Higher Thiobarbituric Acid Reactive Substances Research Articles

Mice lacking mitochondrial ferritin are more sensitive to doxorubicin-mediated cardiotoxicity.

Mitochondrial ferritin is a functional ferritin that localizes in the mitochondria. It is expressed in the testis, heart, brain, and cells with active respiratory activity. Its overexpression in cultured cells protected against oxidative damage and reduced cytosolic iron availability. However, no overt phenotype was described in mice with inactivation of the FtMt gene. Here, we used the doxorubicin model of cardiac injury in a novel strain of FtMt-null mice to investigate the antioxidant role of FtMt. These mice did not show any evident phenotype, but after acute treatment to doxorubicin, they showed enhanced mortality and altered heart morphology with fibril disorganization and severe mitochondrial damage. Signs of mitochondrial damage were present also in mock-treated FtMt−/− mice. The hearts of saline- and doxorubicin-treated FtMt−/− mice had higher thiobarbituric acid reactive substance levels, heme oxygenase 1 expression, and protein oxidation, but did not differ from FtMt+/+ in the cardiac damage marker B-type natriuretic peptide (BNP), ATP levels, and apoptosis. However, the autophagy marker LC3 was activated. The results show that the absence of FtMt, which is highly expressed in the heart, increases the sensitivity of heart mitochondria to the toxicity of doxorubicin. This study represents the first in vivo evidence of the antioxidant role of FtMt.Key message Mitochondrial ferritin (FtMt) expressed in the heart has a protective antioxidant role.Acute treatment with doxorubicin caused the death of all FtMt−/− and only of 60 % FtMt+/+ mice.The hearts of FtMt−/− mice showed fibril disorganization and mitochondrial damage.Markers of oxidative damage and autophagy were increased in FtMt−/− hearts.This is the first in vivo evidence of the antioxidant role of FtMt. Electronic supplementary materialThe online version of this article (doi:10.1007/s00109-014-1147-0) contains supplementary material, which is available to authorized users.

The influence of different dietary oil qualities on growth rate, feed utilization and oxidative stress in Atlantic cod

The aim of our study was to investigate the effects of dietary oils, with different degrees of oxidative stability, on growth performance, lipid and fatty acid (FA) composition, oxidative stress status and health parameters of Atlantic cod. The dietary oils were a traditional fish oil (FO), a FO and rapeseed oil blend (FO-RO, 1:1), or two salmon oil (SO) qualities with low (SO-L) or high (SO-H) level of oxidation products. Fish (479 g) were fed one of the four diets for 112 days (800 g). No significant differences in growth rate, feed efficiency or morphology of the intestine were found. However, there was a tendency to higher thiobarbituric acid reactive substance values in plasma and liver in the FO and SO groups than in the FO-RO group, although only significant for the FO group in plasma. There was also a tendency to reduced activities of catalase and SOD in the FO and SO groups. An increase in transcripts related to oxidative stress in the liver and heart was obvious. The FA composition of liver reflected the FA composition of the diet, with lowest n-3 FA percentage in the FO-RO group, intermediate percentage in the SO groups and highest percentage in the FO group.

Effects of feeding diets containing highly peroxidized distillers dried grains with solubles and increasing vitamin E levels to wean–finish pigs on growth performance, carcass characteristics, and pork fat composition1

Lipid peroxidation in animal feed can negatively affect growth performance and meat quality. Weanling pigs (n = 432; BW = 6.6 ± 0.4 kg) were used to evaluate the effects of feeding peroxidized distillers dried grains with solubles (DDGS) with 3 levels of vitamin E (α-tocopheryl acetate) on growth performance, carcass composition, fatty acid composition of pork fat, and lipid peroxidation in LM. The DDGS source used in this study contained the highest thiobarbituric acid reactive substances (TBARS) value, peroxide value, and total S content (5.2 ng malondialdehyde/mg oil, 84.1 mEq/kg oil, and 0.95%, respectively) among 30 DDGS sources sampled. Pens within blocks were assigned randomly to 1 of 6 diets in a 2 × 3 factorial arrangement of treatments with 8 pens per treatment and 9 pigs per pen. Pigs were fed a corn-soybean meal (CON) or 30% peroxidized DDGS (Ox-DDGS) diets with 3 levels of vitamin E: none supplemented (No-E), NRC (1X-E), or 10X NRC (10X-E). Compared to CON, inclusion of 30% Ox-DDGS in diets reduced (P < 0.001) final BW (110 vs. 107 kg), overall ADG (0.76 vs. 0.74 kg/d), and G:F (0.39 vs. 0.37). Increasing dietary vitamin E concentrations improved G:F (P = 0.03) of pigs fed 10X-E and 1X-E vs. No-E diets (0.39 and 0.39 vs. 0.38, respectively). Hot carcass weight, dressing percentage, backfat depth, and LM area were reduced (P < 0.01) in pigs fed Ox-DDGS compared to CON, but percentage of fat-free carcass lean was not affected. Feeding Ox-DDGS increased (P < 0.001) PUFA concentration, particularly linoleic acid (P < 0.001), and iodine value (P < 0.001) in belly fat and backfat compared to pigs fed CON. Dietary vitamin E levels did not affect fatty acid profiles in belly or back fat. Loin muscle TBARS were measured to determine the lipid peroxidation level in pork loins. Although pigs were fed a Ox-DDGS source in this study, TBARS in LM were similar between Ox-DDGS and CON treatments. There was no interaction between Ox-DDGS and dietary vitamin E concentration in LM TBARS. Alpha-tocopherol concentration in LM was greater (P < 0.001) in 10X-E than No-E or 1X-E dietary treatments. Compared to CON, feeding Ox-DDGS increased α-tocopherol concentration in LM of pigs fed No-E (1.0 vs. 3.1 mg/kg; P = 0.005) but not in those fed 1X-E or 10X-E. These results indicate that feeding diets containing 30% Ox-DDGS to wean-finish pigs may negatively affect growth performance, but supplementation of additional vitamin E in the diet did not counteract these effects.

In vivo antioxidant assessment of two antimalarial plants–Allamamda cathartica and Bixa orellana

ObjectiveTo determine the free radical scavenging potentials pytochemical constituents of ethanol leaves extracts of Allamanda cathartica (A. cathartica) and Bixa orellana (B. orellana) and thus their effects in antimalarial activities. MethodsBoth ethanol extracted plant samples were administered at 50 mg/mL, 100 mg/mL and 200 mg/mL to Albino rats and then administered with CCl4 at 1 mL/kg body weight, in liquid paraffin (1:1, v/v) for 2 days (negative control) and compared with 5% Tween 80 (placebo) and vitamin E (positive control) pretreatments. Thiobarbituric acid reactive substances (TBARS), glutathione (GSH) and catalase (CAT) activities in blood and liver tissues were assessed. ResultsIn CCl4 treated rats, TBARS levels significantly increased, while decreased GSH and CAT levels were recorded for both plant extracts. Generally, higher TBARS and GSH values were recorded for blood than for liver homogenates; with reverse trend observed for CAT level. Increased concentrations of A. cathartica extract recorded significant antioxidant levels similar to tocopherol (vitamin E). Reducing sugars, saponins, flavonoids were recorded for both species; alkaloids in A. cathartica and terpenoids in B. orellana. ConclusionsA. cathartica, possess phytochemicals that recorded significant antioxidative defense activities for blood and liver tissues with increasing concentration. However B. orellana did not record similar results.

Oxidative Stress and Reduced Antioxidative Status, along with Endothelial Dysfunction in Acromegaly

Acromegaly is characterized by high cardiovascular morbidity and mortality. Oxidative stress and endothelial dysfunction are underlying mechanisms of atherosclerosis.The aim of this study was to evaluate the blood redox status and endothelial function by means of nitric oxide (NO) levels in patients with acromegaly. Total antioxidant capacity (TAC), catalase activity and glutathione concentration (GSH), as measures of antioxidative capacity, total oxidized glutathione (GSSG) and thiobarbituric acid reactive substances (TBARS), as indices of oxidative stress, and NO levels were assessed in 15 patients with acromegaly (age 55.4±10.5 years; 6 males) and 15 age- and sex-matched controls (age 58.4±8.1 years; 7 males). Active disease was present in 12 patients: 11 on current pharmacotherapy and 1 newly diagnosed. Three acromegalics were in remission after successful treatment. Acromegalics as compared with controls had significantly lower levels of catalase activity (8.2±5.8 vs. 51.3±29.1 mmol/ml/min, p<0.001), GSH (0.97±0.54 vs. 1.41±0.35 mmol/l, p=0.006), GSSG (0.27±0.19 vs. 2.04±1.32 mmol/l, p=0.002) and NO levels (6.0±3.1 vs. 43.0±29.8 mmol/l, p<0.001), but higher TBARS (16.3±8.9 vs. 10.1±10.8, nmol/ml, p=0.019). After adjustment for confounders, differences in catalase activity, NO levels and TBARS remained significant (p=0.004, p<0.001 and p=0.025, respectively). No association between IGF-I/GH and oxidative stress markers was noticed, except for a positive correlation between nadir GH and GSSG (r²=0.563, p=0.036). Acromegaly is associated with increased levels of oxidative stress coupled by diminished antioxidant capacity and endothelial dysfunction indicated by the presence of decreased NO levels.

Dose- and time-related changes in aerobic metabolism, chorionic disruption, and oxidative stress in embryonic medaka (Oryzias latipes): Underlying mechanisms for silver nanoparticle developmental toxicity

Silver nanoparticles (AgNPs) are widely employed in commercial products, and are thus inevitably released into the aquatic environment. Many studies have indicated that AgNPs could induce toxicological effects on embryonic fish. To understand the mechanism of AgNP developmental toxicity, we determined the effects of AgNPs on the egg membrane, aerobic metabolism, antioxidant system, lipid peroxidation, as well as reactive oxygen species (ROS) and singlet oxygen (1O2) generation in early-life medaka fish (Oryzias latipes). AgNP treatment at 62.5–1000μg/L caused significant increase in retarded development and abnormalities. Destruction of the surface ornamentation and egg envelope was observed at a higher AgNP concentration (≥125μg/L) using light microscopy and scanning electron microscopy. A dose-dependent increase in lactate dehydrogenase activity, an indicator of anaerobic metabolism, and superoxide dismutase activity was observed in the treated embryos. In contrast, the total reduced glutathione level decreased. A high thiobarbituric acid reactive substance concentration was generated upon AgNP exposure from day 1 to day 7 postfertilisation. The biochemical parameters suggested that oxidative stress was induced by the AgNPs. Unexpectedly, a dose-dependent reduction in ROS and 1O2 generation upon high AgNP exposure (≥250μg/L) was observed. Although the morphological damages induced by the AgNPs were irreversible, restorable antioxidant defenses were noted in the well-developed embryos. This finding supported the idea that the stage of morphogenesis and organogenesis is a critical window to chemical exposure or environmental stress. Overall, the results suggested that hypoxia, disturbed egg chorion, and oxidative stress are mechanistically associated with AgNP toxicity in embryonic fish.

Effect of dietary fat source on fatty acid profile and lipid oxidation of eggs

This study investigated the effects of supplementary dietary lipid sources on the fatty acid profile and lipid oxidation of eggs. Five isoenergetic (12.6 MJ AME/kg DM) and isonitrogenous (170 g CP/kg DM) diets were formulated, using a control diet (50 : 50 blend of fish- and linseed oil), fish oil, sunflower oil, high oleic acid (HO) sunflower oil and tallow at a 30 g/kg inclusion level. Two hundred individually caged HyLine Silver-Brown hens (20 weeks of age) were randomly allocated to the five dietary treatments (n = 40 hens/treatment). Birds received the experimental diets from 20 weeks of age. At 30 weeks of age, 12 eggs per treatment were randomly selected for analyses of egg yolk fatty acid methyl esters (FAME), thiobarbituric acid reactive substances (TBARS) and peroxide values (PV). Dietary lipid sources affected FAME, TBARS and PV of egg yolk significantly. The fish oil treatment resulted in the highest TBARS (0.27 mg malonaldehyde/kg yolk) and PV (3.96 milli-equivalent peroxide/kg fat) whereas the HO sunflower oil resulted in the lowest TBARS (0.13 mg malonaldehyde/kg yolk) and PV (2.77 milli-equivalent peroxide/kg fat). Fish oil also resulted in the lowest n-6 to n-3 ratio (1.16 to 1), while sunflower oil resulted in the highest ratio (24.6 to 1). Results indicate that the fatty acid profile of eggs could be altered by means of dietary intervention. However, an improvement of omega-3 type fatty acids of eggs will result in a higher susceptibility to lipid oxidation and possibly a shorter shelf-life of stored eggs.Keywords: Fish oil, high oleic sunflower oil, linseed oil, percentage yolk fat, peroxide value, tallow

Fatty acid profile, oxidative stability, and sensory properties of breast meat from turkeys fed diets with a different n‐6/n‐3 PUFA ratio

AbstractThe objective of this study was to determine the effect of diets with a different n‐6/n‐3 PUFAs ratio (7.31, 4.43, and 0.99), resulting from the addition of different dietary oils: soybean, rapeseed, and linseed (diets S, R, and L, respectively), on the fatty acid (FA) profile, oxidative status, and sensory properties of turkey breast meat. After 15 wk of feeding, breast meat yield and chemical properties of the meat were similar in all groups. Raw breast meat of R turkeys had a significantly higher content of all‐trans‐retinol and α‐tocopherol, compared with S and L. The physicochemical properties of breast meat, including pH, color, drip loss, and cooking loss, did not differ significantly. Cooked meat samples differed significantly with respect to the concentrations of oleic acid, linoleic acid (S and R&gt;L), and linolenic acid (S and R&lt;L). Compared with S and R, breast meat of L turkeys was characterized by higher concentrations of total PUFAs (35.1 vs. 30.1 and 29.3%), a significantly lower n‐6/n‐3 PUFAs ratio (1.51 vs. 5.43 and 5.07%) and a higher thiobarbituric acid reactive substances content (TBARS; 31.9 vs. 26.4 and 26.7 nmol/g). After 4 months of deep‐freeze storage the n‐6/n‐3 PUFAs ratio did not deteriorate. It may be concluded that replacing soybean oil with linseed oil, but not with rapeseed oil, increased the proportion of PUFAs in the total FAs pool and improved the n‐6/n‐3 PUFAs ratio, yet it also adversely affected the sensory properties and oxidative stability of meat. Both raw and stored breast meat from L turkeys was susceptible to oxidative changes, as manifested by the significantly higher TBARS concentrations (17.07 and 81.06) compared with those of the S group (10.91 and 53.00 nmol/g, respectively).Practical applications: Studies investigating the possibility of increasing the health benefits of poultry meat have been performed mostly on broilers, while the problem remains poorly researched in turkeys. Our findings show that linseed oil, in contrast to rapeseed oil, is a good source of PUFAs, in particular n‐3 PUFAs, that can be effectively transferred from feed to carcass lipids. However, desirable changes in the fatty acid profile are accompanied by increased susceptibility to lipid oxidation and deterioration of the sensory properties of meat. Thus, the linseed oil content of turkey diets should be reduced, or diets supplemented with linseed oil should be fed for shorter periods of time to alleviate the negative effects of linseed oil on the sensory attributes and oxidative status of meat.

Oxidative stress in hypertensive children before and after 1 year of antihypertensive therapy

BackgroundThe relation between primary hypertension (PH), target organ damage (TOD) and oxidative stress (SOX) is not known.MethodsWe assessed SOX in 86 children with PH before and after 12 months of standard non-pharmacological and pharmacological therapy based on renin-angiotensin system blockade.ResultsPatients with left ventricular hypertrophy (LVH) and with carotid intima-media thickness (cIMT) >2SDS had higher thiobarbituric acid reactive substances (TBARS) concentrations in comparison to patients without LVH or with normal cIMT. Patients with metabolic syndrome (MS) had lower activity of gluthatione peroxidase, higher asymmetric dimethyloarginine (ADMA) and oxidized LDL cholesterol (oxyLDL) in comparison to patients without MS. TBARS correlated with left ventricular concentric hypertrophy, cIMT, albuminuria and SBP/24 h. ADMA and oxyLDL correlated with CRP and TG/HDL ratio. After 1 year of antihypertensive treatment blood pressure, TOD and prevalence of MS decreased. TBARS decreased and glutathione concentrations increased. The decrease of TBARS concentration correlated with the decrease of body mass index (BMI). Decrease of oxyLDL and ADMA correlated with increased insulin sensitivity, however markers of SOX did not correlate with BP decrease.ConclusionSOX in children with PH correlates with TOD, metabolic abnormalities, changes in fat amount and improvement of insulin sensitivity, but not with BP decrease.

EVALUATION OF A NATURAL PRESERVATIVE IN A BOEREWORS MODEL SYSTEM

Boerewors is a fresh sausage preserved with 450 mg/kg sulfur dioxide (450S). The preservative effect of Citrox (a natural compound) was compared with SO2. Seven boerewors models with different treatments were formulated. Microbial, color, lipid and sensory characteristics were evaluated over a 6-day storage period at 4C. Citrox on its own and in combination with 100S significantly (P < 0.001) decreased the total aerobic plate count (TAPC) and coliform counts and was comparable to 450S. It had a significantly (P < 0.001) better effect on yeast and mold counts than 450S. Citrox had a negative effect, on its own and in combination with 100S, on the redness color (a* value). Citrox did not have antioxidant capabilities. It resulted in significantly (P < 0.001) higher thiobarbituric acid reactive substance values after 100 days of storage at −18C than 450S. Sensory evaluation indicated a slight sour flavor in Citrox models but it was still “liked slightly” to “liked moderately.” PRACTICAL APPLICATIONS This study provided evidence that Citrox may be used as a natural antimicrobial in foods. It was as effective as 450 mg/kg SO2 in controlling TAPC, coliform bacteria, and yeasts and molds when 2% Citrox was used. When used in combination with a lowered concentration of SO2 (100 mg/kg), which is a 77.8% reduction in SO2, it even controlled the microorganisms better, especially yeasts and molds. It is, however, not a good antioxidant and may influence the taste of food products. It may, however, be used as antimicrobial in foods with a citrus-acidic nature.

Antioxidative Effects of Benidipine Hydrochloride in Patients with Hypertension Independent of Antihypertensive Effects

This study investigated the significance of measuring plasma level of thiobarbituric acid reactive substance (TBARS) in patients with hypertension and compared the clinical effects of benidipine hydrochloride (CAS 91599-74-5, Coniel) and amlodipine besylate (CAS 111470-99-6) on plasma TBARS. At first, blood pressure and plasma TBARS were measured in 85 untreated patients (48 males and 37 females, 68 years old on average) with at least one risk factor of cardiovascular disease to investigate factors which had influence on plasma TBARS. As the result, plasma TBARS was significantly higher in those with hypertension, which was also true when adjusted for other factors (r = 0.359, p< 0.01). Among these patients, benidipine hydrochloride at the dose of 4 mg/day was administered to 49 patients with hypertension or angina pectoris. All patients stratified for each factor showed significantly decreased plasma TBARS after benidipine hydrochloride treatment. Second, 40 untreated patients with essential hypertension were randomly assigned to the amlodipine group (5-7.5 mg/day) or benidipine group (4-8 mg/day) to compare the plasma TBARS levels. Plasma TBARS levels were significantly decreased in both groups. The amlodipine group showed a positive correlation between the decrease in plasma TBARS level and those in both diastolic and systolic blood pressures after treatment. On the other hand, benidipine hydrochloride decreased plasma TBARS to a greater degree than both diastolic and systolic blood pressures. These findings suggest that patients with hypertension have high plasma TBARS, and benidipine hydrochloride decreases not only blood pressure but also oxidative stress in the clinical practice.

On the properties of calcium-induced permeability transition in neonatal heart mitochondria

Permeability transition was examined in heart mitochondria isolated from neonate rats. We found that these mitochondria were more susceptible to Ca(2+)-induced membrane leakiness than mitochondria from adult rats. In K(+) containing medium, at 25°C, mitochondria were unable to accumulate Ca(2+). Conversely, in Na(+) containing medium, mitochondria accumulated effectively Ca(2+). At 15°C mitochondria accumulated Ca(2+) regardless of the presence of K(+). Kinetics of Ca(2+) accumulation showed a similar Vmax as that of adult mitochondria. Lipid milieu of inner membrane contained more unsaturated fatty acids than adult mitochondria. Aconitase inhibition and high thiobarbituric acid-reactive substances (TBARS) indicate that oxidative stress caused mitochondrial damage. In addition, proteomics analysis showed that there is a considerable diminution of succinate dehydrogenase C and subunit 4 of cytochrome oxidase in neonate mitochondria. Our proposal is that dysfunction of the respiratory chain makes neonate mitochondria more susceptible to damage by oxidative stress.

Resistance of erythrocytes from Brown trout (Salmo trutta m. trutta L.) affected by ulcerative dermal necrosis syndrome

In the present work we evaluated the effect of ulcerative dermal necrosis (UDN) syndrome on resistance of erythrocytes to haemolytic agents and lipid peroxidation level in the blood from brown trout (Salmo trutta m. trutta L.). Results showed that lipid peroxidation increased in erythrocytes, as evidenced by high thiobarbituric acid reactive substance (TBARS) levels. Compared to control group, the resistance of erythrocytes to haemolytic agents was significantly lower in UDN-positive fish. Besides, UDN increased the percent of hemolysated erythrocytes subjected to the hydrochloric acid, urea and hydrogen peroxide. Results showed that UDN led to an oxidative stress in erythrocytes able to induce enhanced lipid peroxidation level, as suggested by TBARS level and decrease of erythrocytes resistance to haemolytic agents.

Oxidative stress parameters in silver catfish (Rhamdia quelen) juveniles infected with Ichthyophthirius multifiliis and maintained at different levels of water pH

The aim of this study was to determine oxidative stress parameters in the liver, gill and muscle of silver catfish juveniles infected with Ichthyophthirius multifiliis and maintained at pH 5.0 or 7.0 for three days. Juveniles were infected by adding one I. multifiliis-infected juvenile and water containing theronts to tanks. After the appearance of white spots on the skin, infected juveniles exposed to pH 5.0 and 7.0 showed significantly higher thiobarbituric acid reactive substances (TBARS) levels in the liver and gills compared to uninfected juveniles. Liver of infected juveniles exposed to pH 7.0 showed higher catalase (CAT) and lower glutathione-S-transferase (GST) activities, but those maintained at pH 5.0 showed significantly higher GST activity than uninfected juveniles. The gills of infected juveniles showed significantly higher CAT (day two) and GST activity at both pH 5.0 and 7.0 compared to uninfected juveniles. Muscle of infected juveniles showed significantly lower CAT and GST activity and TBARS levels (at day three) when maintained at both pH 5.0 and 7.0 compared to uninfected juveniles. In conclusion, I. multifiliis infection induces liver and gill damage via lipid peroxidation products in silver catfish, but higher antioxidant enzyme activity could indicate a greater degree of protection against this parasite.

Determination of carnosine, anserine, homocarnosine, pentosidine and thiobarbituric acid reactive substances contents in meat from different animal species

The aim of this research was to determine the content of the histidinic antioxidants, advanced glycation end products (pentosidine) and thiobarbituric acid reactive substance (TBARS) in the meat from different animal species. Carnosine, anserine, homocarnosine and pentosidine were quantified by HPLC/MS, while TBARS was determined by photometric measurements. The total CRCs (carnosine+anserine+homocarnosine) content was in the increasing order: beef<rabbit<pork<horse<chicken<turkey. The analysis showed traces of pentosidine above the instrumental determination limits in all the meat samples, while the susceptibility of these meat to lipid oxidation decreased from beef to chicken, with the exception of turkey meat, which presented a high TBARS content towards even though its total CRCs was the highest. The structure of homocarnosine was elucidated by high resolving power multistage mass spectrometry.

Changes in the Chemical Characteristics of Gulbi, Salted and Dried Yellow Corvenia, During Drying at Different Temperatures

A few chemical characteristics of Gulbi, a traditional Korean seafood prepared from salted and dried Yellow corvenia (Pseudosciaena manchurica), were investigated during drying at different temperatures. When Gulbi was manufactured by sun-drying (the control), it had the highest thiobarbituric acid reactive substances (TBARS) and volatile basic nitrogen (VBN) values. They increased with increasing drying time at all temperatures in the hot-air drier. The TBARS value of Gulbi was lower when dried at 30 and 35°C than at 40°C and the control. The VBN of the control was higher than that of hot-air dried Gulbi at 30 and 35°C and lower than that of hot-air dried Gulbi at 40°C. The control had a VBN value of 20.8 ± 0.07% and the hot-air dried at 30°C, 18.0 ± 0.06; at 35°C, 18.6 ± 0.06; at 40°C, 23.8 ± 0.08 (p < 0.05), respectively. The salt content of the control and Gulbi dried at 30, 35, and 40°C were 22.9 ± 0.07%, 17.7 ± 0.06%, 18.0 ± 0.06%, and 24.3 ± 0.08%, respectively. The amino nitrogen content was much lower: 63.1 ± 0.80 mg/100 g and 65.5 ± 0.14 mg/100 g at 30 and 35°C than 78.3 ± 0.21 mg/100 g at 40°C. The results of this study also indicate that the Gulbi dried at 30 and 35°C had better chemical characteristics than those dried at 40°C when using hot-air drying and sun drying.

Effect of saponified high fat sunflower oilcake and lipoic acid

Sheep fat contains relatively high levels of saturated fatty acids while poly-unsaturated fatty acids (PUFA) are toxic to cellulolytic bacteria and are also saturated in the rumen. Stabilization of residual oil in sunflower oilcake by conversion into calcium salts would be advantageous. Alpha lipoic acid acts as an anti-oxidant to ameliorate the effects of oxidative stress caused by high dietary levels of PUFA. Residual oil (14%) in mechanically extracted (expeller) sunflower oilcake (SFOC) was saponifiedin situ and compared in a complete feedlot diet (100 g crude protein and 31 g extractable fat/kg feed) with commercially extracted oilcake containing 2.4% residual oil (control diet with 29 g fat and 123 g crude protein kg feed) fed to four groups of 10 SA Mutton Merino weaner lambs (ca. 23 kg) for nine weeks. Both diets were fed either with, or without a weekly oral dosing of 500 mg &alpha;-lipoic acid. Fatty acid composition was determined on back fat samples while thiobarbituric acid-reactive substances (TBARS) were determined on samples of m. longissimus dorsi stored for zero and six months and displayed for six days. The back fat of the lambs on the saponified expeller SFOC diets contained significantly higher levels of saturated fatty acids and lower levels of mono-unsaturated fatty acids. PUFA were unaffected. High TBARS levels (>1.0) were found after six months storage. Non significant increases in TBARS were observed in the groups that received lipoic acid.

The Nrf2–Keap1 cellular defense pathway and heat shock protein 70 (Hsp70) response. Role in protection against oxidative stress in early neonatal unilateral ureteral obstruction (UUO)

Perturbation of renal tubular antioxidants and overproduction of reactive oxygen species may amplify the proinflammatory state of renal obstruction, culminating in oxidative stress and tubular loss. Here, we analyzed the heat shock protein 70 (Hsp70) response and the function and signal transduction of NF-E2-related protein 2 (Nrf2) transcription factor on oxidative stress modulation in obstruction. Rats were subjected to unilateral ureteral obstruction or sham operation and kidneys harvested at 5, 7, 10, and 14days after obstruction. Hsp70 expression and Nrf2 activity and its downstream target gene products were assessed. After 10 and 14days of obstruction, enhanced lipid peroxidation through higher thiobarbituric acid reactive substances levels and increased oxidative stress resulted in reduced total antioxidant activity and enhanced nicotinamide adenine dinucleotide phosphate reduced (NADPH) oxidase activity were demonstrated. This was accompanied by decreased inducible Hsp70 expression and a progressive reduction of nuclear Nrf2 and its target gene products glutathione S-transferase A2 (GSTA2) and NADPH/quinone oxidoreductase 1 (NQO1), whereas the Nrf2 repressor Kelch-like ECH-associated protein-1 (Keap1) was upregulated. By contrast, on early obstruction for 7days, lack of increased oxidative markers associated with higher inducible Hsp70 protein levels and a rapid nuclear accumulation of Nrf2, Keap1 downregulation, and mRNA induction of the identified Nrf2-dependent genes, NQO1 and GSTA2, were shown. For these results, we suggest that the magnitude of cytoprotection in early obstruction depends on the combined contribution of induced activation of Nrf2 upregulating its downstream gene products and Hsp70 response. Impaired ability to mount the biological response to the prevailing oxidative stress leading to renal injury was shown in prolonged obstruction.

Regulation of oxidative stress in response to acute aerobic and resistance exercise in HIV-infected subjects: a case–control study

Human immunodeficiency virus (HIV)-infected subjects have increased levels of oxidative stress which could impair immunological function and therefore contribute to the progression of AIDS. These characteristics are usually evaluated at rest and responses to exercise have yet to be evaluated. The aim of the present study was to assess the effect of a bout of aerobic exercise followed by resistance exercises on antioxidant system in HIV-infected and non-HIV subjects. There were included 14 cases (HIV-positive) and 14 controls (HIV-negative). The exercise protocol consisted of a single session of 20 minutes on a cycloergometer followed by a set of six resistance exercises. The activity of glutathione S-transferase (GST) and catalase were measured in plasma samples, total glutathione (TGSH) and thiobarbituric acid reactive substances (TBARS) were measured in erythrocytes. T CD4+ cells, T CD8+, viral load, complete blood count, and white blood count were also assessed. All measurements were performed at three times: baseline, after aerobic exercise, and after resistance exercises. At baseline, the HIV group had lower GST activity than controls, but after the exercise session GST values were similar in both groups. Compared to the control group TGSH was significantly lower in the HIV group at baseline, after aerobic and resistance exercises. The control group presented higher TBARS values after aerobic exercise compared to the HIV group. The neutrophil count was lower in the HIV group after aerobic and resistance exercises. These data indicate that HIV-infected subjects had lower antioxidant activity at rest. Physical exercise stimulated the enzymatic activity similarly in both groups.

CHANGE OF LEFT VENTRICULAR MASS (LVM) AND GEOMETRIC PATTERN AFTER 1 YEAR OF NON-PHARMACOLOGICAL AND PHARMACOLOGICAL ANTIHYPERTENSIVE THERAPY IN CHILDREN WITH PRIMARY HYPERTENSION: PP.36.497

in 86 children (14.1 ± 2.4years) with newly diagnosed PH left ventricular (LV) and some biochemical parameters before and after 12 months-long standard antihypertensive therapy was assessed. Results: Normal LV geometry (NG) in 43(50%), concentric remodelling (CR) in 3(3.5%), concentric hypertrophy (CH) in 9(10.5%) and eccentric hypertrophy (EH) in 31(36%) pts were found. The prevalence of stage 2 of HT in NG group was: 32.5%, in CH- 44.4%, in EH- 51.6% and in CR group – 66.7% (ns). Pts with NG had lower WHR and waist-to-height ratio (WHtR) than pts with CH and EH and also lower BMI and waist circumference (WC) than pts with EH (p < 0.05). Pts with CH in comparison to pts with EH had higher values of DBP and higher thiobarbituric acid reactive substances concentration (p < 0.05). The main predictor of LVM was WC (beta = 0.561, R2 = 0.279, p = 0.008). Relative wall thickness (RWT) correlated with LVM (p < 0.05, r = 0.45), WHR (p < 0.05, r = 0.25) and TG/HDL ratio (p < 0.05, r = 0.29). All pts received life style change- and dietary modifications advices. Drug therapy based on ACEi and/or ARB was started in 49 pts (57%), who had a significant target organ damage and/or stage 2 of HT. After 12 months treatment in the whole group SBP/24 h and DBP/24 h decreased significantly (p < 0.001). LV geometry pattern did not change significantly, but LVM (38.5 ± 10.7 vs 35.2 ± 7.5 g/m height2.7, p = 0.0001) and prevalence of the left ventricular hypertrophy (LVH) (46.5% vs 31.4%, chi2 = 4.77, p = 0.03) decreased significantly. LVM regression correlated with changes of RWT, BMI and WC. The main predictor of LVM decrease was decrease of WHtR (â = 0.488, R2 = 0.216, p = 0.003). Discrimination analysis revealed that pts, who lowered LVM, had higher RWT at the diagnosis (p < 0.0001) and after 12 month - lower RWT, insulin- and homocysteine concentrations (p = 0.004). Conclusions: In PH left ventricular abnormalities are strictly related to central fat accumulation. Increase of the lean body mass with the decrease of abdominal obesity and hiperinsulinemia emerges as the most important predictor of LVH regression.