and vegetables suppress blood biomarkers of metabolic stress in overweight women

OBJECTIVE

This study was performed to evaluate the effects of high vegetable-fruit (high-VF) and low vegetable-fruit (low-VF) diet on surrogate biomarkers of adiposity-related metabolic disturbances.

METHODS

Overweight women (n=22, 19-29 years) participated in the study between July and August, 2007 in Seoul, Korea. The intervention consisted of either high-VF diet (12 servings of VF/day) or low-VF diet (2 servings of VF/day). Plasma concentration of carotenoids and biomarkers of inflammation and oxidative stress were determined before and after each intervention period.

RESULTS

Study results indicated that body fat content is positively correlated with plasma interleukin (IL)-6, C-reactive protein (CRP), and leptin concentrations at baseline. Oxidative DNA damage and lipopolysaccharide (LPS)-activated production of IL-1β and IL-6 in peripheral blood mononuclear cells (PBMCs) were decreased with high-VF diet while low-VF diet increased those markers. Changes in the concentration of plasma total carotenoid and β-carotene were inversely correlated with change in plasma IL-1β concentration. Differences in IL-β production in LPS-activated PBMCs were inversely correlated with changes in plasma concentration of lutein-zeaxanthin. Also, changes in plasma total carotenoid and lycopene concentration were inversely correlated with the changes in IL-6 production in LPS-activated PBMCs.

CONCLUSION

Daily intake of vegetables and fruits can modify adiposity-related metabolic disturbances.

Total and individual antioxidant intake and endometrial cancer risk: results from a population-based case-control study in New Jersey

We evaluated the role of total dietary antioxidant capacity and of individual antioxidants on endometrial cancer risk in a population-based case-control study in New Jersey, including 417 cases and 395 controls. Dietary intake was ascertained using a food-frequency questionnaire (FFQ), and total antioxidant capacity (TAC) intake was estimated using the USDA Oxygen Radical Absorbance Capacity (ORAC) database and the University of Oslo's Antioxidant Food Database (AFD) and FFQ-derived estimates of intake. Odds ratios and 95 % confidence intervals were derived using multivariate logistic regression controlling for major endometrial cancer risk factors. Using the ORAC database, after adjusting for major covariates, we found decreased risks for the highest tertile of total phenolic intake compared with the lowest (OR: 0.62; 95 % CI: 0.39-0.98). There was no association for TAC intake based on the AFD, which utilized the ferric-reducing ability of plasma (FRAP) assay to assess antioxidant capacity. There was no strong evidence for an association with intake of any of the individual antioxidants. Our findings suggest that total phenolic consumption may decrease endometrial cancer risk.

Polyhydroxylated fullerene C₆₀(OH)₄₄ suppresses intracellular lipid accumulation together with repression of intracellular superoxide anion radicals and subsequent PPARγ2 expression during spontaneous differentiation of OP9 preadipocytes into adipocytes

Reactive oxygen species has been suggested to be one of the key factors associated with the development of obesity. During spontaneous differentiation of mouse stromal preadipocytes OP9 into adipocytes, intracellular superoxide anion radicals (O (2) (-.) ) level markedly increases and is accompanied by a significant elevation of intracellular lipid accumulation. This differentiation-dependent increase in intracellular O (2) (-.) level positively correlated with the intracellular augmentation of the lipid level. Super-highly hydroxylated fullerene (SHH-F; C(60)(OH)(44)), a novel polyhydroxylated fullerene derivative, quenched intracellular O (2) (-.) , and lipid accumulation to 38.7 and 42.7 % of that in the control, respectively. By thin-layer chromatographic analysis of extracted cellular lipid components, SHH-F clearly decreased the triglycerides ratio in the whole lipid droplet fraction, but scarcely influenced other lipids components. PPARγ2 expression, which plays a key role in regulating adipogenic differentiation, was significantly suppressed by SHH-F at the late stage of differentiation, with unaltered PPARγ1 expression. The intracellular superoxide anion radical augmentation preceded expression of PPARγ2, strongly suggesting that the primary O (2) (-.) generation was closely associated with lipid accumulation and subsequent PPARγ2 induction. These results indicate that SHH-F suppresses intracellular lipid accumulation, particularly in lipid droplets, and decreases O (2) (-.) level and subsequent PPARγ2 upregulation during spontaneous differentiation of OP9 preadipocytes into adipocytes.

Stoichiometry based steady-state hepatic flux analysis: computational and experimental aspects

: The liver has many complex physiological functions, including lipid, protein and carbohydrate metabolism, as well as bile and urea production. It detoxifies toxic substances and medicinal products. It also plays a key role in the onset and maintenance of abnormal metabolic patterns associated with various disease states, such as burns, infections and major traumas. Liver cells have been commonly used in in vitro experiments to elucidate the toxic effects of drugs and metabolic changes caused by aberrant metabolic conditions, and to improve the functions of existing systems, such as bioartificial liver. More recently, isolated liver perfusion systems have been increasingly used to characterize intrinsic metabolic changes in the liver caused by various perturbations, including systemic injury, hepatotoxin exposure and warm ischemia. Metabolic engineering tools have been widely applied to these systems to identify metabolic flux distributions using metabolic flux analysis or flux balance analysis and to characterize the topology of the networks using metabolic pathway analysis. In this context, hepatic metabolic models, together with experimental methodologies where hepatocytes or perfused livers are mainly investigated, are described in detail in this review. The challenges and opportunities are also discussed extensively.