Plasma glutathione of HIV⁺ patients responded positively and differently to dietary supplementation with cysteine or glutamine

ObjectivePatients with positivity for the human immunodeficiency virus (HIV⁺) present low concentrations of antioxidant nutrients, including total glutathione (GSH) and its precursors. We investigated the responses of the sulfur-containing amino acid pathway to cysteine and glutamine (Gln) dietary supplements in patients with HIV⁺ compared with healthy controls.MethodsTwelve treated patients (six men and six women, 22–45 y old) and 20 healthy controls (10 men and 10 women, 20–59 y old) were randomly assigned to 7-d dietary supplements containing N-acetylcysteine (NAC; 1 g/d) or Gln (20 g/d), with a 7-d washout period ingesting their usual diet. Blood samples were drawn after an overnight fast. High-performance liquid chromatographic plasma analysis of sulfur-containing amino acids (methionine, homocysteine, cysteine, and taurine), GSH, oxidized GSH, and serine, glycine, glutamic acid, and Gln was carried out moments before and after 7-d supplementations. Statistical comparisons were undertaken between groups and between dietary supplements (P < 0.05).ResultsPatients with HIV⁺ showed higher oxidized GSH and lower concentrations of GSH and all amino acids except homocysteine. The HIV⁺ group responded to the NAC by increased levels of sulfur-containing amino acids and GSH and equalized taurine and GSH levels in the control group. The Gln supplements also equalized the levels of GSH, Gln, and glycine in the control group.ConclusionAn increase in GSH may be attained by NAC or Gln supplementation, with NAC acting by increasing cysteine levels and Gln likely acting by replenishing the glycine pool (trial registered at http://www.clinicaltrials.gov, identifier NCT00910442).     

The Effects of Creatine Supplementation on Explosive Performance and Optimal Individual Postactivation Potentiation Time

Creatine plays an important role in muscle energy metabolism. Postactivation potentiation (PAP) is a phenomenon that can acutely increase muscle power, but it is an individualized process that is influenced by muscle fatigue. This study examined the effects of creatine supplementation on explosive performance and the optimal individual PAP time during a set of complex training bouts. Thirty explosive athletes performed tests of back squat for one repetition maximum (1RM) strength and complex training bouts for determining the individual optimal timing of PAP, height and peak power of a counter movement jump before and after the supplementation. Subjects were assigned to a creatine or placebo group and then consumed 20 g of creatine or carboxymethyl cellulose per day for six days. After the supplementation, the 1RM strength in the creatine group significantly increased (p < 0.05). The optimal individual PAP time in the creatine group was also significant earlier than the pre-supplementation and post-supplementation of the placebo group (p < 0.05). There was no significant difference in jump performance between the groups. This study demonstrates that creatine supplementation improves maximal muscle strength and the optimal individual PAP time of complex training but has no effect on explosive performance.     

Impact of oral L-glutamine on glutathione, glutamine, and glutamate blood levels in volunteers

OBJECTIVE: We investigated the effect of glutamine supplementation on plasma glutamine (Gln), glutamate (Glu), and whole-blood glutathione (GSH) concentrations in human volunteers. METHODS: Subjects first adapted to a standard diet with known intakes of protein, total GSH, cysteine, methionine, and total Glu (Glu values include Glu and Gln) for 3 d. Plasma Gln, Glu, and whole-blood GSH levels were then measured at 4-h intervals over 24 h. Supplemental oral Gln (0.3 g x kg(-1) x d(-1)) was ingested for 10 d and then 24-h plasma levels of Gln, Glu, and whole-blood GSH were measured. RESULTS: The plasma concentrations of Glu (116%; P = 0.006) and Gln (20%; P = 0.046) were significantly higher, whereas concentrations of GSH were significantly lower (37%; P = 0.00091) after oral Gln supplementation. CONCLUSION: Oral Gln increases Glu and Gln levels in plasma of healthy subjects but does not increase GSH red cell (whole-blood) levels. Thus, GSH biosynthesis and preservation of GHS stores in red blood cells may involve rate-limiting substrates other than Gln.     

L-Arginine attenuates xanthine oxidase and myeloperoxidase activities in hearts of rats during exhaustive exercise

The present study was to investigate the effects of l-arginine (l-Arg) supplementation on cardiac oxidative stress and the inflammatory response in rats following acute exhaustive exercise on a treadmill. Rats were randomly divided into four groups: sedentary control (SC); SC with l-Arg treatment (SC+Arg); exhaustive exercise (E); exhaustive exercise with l-Arg treatment (E+Arg). Rats in groups SC+Arg and E+Arg received a 2 % l-Arg diet. Rats in groups E and E+Arg performed an exhaustive running test on a treadmill at a final speed of 30 m/min, 10 % grade, at approximately 70-75 % VO2max. The results showed a significant increase in cardiac xanthine oxidase (XO) and myeloperoxidase activities and membrane lipid peroxidation endproduct (malondialdehyde; MDA) levels of exercised rats compared with SC rats. The increased cardiac XO activity and MDA levels in exercised rats were significantly decreased in exercised rats supplemented with l-Arg. Myocardial GSSG content increased whereas the GSH:GSSG ratio was depressed in exercised rats compared with SC rats. Cardiac GSSG levels significantly decreased, whereas total glutathione, GSH and the GSH:GSSG ratio increased in exercised rats supplemented with l-Arg compared with exercised rats. The activities of creatinine kinase (CK) and lactate dehydrogenase (LDH), and lactate, uric acid, and nitrite and nitrate levels in the plasma significantly increased in exercised rats compared with SC rats. The activities of plasma CK and LDH were significantly decreased in l-Arg-supplemented plus exercised rats compared with exercised rats. These findings suggest that l-Arg supplementation reduces the oxidative damage and inflammatory response on the myocardium caused by exhaustive exercise in rats.     

The Effect of Elevated Protein Intake on DNA Damage in Older People: Comparative Secondary Analysis of Two Randomized Controlled Trials

A high protein intake at old age is important for muscle protein synthesis, however, this could also trigger protein oxidation with the potential risk for DNA damage. The aim of this study was to investigate whether an increased protein intake at recommended level or well above would affect DNA damage or change levels of reduced (GSH) and oxidised glutathione (GSSG) in community-dwelling elderly subjects. These analyses were performed in two randomized intervention studies, in Austria and in New Zealand. In both randomized control trials, the mean protein intake was increased with whole foods, in the New Zealand study (n = 29 males, 74.2 ± 3.6 years) to 1.7 g/kg body weight/d (10 weeks intervention; p < 0.001)) in the Austrian study (n = 119 males and females, 72.9 ± 4.8 years) to 1.54 g/kg body weight/d (6 weeks intervention; p < 0.001)). In both studies, single and double strand breaks and as formamidopyrimidine—DNA glycosylase-sensitive sites were investigated in peripheral blood mononuclear cells or whole blood. Further, resistance to H₂O₂ induced DNA damage, GSH, GSSG and CRP were measured. Increased dietary protein intake did not impact on DNA damage markers and GSH/GSSG levels. A seasonal-based time effect (p < 0.05), which led to a decrease in DNA damage and GSH was observed in the Austrian study. Therefore, increasing the protein intake to more than 20% of the total energy intake in community-dwelling seniors in Austria and New Zealand did not increase measures of DNA damage, change glutathione status or elevate plasma CRP.     

A randomized controlled clinical trial investigating the effect of DASH diet on insulin resistance,inflammation, and oxidative stress in gestational diabetes

ObjectiveTo our knowledge, no reports are available indicating the effects of the Dietary Approaches to Stop Hypertension (DASH) eating plan on insulin resistance, inflammation, and oxidative stress among pregnant women with gestational diabetes mellitus (GDM).This study was designed to investigate the effects of the DASH diet on insulin resistance, serum high-sensitivity C-reactive protein (hs-CRP) and biomarkers of oxidative stress among pregnant women with GDM.MethodsThis randomized controlled clinical trial was performed with 32 pregnant women diagnosed with GDM at 24 to 28 wk gestation. Participants were randomly assigned to consume either the control (n = 16) or DASH diet (n = 16) for 4 wk. The DASH diet was rich in fruits, vegetables, whole grains, and low-fat dairy products and was low in saturated fats, total fats, cholesterol, refined grains, and sweets, with a total of 2400 mg/d of sodium. The control diet contained 40% to 55% of its energy as carbohydrates, 10% to 20% as proteins, and 25% to 30% as total fats. Fasting blood samples were taken at baseline and after 4 wk of intervention to measure fasting plasma glucose (FPG), serum insulin, and hs-CRP, Homeostasis Model of Assessment—Insulin Resistance (HOMA-IR), plasma total antioxidant capacity (TAC), and total glutathione levels (GSH).ResultsConsumption of the DASH diet compared with the control diet resulted in decreased FPG (–7.62 versus 3.68 mg/dL; P = 0.02), serum insulin levels (–2.62 versus 4.32 μIU/mL, P = 0.03), and HOMA-IR score (–0.8 versus 1.1; P = 0.03). Increased concentrations of plasma TAC (45.2 versus –159.2 mmol/L; P < 0.0001) and GSH (108.1 versus –150.9 μmol/L; P < 0.0001) also were seen in the DASH group compared with control group. We failed to find a significant difference in mean changes of serum hs-CRP levels between the two diets. Within-group comparisons revealed significant reductions in plasma TAC and GSH levels in the control diet, while a significant increase in these biomarkers in the DASH diet.ConclusionConsumption of the DASH diet in pregnant women with GDM had beneficial effects on FPG, serum insulin levels, HOMA-IR score, plasma TAC, and total GSH levels. The effects of this dietary pattern on pregnancy outcomes need to be investigated in future studies.     

Blood antioxidants changes in young women following beta-carotene depletion and repletion.

This study was undertaken to investigate the relationship between beta-carotene intake and biochemical indices of antioxidant status in the blood of nine premenopausal women ages 18 to 42.

Nine healthy adult women were fed a low beta-carotene diet for 68 days. They were repleted with the same diet supplemented with beta-carotene (15 mg beta-carotene) for 28 days. During the last week of the study, they received an additional mixed carotenoid supplement. Indices of blood antioxidant status were measured on days 1, 29, 36, 43, 50, 64, 71, 92, and 99.

We found significant increases of erythrocyte conjugated dienes between the 71st and 99th day of the study; increases of glutathione (GSH) peroxidase (GP) on day 43 and day 92 compared to a decrease on day 29; and decreases of GSH reductase throughout the treatment period. Erythrocyte catalase activities seemed to parallel GP activities. Erythrocyte oxidized glutathione (GSSG) levels were depressed both after beta-carotene depletion and repletion. beta-Carotene depletion/repletion had no effect on plasma vitamin E or GSH levels. Platelet GSH levels were depressed after beta-carotene depletion followed by elevated GSH levels after beta-carotene repletion.

A diet low in beta-carotene and adequate in all other nutrients, including vitamin A, resulted in altered erythrocyte and platelet antioxidant indices; however, it had little impact on plasma GSH or vitamin E levels in young healthy women. Our results are consistent with the suggestion that carotenes may be important in the prevention of oxidative damage.     

Effects of oral supplementation with glutamine and alanyl-glutamine on glutamine,glutamate, and glutathione status in trained rats and subjected to long-duration exercise

ObjectiveWe investigated the effect of supplementation with the dipeptide L-alanyl-L-glutamine (DIP) and a solution containing L-glutamine and L-alanine, both in the free form, on the plasma and tissue concentrations of glutamine, glutamate, and glutathione (GSH) in rats subjected to long-duration exercise.MethodsRats were subjected to sessions of swim training. Twenty-one days before sacrifice, the animals were supplemented with DIP (1.5 g/kg, n = 6), a solution of free L-glutamine (1 g/kg) and free L-alanine (0.61 g/kg; GLN + ALA, n = 6), or water (CON, n = 6). Animals were sacrificed before (TR, n = 6) or after (LD, n = 6) long-duration exercise. Plasma concentrations of glutamine, glutamate, glucose, and ammonia and liver and muscle concentrations of glutamine, glutamate, and reduced and oxidized (GSSG) GSH were measured.ResultsHigher concentrations of plasma glutamine were found in the DIP-TR and GLN + ALA-TR groups. The CON-LD group showed hyperammonemia, whereas the DIP-LD and GLN + ALA-LD groups exhibited lower concentrations of ammonia. Higher concentrations of glutamine, glutamate, and GSH/GSSG in the soleus muscle and GSH and GSH/GSSG in the liver were observed in the DIP-TR and GLN + ALA-TR groups. The DIP-LD and GLN + ALA-LD groups exhibited higher concentrations of GSH and GSH/GSSG in the soleus muscle and liver compared with the CON-LD group.ConclusionChronic oral administration of DIP and free GLN + ALA before long-duration exercise represents an effective source of glutamine and glutamate, which may increase muscle and liver stores of GSH and improve the redox state of the cell.     

谷氨酰胺对创伤感染大鼠抗氧化能力及死亡率的影响

目的　研究经口补充谷氨酰胺 (Gln)对创伤感染大鼠免疫组织抗氧化能力及死亡率的影响。方法　采用闭合性创伤大鼠模型及补充或不补充 Gln两种方法 ,于伤后第 7d静注活绿脓杆菌 ,观察注菌后 7d内动物的死亡率 ,并检测存活动物血浆 Gln浓度、以及血浆、脾脏和肠系膜淋巴结组织内还原型谷胱甘肽 (GSH)和丙二醛 (MDA)水平。结果　创伤感染后第 7d大鼠死亡率 Gln组明显低于 Non- Gln组。Gln组存活动物的血浆 Gln浓度明显高于 Non- Gln组 ;而血浆、脾脏和肠系膜淋巴结组织 GSH水平两组均有明显下降 ,但 Non- Gln组下降程度明显大于 Gln组 ;同时 ,两组 MDA含量均有明显增加 ,但 Non- Gln组增加程度明显大于 Gln组。结论　经口补充Gln能明显降低创伤感染大鼠免疫组织脂质过氧化水平 ,增强其抗氧化损伤的能力 ,提高创伤感染后的存活率。     

Thiol/disulfide redox status is oxidized in plasma and small intestinal and colonic mucosa of rats with inadequate sulfur amino acid intake

Low molecular weight thiol/disulfide redox pools are dependent upon extracellular cysteine (Cys) availability. We determined whether dietary sulfur amino acid (SAA) deficiency induces oxidative stress in vivo, as determined by redox state of major thiol/disulfide couples in plasma [Cys/cystine (CySS)] and intestinal mucosa [glutathione (GSH)/glutathione disulfide (GSSG)]. Rats were fed isocaloric, isonitrogenous semipurified diets: either SAA-adequate (control), SAA-deficient, or SAA-supplemented, pair-fed to intake of the SAA-deficient group. Reference rats consumed standard rat food ad libitum. After 7 d, plasma and gut mucosal samples were analyzed for Cys, CySS, GSH and GSSG, and the redox potentials of Cys/CySS and GSH/GSSG were determined. Mean daily food intake in the pair-fed rats was similar (approximately one-half of reference-rat intake). Body weight decreased in all pair-fed groups, but rats fed the SAA-deficient diet lost significantly more body weight. Dietary SAA deficiency decreased GSH concentrations in both plasma and gut mucosa, increased plasma GSSG, and oxidized plasma and gut mucosal GSH/GSSG redox and plasma Cys/CySS redox. SAA supplementation resulted in a more reducing plasma Cys/CySS redox potential. Reference rats exhibited similar tissue and plasma GSH/GSSG redox as rats that ate semipurified SAA-adequate rat food, which provided similar net SAA intake. Our in vivo data show that inadequate dietary SAA intake oxidizes the thiol/disulfide redox status in rat-gut mucosa and plasma. Such oxidation of redox pools is associated with oxidative stress and the onset or progression of several pathological conditions. Thus, dietary SAA deficiency could contribute to the progression of disease by causing an oxidation of these components.     

American Ginseng Supplementation Induces an Oxidative Stress in Postmenopausal Women

Objective: To determine whether American ginseng (Panax Quinquefolium) confers antioxidant protection to postmenopausal women at rest and after a mild aerobic exercise session.

Methods: In this double-blinded parallel study, 12 female subjects (age range 55–75) consumed two capsules, containing 500 mg of dry American ginseng whole-root powder, everyday for 4 months, whereas 13 female control subjects of the same age range consumed two placebo capsules. Before and after the supplementation regimen each subject performed 30 minutes of treadmill walking on a 5% grade incline at an estimated 60% of VO₂max.

Results: Ginseng supplementation had no effect on heart rate, blood pressure, plasma blood glucose, or lactate concentration at rest or immediately after exercise tests. The ginseng supplemented group displayed a higher resting plasma glutathione disulfide (GSSG) concentration and lower glutathione (GSH):GSSG ratio, as well as a lower resting total antioxidant content (TAC). Plasma GSSG concentration decreased, whereas the GSH:GSSG ratio and TAC increased after exercise in all subjects. Furthermore, plasma malondialdehyde and urine 8-hydroxydeoxyguanosine concentrations were elevated in the ginseng-supplemented group. Erythrocyte superoxide dismutase and GSH reductase activities were increased after ginseng supplementation. The 30-minute treadmill walking, however, did not alter these changes.

Conclusions: These data suggest that chronic American ginseng supplementation at the given dose can cause an oxidative stress in postmenopausal women, as reflected by the elevated oxidative damage markers and the increased erythrocyte antioxidant enzyme activity.     

Glutathione level after long-term occupational elemental mercury exposure

Many in vitro and in vivo studies have elucidated the interaction of inorganic mercury (Hg) and glutathione. However, human studies are limited. In this study, we investigated the potential effects of remote long-term intermittent occupational elemental Hg vapour (Hg degrees ) exposure on erythrocyte glutathione levels and some antioxidative enzyme activities in ex-mercury miners in the period after exposure. The study included 49 ex-mercury miners divided into subgroups of 28 still active, Hg degrees -not-exposed miners and 21 elderly retired miners, and 41 controls, age-matched to the miners subgroup. The control workers were taken from "mercury-free works". Reduced glutathione (GSH) and oxidized disulphide glutathione (GSSG) concentrations in haemolysed erythrocytes were determined by capillary electrophoresis, while total glutathione (total GSH) and the GSH/GSSG ratio were calculated from the determined values. Catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities in erythrocytes were measured using commercially available reagent kits, while urine Hg (U-Hg) concentrations were determined by cold vapour atomic absorption (CVAAS). No correlation of present U-Hg levels, GSH, GSSG, and antioxidative enzymes with remote occupational biological exposure indices were found. The mean CAT activity in miners and retired miners was significantly higher (p<0.05) than in the controls. No differences in mean GPx activity among the three groups were found, whereas the mean GR activity was significantly higher (p<0.05) in miners than in retired miners. The mean concentrations of GSH (mmol/g Hb) in miners (13.03+/-3.71) were significantly higher (p<0.05) than in the control group (11.68+/-2.66). No differences in mean total GSH, GSSG levels, and GSH/GSSG ratio between miners and controls were found. A positive correlation between GSSG and present U-Hg excretion (r=0.41, p=0.001) in the whole group of ex-mercury miners was observed. The significantly lower GSH level (p<0.05) determined in the group of retired miners (9.64+/-1.45) seems to be age-related (r= -0.39, p=0.001). Thus, the moderate but significantly increased GSH level, GR and CAT activity in erythrocytes in the subgroup of miners observed in the period after exposure to Hg degrees could be an inductive and additive response to maintain the balance between GSH and antioxidative enzymes in interaction with the Hg body burden accumulated during remote occupational exposure, which does not represent a severely increased oxidative stress.     

Diurnal variation in glutathione and cysteine redox states in human plasma

BACKGROUND: Plasma glutathione/glutathione disulfide (GSH/GSSG) and cysteine/cystine (Cys/CySS) couples are oxidized in humans in association with oxidative stress and cardiovascular disease risk. Animal studies show that both pools undergo diurnal variations associated with dietary intake of sulfur amino acids. OBJECTIVE: The objective of this study was to determine whether the redox state of GSH, Cys, GSH/GSSG, or Cys/CySS undergoes diurnal variation in healthy adults. DESIGN: Plasma samples were collected every hour for 24 h from 63 persons aged 18-86 y who were consuming normal food (protein, 0.8 g kg(-1) d(-1); sulfur amino acids, 20 mg kg(-1) d(-1)) at standardized mealtimes. Measurements of Cys, CySS, GSH, and GSSG were used with the Nernst equation to calculate the redox states. RESULTS: Plasma Cys and GSH concentrations varied with the time of day. The highest values for plasma Cys occurred approximately 3 h after meals. Glutathione was maximal 6 h after peak plasma Cys. The calculated redox states of the GSH/GSSG and Cys/CySS couples varied in association with the concentrations of the thiol forms. Maximal reduction and oxidation of the Cys/CySS couple occurred at 2130 and 0630, whereas the respective values for the GSH/GSSG couple occurred at 0330 and 1330. The mean diurnal variation for Cys/CySS redox in persons aged >or=60 y was 1.8-fold that in persons aged <40 y. CONCLUSIONS: Cys/CySS and GSH/GSSG redox states in human plasma undergo diurnal variation with an increased magnitude of variation in Cys/CySS redox state in older persons. This variation could alter sensitivity to oxidative stress over a course of hours.     

慢性收缩性心力衰竭患者血尿酸浓度改变及其与氧化应激的关系研究

目的 研究慢性收缩性心力衰竭(CSHF)患者血尿酸(UA)浓度改变与心功能及谷胱甘肽抗氧化系统的关系.方法 选择2006年6月至2007年3月109例患者,根据有无器质性心脏病及心功能情况分为CSHF组81例,对照组28例,CSHF组又按纽约心脏病协会(NYHA)心功能分级分为心功能Ⅱ级组28例,心功能Ⅲ级组28例,心功能Ⅳ级组25例.所有患者均于入院第2天采空腹静脉血,应用酶循环法测定血浆还原型谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)浓度,并利用Nernst公式计算氧化还原电位Eh值.结果 CSHF组患者血UA浓度[(499.09±168.04)μmol/L]较对照组[(310.54±99.92)μmol/L]明显升高(P<0.01),且随着心功能分级的增加而升高,与LVEF呈负相关(r=-0.247,P=0.026),与左室舒张末期内径(LVEDD)呈正相关(r=0.266,P=0.016).血UA浓度与血浆GSH浓度呈负相关(r=-0.328,P=0.003),与血浆GSSG浓度呈正相关(r=0.244,P=0.028),与Eh值呈正相关(r=0.309,P=0.005).结论 CHF时血UA浓度升高,且与心功能分级、LVEF、LVEDD存在相关性,可作为反映收缩性心功能不全患者心功能状态的补充指标;血UA浓度还与血浆GSH浓度呈负相关、与血浆GSSG浓度及Eh值呈正相关,结合CSHF时UA的代谢途径,提示UA有可能作为氧化应激的指标.     

Plant-Based,Antioxidant-Rich Snacks Elevate Plasma Antioxidant Ability and Alter Gut Bacterial Composition in Older Adults

Plant-rich diets alleviate oxidative stress and gut dysbiosis and are negatively linked to age-associated chronic disorders. This study examined the effects of consuming plant-based, antioxidant-rich smoothies and sesame seed snacks (PBASS) on antioxidant ability and gut microbial composition in older adults. Healthy and sub-healthy older adults (n = 42, 79.7 ± 8.6 years old) in two senior living facilities were given PBASS for 4 months. Blood and fecal samples were collected from these individuals at the baseline and after 2 and 4 months of PBASS consumption. After 2 months, serum levels of albumin and high-density lipoprotein-cholesterol and the ratio of reduced to oxidized glutathione (GSH/GSSG) had increased significantly and erythrocytic glutathione, GSH/GSSG and superoxide dismutase activity had decreased significantly compared with baseline levels (p < 0.05). After 4 months, red blood cells, hematocrit, serum blood urea nitrogen and erythrocyte glutathione peroxidase activity had decreased significantly, whereas plasma and erythrocyte protein-bound sulfhydryl groups had increased significantly. Furthermore, plasma glutathione and total antioxidant capacity were significantly greater after 2 months and increased further after 4 months of PBASS consumption. The results of next generation sequencing showed that PBASS consumption prompted significant decreases in observed bacterial species, their richness, and the abundance of Actinobacteria and Patescibacteria and increases in Bacteroidetes in feces. Our results suggest that texture-modified, plant-based snacks are useful nutrition support to benefit healthy ageing via the elevation of antioxidant ability and alteration of gut microbiota.     

Association of homocysteinemia with high concentrations of serum insulin and uric acid in Brazilian subjects with metabolic syndrome genotyped for C677T polymorphism in the methylenetetrahydrofolate reductase gene

Information on plasma homocysteine concentrations and their associated factors in Brazilian subjects with metabolic syndrome (MS) is nonexistent. Therefore, a cross-sectional study was conducted to investigate the association of homocysteinemia with MS components; folate and cobalamin biochemical and dietary indices of nutritional status; and genetic, anthropometric, and lifestyle factors in Brazilian subjects with MS. Waist circumference; body fat; body mass index; insulin resistance; lipid profiles; glycemia; uricemia; insulinemia; erythrocyte folate and plasma homocysteine; folate and cobalamin concentrations; C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene; coffee and alcohol intake; and smoking were determined in 63 subjects (24 males and 39 females) with MS. No difference in homocysteine plasma was observed between sexes. Hyperhomocysteinemia (Hhcy) frequency was 49.2% (n = 31) in the group studied. The distribution of MTHFR genotypes was as follows: CC, 64% (n = 42); CT, 32% (n = 19); and TT, 4% (n = 2). No association was found between Hhcy and C677T polymorphism in the MTHFR gene. Plasma homocysteine concentrations showed no association with age; blood pressure; dietary intakes of folate, cobalamin, and pyridoxine; body mass index; waist circumference; body fat; glycemia; lipid profile; insulin resistance; and concentrations of folate erythrocyte and plasma folate and cobalamin. Also, there was no correlation between Hhcy, sex, and lifestyle factors. In this study, the variables uricemia (C = 0.67, χ² = 2.23, P = .27) and insulinemia (C = 0.86, χ² = 2.98, P = .07) were positively associated with homocysteinemia. In conclusion, our results suggest that high concentrations of serum insulin and uric acid are associated with an increased risk of developing Hhcy in subjects with MS.     

Chronic Arsenic Exposure and Blood Glutathione and Glutathione Disulfide Concentrations in Bangladeshi Adults

Background: In vitro and rodent studies have shown that arsenic (As) exposure can deplete glutathione (GSH) and induce oxidative stress. GSH is the primary intracellular antioxidant; it donates an electron to reactive oxygen species, thus producing glutathione disulfide (GSSG). Cysteine (Cys) and cystine (CySS) are the predominant thiol/disulfide redox couple found in human plasma. Arsenic, GSH, and Cys are linked in several ways: a) GSH is synthesized via the transsulfuration pathway, and Cys is the rate-limiting substrate; b) intermediates of the methionine cycle regulate both the transsulfuration pathway and As methylation; c) GSH serves as the electron donor for reduction of arsenate to arsenite; and d) As has a high affinity for sulfhydryl groups and therefore binds to GSH and Cys.Objectives: We tested the hypothesis that As exposure is associated with decreases in GSH and Cys and increases in GSSG and CySS (i.e., a more oxidized environment).Methods: For this cross-sectional study, the Folate and Oxidative Stress Study, we recruited a total of 378 participants from each of five water As concentration categories: < 10 (n = 76), 10–100 (n = 104), 101–200 (n = 86), 201–300 (n = 67), and > 300 µg/L (n = 45). Concentrations of GSH, GSSG, Cys, and CySS were measured using HPLC.Results: An interquartile range (IQR) increase in water As was negatively associated with blood GSH (mean change, –25.4 µmol/L; 95% CI: –45.3, –5.31) and plasma CySS (mean change, –3.00 µmol/L; 95% CI: –4.61, –1.40). We observed similar associations with urine and blood As. There were no significant associations between As exposure and blood GSSG or plasma Cys.Conclusions: The observed associations are consistent with the hypothesis that As may influence concentrations of GSH and other nonprotein sulfhydryls through binding and irreversible loss in bile and/or possibly in urine.Citation: Hall MN, Niedzwiecki M, Liu X, Harper KN, Alam S, Slavkovich V, Ilievski V, Levy D, Siddique AB, Parvez F, Mey JL, van Geen A, Graziano J, Gamble MV. 2013. Chronic arsenic exposure and blood glutathione and glutathione disulfide concentrations in Bangladeshi adults. Environ Health Perspect 121:1068–1074; http://dx.doi.org/10.1289/ehp.1205727     

二氧化硫吸入对小鼠9种脏器GSH和GSH/GSSG的影响

为研究二氧化硫 (SO2 )吸入后小鼠多种脏器内抗氧化物质谷胱甘肽 (GSH)和抗氧化系统GSH GSSG(GSSG为氧化型谷胱甘肽 )的变化 ,采用SO2 动态吸入染毒技术 ,使昆明小鼠吸入不同浓度SO2 后 ,用分光光度法测定不同脏器GSH含量 ,并计算GSH GSSG比值。结果表明 :(1)在SO2 浓度为 2 2mg m3时 ,雌、雄鼠所试脏器GSH水平和GSH GSSG均无显著变化 ;(2 )在SO2 浓度为 64mg m3时 ,雌鼠GSH水平和GSH GSSG变化不大 ,而雄鼠肺、肾、脑、胃、睾丸中GSH水平显著降低 ;(3 )在SO2 浓度为 148mg m3时 ,雌、雄鼠各脏器GSH水平和GSH GSSG均有下降 ,其中GSH在雄鼠肝、肺、肾、心、脑、胃、小肠、睾丸和雌鼠肝、肺、肾、小肠中下降显著 ,GSH GSSG在雄鼠肝、肾、小肠、睾丸和雌鼠肝、肺、肾、脑、胃、小肠中下降显著。以上结果说明一定浓度的SO2 吸入不仅影响小鼠呼吸器官 ,而且对多种脏器都有作用 ,同时显示雌、雄小鼠对SO2 的敏感性不同。GSH含量减少和GSH GSSG下降提示SO2 的毒作用与其降低体内抗氧化物质水平、削弱体内抗氧化防御系统有关     

Effect of walnut-enriched restructured meat in the antioxidant status of overweight/obese senior subjects with at least one extra CHD-risk factor

BACKGROUND: A number of recent studies indicate that antioxidants reduce the oxidative stress associated with the development of coronary heart diseases (CHD). OBJECTIVE: (i) To investigate whether the erythrocyte catalase (CAT), superoxide dismutase (SOD), total glutathione, reduced glutathione (GSH), oxidized glutathione (GSSG), and lipid peroxidation (LPO), and serum uric acid and paraoxonase-1 (PON1) are modified at increased CHD-risk individuals consuming walnut-enriched meat (WM), (ii) to evaluate whether these changes were influenced by basal serum cholesterol, body mass index or smoking habit. DESIGN: The study was a non blinded, cross-over, placebo-controlled trial in which 22 volunteers (60% overweight and 40% obese) with increased CHD-risk were randomly assigned to receive WM or control meat (CM) during two different periods of 5 weeks. RESULTS: A significant interaction time*treatment (p < 0.05) was observed in all enzymes and substrates tested except HDL-C, uric acid and LPO. The treatment significantly increased CAT activity, total glutathione and GSSG (p < 0.05). Significant gender*time*treatment interaction (p = 0.043) for total glutathione was found increasing at the end of the WM period in male but not changing in female. Total glutathione and GSH/GSSG ratio (p < 0.05) were lower in smokers. Hypercholesterolemics presented higher uric acid (p < 0.05) but no enzyme activities or substrate concentrations were different from those of normocholesterolemics. CONCLUSIONS: The WM tested appears to be a functional food as it improved the antioxidant status of increased CHD-risk volunteers. Despite its high energy content, it also appears adequate for overweight and obese people because did not exert negative effect upon body weight.     

High Fat Diet Exposure during Fetal Life Enhances Plasma and Hepatic Omega-6 Fatty Acid Profiles in Fetal Wistar Rats

Pregnant rats were fed a high fat diet (HFD) for the first (HF1), second (HF2), third (HF3) or all three weeks (HFG) of gestation. Maintenance on a HFD during specific periods of gestation was hypothesized to alter fetal glycemia, insulinemia, induce insulin resistance; and alter fetal plasma and hepatic fatty acid (FA) profiles. At day 20 of gestation, fetal plasma and hepatic FA profiles were determined by gas chromatography; body weight, fasting glycemia, insulinemia and the Homeostasis Model Assessment (HOMA-insulin resistance) were also determined. HF3 fetuses were heaviest concomitant with elevated glycemia and insulin resistance (p < 0.05). HFG fetuses had elevated plasma linoleic (18:2 n-6) and arachidonic (20:4 n-6) acid proportions (p < 0.05). In the liver, HF3 fetuses displayed elevated linoleic, eicosatrienoic (20:3 n-6) and arachidonic acid proportions (p < 0.05). HFG fetuses had reduced hepatic docosatrienoic acid (22:5 n-3) proportions (p < 0.05). High fat maintenance during the final week of fetal life enhances hepatic omega-6 FA profiles in fetuses concomitant with hyperglycemia and insulin resistance thereby presenting a metabolically compromised phenotype.