Muscle GSH Research Articles

35 Role and mechanism of supplemental methionine in metabolic stress of broilers raised at high ambient temperature or stock density

Abstract Current poultry production practices may render fast-growing broilers prone to metabolic stresses induced by high ambient temperatures and(or) high stocking densities. As the first limiting amino acid of broilers fed corn-soy diets, methionine also serves as a free radical scavenger. Our laboratory has explored metabolic effects and biochemical mechanisms of supplemental methionine in grower and finisher diets for broilers raised at high temperature or high stock density. In Experiment 1, a total of 360 male, 1 d-old Cornish cockerel chicks were fed four diets (10 pens/treatment, 9 chicks/pen): 100 or 130% required methionine in the diets as DL-methionine (DL-MET) or 2-hydroxy-4-(methylthio)butanoate (HMTBA). The room was maintained at 4 to 13oC above the suggested thermoneutral temperature. The 130% DL-MET and HMTBA diets enhanced (P < 0.05) hepatic GSH concentrations of growers and plasma ferric reducing ability of finishers than the 100% diets. The DL-MET-fed growers had greater (P < 0.05%) muscle GSH and hepatic unsaturated fatty acid concentrations than those fed HMTBA. The methionine form and concentration exerted an interaction effect (P < 0.05) on the expression of inflammation-related genes in the liver of finishers. In Experiment 2, we determined if 30% extra DL-MET alleviated adverse effects of a greater stocking density on broilers. A total of 560 male, 1 d-old Cornish cockerels were housed at two stocking densities (9 and 12 birds/m2) and fed two concentrations of DL-MET (grower: 2.90 or 3.77 g/kg and finisher: 2.60 or 3.38 g/kg). The high stocking density decreased (P < 0.05) body weight and growth performance of growers and(or) finishers. Those differences were largely removed or attenuated by the 130% DL-MET diet. There were interaction effects (P < 0.05) between dietary DL-MET concentrations and stocking densities on activities of glutathione S-transferase in the liver of growers and the breast, thigh, and adipose tissue of finishers as well as on activities of glutathione peroxidase and superoxide dismutase in the thigh of growers. The 130% DL-MET diet decreased (P < 0.05) hepatic gene expression of heat shock protein 90 (18%) and malondialdehyde concentrations in the thigh and breast of finishers (35%). In summary, the high ambient temperature-induced metabolic responses of broilers were mediated by the extra methionine supplementation. That function varied with the chicken age and(or) tissue and the methionine form. Meanwhile, the 30% extra DL-MET addition partially reversed adverse effects caused by the greater stocking density, partially via improving tissue redox status. (This research was supported in part by Evonik Nutrition & Care GmbH, and was published: J. Anim. Sci. 97:4883-4894; J. Anim. Sci. 98:skaa092. doi: 10.1093/jas/skaa092).

Skeletal muscle and erythrocyte redox status is associated with dietary cysteine intake and physical fitness in healthy young physically active men.

To investigate the association between redox status in erythrocytes and skeletal muscle with dietary nutrient intake and markers of physical fitness and habitual physical activity (PA). Forty-five young physically active men were assessed for body composition, dietary nutrient intake, muscle strength, cardiorespiratory capacity and habitual PA. Blood and muscle samples were collected to estimate selected redox biomarkers. Partial correlation analysis was used to evaluate the independent relationship of each factor with redox biomarkers. Dietary cysteine intake was positively correlated (p < 0.001) with both erythrocyte (r = 0.697) and muscle GSH (0.654, p < 0.001), erythrocyte reduced/oxidized glutathione ratio (GSH/GSSG) (r = 0.530, p = 0.001) and glutathione reductase (GR) activity (r = 0.352, p = 0.030) and inversely correlated with erythrocyte protein carbonyls (PC) levels (r = -0.325; p = 0.046). Knee extensors eccentric peak torque was positively correlated with GR activity (r = 0.355; p = 0.031) while, one-repetition maximum in back squat exercise was positively correlated with erythrocyte GSH/GSSG ratio (r = 0.401; p = 0.014) and inversely correlated with erythrocyte GSSG and PC (r = -0.441, p = 0.006; r = -0.413, p = 0.011 respectively). Glutathione peroxidase (GPx) activity was positively correlated with step count (r = 0.520; p < 0.001), light (r = 0.406; p = 0.008), moderate (r = 0.417; p = 0.006), moderate-to-vigorous (r = 0.475; p = 0.001), vigorous (r = 0.352; p = 0.022) and very vigorous (r = 0.326; p = 0.035) PA. Muscle GSSG inversely correlated with light PA (r = -0.353; p = 0.022). These results indicate that dietary cysteine intake may be a critical element for the regulation of glutathione metabolism and redox status in two different tissues pinpointing the independent significance of cysteine for optimal redox regulation. Musculoskeletal fitness and PA levels may be predictors of skeletal muscle, but not erythrocyte, antioxidant capacity. Registry: ClinicalTrials.gov, identifier: NCT03711838, date of registration: October 19, 2018.

Alteration of Glutathione and Antioxidant Status with Exercise in Unfed and Refed Rats

The influences of food deprivation and refeeding on glutathione (GSH) status, antioxidant enzyme activity and lipid peroxidation in response to an acute bout of exercise were investigated in the liver and skeletal muscles of male Sprague-Dawley rats randomly divided into three groups: starved for 48 h without refeeding; starved for 48 h and refed for 24 or 48 h. Half of each group of rats was exercised on a treadmill until exhaustion and killed immediately, whereas the other half group was killed at rest. Food-deprived rats had significantly lower liver GSH concentration and GSH:glutathione disulfide (GSSG) ratio. Malondialdehyde concentrations in the liver and skeletal muscle were both higher in the starved than in the refed rats (P < 0.05). Refed rats had significantly greater liver GSH level, γ-glutamylcysteine synthetase and glucose 6-phosphate dehydrogenase activities and plasma insulin concentration than unfed rats. Exercised 24- and 48-h refed rats had 27% and 31% lower liver GSH (P < 0.05), respectively, and a 21% lower GSH:GSSG ratio (P < 0.05) than their rested counterparts. Plasma insulin concentrations were significantly lower, whereas glucagon concentrations were greater in the exercised than in the rested rats. Muscle GSH concentration was significantly lower in the food-deprived than in the refed rats (P < 0.05) but was unaffected by exercise. Exercised 24-h refed rats had significantly elevated muscle GSSG concentration compared with rested rats, along with a higher GSH peroxidase and a lower γ-glutamyltranspeptidase activity (P < 0.05). These data indicate that both food deprivation-refeeding and exhaustive exercise influence liver and skeletal muscle glutathione status and that these changes may be controlled by hepatic glutathione synthesis and release due to hormonal stimulation.

Impact of Coenzyme Q10 Supplementation on Skeletal Muscle Respiration, Antioxidants, and the Muscle Proteome in Thoroughbred Horses.

Coenzyme Q10 (CoQ10) is an essential component of the mitochondrial electron transfer system and a potent antioxidant. The impact of CoQ10 supplementation on mitochondrial capacities and the muscle proteome is largely unknown. This study determined the effect of CoQ10 supplementation on muscle CoQ10 concentrations, antioxidant balance, the proteome, and mitochondrial respiratory capacities. In a randomized cross-over design, six Thoroughbred horses received 1600 mg/d CoQ10 or no supplement (control) for 30-d periods separated by a 60-d washout. Muscle samples were taken at the end of each period. Muscle CoQ10 and glutathione (GSH) concentrations were determined using mass spectrometry, antioxidant activities by fluorometry, mitochondrial enzyme activities and oxidative stress by colorimetry, and mitochondrial respiratory capacities by high-resolution respirometry. Data were analyzed using mixed linear models with period, supplementation, and period × supplementation as fixed effects and horse as a repeated effect. Proteomics was performed by tandem mass tag 11-plex analysis and permutation testing with FDR < 0.05. Concentrations of muscle CoQ10 (p = 0.07), GSH (p = 0.75), and malondialdehyde (p = 0.47), as well as activities of superoxide dismutase (p = 0.16) and catalase (p = 0.66), did not differ, whereas glutathione peroxidase activity (p = 0.003) was lower when horses received CoQ10 compared to no supplement. Intrinsic (relative to citrate synthase activity) electron transfer capacity with complex II (ECII) was greater, and the contribution of complex I to maximal electron transfer capacity (FCRPCI and FCRPCIG) was lower when horses received CoQ10 with no impact of CoQ10 on mitochondrial volume density. Decreased expression of subunits in complexes I, III, and IV, as well as tricarboxylic acid cycle (TCA) enzymes, was noted in proteomics when horses received CoQ10. We conclude that with CoQ10 supplementation, decreased expression of TCA cycle enzymes that produce NADH and complex I subunits, which utilize NADH together with enhanced electron transfer capacity via complex II, supports an enhanced reliance on substrates supplying complex II during mitochondrial respiration.

Hyperbaric oxygenation applied before or after mild or hard stress: effects on the redox state in the muscle tissue.

The mechanism is unclear for the reported protective effect of hyperbaric oxygen preconditioning against oxidative stress in tissues, and the distinct effects of hyperbaric oxygen applied after stress. The trained mice were divided into three groups: the control, hyperbaric oxygenation preconditioning, and hyperbaric oxygenation applied after mild (fasting) or hard (prolonged exercise) stress. After preconditioning, we observed a decrease in basal levels of nitric oxide, tetrahydrobiopterin, and catalase despite the drastic increase in inducible and endothelial nitric oxide synthases. Moreover, the basal levels of glutathione, related enzymes, and nitrosative stress only increased in the preconditioning group. The control and preconditioning groups showed a similar mild stress response of the endothelial and neuronal nitric oxide synthases. At the same time, the activity of all nitric oxide synthase, glutathione (GSH) in muscle, declined in the experimental groups but increased in control during hard stress. The results suggested that hyperbaric oxygen preconditioning provoked uncoupling of nitric oxide synthases and the elevated levels of GSH in muscle during this study, while hyperbaric oxygen applied after stress showed a lower level of GSH but higher recovery post-exercise levels in the majority of antioxidant enzymes. We discuss the possible mechanisms of the redox response and the role of the nitric oxide in this process.

Activation of the eIF2α-ATF4 Pathway by Chronic Paracetamol Treatment Is Prevented by Dietary Supplementation with Cysteine.

Chronic treatment with acetaminophen (APAP) induces cysteine (Cys) and glutathione (GSH) deficiency which leads to adverse metabolic effects including muscle atrophy. Mammalian cells respond to essential amino acid deprivation through the phosphorylation of the eukaryotic translation initiation factor 2α (eIF2α). Phosphorylated eIF2α leads to the recruitment of activating transcription factor 4 (ATF4) to specific CCAAT/enhancer-binding protein-ATF response element (CARE) located in the promoters of target genes. Our purpose was to study the activation of the eIF2α-ATF4 pathway in response to APAP-induced Cys deficiency, as well as the potential contribution of the eIF2α kinase GCN2 and the effect of dietary supplementation with Cys. Our results showed that chronic treatment with APAP activated both GCN2 and PERK eIF2α kinases and downstream target genes in the liver. Activation of the eIF2α-ATF4 pathway in skeletal muscle was accompanied by muscle atrophy even in the absence of GCN2. The dietary supplementation with cysteine reversed APAP-induced decreases in plasma-free Cys, liver GSH, muscle mass, and muscle GSH. Our new findings demonstrate that dietary Cys supplementation also reversed the APAP-induced activation of GCN2 and PERK and downstream ATF4-target genes in the liver.

Stroke preventing effect of resveratrol isolated from fungi and in vivo activity in male albino rats

The main objective of the study was to analyze the stroke preventing property of resveratrol from Alternaria alternata SK. The endophytic fungus A. alternata SK was isolated from the Brinjal plant. The isolated fungus was characterized based on morphological characters and molecular methods. It was cultured in submerged cultivation and resveratrol was isolated. The isolated resveratrol was used to test stroke preventing properties using animal model. The experimental male Albino rat fed with resveratrol decreased HDL cholesterol level in serum. The amount of malondialdehyde significantly lower in the cardiac tissues of Albino AD rat treated with resveratrol (P < 0.05). Likewise, the level of malondialdehyde in the haemolysate sample showed significant variation than control animal (P < 0.05). Administered resveratrol improved antioxidant potential. The amount of antioxidant enzymes such as, SOD, CAT and GPx significantly higher in resveratrol administered Albino rats (P < 0.05) than control rat. The amount of GSH, α-tocopherol and ascorbate in cardiac muscle of AD rats fed with resveratrol increased significantly than in AD Albino rats (P < 0.05). The amount of aspartate amino transferase, alanine amino transferase, alkaline phosphatase, and lactate dehydrogenate were reduced in experimental rats treated with resveratrol than control (P < 0.05). The experimental group treated with resveratrol decreased the level of LDH (1.63 ± 0.128 nmol NADPH/mg) than ischemia group (2.08 ± 0.11 nmol NADPH/mg) (P < 0.05). The amount of H2O2 was found to be high in ischemia group (428.2 ± 2.9 nmol) and it reduced (320.3 ± 10.2 nmol) in resveratrol treated animal (P < 0.05). In vivo analysis of cerebral ischemia/reperfusion in Albino rats revealed the protective role of resveratrol on LDH and H2O2 in hippocampus region.

Effects of glutamine on exercise-induced fatigue, skeletal muscle oxidation and liver cell apoptosis in rats

Objective: To investigate the effects of glutamine on exercise-induced fatigue, skeletal muscle oxidation and liver cell apoptosis in rats. Methods: Twenty SPF grade SD rats aged at 8 week and weight from 180 to 220 g, were divided into control group and glutamine-treated group after one week of feeding, 10 rats in each group. The rats in the glutamine group were treated with glutamine at the dose of 1.0 g/(kg·d)by intragastric administration, and the rats in control group were administrated with equal volume of normal saline. After 7 days, the exhaustion test was conducted, the content of glutathione (GSH) was detected by high-performance liquid chromatography. Superoxide dismutase (SOD), malondialdehyde (MDA), lactic acid (2-hydroxypropanoic acid (LD) were detected by enzyme-linked immunosorbent assay, and the creatine kinase(CK) was detected by electroluminescence. Activities of CK, Lactate dehydrogenase (LDH), and expression levels of Bcl-2 and Bax mRNA were detected by fluorescence quantitative RT-PCR. Results: The duration of exhaustion in the glutamine group was greater than that in the control group (P＜0.05). The serum glutathione level in the glutamine group was lower than that in the control group (P＜0.05). After exhaustion, the levels of GSH, SOD and MDA in serum and skeletal muscle of the glutamine group were higher than those of the control group significantly differences (P＜ 0.05). The serum Bax mRNA level in the glutamine group was lower than that in the control group significantly (P＜0.05). The serum bcl-2 mRNA level in the glutamine group was higher than that in the control group significantly (P＜0.05). Conclusion: Glutamine can effectively alleviate exercise-induced fatigue in rats, reduce the oxidation degree of skeletal muscle, and decrease the apoptosis rate of liver cells.

The effects of 3 weeks of oral glutathione supplementation on whole body insulin sensitivity in obese males with and without type 2 diabetes: a randomized trial.

The effect of oral glutathione (GSH) supplementation was studied in obese subjects with and without type 2 diabetes (T2DM) on measures of glucose homeostasis and markers of oxidative stress. Twenty subjects (10 patients with T2DM and 10 obese subjects) were recruited for the study, and randomized in a double-blinded placebo-controlled manner to consume either 1000 mg GSH per day or placebo for 3 weeks. Before and after the 3 weeks insulin sensitivity was measured with the hyperinsulinemic-euglycemic clamp and a muscle biopsy was obtained to measure GSH and skeletal muscle mitochondrial hydrogen peroxide (H2O2) emission rate. Whole body insulin sensitivity increased significantly in the GSH group. Skeletal muscle GSH was numerically increased (∼19%) in the GSH group; no change was seen in GSH to glutathione disulfide ratio. Skeletal muscle mitochondrial H2O2 emission rate did not change in response to the intervention and neither did the urinary excretion of the RNA oxidation product 8-oxo-7,8-dihydroguanosine or the DNA oxidation product 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), although 8-oxodG decreased as a main effect of time. Oral GSH supplementation improves insulin sensitivity in obese subjects with and without T2DM, although it does not alter markers of oxidative stress. The study has been registered in clinicaltrials.gov (NCT02948673). Novelty: Reduced glutathione supplementation increases insulin sensitivity in obese subjects with and without T2DM. H2O2 emission rate from skeletal muscle mitochondria was not affected by GSH supplementation.

Supplementing Glycine and N-acetylcysteine (GlyNAC) in Aging HIV Patients Improves Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Endothelial Dysfunction, Insulin Resistance, Genotoxicity, Strength, and Cognition: Results of an Open-Label Clinical Trial.

Background: Patients with HIV (PWH) develop geriatric comorbidities, including functional and cognitive decline at a younger age. However, contributing mechanisms are unclear and interventions are lacking. We hypothesized that deficiency of the antioxidant protein glutathione (GSH) contributes to multiple defects representing premature aging in PWH, and that these defects could be improved by supplementing the GSH precursors glycine and N-acetylcysteine (GlyNAC). Methods: We conducted an open label clinical trial where eight PWH and eight matched uninfected-controls were studied at baseline. PWH were studied again 12-weeks after receiving GlyNAC, and 8-weeks after stopping GlyNAC. Controls did not receive supplementation. Outcome measures included red-blood cell and muscle GSH concentrations, mitochondrial function, mitophagy and autophagy, oxidative stress, inflammation, endothelial function, genomic damage, insulin resistance, glucose production, muscle-protein breakdown rates, body composition, physical function and cognition. Results: PWH had significant defects in measured outcomes, which improved with GlyNAC supplementation. However, benefits receded after stopping GlyNAC. Conclusions: This open label trial finds that PWH have premature aging based on multiple biological and functional defects, and identifies novel mechanistic explanations for cognitive and physical decline. Nutritional supplementation with GlyNAC improves comorbidities suggestive of premature aging in PWH including functional and cognitive decline, and warrants additional investigation.

Effects of dietary incorporation of linseed oil with soybean isoflavone on fatty acid profiles and lipid metabolism-related gene expression in breast muscle of chickens

The meat quality of chicken is an important factor affecting the consumer’s health. It was hypothesized that n-3 polyunsaturated fatty acid (n-3 PUFA) could be effectively deposited in chicken, by incorporating antioxidation of soybean isoflavone (SI), which led to improved quality of chicken meat for good health of human beings. Effects of partial or complete dietary substitution of lard (LA) with linseed oil (LO), with or without SI on growth performance, biochemical indicators, meat quality, fatty acid profiles, lipid-related health indicators and gene expression of breast muscle were examined in chickens. A total of 900 males were fed a corn–soybean meal diet supplemented with 4% LA, 2% LA + 2% LO and 4% LO and the latter two including 30 mg SI/kg (2% LA + 2% LO + SI and 4% LO + SI) from 29 to 66 days of age; each of the five dietary treatments included six replicates of 30 birds. Compared with the 4% LA diet, dietary 4% LO significantly increased the feed efficiency and had no negative effect on objective indices related to meat quality; LO significantly decreased plasma triglycerides and total cholesterol (TCH); abdominal fat percentage was significantly decreased in birds fed the 4% LO and 4% LO + SI diets. Chickens with LO diets resulted in higher contents of α-linolenic acid (C18:3n-3), EPA (C20:5n-3) and total n-3 PUFA, together with a lower content of palmitic acid (C16:0), lignoceric acid (C24:0), saturated fatty acids and n-6:n-3 ratio in breast muscle compared to 4% LA diet (P < 0.05); they also significantly decreased atherogenic index, thrombogenic index and increased the hypocholesterolemic to hypercholesterolemic ratio. Adding SI to the LO diets enhanced the contents of EPA and DHA (C22:6n-3), plasma total superoxide dismutase, reduced glutathione (GSH)/oxidized glutathione and muscle GSH content, while decreased plasma total triglyceride and TCH and malondialdehyde content in plasma and breast muscle compared to its absence (P < 0.05). Expression in breast muscle of fatty acid desaturase 1 (FADS1), FADS2, elongase 2 (ELOVL2) and ELOVL5 genes were significantly higher with the LO diets including SI than with the 4% LA diet. Significant interactions existed between LO level and inclusion of SI on EPA and TCH contents. These findings indicate that diet supplemented with LO combined with SI is an effective alternative when optimizing the nutritional value of chicken meat for human consumers.

Supplemental methionine exerted chemical form-dependent effects on antioxidant status, inflammation-related gene expression, and fatty acid profiles of broiler chicks raised at high ambient temperature1.

This study was to explore metabolic effects of two forms and concentrations of supplemental methionine in grower and finisher diets for broiler chickens raised at high temperature. Male Cornish cockerel chicks (total = 360, day-old) were divided into four groups (10 pens/treatment, 9 chicks/pen) and fed with 100% or 130% required methionine in the diets as DL-methionine (DL-MET) or 2-hydroxy-4-(methylthio)butanoate (HMTBA). The room was maintained at 4 to 13 °C above the suggested thermoneutral temperature. The higher concentration of both DL-MET and HMTBA enhanced (P < 0.05) hepatic GSH concentrations of the growers and plasma ferric reducing ability of the finishers. The DL-MET-fed growers had greater (P < 0.05%) muscle GSH and hepatic unsaturated fatty acid concentrations than those fed HMTBA. Expression of inflammation-related genes in the liver of finishers was affected (P < 0.05) by interaction effects of the methionine form and concentration. In conclusion, effects of the extra methionine supplementation on the high ambient temperature-related metabolic responses of broilers varied with their age and(or) tissue and the methionine form.

Oral glutamine supplementation attenuates inflammation and oxidative stress-mediated skeletal muscle protein content degradation in immobilized rats: Role of 70 kDa heat shock protein

Skeletal muscle disuse results in myofibrillar atrophy and protein degradation, via inflammatory and oxidative stress-mediated NF-kB signaling pathway activation. Nutritional interventions, such as l-glutamine (GLN) supplementation have shown antioxidant properties and cytoprotective effects through the modulation on the 70-kDa heat shock protein (HSP70) expression. However, these GLN-mediated effects on cell signaling pathways and biochemical mechanisms that control the myofibrillar protein content degradation in muscle disuse situations are poorly known yet. This study investigated the effects of oral GLN plus l-alanine (ALA; GLN ​+ ​ALA-solution) supplementation, either in their free or dipeptide (L-alanyl-l-glutamine-DIP) form, on GLN-glutathione (GSH) axis and cytoprotection mediated by HSP70 protein expression in the slow-twitch soleus and fast-twitch gastrocnemius skeletal muscle of rats submitted to 14-days of hindlimb immobilization-induced disuse muscle atrophy. Forty-eight Wistar rats were distributed into 6 groups: hindlimb immobilized (IMOB group) and hindlimb immobilized orally supplemented with either GLN (1 g kg−1) plus ALA (0.61 g kg−1) ​(GLN ​+ ​ALA-IMOB group) or 1.49 ​g ​kg−1 of DIP (DIP-IMOB group) and; no-immobilized (CTRL) and no-immobilized supplemented GLN ​+ ​ALA and DIP baselines groups. All animals, including CTRL and IMOB rats (water), were supplemented via intragastric gavage for 14 days, concomitantly to immobilization period. Plasma and muscle GLN levels, lipid (thiobarbituric acid reactive substances-TBARS) and protein (carbonyl) peroxidation, erythrocyte concentration of reduced GSH and GSH disulfide (GSSG), plasma and muscle pro-inflammatory TNF-α levels, muscle IKKα/β-NF-kB signaling pathway and, the myofibrillar protein content (MPC) were measured. The MPC was significantly lower in IMOB rats, compared to CTRL, GLN ​+ ​ALA, and DIP animals (p ​< ​0.05). This finding was associated with reduced plasma and muscle GLN concentration, equally in IMOB animals. Conversely, both GLN ​+ ​ALA and DIP supplementation restored plasma and muscle GLN levels, which equilibrated GSH and intracellular redox status (GSSG/GSH ratio) in erythrocytes and skeletal muscle even as, increased muscle HSP70 protein expression; attenuating oxidative stress and TNF-α-mediated NF-kB pathway activation, fact that reverberated on reduction of MPC degradation in GLN ​+ ​ALA-IMOB and DIP-IMOB animals (p ​< ​0.05). In conclusion, the findings shown herein support the oral GLN ​+ ​ALA and DIP supplementations as a therapeutic and effective nutritional alternative to attenuate the deleterious effects of the skeletal muscle protein degradation induced by muscle disuse.

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

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

Cycling with blood flow restriction improves performance and muscle K+ regulation and alters the effect of anti-oxidant infusion in humans.

Training with blood flow restriction (BFR) is a well-recognized strategy for promoting muscle hypertrophy and strength. However, its potential to enhance muscle function during sustained, intense exercise remains largely unexplored. In the present study, we report that interval training with BFR augments improvements in performance and reduces net K+ release from contracting muscles during high-intensity exercise in active men. A better K+ regulation after BFR-training is associated with an elevated blood flow to exercising muscles and altered muscle anti-oxidant function, as indicated by a higher reduced to oxidized glutathione (GSH:GSSG) ratio, compared to control, as well as an increased thigh net K+ release during intense exercise with concomitant anti-oxidant infusion. Training with BFR also invoked fibre type-specific adaptations in the abundance of Na+ ,K+ -ATPase isoforms (α1 , β1 , phospholemman/FXYD1). Thus, BFR-training enhances performance and K+ regulation during intense exercise, which may be a result of adaptations in anti-oxidant function, blood flow and Na+ ,K+ -ATPase-isoform abundance at the fibre-type level. We examined whether blood flow restriction (BFR) augments training-induced improvements in K+ regulation and performance during intense exercise in men, and also whether these adaptations are associated with an altered muscle anti-oxidant function, blood flow and/or with fibre type-dependent changes in Na+ ,K+ -ATPase-isoform abundance. Ten recreationally-active men (25±4years, 49.7±5.3mLkg-1 min-1 ) performed 6 weeks of interval cycling, where one leg trained without BFR (control; CON-leg) and the other trained with BFR (BFR-leg, pressure: ∼180mmHg). Before and after training, femoral arterial and venous K+ concentrations and artery blood flow were measured during single-leg knee-extensor exercise at 25% (Ex1) and 90% of thigh incremental peak power (Ex2) with i.v. infusion of N-acetylcysteine (NAC) or placebo (saline) and a resting muscle biopsy was collected. After training, performance increased more in BFR-leg (23%) than in CON-leg (12%, P<0.05), whereas K+ release during Ex2 was attenuated only from BFR-leg (P<0.05). The muscle GSH:GSSG ratio at rest and blood flow during exercise was higher in BFR-leg than in CON-leg after training (P<0.05). After training, NAC increased resting muscle GSH concentration and thigh net K+ release during Ex2 only in BFR-leg (P<0.05), whereas the abundance of Na+ ,K+ -ATPase-isoform α1 in type II (51%), β1 in type I (33%), and FXYD1 in type I (108%) and type II (60%) fibres was higher in BFR-leg than in CON-leg (P<0.05). Thus, training with BFR elicited greater improvements in performance and reduced thigh K+ release during intense exercise, which were associated with adaptations in muscle anti-oxidant function, blood flow and Na+ ,K+ -ATPase-isoform abundance at the fibre-type level.

Activin Receptor Ligand Blocking and Cancer Have Distinct Effects on Protein and Redox Homeostasis in Skeletal Muscle and Liver.

Muscle wasting in cancer cachexia can be alleviated by blocking activin receptor type 2 (ACVR2) ligands through changes in protein synthesis/degradation. These changes in cellular and protein metabolism may alter protein homeostasis. First, we elucidated the acute (1–2 days) and 2-week effects of blocking ACVR2 ligands by soluble activin receptor 2B (sACVR2B-Fc) on unfolded protein response (UPR), heat shock proteins (HSPs) and redox balance in a healthy mouse skeletal muscle. Second, we examined UPR, autophagy and redox balance with or without sACVR2B-Fc administration in muscle and liver of C26 tumor-bearing mice. The indicators of UPR and HSPs were not altered 1–2 days after a single sACVR2B-Fc administration in healthy muscles, but protein carbonyls increased (p < 0.05). Two weeks of sACVR2B-Fc administration increased muscle size, which was accompanied by increased UPR markers: GRP78 (p < 0.05), phosphorylated eIF2α (p < 0.01) and HSP47 (p < 0.01). Additionally, protein carbonyls and reduced form of glutathione increased (GSH) (p < 0.05). On the other hand, C26 cancer cachexia manifested decreased UPR markers (p-eIF2α, HSP47, p-JNK; p < 0.05) and antioxidant GSH (p < 0.001) in muscle, whereas the ratio of oxidized to reduced glutathione increased (GSSG/GSH; p < 0.001). Administration of sACVR2B-Fc prevented the decline in GSH and increased some of the UPR indicators in tumor-bearing mice. Additionally, autophagy markers LC3II/I (p < 0.05), Beclin-1 (p < 0.01), and P62 (p < 0.05) increased in the skeletal muscle of tumor-bearing mice. Finally, indicators of UPR, PERK, p-eIF2α and GRP78, increased (p < 0.05), whereas ATF4 was strongly decreased (p < 0.01) in the liver of tumor-bearing mice while sACVR2B-Fc had no effect. Muscle GSH and many of the altered UPR indicators correlated with tumor mass, fat mass and body mass loss. In conclusion, experimental cancer cachexia is accompanied by distinct and tissue-specific changes in proteostasis. Muscle hypertrophy induced by blocking ACVR2B ligands may be accompanied by the induction of UPR and increased protein carbonyls but blocking ACVR2B ligands may upregulate antioxidant protection.

Dietary coated cysteamine improves antioxidant status of muscle in pig model

BackgroundMuscle fatigue and injury is common in daily life. Contracting skeletal muscles generate free radicals, which can result in oxidative damage to cellular constituents. The development of targeted antioxidants remains an important area of research in redox biology. Cysteamine is used as a novel feed additive in animal production in the form of coated cysteamine because of its antioxidant activities. However, oral formulations of cysteamine may cause adverse effects, including reduction of motor activity and generalized hemorrhage in gastrointestinal tract and kidneys. An enteric coating is a polymer barrier applied on oral medication that prevents its dissolution or disintegration in the gastric environment. The effects of coated cysteamine on oxidation in muscle and lesions in gastrointestinal (GI) mucosal were investigated in this experiment using a pig model.MethodsA total of 288 crossbred finishing pigs (Duroc × Landrace × Yorkshire) with an initial BW of 88.3 ± 0.3 kg were randomly assigned into 4 dietary groups, with 8 pens/group and 9 pigs/pen. Castrated pigs had free access to feed and drinking water, and they were fed a corn‐soybean meal diet containing 0 (control), 0.035, 0.070, or 0.140 g kg‐1 of CC for 29 days. Coated cysteamine hydrochloride contained 270 g kg‐1 cysteamine hydrochloride. At the end of experiment, one pig was randomly selected from each pen and was slaughtered by exsanguination after electrical stunning to collect samples of the longissimus dorsi muscle and GI tissue.ResultsDietary CC increased (P &lt; 0.05) the a*(redness) and H* values, reduced (P &lt; 0.05) the L* (lightness) value in the muscles at 48 h postmortem (P &lt; 0.05). The contents of deoxymyoglobin (deoxyMb) was enhanced (P &lt; 0.05) and the contents of metmyoglobin (MetMb) and malondialdehyde (MDA) were reduced (P &lt; 0.05) in pig fed the dietary CC. Pigs fed a dietary CC of 0.035 g kg−1 had a higher a* (24 h) value in the longissimus dorsi muscles than control treatment. Pig fed the dietary CC of 0.140 g kg−1 had a higher GSH (P &lt; 0.05) in muscle. And the mRNA expression of SOD1 was up‐regulated (P &lt; 0.05) in the muscle of pigs fed the dietary CC of 0.140 g kg−1. Supplementation with CC in the 0.035 g kg−1 increased villus height:crypt depth ratio in ileum (P&lt;0.01). Ileal lesion score was decreased in pigs fed a dietary CC of 0.035 g kg−1 (P&lt;0.01).ConclusionDietary supplementation with CC could improve antioxidant status by improving GSH levels and antioxidase activity during a long recovery (48 h). Dietary supplementation with coated cysteamine hydrochloride in the 0.035 g kg−1 may improve the muscle antioxidant status without mucosal injury of GI.Support or Funding InformationWe would like to express our sincere gratitude to the National Natural Science Foundation of China (31501964; 31402088) and China Agriculture Research System (CARS‐35). The research was also funded by a research program of the State Key Laboratory of Food Science and Technology and Key Research and Development program of Shandong province (2015STS007).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The levels of oxidative stress and antioxidant capacity in hibernating Nanorana parkeri

The effect of hibernation on oxidative stress and antioxidant defense was assessed in the frog Nanorana parkeri which inhabits the southern Tibetan Plateau. We compared the indices of oxidative stress (GSSG/GSH), the degree of oxidative damage (content of carbonyl proteins and lipid peroxide products) and the activities of antioxidant enzymes (SOD, CAT, GPx, GST and GR) in liver, brain, heart and muscle of N. parkeri sampled during summer and winter. Obtained results showed that hibernation induced a significant decrease in the level of GSH in heart, liver, and muscle, while the ratio of GSSG/GSH markedly increased in all tissues except for muscle. Regarding oxidative damage, significant increases in TBARS were observed in all tissues of N. parkeri in the midst of hibernation, and the lipid peroxides level also clearly elevated in these tissues except the liver. In liver and brain, the level of carbonyl proteins was significantly higher in winter relative to summer. Additionally, the activity of antioxidant enzymes obviously reduced in the liver of hibernating N. parkeri. The total antioxidant capacity was also significantly lower in all tissues during winter than summer. In conclusion, hibernation in N. parkeri induced oxidative stress which was supported by oxidative damage to lipids and proteins with suppression of antioxidant defense.

Immunity, Antioxidant Status, and Performance of Broiler Chickens Fed Turmeric (Curcuma Longa) Rhizome Powder

The immunostimulant effect, antioxidant status, and growth performance of turmeric (Curcuma longa) feed supplementation in broiler chickens were evaluated by the determination of serum total protein, albumin, globulin, alanine aminotransferase (ALT), creatinine, total cholesterol, triacylglycerol (TAG), serum immunoglobulins (IgA, IgM, and IgG), interferon-γ (INF-γ), and interleukin-10 (IL-10). Also, the malondialdehyde (MDA), glutathione reduced (GSH), total superoxide dismutase (T.SOD) and glutathione S-transferase (GST) levels in the thigh and breast muscles were evaluated. To achieve this objective, 120 Cobb of one-day-old chicks were allocated into four equal groups that kept as a control group that supplemented with the basal diet, Turmeric I (0.5% of basal diet), Turmeric II (1.0% of basal diet) and Turmeric III (1.5% of basal diet) groups. Turmeric significantly increased the serum total protein, globulin, immunoglobulins, INF-γ, IL-10, muscle GSH, T.SOD, and GST. Whereas, serum total cholesterol, TAG, and muscle MDA levels were significantly decreased. The obtained results stated that Turmeric I (0.5%) gives the best feed conversion ratio with less feed intake as compared with the other turmeric-treated and control groups with enhancement of immunity and antioxidant activities. Also, birds in Turmeric I group had a significant decline in breast and thigh muscles MDA that produce a meat product of high quality and health benefits for human consumption.

Effect of Rosemary (Rosmarinus Officinalis) Dietary Supplementation in Broiler Chickens Concerning immunity, Antioxidant Status, and Performance

This study was conducted to evaluate the effect of rosemary leaves on the growth performance, blood parameters, and immune response of broiler chickens by determination of the serum immunoglobulins (IgA, IgM, and IgG), interferon-γ (INF-γ) and interleukin-10 (IL-10). Also, malondialdehyde (MDA), total superoxide dismutase (T.SOD), glutathione S-transferase (GST), and glutathione reduced (GSH) levels in the thigh and breast muscles were determined to evaluate the effect of rosemary in the broiler chicken’s muscles. To achieve this aim, 120 Cobb of one-day-old chicks were allocated into four equal groups as a control group that supplemented by the basal diet, while the other three groups were fed basal diet supplemented with 0.5, 1.0, and 1.5% of rosemary. The data of growth performance indicated that supplementation of broiler with rosemary had no growth-promoting effects. Feeding diet with rosemary leaves meal significantly increased the serum total protein and globulin, while significantly decreased total cholesterol and triacylglycerol levels. Rosemary significantly increased the IgG, IgM, INF-γ, IL-10, and muscle GSH levels and T. SOD and GST activities. Whereas, muscle MDA levels were significantly decreased, so rosemary could be considered as a natural antioxidant in broiler diet. Concomitantly, provide a healthy broiler’s meat with less MDA that favorable to human consumption.