Genetics of oxidative stress in obesity

Non-Hereditary Obesity Type Networks and New Drug Targets: An In Silico Approach

Obesity, a chronic, preventable disease, has significant comorbidities that are associated with a great human and financial cost for society. The aim of the present work is to reconstruct the interactomes of non-hereditary obesity to highlight recent advances of its pathogenesis, and discover potential therapeutic targets. Obesity and biological-clock-related genes and/or gene products were extracted from the biomedical literature databases PubMed, GeneCards and OMIM. Their interactions were investigated using STRING v11.0 (a database of known and predicted physical and indirect associations among genes/proteins), and a high confidence interaction score of >0.7 was set. We also applied virtual screening to discover natural compounds targeting obesity- and circadian-clock-associated proteins. Two updated and comprehensive interactomes, the (a) stress- and (b) inflammation-induced obesidomes involving 85 and 93 gene/gene products of known and/or predicted interactions with an average node degree of 9.41 and 10.8, respectively, were produced. Moreover, 15 of these were common between the two non-hereditary entities, namely, ADIPOQ, ADRB2/3, CCK, CRH, CXCL8, FOS, GCG, GNRH1, IGF1, INS, LEP, MC4R, NPY and POMC, while phelligridin E, a natural product, may function as a potent FOX1-DBD interaction blocker. Molecular networks may contribute to the understanding of the integrated regulation of energy balance/obesity pathogenesis and may associate chronopharmacology schemes with natural products.

Urine metabolomics unravel the effects of short-term dietary interventions on oxidative stress and inflammation: a randomized controlled crossover trial

Dietary biomarkers in urine remain elusive when evaluating diet-induced oxidative stress and inflammation. In our previous study, we conducted a randomized controlled crossover trial to compare the short-term (4-weeks) effects of the balanced Korean diet (BKD) with Western diets, including the 2010 dietary guidelines for Americans (2010 DGA) and typical American diet (TAD), on various metabolic indices in obese Korean adults. Building on this work, the current research focuses on the impact of these dietary interventions on oxidative stress (d-ROMs and BAP) and inflammation (CRP, TNF-α, IL-6, IL-1β, MCP-1) biomarkers in serum, and the concurrent urine metabolomes. Each dietary regimen was in silico and experimentally examined for their antioxidant levels using ABTS, DPPH, and FRAP assays, as well as total flavonoid (TFC) and total phenolic (TPC) contents. We assessed post-intervention variations in oxidative stress and inflammation biomarkers in serum, as well as the urine metabolite profiles for the participants (n = 48, average age: 41 years). Antioxidant contents and associated total antioxidant capacity (TAC) were significantly higher for the recommended diets (BKD and 2010 DGA) compared to TAD (p < 0.05). Butanol extracts from recommended diets (BKD and 2010 DGA) showed significantly higher antioxidant activity compared to TAD in ABTS (p < 0.01), DPPH, and FRAP (p < 0.05) assays. Consistent results were observed in total phenolic and flavonoid contents, mirroring their respective antioxidant activities. Following the intervention period, oxidative stress & inflammation markers in serum varied marginally, however, the urine metabolite profiles were clearly demarcated for the BKD and Western dietary groups (PC1 = 5.41%). For BKD group, the pre- and post-intervention urine metabolite profiles were clearly segregated (PLS2 = 2.93%). Compared to TAD, urine extracts from the recommended dietary group showed higher abundance of benzoic acid & phenolic derivatives (VIP > 0.7, p < 0.05). Metabolites associated with oxidative stress were observed higher in the urine samples from Western dietary groups compared to BKD. Urine metabolomics data delineated the post-intervention effects of three dietary interventions which corroborates the respective findings for their effects on metabolic indices.

Chronic consumption of imbalance diets high in sucrose or fat induces abdominal obesity with different pattern of metabolic disturbances and lost in Langerhans cells population

AIM

Obesity is a worldwide health issue, associated with development of type 2 Diabetes Mellitus. The aim of this study is to analyze the effect of consumption of two hypercaloric diets on metabolic disturbance and beta cells damage.

MAIN METHODS

Male Wistar rats were subjected to twelve months consumption of three diets: a Control balanced diet (CTD, carbohydrates 58 %, proteins 29 %, lipids 13 %) and two hypercaloric diets, high in sucrose (HSD, carbohydrates 68 %, proteins 22 %, lipids 10 %) or high in fat (HFD, carbohydrates 31 %, proteins 14 %, lipids 55 %). Serum levels of glucose, triglycerides and free fatty acids were measured after zoometric parameters determination. Antioxidant enzymes activity and oxidative stress-marker were measured in pancreas tissue among histological analysis of Langerhans islets.

KEY FINDINGS

Although diets were hypercaloric, the amount of food consumed by rats decreased, resulting in an equal caloric consumption. The HSD induced hypertriglyceridemia and hyperglycemia with higher levels in free fatty acids (FFA, lipotoxicity); whereas HFD did not increased neither the triglycerides nor FFA, nevertheless the loss of islets' cell was larger. Both diets induced obesity with hyperglycemia and significant reduction in Langerhans islets size.

SIGNIFICANCE

Our results demonstrate that consumption of HSD induces more significant metabolic disturbances that HFD, although both generated pancreas damage; as well hypercaloric diet consumption is not indispensable to becoming obese; the chronic consumption of unbalanced diets (rich in carbohydrates or lipids) may lead to abdominal obesity with metabolic and functional disturbances, although the total amount of calories are similar.

Zexie decoction reduce glucose-dependent lipid accumulation and oxidative stress in Caenorhabditis elegans

BACKGROUND

Obesity has become a global public health problem. Zexie decoction (ZXT) is a classic formula from Synopsis of the Golden Chamber. However, the long-term effect of ZXT in lipid accumulation remain unclear.

PURPOSE

This study aims to investigate the effect of ZXT on aging, lipid metabolism and oxidative stress.

METHODS

Different concentration of ZXT was administered to Caenorhabditis elegans (C. elegans) cultured in NGM or the high glucose nematode growth media (GNGM). The lifespan, heat stress resistance, lipid accumulation and related mRNA expression of the worms were examined. Oil Red staining and triglyceride were used to evaluated the lipid accumulation. Nhr-49, fat-5/fat-7, fat-5/fat-6 or skn-1 knockout mutants were used to clarify the effect on lipid metabolism of ZXT. GFP-binding mutants were used to observe the changes in protein expression.

RESULTS

ZXT improved the survival rate of C. elegans in lifespan test and heat stress test. ZXT also reduced lipid accumulation in C. elegans and significantly changed the expression of fatty acid synthesis related genes and lipid metabolism related genes. In addition, ZXT-treated C. elegans showed a higher expression of anti-oxidative protein, and reduced the expression of oxidative stress and mitochondrial dysfunction marker. However, when skn-1 was knockdown, ZXT no longer had the effect of maintaining the mitochondria membrane potential and lipid lowering but still effectively decreased the O2·- induced by high glucose.

CONCLUSIONS

ZXT reduced fat accumulation by regulating lipid metabolism via multiple targets and enhanced stress resistance by its antioxidant effect in C. elegans.

Serum Oxidative Status in People with Obesity: Relation to Tissue Losses, Glucose Levels, and Weight Reduction

BACKGROUND

This work aims to study the effect of reductions in various body mass components on the oxidative, glycemic, and lipid parameters of people with obesity (PWO).

METHODS

A total of 53 PWO underwent a six-month individualized low-calorie diet combined with moderate exercise, during which anthropometric, biochemical, and oxidative parameters were measured. Probands were divided into groups based on weight, visceral fat area (VFA), total body water (TBW), and skeletal muscle mass (SMM) losses.

RESULTS

Weight reduction normalizes glycemia, but VFA reduction is less pronounced, while SMM and TBW reductions are more pronounced in patients with higher initial concentrations of glucose and fructosamine. Moreover, changes in oxidative parameters correlate with changes in glucose.

CONCLUSIONS

Weight loss, regardless of the reduced tissue, decreases cardiovascular risk. We observed a significant change in almost all parameters related to the redox state. In general, parameters responsible for antioxidant action improved, and markers of oxidative damage decreased. Malondialdehyde, lipid peroxides, and total oxidative status levels can be considered biomarkers reflecting only the current severity of reactive oxygen species genesis processes. When considering the glycemic state, the results are not as clear due to the substantial differences between normoglycemic and hyperglycemic patients. Glycemic status is a factor playing a crucial role in weight reduction.

Is more prolonged sun exposure associated with healthier life habits and obesity indicators in Portuguese children?

OBJECTIVES

Sun exposure seems to have an indirect effect on the development of obesity through vitamin D synthesis in the skin, the primary source of this vitamin. The present study aimed to investigate associations among sun exposure time, obesity indicators, and lifestyle habits in children.

METHODS

A total of 4755 children (3-10 years; 49.86% boys) from the north, center and south-central Portugal were included in the present study. During 2016/2017 children's sun exposure time, screen time, time devoted to the practice of physical activity and active play were collected through standard questionnaires answered by parents. Statistical analyses were conducted to investigate differences among sun exposure time according to the sex, age, obesity indicators and lifestyle habits.

RESULTS

Linear regression analysis showed that sun exposure time presented a negative association with Body Mass Index (β = -0.09, 95% CI: -0.18; -0.003; p = .042), body fat % (β = -0.31, 95%; CI: -0.54; -0.07; p = .010), computer time (β = -0.08, 95% CI: -0.12; - 0.05; p < .0001) and a positive association with active play time (β = 0.22, 95% CI: 0.17; 0.27; p < .0001) and total time of physical activity practice (β = 10.01, 95% CI: 4.52; 15.20; p < .0001).

CONCLUSIONS

The results reinforce the need for future guidance on the ideal sun exposure time, especially in children, who are at risk for vitamin D deficiency. Standardization of criteria for classifying optimal sun exposure time in this age group, considering the parameters that affect vitamin D status, such as age and seasonality, should be considered when planning future guidelines.

Large-scale exome sequence analysis identifies sex- and age-specific determinants of obesity

Obesity contributes substantially to the global burden of disease and has a significant heritable component. Recent large-scale exome sequencing studies identified several genes in which rare, protein-coding variants have large effects on adult body mass index (BMI). Here we extended such work by performing sex-stratified associations in the UK Biobank study (N∼420,000). We identified genes in which rare heterozygous loss-of-function increases adult BMI in women (DIDO1, PTPRG, and SLC12A5) and in men (SLTM), with effect sizes up to ∼8 kg/m2. This is complemented by analyses implicating rare variants in OBSCN and MADD for recalled childhood adiposity. The known functions of these genes, as well as findings of common variant genome-wide pathway enrichment analyses, suggest a role for neuron death, apoptosis, and DNA damage response mechanisms in the susceptibility to obesity across the life-course. These findings highlight the importance of considering sex-specific and life-course effects in the genetic regulation of obesity.

Transcriptomic Changes toward Osteogenic Differentiation of Mesenchymal Stem Cells on 3D-Printed GelMA/CNC Hydrogel under Pulsatile Pressure Environment

Biomimetic soft hydrogels used in bone tissue engineering frequently produce unsatisfactory outcomes. Here, it is investigated how human bone-marrow-derived mesenchymal stem cells (hBMSCs) differentiated into early osteoblasts on remarkably soft 3D hydrogel (70 ± 0.00049 Pa). Specifically, hBMSCs seeded onto cellulose nanocrystals incorporated methacrylate gelatin hydrogels are subjected to pulsatile pressure stimulation (PPS) of 5-20 kPa for 7 days. The PPS stimulates cellular processes such as mechanotransduction, cytoskeletal distribution, prohibition of oxidative stress, calcium homeostasis, osteogenic marker gene expression, and osteo-specific cytokine secretions in hBMSCs on soft substrates. The involvement of Piezo 1 is the main ion channel involved in mechanotransduction. Additionally, RNA-sequencing results reveal differential gene expression concerning osteogenic differentiation, bone mineralization, ion channel activity, and focal adhesion. These findings suggest a practical and highly scalable method for promoting stem cell commitment to osteogenesis on soft matrices for clinical reconstruction.

Microalgae as a Nutraceutical Tool to Antagonize the Impairment of Redox Status Induced by SNPs: Implications on Insulin Resistance

Microalgae represent a growing innovative source of nutraceuticals such as carotenoids and phenolic compound which are naturally present within these single-celled organisms or can be induced in response to specific growth conditions. The presence of the unfavourable allelic variant in genes involved in the control of oxidative stress, due to one or more SNPs in gene encoding protein involved in the regulation of redox balance, can lead to pathological conditions such as insulin resistance, which, in turn, is directly involved in the pathogenesis of type 2 diabetes mellitus. In this review we provide an overview of the main SNPs in antioxidant genes involved in the promotion of insulin resistance with a focus on the potential role of microalgae-derived antioxidant molecules as novel nutritional tools to mitigate oxidative stress and improve insulin sensitivity.

Global impact on human obesity - A robust non-linear panel data analysis

Purpose: Recent studies in economics showed that humans are bounded rational. This being consumers, they are not perfect judges of what matters for the standard of living. While with a marked increase in economic and social wellbeing, there is a consistent rise in obesity levels, especially in the developed world. Thus, this study intends to explore the empirical and socio-economic antecedents of human obesity across countries using six global indexes. Methods: This study used the data of 40 countries between 1975 to 2018 and used the Panel FGLS Regression with the quadratic specification. Findings: The results showed that health and food indicators increase global human obesity, environment and education indicators decrease global human obesity, and economic and social indicators follow an inverted U-shaped pattern in affecting global human obesity. Originality: Previous studies have used infant mortality and life expectancy as the major health indicator in determining the standard of living while overlooking global human obesity as a major deterrent to welfare. This study has provided a holistic assessment of the causes of obesity in global contexts.

Effects of an obesogenic diet on the oviduct depend on the duration of feeding

Research question

How long does it take for an obesogenic (high-fat/high-sugar, HF/HS) diet to influence the oviductal microenvironment? What are the affected cellular pathways and are they dependent on the genetic background of the mouse model?

Design

Female Swiss (outbred) and C57BL/6N (B6, inbred) mice were fed either a control (10% fat) or HF/HS (60% fat, 20% fructose) diet. Body weight was measured weekly. Mice were sacrificed at 3 days (3d), 1 week (1w), 4w, 8w, 12w and 16w on the diet (n = 5 per treatment per time point). Total cholesterol concentrations and inflammatory cytokines were measured in serum. Oviductal epithelial cells (OECs) were used to study the expression of genes involved in (mitochondrial) oxidative stress (OS), endoplasmic reticulum (ER) stress and inflammation using qPCR.

Results

Body weight and blood cholesterol increased significantly in the HF/HS mice in both strains compared to controls. In Swiss mice, HF/HS diet acutely increased ER-stress and OS-related genes in the OECs already after 3d. Subsequently, mitochondrial and cytoplasmic antioxidants were upregulated and ER-stress was alleviated at 1w. After 4-8w (mid-phase), the expression of ER-stress and OS-related genes was increased again and persisted throughout the late-phase (12-16w). Serum inflammatory cytokines and inflammatory marker-gene expression in the OECs were increased only in the late-phase. Some of the OEC stress responses were stronger or earlier in the B6.

Conclusions

OECs are sensitive to an obesogenic diet and may exhibit acute stress responses already after a few days of feeding. This may impact the oviductal microenvironment and contribute to diet-induced subfertility.

Association of dietary antioxidant index with body mass index in adolescents

Background

Dietary antioxidants may decrease body fat through reduction of oxidative stress. This study aimed to examine the association between dietary antioxidant index (DAI) and body mass index (BMI) in adolescent boys.

Methods

In this cross-sectional study, 593 adolescent boys aged 12-16 years were randomly selected and were divided into two groups of overweight and non-overweight individuals. Data on physical activity and anthropometric measurements were collected. Dietary intake was assessed using 168-item semi quantitative food frequency questionnaire and the DAI score was calculated to measure the antioxidant capacity of the diet.

Results

The overweight adolescents had higher intake of energy (2490.55 ± 632.49 vs. 2354.33 ± 632.64 kcal/d, p = 0.01), carbohydrate (290.21 ± 71.41 vs. 272.93 ± 79.22 g/d, p = 0.01), fat (111.51 ± 40.76 vs. 104.51 ± 35.56 g/d, p = 0.04), calcium (811.70 ± 283.70 vs. 741.06 ± 251.17 g/d, p = 0.003), and vitamin D (1.41 ± 1.17 vs. 1.18 ± 1.19 μg/d, p = 0.031) in comparison with normal weight adolescents. The DAI had an inverse association with BMI after adjustment for age and caloric intake (OR: 0.85, 95% CI: 0.76-0.96, p = 0.009). Additional adjustment for dietary intake of vitamin A, vitamin E, vitamin C, zinc, manganese, and selenium did not change the results.

Conclusion

The results of the study showed that following a diet rich in antioxidants may be effective in preventing obesity in adolescent boys. Further longitudinal studies are needed to confirm these finding and to determine the underlying mechanisms.

Transcriptional modulation of inflammation, and aging in Indian obese adults following a 12-week yoga-based lifestyle intervention: A randomized controlled trial

Introduction

Obesity is one of the major global problems in today's world, both in children, and the adult age group. Current evidence suggests obesity alters the expression of various genes related to oxidative stress, inflammation, and aging. In recent times complementary therapy like yoga-based lifestyle intervention (YBLI) is used as an adjunct therapy to modern medicine. This study examines the efficacy of 12 weeks of yoga-based lifestyle intervention with standard care (SC) on the expression of genes related to oxidative stress, inflammation, and aging in obese adults.

Methods

This was a two-arm parallel randomized control trial implemented at Integral Health Clinic (IHC), an outpatient facility that regularly conducted YBLI programs for the prevention of lifestyle diseases like obesity and diabetes in the Department of Physiology, All India Institute of Medical Sciences (AIIMS), New Delhi. Blood samples at baseline and weeks 2,4, and 12 were collected from 72 adults (male n = 21; female n = 51) of age 20–45 years with a body–mass index (BMI) of 25–35 kg/m² who were randomized to receive either a 12-week SC (n = 36) or YBLI (n = 36). SC included recommendations for the management of obesity as per Indian guidelines including a low-calorie individualized diet and physical activity. Asana (physical postures), pranayama (breathing exercises), and meditation were all part of the YBLI. Primary outcomes were relative fold change in the expression of genes associated with oxidative stress [Nuclear factor-kappa B (NF-Kappa B)], inflammation [Tumor necrosis factor-α (TNFα), interleukin-6 (IL-6)], and aging [human telomerase reverse transcriptase (TERT)] in peripheral blood mononuclear cells between the two groups at week-12.

Results

There were no significant changes in fold change of TERT, IL-6, and NF-kappa B between the groups at week 12. The relative fold change of TERT was significantly greater in the YBLI group (p = <0.0001) vs the SC group at 2 weeks. The relative fold change of TNF α was significantly lower at week 12 in YBLI though the change was not continuous and reliable. Within both groups, TERT expression was significantly increased at week 2 though the change was greater in the YBLI group (p < 0.0001). TNF α gene expression was significantly lower at weeks 2 and 4, compared to baseline level, in the SC group but it increased at week 12.

Conclusion

The results while did not confirm our hypothesis, are important to share with the scientific society, to be able to improve prospective study designs and find optimal time/intervention/biological marker settings for this highly important scientific field. The results are suggestive of a positive impact of YBLI and SC on the fold change of aging-related TERT gene in obesity, though the benefit was not evident till week 12. However, the results should be evaluated with caution and in light of other published studies. To better understand the positive effects of YBLI on oxidative stress, inflammation, and aging-related gene expression in obesity, larger studies are recommended.

Oxidative Stress in Men with Obesity, Metabolic Syndrome and Type 2 Diabetes Mellitus: Mechanisms and Management of Reproductive Dysfunction

Reactive oxygen species (ROS) are critical physiological mediators of cellular function, including male fertility. When ROS exceed antioxidant regulation, oxidative stress occurs which is detrimental to cellular function. Oxidative stress has been found to be a central mediator of obesity, metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM), as well as with male infertility. Human studies have correlated testicular oxidative stress in obese males, and animal studies have further provided insight into potential mechanisms of action. Management of oxidative stress is not well defined. Appropriate nutrition and exercise can be recommended for all diabetic patients, and weight loss for obese patients with MetS and T2DM. Consideration of dietary supplements including micronutrients, antioxidants or medicinal herbs are recommended. Metformin may also offer benefits on testicular oxidative stress and fertility parameters. Significantly more research on causation, mechanisms, clinical assessments and appropriate management of infertility on obesity, MetS and T2DM is still required.

The Mechanisms and Management of Age-Related Oxidative Stress in Male Hypogonadism Associated with Non-communicable Chronic Disease

Androgens have diverse functions in muscle physiology, lean body mass, the regulation of adipose tissue, bone density, neurocognitive regulation, and spermatogenesis, the male reproductive and sexual function. Male hypogonadism, characterized by reduced testosterone, is commonly seen in ageing males, and has a complex relationship as a risk factor and a comorbidity in age-related noncommunicable chronic diseases (NCDs), such as obesity, metabolic syndrome, type 2 diabetes, and malignancy. Oxidative stress, as a significant contributor to the ageing process, is a common feature between ageing and NCDs, and the related comorbidities, including hypertension, dyslipidemia, hyperglycemia, hyperinsulinemia, and chronic inflammation. Oxidative stress may also be a mediator of hypogonadism in males. Consequently, the management of oxidative stress may represent a novel therapeutic approach in this context. Therefore, this narrative review aims to discuss the mechanisms of age-related oxidative stress in male hypogonadism associated with NCDs and discusses current and potential approaches for the clinical management of these patients, which may include conventional hormone replacement therapy, nutrition and lifestyle changes, adherence to the optimal body mass index, and dietary antioxidant supplementation and/or phytomedicines.

NMR-Based Metabolomics Approach to Investigate the Effects of Fruits of Acanthopanax sessiliflorus in a High-Fat Diet Induced Mouse Model

The prevalence of obesity is rapidly increasing and is recognized as a serious health problem. To investigate metabolic changes in an obese model after administration of Acanthopanax sessiliflorus, mice were divided into four groups: normal diet, high-fat diet (HFD), HFD with treatment fenofibrate, and A. sessiliflorus fruit extract. The liver tissue of mice was analyzed using nuclear magnetic resonance (NMR) spectrometry-based metabolomics. In multivariate statistical analyses, the HFD group was discriminated from the normal diet group, and the group fed A. sessiliflorus fruit was discriminated from the HFD group. In biomarker analysis between the HFD group and the group fed A. sessiliflorus fruit, alanine, inosine, formate, pyroglutamate, taurine, and tyrosine, with AUC values of 0.7 or more, were found. The levels of these metabolites were distinguished from the HFD mouse model. Changes in these metabolites were confirmed to act on metabolic pathways related to antioxidant activity.

Selenium status and its relationship with thyroid hormones in obese women

BACKGROUND AND AIMS

Studies have been conducted with the purpose of elucidating thyroid gland dysfunction in obesity, however the contributing factors for such dysfunction are not yet fully understood. Selenium is notable for its role in thyrocyte protection against oxidative damage and control of thyroid hormone synthesis. In addition, subjects with obesity may exhibit alterations in the selenium homeostasis. Therefore, the present study aimed to examine the selenium status and its relationship with serum thyroid hormone levels in obese women.

METHODS

This cross-sectional study included 69 euthyroid women, aged between 18 and 50 years, who were divided in two groups: an obese group (n = 35) and a control group with women of normal weight (n = 34). Selenium intake was assessed by three-day diet records and analyzed using NutWin software version 1.5. Plasma, erythrocyte, and urinary selenium levels were determined using inductively coupled plasma optical emission spectrometry. Testing for thyroid hormones and thyroid autoantibodies was performed based on chemiluminescence.

RESULTS

The median dietary selenium content was adequate according to the recommendations, with no statistical difference between groups. Obese women had reduced plasma and erythrocyte selenium levels compared to the control group, although selenium concentration in erythrocytes was adequate within the normal range for both groups. There was no significant difference between the urinary selenium concentrations in the subjects; however, the mineral clearance was higher in the obese group. Free triiodothyronine (fT3) and free thyroxine (fT4) levels were higher in obese women with class II obesity when compared to the control group. There was a negative correlation between plasma selenium and serum fT4 levels.

CONCLUSIONS

Obese women showed impairment in selenium homeostasis, however, this fact did not seem to adversely affect thyroid metabolism.

The effect of newly initiated exercise training on dynamic thiol / disulphide homeostasis in sedentary obese adults

We studied dynamic thiol/disulphide homeostasis, an indicator of oxidative stress, to investigate the effects of newly initiated exercise training on sedentary obese adults. Seventeen sedentary obese adults and 15 normal-weight controls were included in the sample for this study. The obese adults were given a physical exercise training program that lasted twelve weeks. Before and after the exercise training program, blood samples were collected, and serum thiol/disulphide parameters were measured by using a novel technique. Before the start of the exercise training, it was observed that thiol/disulphide homeostasis was impaired, and this impairment was positively correlated with body mass index in sedentary obese adults because of the higher reactive oxygen species production in adipose tissue. However, while the obese participants' body mass index significantly decreased, the thiol/disulphide homeostasis parameters in the obese adults did not change over time as calculated at the baseline and compared to the calculation after the twelve weeks of exercise training. Despite a decrease in body mass index that occurred after the twelve weeks of exercise training, there was a lack of improvement in the obesity-induced impairment of thiol/disulphide homeostasis, which suggests that a newly initiated exercise training program may lead to oxidative stress.

Reduced Stability and pH-Dependent Activity of a Common Obesity-Linked PCSK1 Polymorphism, N221D

Common mutations in the human prohormone convertase (PC)1/3 gene (PCKSI) are linked to increased risk of obesity. Previous work has shown that the rs6232 single-nucleotide polymorphism (N221D) results in slightly decreased activity, although whether this decrease underlies obesity risk is not clear. We observed significantly decreased activity of the N221D PC1/3 enzyme at the pH of the trans-Golgi network; at this pH, the mutant enzyme was less stable than wild-type enzyme. Recombinant N221D PC1/3 also showed enhanced susceptibility to heat stress. Enhanced susceptibility to tunicamycin-induced endoplasmic reticulum stress was observed in AtT-20/PC2 cell clones in which murine PC1/3 was replaced by human N221D PC1/3, as compared with wild-type human PC1/3. However, N221D PC1/3-expressing AtT-20/PC2 clones processed proopiomelanocortin to α-MSH similarly to wild-type PC1/3. We also generated a CRISPR-edited mouse line expressing the N221D mutation in the PCKSI gene. When homozygous N221D mice were fed either a standard or a high-fat diet, we found no increase in body weight compared with their wild-type sibling controls. Sexual dimorphism was observed in pituitary ACTH for both genotypes, with females exhibiting lower levels of pituitary ACTH. In contrast, hypothalamic α-MSH content for both genotypes was higher in females compared with males. Hypothalamic corticotropin-like intermediate peptide content was higher in wild-type females compared with wild-type, but not N221D, males. Taken together, these data suggest that the increased obesity risk linked to the N221D allele in humans may be due in part to PC1/3-induced loss of resilience to stressors rather than strictly to decreased enzymatic activity on peptide precursors.

Immunomodulatory effect of mancozeb, chlorothalonil, and thiophanate methyl pesticides on macrophage cells

Mancozeb (MZ), chlorothalonil (CT), and thiophanate methyl (TM) are pesticides commonly used in agriculture due to their efficacy, low acute toxicity to mammals, and short environmental persistence. Although the toxic effects of these pesticides have been previously reported, studies regarding their influence on the immune system are limited. As such, this study focused on the immunomodulatory effect of MZ, CT, and TM pesticides on macrophage cells. RAW 264.7 cells were exposed to a range of concentrations (0.1-100 μg/mL) of these pesticides. CT exposure promoted an increase in reactive oxygen species (ROS) and nitric oxide (NO) levels. The MTT and ds-DNA assay results demonstrated that MZ, CT, and TM exposure induced macrophage proliferation. Moreover, MZ, CT, and TM promoted cell cycle arrest at S phase, strongly suggesting macrophage proliferation. The levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, and IFN-γ) and caspases (caspase 1, 3, and 8) in macrophages exposed to MZ, CT, and TM pesticides increased, whereas the anti-inflammatory cytokine levels decreased. These results suggest that MZ, CT, and TM exert an immunomodulatory effect on the immune system, inducing macrophage activation and enhancing the inflammatory response.

Common Variants in 22 Genes Regulate Response to Metformin Intervention in Children with Obesity: A Pharmacogenetic Study of a Randomized Controlled Trial

Metformin is a first-line oral antidiabetic agent that has shown additional effects in treating obesity and metabolic syndrome. Inter-individual variability in metformin response could be partially explained by the genetic component. Here, we aimed to test whether common genetic variants can predict the response to metformin intervention in obese children. The study was a multicenter and double-blind randomized controlled trial that was stratified according to sex and pubertal status in 160 children with obesity. Children were randomly assigned to receive either metformin (1g/d) or placebo for six months after meeting the defined inclusion criteria. We conducted a post hoc genotyping study in 124 individuals (59 placebo, 65 treated) comprising finally 231 genetic variants in candidate genes. We provide evidence for 28 common variants as promising pharmacogenetics regulators of metformin response in terms of a wide range of anthropometric and biochemical outcomes, including body mass index (BMI) Z-score, and glucose, lipid, and inflammatory traits. Although no association remained statistically significant after multiple-test correction, our findings support previously reported variants in metformin transporters or targets as well as identify novel and promising loci, such as the ADYC3 and the BDNF genes, with plausible biological relation to the metformin's action mechanism. Trial Registration: Registered on the European Clinical Trials Database (EudraCT, ID: 2010-023061-21) on 14 November 2011 (URL: https://www.clinicaltrialsregister.eu/ctr-search/trial/2010-023061-21/ES).

Glutathione-dependent enzyme activities of peripheral blood mononuclear cells decrease during the winter season compared with the summer in normal-weight and severely obese adolescents

Oxidative stress-related inflammation is known to play a vital role in obesity-associated cardiovascular disease, contributing to the early stages of the pathology as well as during its development. Therefore, it is of great interest to understand how obesity-induced stress modulates antioxidant enzyme activity during puberty. To this end, 27 severely obese adolescents (body mass index > 30, z-score > 3.7) were recruited from a paediatric weight management centre. Eighteen were recruited during the summer and nine in the winter. All underwent a 4-month weight loss programme consisting in diet and physical activity. Twenty normal-weight age-matched adolescents were recruited from the same geographical area to serve as controls. Blood samples were extracted, and antioxidant enzyme activities were determined in peripheral blood mononuclear cells (PBMCs) and erythrocytes. The enzymes studied included catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase. Severely obese adolescents presented lower PBMC-glutathione reductase activity than their corresponding normal-weight counterparts. In addition, glutathione-dependent activities tended to be lower in both groups during the winter compared with summer. These changes coincided with differences in circulating vitamin D levels. Results may suggest that season-dependent factors such as vitamin D could affect glutathione-dependent activities in severely obese as well as in normal-weight adolescents.

Ginkgo biloba Extract Modulates the Retroperitoneal Fat Depot Proteome and Reduces Oxidative Stress in Diet-Induced Obese Rats

The rapid increase in the number of individuals with obesity, over the past four decades, is triggered by a number of complex interactions among factors. Despite the plethora of treatments available, side effects are commonly observed and, in this context, herbal medicines have been employed as an alternative form of therapy. Ginkgo biloba extract (GbE) has been described as a promising new pharmacological approach to treat obesity. In order to better comprehend the mechanisms involved with this potential effect, the present study evaluated the effects of GbE treatment on diet-induced obese rats, focusing on the proteome and the oxidative stress defense system of visceral adipose tissue. After 14 days treatment, GbE significantly modulated 25 proteins. Retroperitoneal adipose tissue of treated animals exhibited higher amounts of proteins associated with adipogenesis (decorin), carbon metabolism and mitochondrial function (citrate synthase), and a concomitant reduction in adipocyte hypertrophy. In parallel, GbE down-regulated proteins involved in oxidative stress (peroxiredoxin) and the inflammatory response (complement C3, mast cell protease 1, and Ig gamma-2B chain C region). Moreover, also related to oxidative stress defense, GbE stimulated catalase activity, reduced malondialdehyde levels (lipid peroxidation indicator), and increased lactoylglutathione lyase levels. It was concluded that GbE acts as an antioxidant agent, and improved the proteome profile and oxidative stress response in the adipose tissue of diet-induced obese rats.

Transcriptomic and microRNA analyses of gene networks regulated by eicosapentaenoic acid in brown adipose tissue of diet-induced obese mice

Brown adipose tissue (BAT) dissipates chemical energy as heat via thermogenesis and protects against obesity by increasing energy expenditure. However, regulation of BAT by dietary factors remains largely unexplored at the mechanistic level. We investigated the effect of eicosapentaenoic acid (EPA) on BAT metabolism. Male C57BL/6J (B6) mice were fed either a high-fat diet (HF, 45% kcal fat) or HF diet supplemented with EPA (HF-EPA, 6.75% kcal EPA) for 11 weeks. RNA sequencing (RNA-Seq) and microRNA (miRNA) profiling were performed on RNA from BAT using Illumina HiSeq and Illumina Genome Analyzer NextSeq, respectively. We conducted pathway analyses using ingenuity pathway analysis software (IPA®) and validated some genes and miRNAs using qPCR. We identified 479 genes that were differentially expressed (2-fold change, n = 3, P ≤ 0.05) in BAT from HF compared to HF-EPA. Genes negatively correlated with thermogenesis such as hypoxia inducible factor 1 alpha subunit inhibitor (Hif1an), were downregulated by EPA. Pathways related to thermogenesis such as peroxisome proliferator-activated receptor (PPAR) were upregulated by EPA while pathways associated with obesity and inflammation such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) were downregulated by EPA. MiRNA profiling identified nine and six miRNAs that were upregulated and downregulated by EPA, respectively (log2 fold change > 1.25, n = 3, P ≤ 0.05). Key regulatory miRNAs which were involved in thermogenesis, such as miR-455-3p and miR-129-5p were validated using qPCR. In conclusion, the depth of transcriptomic and miRNA profiling revealed novel mRNA-miRNA interaction networks in BAT which are involved in thermogenesis, and regulated by EPA.

Interplay between diet-induced obesity and oxidative stress: Comparison between Drosophila and mammals

Obesity caused by excessive fat accumulation in adipocytes is a growing global problem and is a major contributing risk factor for many chronic metabolic diseases. There is increasing evidence that oxidative stress plays a crucial role in both obesity progression and obesity-related complications. In recent years, Drosophila models of diet-induced obesity and associated pathologies have been successfully developed through manipulation of carbohydrate or fat concentrations in the food. Obese flies accumulate triacylglycerols in the fat body, an organ homologous to mammalian adipose tissue and exhibit metabolic and physiological complications including hyperglycemia, redox imbalance and shortened longevity; these are all similar to those observed in obese humans. In this review, we summarize current data on the mechanisms of oxidative stress induction in obesity, with emphasis on metabolic switches and the involvement of redox-responsive signaling pathways such as NF-κB and Nfr2. The recent achievements with D. melanogaster model suggest a complicated relationship between obesity, oxidative stress, and longevity but the Drosophila model offers probably the best opportunities to delve further into unraveling these interactions, particularly the roles of antioxidants and of Nrf2-regulated responses, in order to increase our understanding of the obese metabolic phenotype and test and develop anti-obesity pharmaceuticals.

Protective effects of tricetinidin against oxidative stress inducers in rat kidney cells: A comparison with delphinidin and standard antioxidants

The potential protective effect of tricetinidin as novel antioxidant is investigated and compared with selected known antioxidant substances in vitro. Dihydroethidium staining was performed to detect intracellular ROS formation and the protective effect of the antioxidant substances in combination with the superoxide-inducer antimycin a (AMA). Glutathione level, mitochondrial membrane potential and HO-1 expression were analysed for further characterization of the cellular response. The cytokinesis block micronucleus test was applied to investigate the anti-genotoxic effect of the substances against insulin induced genomic damage. AMA treatment caused a significant increase in intracellular ROS formation and insulin treatment induced a significant micronucleus induction in NRK cells. Combination of the antioxidant substances with AMA or insulin protected from the oxidative stress and the micronucleus-induction. All analysed antioxidants showed comparable effects on GSH production and mitochondrial membrane potential. Only delphinidin and tricetinidin caused an increase in HO-1 expression. Tricetinidin and delphinidin might be good candidates for development as an antioxidant supplement. Further research is necessary to show possible therapeutic and preventive effects of tricetinidin and delphinidin in vivo.

DNA damage in obesity: Initiator, promoter and predictor of cancer

Epidemiological evidence linking obesity with increased risk of cancer is steadily growing, although the causative aspects underpinning this association are only partially understood. Obesity leads to a physiological imbalance in the regulation of adipose tissue and its normal functioning, resulting in hyperglycaemia, dyslipidaemia and inflammation. These states promote the generation of oxidative stress, which is exacerbated in obesity by a decline in anti-oxidant defence systems. Oxidative stress can have a marked impact on DNA, producing mutagenic lesions that could prove carcinogenic. Here we review the current evidence for genomic instability, sustained DNA damage and accelerated genome ageing in obesity. We explore the notion of genotoxicity, ensuing from systemic oxidative stress, as a key oncogenic factor in obesity. Finally, we advocate for early, pre-malignant assessment of genome integrity and stability to inform surveillance strategies and interventions.

Evaluation of Mn-superoxide dismutase and catalase gene expression in childhood obesity: its association with insulin resistance

Background Obesity is associated with oxidative stress. Superoxide dismutase (SOD) is the first line of defense against reactive oxygen species (ROS), eliminating the strong superoxide radical and producing H2O2, which can then be degraded by catalase (CAT). The main objective of this study was to evaluate the gene expression antioxidant enzymes (Mn-SOD and CAT) in peripheral blood mononuclear cells (PBMCs) of obese and normal-weight children, and its association with anthropometric and biochemical parameters. Methods Thirty obese and 30 control subjects between the ages of 8 and 16 years were enrolled in this study. Serum insulin levels were measured using enzyme-linked immunosorbent assay (ELISA), and insulin resistance was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR). Biochemical parameters were also measured. PBMCs of the subjects were separated and Mn-SOD and CAT gene expression was measured using real-time polymerase chain reaction (PCR). Results Mn-SOD and CAT gene expression was significantly lower in the obese group compared with the control group (p<0.01). Also, a positive correlation was observed between the gene expression of Mn-SOD and CAT and body mass index (BMI), fasting blood sugar, insulin resistance, low density lipoprotein-cholesterol (LDL-C) cholesterol, triglycerides (TG) and systolic blood pressure (SBP). Conclusions Induction of antioxidants, especially Mn-SOD and CAT, can lead to reduction of oxidative stress and prevent the complications of obesity in children.

Genetic polymorphisms of antioxidant enzymes CAT and SOD affect the outcome of clinical, biochemical, and anthropometric variables in people with obesity under a dietary intervention

BACKGROUND

Genetic polymorphisms of antioxidant enzymes CAT, GPX, and SOD are involved in the etiology of obesity and its principal comorbidities. The aim of the present study was to analyze the effect of aforementioned SNPs over the output of several variables in people with obesity after a nutritional intervention. The study included 92 Mexican women, which received a dietary intervention by 3 months. Participants were genotyped and stratified into two groups: (1) carriers; mutated homozygous plus heterozygous (CR) and (2) homozygous wild type (WT). A comparison between CR and WT was done in clinical (CV), biochemical (BV), and anthropometric variables (AV), at the beginning and at the end of the intervention.

RESULTS

Participants (n = 92) showed statistically significant differences (p < 0.05) at the end of the nutritional intervention in several CV, BV, and AV. However, two kinds of responses were observed after genotyping participants: (A) CR and WT showed statistically significant differences (p < 0.05) in several CV, BV, and AV for the SNPs 599C>T GPX1 (rs1050450), - 251A>G SOD1 (rs2070424), and - 262C>T CAT (rs1001179). (B) Only CR showed statistically changes (p < 0.05) in several CV, BV, and AV for the SNPs - 21A>T CAT (rs7943316) and 47C>T SOD2 (rs4880). The dietary intervention effect was statistically significantly between the polymorphisms of 47C>T SOD2 and BMI, SBP, TBARS, total cholesterol, and C-LCL (p < 0.05) and between the polymorphisms of - 21A>T CAT (rs7943316) and SBP, DBP, total cholesterol, and atherogenic index (p < 0.05).

CONCLUSION

People with obesity display different response in several CV, BV, and AV after a nutritional intervention, depending on the antioxidant genetic background of SOD and CAT enzymes.

Allopurinol and risk of benign prostatic hyperplasia in a Finnish population-based cohort

BACKGROUND

Metabolic syndrome and obesity are linked with hyperuricemia, and it has also been proposed that oxidative stress associated with hyperuricemia may promote benign prostatic hyperplasia (BPH). However, it is currently unknown whether use of antihyperuricemic medication is associated with risk of developing BPH. We studied the association between BPH and use of antihyperuricemic allopurinol in a Finnish population-based cohort.

METHODS

The study cohort consisted of 74,754 men originally identified for the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). Information on gout and BPH medication usage (5α-reductase inhibitors, 5ARIs) during 1996-2014 was obtained from the National medication reimbursement database. Information on BPH diagnoses from in- and outpatient hospital visits and BPH-related surgery was obtained from the National Health Care Registry. Men with a record of BPH at baseline was excluded. We used Cox regression to analyze risk of starting BPH medication, having a recorded diagnosis or undergoing BPH surgery by allopurinol use with adjustment for age and simultaneous use of statins, antidiabetic or antihypertensive drugs and aspirin or other NSAIDs. Medication use was analyzed as a time-dependent variable to minimize immortal time bias.

RESULTS

Men using allopurinol had a decreased risk for all three BPH endpoints: BPH medication (HR 0.81; 95% CI 0.75-0.88), BPH diagnosis (HR 0.78; 95% CI 0.71-0.86) and BPH-related surgery (HR 0.67; 95% CI 0.58-0.76) after multivariable adjustment. The risk association did not change by cumulative use. The risk decrease disappeared after 1-2 years lag time. Only BMI modified the risk association; the risk decrease was observed only among men with BMI above the median (27.3 kg/m²); p for interaction <0.05 for each endpoint.

CONCLUSIONS

We found that allopurinol use is associated with lowered risk of BPH medication, diagnosis and surgery. A possible explanation could be antioxidative effects of urate-lowering allopurinol.

Genetic Polymorphisms in SOD (rs2070424, rs7880) and CAT (rs7943316, rs1001179) Enzymes Are Associated with Increased Body Fat Percentage and Visceral Fat in an Obese Population from Central Mexico

BACKGROUND AND AIMS

Oxidative disturbance is an important factor involved in the etiology of comorbidities associated with obesity. Genetic polymorphisms such as SOD1 -251A>G, SOD2 47 C>T, CAT -21A>T and CAT -262 C>T have been described to alter the activity of antioxidant enzymes. The aim of the present work was to analyze the association of the mentioned SNPs with obesity and their relationship with anthropometric and clinical variables in this group.

METHODS

The study included 416 Mexican women (208 normal weight, NW and 208 subjects with obesity, OB). Dietary intake, anthropometric, biochemical and clinical features were evaluated and then analyzed in function of the genotypes.

RESULTS

The mutated carriers (GA+GG) of SOD -251 were significantly higher in the OB group (0.24) compared to the NW group (0.08). The other SNPs showed no differences compared with control group. When comparing carrier mutated subjects with obesity vs. wild-type obese participants with the SNPs SOD1 -251, SOD2 47 and CAT -262, the carriers showed a significantly (p <0.05) higher value in body fat percentage. Also, carriers of SOD2 47 and CAT-262 showed significantly higher values (p = 0.002) and (p = 0.01), respectively, when visceral fat was compared between groups. Systolic blood pressure was significantly higher (p = 0.02) in carriers of mutated CAT-21.

CONCLUSION

SOD1 -251A>G is associated with obesity independent of the presence of diabetes or dyslipidemia. Mutated obese carries of SOD1 -251, SOD2 47 and CAT -262 are associated with a higher distribution of fat in comparison with obese wild-type carriers.

Obesity-associated digestive cancers: A review of mechanisms and interventions

The prevalence of obesity has steadily increased over the past few decades. Previous studies suggest that obesity is an oncogenic factor and that over 20% of all cancers are obesity-related. Among such cancers, digestive system malignancies (including esophageal adenocarcinomas, colorectal cancers, and cancers of the gastric cardia, liver, and pancreas) are reported most frequently. While the 5-year survival rates of cancers of the breast and prostate are 90%, that rate is only 45% for digestive cancers. In this review, the mechanisms of obesity-associated digestive cancers are discussed, with an emphasis on obesity-related gene mutations, insulin and insulin-like growth factor signaling pathways, chronic inflammation, and altered adipokine levels. Evidence that these factors often function interdependently rather than independently in carcinogenesis is presented. Recommended interventions that may reduce the burden of obesity-associated digestive cancers, such as participation in physical activity, diet modulation, and calorie restriction, are also described.

Reactive Oxygen Species and Oxidative Stress in Obesity-Recent Findings and Empirical Approaches

OBJECTIVE

High levels of reactive oxygen species (ROS) are intricately linked to obesity and associated pathologies, notably insulin resistance and type 2 diabetes. However, ROS are also thought to be important in intracellular signaling, which may paradoxically be required for insulin sensitivity. Many theories have been developed to explain this apparent paradox, which have broadened our understanding of these important small molecules. While many sites for intracellular ROS production have been described, mitochondrial generated ROS remain a major contributor in most cell types. Mitochondrial ROS generation is controlled by a number of factors described in this review. Moreover, these studies have established both a demand for novel sensitive approaches to measure ROS, as well as a need to standardize and review their suitability for different applications.

METHODS

To properly assess levels of ROS and mitochondrial ROS in the development of obesity and its complications, a growing number of tools have been developed. This paper reviews many of the common methods for the investigation of ROS in mitochondria, cell, animal, and human models.

RESULTS

Available approaches can be generally divided into those that measure ROS-induced damage (e.g., DNA, lipid, and protein damage); those that measure antioxidant levels and redox ratios; and those that use novel biosensors and probes for a more direct measure of different forms of ROS (e.g., 2',7'-di-chlorofluorescein (DCF), dihydroethidium (DHE) and its mitochondrial targeted form (MitoSOX), Amplex Red, roGFP, HyPer, mt-cpYFP, ratiometric H₂ O₂ probes, and their derivatives). Moreover, this review provides caveats and strengths for the use of these techniques in different models.

CONCLUSIONS

Advances in these techniques will undoubtedly advance the understanding of ROS in obesity and may help resolve unanswered questions in the field.

Role of oxidative stress and antioxidants in daily nutrition and human health

Diet may be defined as a complex process that should involve a deeper comprehension of metabolism, energy balance, and the molecular pathways involved in cellular stress response and survival, gut microflora genetics, enzymatic polymorphism within the human population, and the role of plant-derived polyphenols in this context. Metabolic syndrome, encompassing pathologies with a relatively high morbidity, such as type 2 diabetes, obesity, and cardiovascular disease, is a bullet point of the big concern about how daily dietary habits should promote health and prevent metabolic impairments to prevent hospitalization and the need for health care. From a clinical point of view, very few papers deal with this concern, whereas most of the evidence reported focuses on in vitro and animal models, which study the activity of phytochemicals contained in the daily diet. A fundamental issue addressed by dietitians deals with the role exerted by redox-derived reactive species. Most plant polyphenols act as antioxidants, but recent evidence supports the idea that these compounds primarily activate a mild oxidative stress to elicit a positive, beneficial response from cells. How these compounds may act upon the detoxifying system exerting a scavenging role from reactive oxygen or nitrogen species is still a matter of debate; however, it can be argued that their role is even more complex than expected, acting as signaling molecules in the cross-talk mitochondria-endoplasmic reticulum and in enzymatic pathways involved in the energetic balance. In this relationship, a fundamental role is played by the brain-adipose tissue-gut axis. The aim of this review was to elucidate this topic and the state of art about the role of reactive species in cell signaling and the function of metabolism and survival to reappraise the role of plant-derived chemicals.

Impact of weight loss induced by gastric bypass or caloric restriction on oxidative stress and genomic damage in obese Zucker rats

BACKGROUND

Evidence on bariatric surgery induced weight loss and its possible impact on cancer risk is limited, but also controversial. We used obese Zucker(fa/fa) and lean Zucker(fa/+) to investigate the association between obesity, oxidative stress and genomic damage after weight loss induced either by Roux-en-Y gastric bypass surgery (RYGB) or caloric restriction.

METHODS

Male Zucker(fa/fa) rats underwent RYGB (n=15) or sham surgery (n=17). Five shams were food restricted and body weight matched (BWM) to RYGB. Twelve Zucker(fa/+) rats served as lean controls. Body weight and food intake were measured daily. An oral glucose tolerance test was performed on day 27. DHE staining and western blots of HSP70 and HO-1 were used to evaluate oxidative stress and anti-3-nitrotyrosine antibody staining for nitrative stress detection in colon and kidney. Lipid peroxidation products in urine were quantified by TBARS assay. LC/MS/MS was applied to measure urinary excretion of 8-oxoGua (oxidized DNA derived base), 8-oxodG (oxidized DNA derived nucleoside) and 8-oxoGuo (oxidized RNA derived nucleoside). DNA double strand breaks (DSBs) and cell proliferation (PCNA) were detected by immunohistochemistry.

RESULTS

Sham-operated rats showed impaired glucose tolerance, elevated plasma insulin levels as well as elevated oxidative stress and nitrative stress markers, which were less severe after weight loss by RYGB or caloric restriction. Cell proliferation showed similar trends but no significant alteration. DNA DSBs were more frequent in sham-operated compared to all other groups. DNA damage in Zucker(fa/fa) rats positively correlated with basal plasma insulin values (Spearman's correlation coefficient for colon, 0.634 and for kidney, 0.525).

CONCLUSIONS

RYGB and caloric restriction were sufficient to significantly reduce elevated oxidative/nitrative stress and genomic damage in obese Zucker(fa/fa) rats. Further investigations are needed to elucidate the underlying mechanism of these genome protective effects.

Impact of 3-Amino-1,2,4-Triazole (3-AT)-Derived Increase in Hydrogen Peroxide Levels on Inflammation and Metabolism in Human Differentiated Adipocytes

Obesity is characterized by an excessive accumulation of fat in adipose tissue, which is associated with oxidative stress and chronic inflammation. Excessive H2O2 levels are degraded by catalase (CAT), the activity of which is decreased in obesity. We investigated the effects of inhibition of catalase activity on metabolism and inflammation by incubating human differentiated adipocytes with 10 mM 3-amino-1,2,4-triazole (3-AT) for 24 h. As expected, the treatment decreased CAT activity and increased intracellular H2O2 levels significantly. Glutathione peroxidase (GPX) activity was also reduced, and the gene expression levels of the antioxidant enzymes GPX4 and peroxiredoxins (1, 3 and 5) were inhibited. Interestingly, this occurred along with lower mRNA levels of the transcription factors nuclear factor (erythroid 2-like 2) and forkhead box O, which are involved in redox homeostasis. However, superoxide dismutase activity and expression were increased. Moreover, 3-AT led to nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation and increased tumor necrosis alpha and interleukin 6 protein and gene expression levels, while lowering peroxisome proliferator-activated receptor gamma (PPARγ) mRNA and protein levels. These alterations were accompanied by an altered glucose and lipid metabolism. Indeed, adipocytes treated with 3-AT showed reduced basal glucose uptake, reduced glucose transporter type 4 gene and protein expression, reduced lipolysis, reduced AMP-activated protein kinase activation and reduced gene expression of lipases. Our results indicate that increased H2O2 levels caused by 3-AT treatment impair the antioxidant defense system, lower PPARγ expression and initiate inflammation, thus affecting glucose and lipid metabolism in human differentiated adipocytes.

Oxidative stress, type 2 diabetes and vitamin D: past, present and future

Oxidative stress refers to an imbalance between potentially harmful free radicals and the body's mechanisms to efficiently detoxify them in favor of the free radicals. Consequently, excess free radicals can attack and damage a wide range of biomolecules including proteins, lipids and nucleic acids. Antioxidant mechanisms of the body are under the influence of genetic and environmental (including dietary) factors. Diabetes is one of the most common metabolic disorders around the world. A huge body of evidence indicates a role for oxidative stress in development of many human diseases including diabetes. In this article, the latest information on the possible links of oxidative stress with diabetes development, control and complications as well as the newest results of antioxidant supplementation trials is reviewed. In addition, the possible role of vitamin D, as a newly recognized antioxidant in diabetes is discussed. Finally, concluding remarks on pivotal issues and future studies are presented.

Nrf2 signaling and redox homeostasis in the aging heart: A potential target to prevent cardiovascular diseases?

Aging process is often accompanied with a high incidence of cardiovascular diseases (CVD) due to the synergistic effects of age-related changes in heart morphology/function and prolonged exposure to injurious effects of CVD risk factors. Oxidative stress, considered a hallmark of aging, is also an important feature in pathologies that predispose to CVD development, like hypertension, diabetes and obesity. Approaches directed to prevent the occurrence of CVD during aging have been explored both in experimental models and in controlled clinical trials, in order to improve health span, reduce hospitalizations and increase life quality during elderly. In this review we discuss oxidative stress role as a main risk factor that relates CVD with aging. As well as interventions that aim to reduce oxidative stress by supplementing with exogenous antioxidants. In particular, strategies of improving the endogenous antioxidant defenses through activating the nuclear factor related-2 factor (Nrf2) pathway; one of the best studied molecules in cellular redox homeostasis and a master regulator of the antioxidant and phase II detoxification response.

The Effect of Tomato Juice Consumption on Antioxidant Status in Overweight and Obese Females

Tomatoes and their products are the main source of lycopene, a powerful potent antioxidant. Tomato products improve antioxidant defenses and reduce the risk of oxidative stress, at least partly, due to the presence of lycopene. Lycopene, as an antioxidant, induces the upregulation of antioxidant enzymes and reinforces the total enzyme capacity of the human body. Obesity is a chronic condition in which destructive mechanisms increase the reactive oxygen species and attenuation of antioxidant status. We hypothesized that the consumption of a lycopene-rich food would improve the antioxidant defense of women who were overweight or obese. A total of seventy-five overweight or obese female students of the Tehran University of Medical Sciences were enrolled and randomly allocated to one of two groups, intervention (n = 40) or control (n = 35), consuming 330 ml/d of tomato juice or water, respectively, for a 20-day period. At baseline and day 20, total antioxidant capacity and antioxidant enzyme activity (superoxide dismutase, glutathione peroxidase, and catalase) were analyzed using ELISA kits and spectrophotometric methods and then compared between the two groups. Lycopene consumption had no effect on these aforementioned variables. Therefore, it seems that more research with longer duration and more sensitive indicators will be required.

The antioxidant machinery of the endoplasmic reticulum: Protection and signaling

Cellular metabolism is inherently linked to the production of oxidizing by-products, including reactive oxygen species (ROS) hydrogen peroxide (H2O2). When present in excess, H2O2 can damage cellular biomolecules, but when produced in coordinated fashion, it typically serves as a mobile signaling messenger. It is therefore not surprising that cell health critically relies on both low-molecular-weight and enzymatic antioxidant components, which protect from ROS-mediated damage and shape the propagation and duration of ROS signals. This review focuses on H2O2-antioxidant cross talk in the endoplasmic reticulum (ER), which is intimately linked to the process of oxidative protein folding. ER-resident or ER-regulated sources of H2O2 and other ROS, which are subgrouped into constitutive and stimulated sources, are discussed and set into context with the diverse antioxidant mechanisms in the organelle. These include two types of peroxide-reducing enzymes, a high concentration of glutathione derived from the cytosol, and feedback-regulated thiol-disulfide switches, which negatively control the major ER oxidase ER oxidoreductin-1. Finally, new evidence highlighting emerging principles of H2O2-based cues at the ER will likely set a basis for establishing ER redox processes as a major line of future signaling research. A fundamental problem that remains to be solved is the specific, quantitative, time resolved, and targeted detection of H2O2 in the ER and in specialized ER subdomains.

High-cholesterol diet enriched with onion affects endothelium-dependent relaxation and NADPH oxidase activity in mesenteric microvessels from Wistar rats

BACKGROUND

The aim of the present study was to examine the effects of onion as functional ingredient on the oxidative status, lipoprotein levels (total cholesterol-TC, HDL-C, LDL-C), triacylglycerides (TAG) and vascular reactivity of mesenteric arteries in hypercholesterolemic Wistar rats.

METHODS

Twenty-four animals were fed with three different diets [control, high-cholesterol diet (HC) and high-cholesterol enriched with onion diet (HCO)]. After seven weeks of experimental feeding the rats were euthanized for blood and tissues collection. TC, HDL-C, LDL-C and TAG were measured, and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS(•+)) scavenging capacity and ferric reducing antioxidant power (FRAP) were determined in plasma. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities were assayed in erythrocyte lysates. Endothelium-dependent vasodilation to acetylcholine was evaluated in mesenteric arterial segments. NADPH oxidase (NOX) was also measured by lucigenin-derived chemiluminiscence.

RESULTS

The dietary cholesterol content significantly affected plasma lipoprotein levels, increased superoxide generation from NOX, and caused impaired endothelium-dependent vasodilation in the rat mesenteric arteries. Onion ingredient improved antioxidant status in HCO group, as it was evidenced by ABTS(•+) and FRAP values and SOD and GPx enzyme activities compared to the HC-fed group, reduced the increment in NOX activity and reversed endothelial dysfunction promoted by the HC diet. Scavenging of superoxide with TEMPOL or inhibition of NOX with apocynin improved endothelium-dependent vasodilation only in HC-fed rats.

CONCLUSIONS

Enrichment of diet with onion as functional ingredient could be proposed as a complementary approach to prevent or partially modulate vascular dysfunction, reducing some of the risk indexes linked to initial development of atherosclerosis.