Higher Levels Of TBARS Research Articles

A trait-based approach to determine the risks of Zn to the overall health status of native fish species Barbus meridionalis

Fish adapt to changing environments by maintaining homeostasis or making energy trade-offs that impact fitness. We investigated the effect of Zn on the fitness and physiology of Barbus meridionalis, a native cyprinid fish species, under two exposure scenarios. The Osor stream's mine-effluent reach represented long-term (chronic) exposure, while the upstream reach served as a control/acute exposure. Acute exposure involved exposing B. meridionalis to 1mg/L Zn for 96 h in the laboratory. We examined physiological traits (Standard metabolic rate SMR, Maximum metabolic rate MMR, Absolute Aerobic scope AAS, Critical swimming capacity Ucrit) and antioxidant system, AS (Superoxide dismutase, SOD; Catalase, CAT; Glutathione peroxidase, GPX; Glutathione-S-transferase, GST; Glutathione, GSH; Thiobarbaturic acid reactive substances, TBARS) biomarkers. The results indicated that Zn had no significant effect on osmoregulatory cost (SMR) in either exposure scenario but impaired energetically costly exercise (low MMR). AAS reduction in both exposure groups suggested compromised energy allocation for life-history traits, evidenced by decreased locomotor performance (Ucrit) after acute exposure. Tissue-specific and time-dependent responses were observed for AS biomarkers. The fish exhibited ineffective control of oxidative damage, as evidenced by high TBARS levels in the liver and gills, despite increased CAT and GSH in the liver under acute conditions. Our findings demonstrate differential responses at the subcellular level between the two exposure scenarios, while trait-based endpoints followed a similar pattern. This highlights the utility of a trait-based approach as a supplementary endpoint in biomonitoring studies, which provides insights into impacts on individual fitness and population demography.

Peripheral and regional blood bloodstreams lipid peroxidation comparative analysis in women with pelvic venous disorder.

Pelvic venous disorder (PVD) in women is a polyetiological multifactorial disease characterized by a high prevalence (up to 80%), a high risk of infertility, and a progressive recurrent course. Morphological changes of the venous bed occur in PVD, contributing to retrograde blood flow and pelvic phlebohypertension. It is occur due to dynamic hypervolemia and hypertension long-term exposure on the venous wall. However, PVD pathogenesis analysis only from venous hemodynamic disorders position does not explain all mechanisms of the disease development and does not contribute to the treatment measures effectiveness. Currently oxidative stress reactions are considered as the most important markers of the pathological process. The aim of our work was a comparative analysis of lipid peroxidation-antioxidant defense component changes in the peripheral and regional blood flow in women with primary pelvic venous disorder depending on the disease stage. The study involved 137 women of reproductive age (mean age 37.4±9.1 years old) with diagnosed primary PVD divided into 3 groups according to the pathological process stages (stages I, II, III). Data from 30 practically healthy women (mean age 33.5±6.3 years old) were used as controls. Spectrophotometric, fluorometric, immunoassay and statistical methods were used. In patients with PVD stage I in peripheral bloodstream were higher values of SOD and GPO activity; in the regional bloodstream were higher levels of TBARs, SOD, catalase, GPO and lower GSH. In PVD stage II the peripheral bloodstream showed elevated levels of DC, GSH and SOD reduced levels; the regional bloodstream showed higher levels of DC, TBARs, GPO and GSH reduced levels relative to controls. PVD stage III was characterized by: higher levels of DC and TBARs and lower levels of SOD and GSH in the peripheral bloodstream; higher levels of DC, TBARs and lower levels of GSH and catalase in the regional bloodstream compared with control. Thus, the results of our study showed no significant differences in the LPO-AOD system between peripheral and regional bloodstreams in patients with PVD depending on the disease stage. However, negative changes in the redox balance in the regional bloodstream were earlier and were already registered at the first stage of the disease. It is likely that control of antioxidant insufficiency in patients with PVD should be an important component of preventive measures in the early stages and pathogenetic treatment in the pathological process progression, particularly in stage III of the disease.

Resveratrol exerts anti-oxidant and anti-inflammatory actions and prevents oxaliplatin-induced mechanical and thermal allodynia

Chemotherapy-induced peripheral neuropathic pain (CIPNP) is a frequent and devastating side effect of cancer therapy. No preventive strategies are currently available. We investigated the use of resveratrol (RESV) in the prevention of CIPNP and evaluated key components of the antioxidant defense system and neuroinflammatory factors as possible mediators contributing to RESV actions. Male rats were injected with oxaliplatin (OXA) and received daily oral RESV. Paw mechanical and thermal allodynia, oxidative stress, antioxidant, pro-inflammatory and neuronal injury/activation markers were evaluated in the sciatic nerve (SN), lumbar dorsal root ganglia (DRG) and spinal cord (SC). OXA-injected animals developed mechanical and thermal allodynia, while those receiving OXA + RESV showed patterns of response similar to control animals. Higher TBARS levels and lower GSH/GSSG ratios were observed in the SN of animals receiving OXA. The mRNA levels of the transcription factor NFκB and the pro-inflammatory cytokine TNFα were found to be upregulated both in lumbar DRG and SC. In addition, the antioxidant enzymes NQO-1 and HO-1 and the neuronal injury marker ATF3 showed increased levels of expression in lumbar DRG. In the dorsal SC the neuronal activation marker c-fos and the transcription factor Nrf2, main regulator of antioxidant defenses, were found to be upregulated. RESV early and sustained administration prevented NFκB, TNFα, ATF3 and c-fos upregulation, while increasing the expression of Nrf2, NQO-1, HO-1 and the redox-sensitive deacetylase SIRT1. RESV treatment was also able to restore TBARS levels and GSH/GSSG ratio. Thus, RESV administration resulted in the upregulation of antioxidant mediators, suppression of pro-inflammatory parameters and prevention of OXA-induced mechanical and thermal allodynia.

Inflammatory and oxidative stress biomarkers induced by silica exposure in crystal craftsmen.

Identification of biomarkers associated with the diagnosis and prognosis of silicosis would be highly advantageous in the clinical setting. The aim of this study is to evaluate inflammatory and oxidative stress biomarkers in subjects exposed to silica. A cross-sectional study of crystal craftsmen currently (n = 34) or formerly (n = 35) exposed and a group of nonexposed subjects (n = 12) was performed. Personal respirable dust samples were collected. Plasma inflammatory mediators (bone morphogenetic protein- BMP2 and chemokines CXCL16, and CCL5), oxidative stress enzymes (thiobarbituric acid reactive substances [TBARs] and superoxide dismutase [SOD]), and nitrite (NO2- ) were analyzed in parallel with nitric oxide in exhaled breath (FeNO). Being currently or formerly exposed to silica was related to increased levels of CXCL16 and TBARs. Currently, exposed subjects showed decreased levels of SOD. Thirty-seven craftsmen with silicosis (26 formerly and 11 currently exposed) showed higher levels of CXCL16, which was positively associated with the radiological severity of silicosis. Compared with the nonexposed, subjects with silicosis had higher levels of TBARs and those with complicated silicosis had lower levels of SOD. In multivariate analysis, higher levels of CXCL16 were associated with exposure status and radiological severity of silicosis. Smoking was not a confounder. FeNO did not distinguish between the exposure status and the presence of silicosis. CXCL16 emerged as a potential biomarker that could distinguish both silica exposure and silicosis. TBARs were elevated in exposed individuals. However, their clinical applications demand further investigation in follow-up studies of representative samples.

The evaluation of oxidative stress parameters in the benign prostatic hyperplasia, prostatitis and prostate cancer

Aim: Recently, oxidative stress has been well known that it has especially important a role in benign prostatic hyperplasia, prostatitis, and prostate cancer. The present study has planned to estimate parameters of the oxidative stress and the antioxidant status in patients with benign prostatic hyperplasia, prostatitis and prostate cancer.Material and Method: For this aim totally fourty men with benign prostatic hyperplasia (n=14), prostatitis (n=15) and prostate cancer (n=11) without any other chronic disease, and who not use cigarettes and alcohol were subjected. Venous blood samples were taken. Thiobarbituric acid reaction (TBARS), total oxidant status (TOS), total antioxidant capacity (TAC), glutathione (GSH) levels, and catalase (CAT) activity in serum were assessed in patient with prostatitis, and prostate cancer compared to benign prostatic hyperplasia.Results: It was viewed that GSH levels were significantly lower, TBARS and TOS levels were significantly higher in patients with of prostate cancer compared to benign prostatic hyperplasia. Also, GSH and CAT significant different was determined in prostatitis compared to BPH. Oxidative stress may be concluded in prostate cancer and prostatitis, proved via the higher TBARS levels and lower GSH levels.Conclusion: The increased activity of antioxidant enzyme may be a compensatory regulation in response to oxidative stress.

Perinatal complications, lipid peroxidation, and mental health problems in a large community pediatric sample.

Replicated evidence indicates that perinatal complications are associated with increased markers of oxidative stress and with mental health problems in children. However, there are fewer reports on the impact of perinatal complications in later phases of development. We aimed to investigate the estimated effects of perinatal complications on levels of lipid peroxidation and on psychopathology in children and adolescents. The study is part of the High Risk Cohort Study for Psychiatric Disorders; the population was composed by 554 students, 6-14years of age. Serum levels of malondialdehyde, a product of lipid peroxidation, were measured by the TBARS method. A household interview with parents and caregivers was conducted and included inquiries about perinatal history, the Child Behavior Checklist (CBCL), and parent's evaluation, using the Mini International Psychiatric Interview (MINI). We created a cumulative risk index, conceptualized as each individual's cumulative exposure to perinatal complications. Results indicate that perinatal complications were associated with higher levels of TBARS. After adjusting for age, gender, socio-economic status, CBCL total problems score, parental psychopathology, and childhood maltreatment, children exposed to 3 or more perinatal complications had an 26.9% (95% CI 9.9%, 46.6%) increase in TBARS levels, relative to the unexposed group. Exploratory mediation analysis indicated that TBARS levels partially mediated the association between perinatal complications and externalizing problems. In conclusion, an adverse intrauterine and/or early life environment, as proxied by the cumulative exposure to perinatal complications, was independently associated with higher levels of lipid peroxidation in children and adolescents.

MCD diet-induced steatohepatitis is associated with alterations in asymmetric dimethylarginine (ADMA) and its transporters.

Using an experimental model of NASH induced by a methionine-choline-deficient (MCD) diet, we investigated whether changes occur in serum and tissue levels of asymmetric dimethylarginine (ADMA). Male Wistar rats underwent NASH induced by 8-week feeding with an MCD diet. Serum and hepatic biopsies at 2, 4 and 8weeks were taken, and serum enzymes, ADMA and nitrate/nitrite (NOx), were evaluated. Hepatic biopsies were used for mRNA and protein expression analysis of dimethylarginine dimethylaminohydrolase-1 (DDAH-1) and protein methyltransferases (PRMT-1), enzymes involved in ADMA metabolism and synthesis, respectively, and ADMA transporters (CAT-1, CAT-2A and CAT-2B). Lipid peroxides (TBARS), glutathione, ATP/ADP and DDAH activity were quantified. An increase in serum AST and ALT was detected in MCD animals. A time-dependent decrease in serum and tissue ADMA and increase in mRNA expression of DDAH-1 and PRMT-1 as well as higher rates of mRNA expression of CAT-1 and lower rates of CAT-2A and CAT-2B were found after 8-week MCD diet. An increase in serum NOx and no changes in protein expression in DDAH-1 and CAT-1 and higher content in CAT-2 and PRMT-1 were found at 8weeks. Hepatic DDAH activity decreased with a concomitant increase in oxidative stress, as demonstrated by high TBARS levels and low glutathione content. In conclusion, a decrease in serum and tissue ADMA levels in the MCD rats was found associated with a reduction in DDAH activity due to the marked oxidative stress observed. Changes in ADMA levels and its transporters are innovative factors in the onset and progression of hepatic alterations correlated with MCD diet-induced NASH.

Innovative targets involved in the progression of NASH: Asymmetric-dymethylarginine (ADMA) and its cationic transporters

Background: The methionine choline-deficient (MCD) diet results in liver injury similar to humannonalcoholic steatohepatitis (NASH). Recent data demonstrated that after methionine administration an increase in plasma asymmetric-dimethylarginine (ADMA), an inhibitor of nitric oxide synthase, and a decrease in hepatic dimethylarginine-dimethylaminohydrolase (DDAH-1), enzyme involved in ADMA metabolism, occur. Aim: Using an experimental model of NASH induced by MCD diet, this study investigated whether changes in serum levels of ADMA and tissue content of DDAH-1 occur [Kusku-Kiraz Z., Genc S., Bekpinar S., et al. Circulating levels of apelin, glucagon-like peptide and visfatin in hypercholesterolemic–hyperhomocysteinemic guinea-pigs: their relation with NO metabolism. Molecular and Cellular Biochemistry 2015;400:69–75;Magne J., Huneau J.-F., Borderie D., Mathe V., Bos C., Mariotti F. Plasma asymmetric and symmetric dimethylarginine in a rat model of endothelial dysfunction induced by acute hyperhomocysteinemia. Amino Acids 2015, http://dx.doi.org/10.1007/s00726-015-1959-4]. Materials and methods: Male Wistar rats underwent to NASH induced by 8 weeks of feeding with MCD diet. Serum and hepatic biopsies at 2, 4 and 8 weeks were used: serum enzymes (AST, ALT) and ADMA were evaluated. Hepatic biopsies were used for the analysis of mRNA expression of DDAH-1 and ADMA transporters (CAT-1, CAT-2A and CAT-2B). Tissue total lipids, lipid peroxides (TBARS), glutathione and DDAH activity were also quantified. Results: As expected, an increase in serum AST and ALT and in hepatic total lipids were detected in MCD animals. A time-dependent decrease in serum ADMA and increase in mRNA expression of DDAH-1 were found in MCD group. Higher mRNA expression of CAT-1, lower mRNA expression of CAT-2A and no changes in CAT-2B were found after 8 weeks using MCD diet. The hepatic DDAH activity decreased with a concomitant increase in oxidative stress, as demonstrated by high TBARS levels and low glutathione content. Conclusions: A decrease in serum ADMA levels and an increase in DDAH-1mRNA found inMCD rats were associated with a reduction in DDAH activity due to the marked oxidative stress observed. Changes in ADMA levels and its transporters represent innovative factors involved in the onset and the progression of hepatic alteration correlated with MCD-diet-induced NASH. Funding: Supported by Fondazione Cariplo, grant n◦ 2011-0439.

Effects of heavy metals on biomarkers for oxidative stress in Griffon vulture (Gyps fulvus)

Metals are involved in the formation of reactive oxygen species (ROS) which may result in metal-related oxidative stress that can lead to oxidative damage to lipids, DNA and proteins. It is necessary to understand the mechanisms of metal toxicity in wild birds, and the concentrations that cause effects on oxidative stress biomarkers. The aim of this study is to assess the concentrations of lead (Pb), cadmium (Cd), mercury (Hg), copper (Cu) and zinc (Zn) with regards to oxidative stress in blood samples of 66 Griffon vultures (Gyps fulvus) from two areas of the Autonomous Community of Valencia (East of Spain). The two study areas (Alcoy n=36 and Cinctorres n=30) were selected as random locations of interest that had not yet been studied, and are feeding stations where supplementary food, mainly of pork origin, is provided for vultures. Given that the two study areas are not considered polluted sites, we expected to find low metal concentrations. However, there are no known threshold concentrations at which metals can affect antioxidant systems, and low metal levels may have an effect on antioxidant biomolecules. In this study, since sampling was done at the beginning of the hunting season, the low Pb levels found in most Griffon vultures from Alcoy and Cinctorres (median=12.37 and 16.26μg/dl, respectively) are suggestive of background levels usually found in vultures that feed on pork carcasses all year round. The ingestion of game meat with bullet fragments in carcasses or with Pb shots embedded in the flesh could be the cause of the high blood Pb concentrations found in three vultures from Cinctorres (83, 290 and 362μg/dl). Griffon vultures feeding in Cinctorres had enhanced CAT and GST activities and tGSH concentrations, which may be interpreted as protective response against the higher TBARS levels. This study provides threshold concentrations at which metals affect antioxidant system derived from 66 samples of Griffon vulture. Blood Cd concentrations greater than 0.05μg/dl produced an induction of 33% in GPx and of 44% in CAT activity in erythrocytes of vultures from Alcoy. Hg concentrations in blood higher than 3μg/dl produced an induction of 10% in SOD activity. Concentrations of Pb above 15µg/dl in blood produced an inhibition of 12.5% in GPx and 11.3% in CAT activity, and a TBARS induction of 10.7% in erythrocytes of Griffon vultures.

Intermediate osteopetrosis upon loss of H+−driven lysosomal CL-accumulation

Intermediate osteopetrosis upon loss of H+−driven lysosomal CL-accumulation

Isoprostane levels are altered in rheumatoid arthritis and suppress NFκB activity to inhibit osteoclast formation

Isoprostane levels are altered in rheumatoid arthritis and suppress NFκB activity to inhibit osteoclast formation

Thiobarbituric acid reactive substances (TBARs) in follicular fluid – relation with oocyte degeneration

OBJECTIVE: Follicular fluid is comprised of a series of proteins, ions, growth factors, and metabolites which participate in oocyte maturation during the FSH-responsive antral stage. Exogenous FSH may allow development of incompetent oocytes, and thus generate follicular fluid with altered levels of metabolites. We wished to verify levels of TBARs – indicative of lipid peroxidation – in follicular fluid of women undergoing controlled ovarian stimulation.DESIGN: Prospective study.MATERIALS AND METHODS: Follicular fluid was retrieved following oocyte recovery, and separated for analysis. TBARs were measured using a spectrophotometric assay. In order to verify if TBARs were different in follicles with oocytes, 73 follicles were included. Subsequently, correlations were verified between TBARs levels and oocyte maturity and number of degenerated oocytes, according to cycle outcome.RESULTS: Although cluster analysis demonstrated two separate clusters: one with only follicles presenting oocytes and lower TBARs levels and the other with only follicles not presenting oocytes and higher TBARs levels, there was no difference between TBARs levels in oocyte or non-oocyte-containing follicles. Interestingly, TBARs levels were correlated with the number of degenerated oocytes in negative outcome cycles (r=0.549), but not in cycles leading to pregnancy (r=0.034).CONCLUSIONS: Although TBARs seem to be lower in follicles containing oocytes, this has yet to be demonstrated. However, the association between the presence degenerated oocytes and TBARs levels may be indicative that oxidative stress plays a role in decreasing oocyte quality. OBJECTIVE: Follicular fluid is comprised of a series of proteins, ions, growth factors, and metabolites which participate in oocyte maturation during the FSH-responsive antral stage. Exogenous FSH may allow development of incompetent oocytes, and thus generate follicular fluid with altered levels of metabolites. We wished to verify levels of TBARs – indicative of lipid peroxidation – in follicular fluid of women undergoing controlled ovarian stimulation. DESIGN: Prospective study. MATERIALS AND METHODS: Follicular fluid was retrieved following oocyte recovery, and separated for analysis. TBARs were measured using a spectrophotometric assay. In order to verify if TBARs were different in follicles with oocytes, 73 follicles were included. Subsequently, correlations were verified between TBARs levels and oocyte maturity and number of degenerated oocytes, according to cycle outcome. RESULTS: Although cluster analysis demonstrated two separate clusters: one with only follicles presenting oocytes and lower TBARs levels and the other with only follicles not presenting oocytes and higher TBARs levels, there was no difference between TBARs levels in oocyte or non-oocyte-containing follicles. Interestingly, TBARs levels were correlated with the number of degenerated oocytes in negative outcome cycles (r=0.549), but not in cycles leading to pregnancy (r=0.034). CONCLUSIONS: Although TBARs seem to be lower in follicles containing oocytes, this has yet to be demonstrated. However, the association between the presence degenerated oocytes and TBARs levels may be indicative that oxidative stress plays a role in decreasing oocyte quality.

Antioxidant Enzymes and Heavy Metal Levels in Tissues of the Black Chocolate Clam Megapitaria squalida in Bahía de La Paz, Mexico

The black chocolate clam Megapitaria squalida is a commercially important bivalve along the Pacific coast of Mexico and is used as a bioindicator in environmental health studies. Previous studies of Bahía de La Paz indicated significant differences in heavy metal content among localities in this clam. To identify areas affected by heavy metal pollution, lipid peroxidation (TBARS) levels and activity of superoxide dismutase (SOD) and glutathione S-transferase (GST) were measured in muscle, gonad, and digestive gland tissue and correlated with heavy metal levels of clams from six localities along the shore of the bay. Significant differences in TBARS levels and antioxidant enzyme activity were found among these tissues at all localities. Such differences are ascribed to the physiology of each organ. Higher levels of TBARS were found in areas with higher cadmium content. SOD activity in muscle correlated positively with cadmium, lead, and iron in areas with a higher content of those elements. This study suggests that TBARS levels and SOD and GST activity are affected by biotic and abiotic factors and have potential as indicators of heavy metal contamination.

Insinuation of exacerbated oxidative stress in sucrose-fed rats with a low dietary intake of magnesium: Evidence of oxidative damage to proteins

High sucrose diets and low magnesium intake have been independently implicated in induction of oxidative stress in animal models. The aim of this study was to investigate whether low dietary magnesium intake exacerbates the prooxidant effects of high sucrose feeding. Rats were fed control (C), high sucrose (HS); low magnesium (LM) and high sucrose low magnesium (HSLM) diets for 90 days and oxidative stress evaluated in terms of formation of TBARS, advanced oxidation protein products and protein carbonyls. HS and LM rats showed evidence of lipid peroxidation and protein oxidation in plasma and liver. Enhanced oxidative injury to lipids and proteins after HSLM feeding was indicated by increased carbonyl content (p <0.01) and significantly (p <0.005) higher levels of TBARS in plasma and hepatic tissue relative to both HS and LM groups. Altogether, these results illustrate the potential detrimental and cumulative effects of low magnesium intake combined with high sucrose consumption on oxidative stress variables.

Chronic low vitamin intake potentiates cisplatin-induced intestinal epithelial cell apoptosis in WNIN rats

To investigate if cisplatin alters vitamin status and if VR modulates cisplatin induced intestinal apoptosis and oxidative stress in Wistar/NIN (WNIN) male rats. Weanling, WNIN male rats (n = 12 per group) received adlibitum for 17 wk: control diet (20% protein) or the same with 50% vitamin restriction. They were then sub-divided into two groups of six rats each and administered cisplatin (2.61 mg/kg bodyweight) once a week for three wk or PBS (vehicle control). Intestinal epithelial cell (IEC) apoptosis was monitored by morphometry, Annexin-V binding, M30 cytodeath assay and DNA fragmentation. Structural and functional integrity of the villus were assessed by villus height/crypt depth ratio and activities of alkaline phosphatase, lys, ala-dipeptidyl amino-peptidase, respectively. To assess the probable mechanism(s) of altered apoptosis, oxidative stress parameters, caspase-3 activity, and expression of Bcl-2 and Bax were determined. Cisplatin per se decreased plasma vitamin levels and they were the lowest in VR animals treated with cisplatin. As expected VR increased only villus apoptosis, whereas cisplatin increased stem cell apoptosis in the crypt. However, cisplatin treatment of VR rats increased apoptosis both in villus and crypt regions and was associated with higher levels of TBARS, protein carbonyls and caspase-3 activity, but lower GSH concentrations. VR induced decrease in Bcl-2 expression was further lowered by cisplatin. Bax expression, unaffected by VR was increased on cisplatin treatment. Mucosal functional integrity was severely compromised in cisplatin treated VR-rats. Low intake of vitamins increases the sensitivity of rats to cisplatin and promotes intestinal epithelial cell apoptosis.

Effect of pasture vs. concentrate feeding with or without antioxidants on carcass characteristics, fatty acid composition, and quality of Uruguayan beef

Thirty Hereford steers were finished either on pasture ( n=10) or concentrate ( n=20) to determine dietary and antioxidant treatment effects on carcass characteristics, fatty acid composition, and quality of Uruguayan beef. Half of the steers finished on concentrate were supplemented with 1000 I.U. vitamin E head −1 day −1 for 100 days. Postmortem vitamin C was added to ground beef (0.05% v/w) displayed for 8 days at 2 °C. Carcasses from steers finished on concentrate had greater ( P<0.05) carcass weight, conformation, degree of finishing, fat depth, and ribeye area than pasture finished animals. Carcasses from pasture-fed steers showed darker ( P<0.05) longissimus color and yellower ( P<0.05) fat at 24 h postmortem than concentrate-fed. Initial longissimus Warner-Bratzler shear force (WBSF) values were similar ( P>0.05) between pasture- and concentrate-fed animals. However, beef from pasture-fed cattle had lower ( P<0.05) WBSF values at 7 and 14 days postmortem. Longissimus α-tocopherol concentrations were greater ( P<0.01) for pasture- and concentrate-fed animals that were supplemented with vitamin E compared to concentrate-fed. Steaks from pasture-fed and vitamin E supplemented cattle had similar ( P>0.05) TBARS values, which were lower ( P<0.05) than steaks from concentrate-fed steers during 21 days of display. Ground beef from vitamin E supplemented steers had the lowest TBARS values; whereas samples from pasture-fed animals had the lowest lipid stability with higher TBARS levels than other treatments. Vitamin C addition to ground beef did not ( P>0.05) reduce lipid oxidation. Vitamin E supplementation of concentrate-fed cattle had no effect ( P>0.05) on color stability of ground beef or steaks. The a ∗ (redness) and b ∗ (yellowness) values were higher ( P<0.05) when vitamin C was added to ground beef. Longissimus fatty acid content of concentrate-fed animals was twofold greater ( P<0.01) than pasture-fed. The percentages of C14:0, C16:0, and C18:1 fatty acids were higher ( P<0.01) in the intramuscular fat of concentrate-fed steers, whereas pasture-fed cattle showed greater ( P<0.01) proportions of C18:0, C18:2, C18:3, C20:4, C20:5, and C22:5. Total conjugated linoleic acid (CLA) and CLA isomer c9t11 were higher ( P<0.01) for pasture- than concentrate-fed cattle. Vitamin E supplementation of concentrate-fed steers increased lipid stability of ground beef and steaks, but was unable to improve color stability; whereas vitamin C addition to ground beef increased color stability without altering lipid oxidation. Finishing cattle on pasture enhanced the unsaturated fatty acid profile of intramuscular fat in beef including CLA and omega-3 fatty acids.

Mussel transplantation and biomarkers as useful tools for assessing water quality in the NW Mediterranean

Mussels, coming from an aquaculture farm located in a clean open bay, were transplanted to several stations of the bays of Nice and Cannes (NW Mediterranean) including a reference site for one month at three periods. Several biomarkers: activities of glutathione S-transferase (GST; exposure to organics), of catalase (exposure to oxidative stress) and of acetylcholinesterase (inhibited by some pesticides) and the lipid peroxidation (thiobarbituric acid reactive substances: TBARS) were measured in transplanted mussels. Cd, Cu and Zn concentrations were also measured as well as their condition index. The results demonstrated some seasonal variations in GST and catalase activities with higher levels in June compared to October. The condition index was also higher in June than in October. Principal component analyses performed with the whole set of data allowed to separate stations or groups of stations according to their responses. The mussels from the harbour of Nice were characterized by high TBARS levels and catalase activity in October 1999 whereas in the harbour of Cannes, animals presented very high copper concentrations and GST activities in June 2000. At the reference site, mussels generally presented low enzymatic activities (except AChE activity) and peroxidation levels and low heavy metal concentrations.

Behavior of thiobarbituric acid reactive substances, alpha-tocopherol, glutathione and selenium during hypertension in pregnancy

In a longitudinal study the changes of serum or plasma levels of TBARS, alpha-tocopherol, glutathione and selenium were investigated comparing 46 pregnant women with hypertensive syndrome and 18 women with normal pregnancies. A significant increase in TBARS serum level was found in women suffering from hypertension. There was no correlation between the severity of hypertension and the extent of the TBARS rise. An absolute deficiency of the antioxidants alpha-tocopherol, glutathione and the elements selenium, calcium, magnesium, iron and zinc as a cause or a consequence of hypertension in pregnancy could be excluded. Low serum levels of copper and selenium could decrease the activity of glutathione peroxidase (Gpx) resulting in higher levels of TBARS and glutathione during the last trimester of pregnancy and delivery. Increased concentrations of iron in women with hypertensive syndrome may affect the formation of lipid peroxides. The outcome of children was unaffected by increased lipid peroxide levels when an antihypertensive therapy was consequently performed.