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Acid-reactive Substances (acid-reactive + substance)
Kinds of Acid-reactive Substances Selected AbstractsPreventive effects of ME3738 on hepatic fibrosis induced by bile duct ligation in ratsHEPATOLOGY RESEARCH, Issue 7 2008Kazunori Maeda Aim:, The aim of this study was to examine the preventive effects of ME3738 on hepatic fibrosis induced by bile duct ligation (BDL) in rats. Methods:, ME3738 (20 mg/day) was administered orally for 21 days immediately after BDL. Fibrosis was assessed by measuring hepatic hydroxyproline (Hyp) content. Activated hepatic stellate cells (HSCs) were assessed by ,-smooth muscle actin (,-SMA) immunostaining. Hepatic thiobarbituric acid-reactive substance (TBARS), 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxy-2-deoxyguanosine (8-OHdG) immunostaining were used to analyze oxidative stress. The gene expressions of collagen-I, transforming growth factor-,1 (TGF-,1), tissue inhibitor of metalloproteinases-1 (TIMP-1), interleukin-6 (IL-6) and heme oxygenase-1 (HO-1) in the liver were examined by real-time reverse transcriptase polymerase chain reaction (RT,PCR). Results:, Hepatic Hyp content and the area of hepatic fibrosis in BDL rats treated with ME3738 were reduced by 24% and 39% compared with non-treated BDL rats (hepatic Hyp, 9.40 ± 2.85 vs. 12.39 ± 3.91 mg/liver; P = 0.036; area of hepatic fibrosis, 13.1 ± 3.8 vs. 21.5 ± 10.9; P = 0.045). Furthermore, ,-SMA-positive cells were significantly reduced by 40% (22.3 ± 14.8 vs. 37.6 ± 14.2; P = 0.011), collagen-I mRNA by 83% (6.5 ± 2.2 vs. 38.3 ± 9.1; P = 0.002), HO-1 mRNA by 58% (4.13 ± 1.22 vs. 9.73 ± 1.80; P = 0.018) and hepatic HO-1 content by 26% (2.13 ± 0.80 vs. 2.87 ± 0.19; P = 0.01) following ME3738 treatment. The hepatic expression of TBARS, 4-HNE, 8-OHdG and mRNA levels of TGF-,1, TIMP-1 and IL-6 in the liver were unchanged by ME3738 treatment. Conclusion:, Oral ME3738 administration may prevent the progression of hepatic fibrosis in BDL rats through suppression of the activation and collagen synthesis of HSC and, in part, oxidative stress. ME3738 has potential as a therapeutic drug for cholestatic liver fibrosis. [source] N -3 enrichment of pork with fishmeal: Effects on production and consumer acceptabilityEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2008Stelios Sioutis Abstract This study aimed to develop pork products of acceptable organoleptic quality enriched with long-chain n -3 polyunsaturated fatty acids (LC n -3 PUFA). Female pigs were fed a finisher diet containing 15% PorcOmegaÔ tuna fishmeal or a commercial diet. Pigs and rations were weighed weekly. The feed conversion ratio was significantly lower in pigs fed fishmeal than in controls (2.61,±,0.01 versus 2.96,±,0.06, p,<0.05). After 6,weeks, the pigs were butchered and the fatty acid contents of selected pork products were analyzed by gas chromatography. Shelf life was tested by thiobarbituric acid-reactive substances (TBARS), initially and after 5,days of cold storage, and sensory qualities were evaluated after cooking. LC n -3 PUFA contents of pork products from pigs fed fishmeal were higher than in controls (steak 300%, stir-fry 250%, diced 520%, mince 480%, sausage 360%; p,<0.05 in all cases). There were no differences between n -3-enriched and regular pork in either TBARS content of stored raw products or sensory characteristics after cooking. Incorporating fishmeal in the finisher diet resulted in greater feed efficiency and production of nutritionally enhanced pork products with organoleptic profiles and stability comparable to those of regular pork. [source] High-dose methylprednisolone influences the physiology and virulence of Candida albicans ambiguously and enhances the candidacidal activity of the polyene antibiotic amphotericin B and the superoxide-generating agent menadioneFEMS YEAST RESEARCH, Issue 2 2007Ágnes Gyetvai Abstract Although exposure of Candida albicans cells to high-dose (4 mM) methylprednisolone stimulated microbial growth, germination rate in serum and phospholipase release, it also promoted the recognition of C. albicans cells by polymorphonuclear leukocytes. Pretreatment of C. albicans cells with methylprednisolone did not result in any increase in the pathogenicity of the fungus in intraperitoneal and intravenous mouse assays. Therefore, the virulence of C. albicans is unlikely to increase in patients treated with comparably high-dose methylprednisolone on skin and mucosal membranes. Methylprednisolone treatments also increased the production of conjugated dienes and thiobarbituric acid-reactive substances, and the menadione sensitivity of C. albicans cells, which can be explained by a significant decrease in the specific activities of several antioxidant enzymes. The combination of methylprednisolone with oxidants, e.g. in topical applications, may be of clinical importance when the predisposition to candidiasis is high. Methylprednisolone treatments negatively affected membrane fluidity and decreased the antifungal effects of both the polyene antibiotic nystatin and the ergosterol biosynthesis inhibitor lovastatin, and also enhanced the deleterious effects of the polyene antimycotic amphotericin B on C. albicans cells. These corticosteroid,polyene drug interactions should be considered in the treatment of C. albicans infections in patients with prolonged topical application of corticosteroids. [source] Ferulic acid, a natural protector against carbon tetrachloride-induced toxicityFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 4 2005M. Srinivasan Abstract The present work is aimed at evaluating the protective effect of ferulic acid (FA), a naturally occurring phenolic compound on CCl4 induced toxicity. The activities of liver markers (alanine transaminase, aspartate transaminase, alkaline phosphatase, , -glutamyl transferase), lipid peroxidative index (thiobarbituric acid-reactive substances, hydroperoxides, nitric oxide, protein carbonyl content), the antioxidant status (superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione) were used as biomarkers to monitor the protective role of FA. The liver marker enzymes in plasma and lipid peroxidative index in liver and kidney were increased in CCl4 -treated groups, which were decreased significantly on treatment with FA. The antioxidants, which were depleted in CCl4 -treated groups, were improved significantly by FA treatment. Administration of FA to normal rats did not produce any harmful effects. Thus our results show that FA is an effective antioxidant without any side-effects and may be a great gain in the current search for natural therapy. [source] Antioxidative ability of native and thermized sour whey in oxidation-catalysed model systems,INTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 2 2007JINHAN SHON Antioxidative properties of sour (cottage) were evaluated with (thermized) and without (native) heat treatment (80°C for 30 min). A model system comprising a Tween 20 stabilized peanut oil in phosphate buffer (pH 7.0) emulsion containing lipid oxidation catalysts, FeCl3, H2O2 and ascorbate was used. Native sour whey powder (SWP) was significantly better than thermized whey in terms of limiting the formation of thiobarbituric acid-reactive substances and peroxide value. Antioxidative ability was best at pH 3.0 and decreased with increasing pH. SWP (20%, w/v) was significantly better than all commonly used antioxidants tested after 96 h of incubation at 40°C. [source] Influence of high levels of vitamin E on semen parameters of cocksJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 11-12 2002S. Danikowski Summary This study was an attempt to find whether the reproductive performance of cocks would be influenced by oral administration of different amounts of dietary vitamin E over a long period of time. For that purpose 60 cocks were divided into five dietary groups of 12 animals each, and supplemented with 0 (control group), 100, 1000, 10 000 or 20 000 IU ,-tocopherol/kg diet, respectively, over a period of 12 months. The effect on semen parameters and biochemical parameters measured in pooled semen samples and the weight of the testes were determined. The weight of testes decreased with increasing amounts of supplemented vitamin E. Volume, pH, colour, consistency and motility were not influenced by the diets, but density of ejaculate (sperm/,l), total amount of spermatozoa and morphology of sperm were significantly lowered by increasing amounts of supplemented vitamin E. The ,-tocopherol concentration in ejaculates increased significantly in relation to the diet whereas phospholipid content and thiobarbituric acid-reactive substances (TBARS) of the semen samples decreased significantly with increasing vitamin E supplementation. The reproductive performance of cocks was negatively influenced by high doses of vitamin E although decreased TBARS indicated rising oxidative defence. [source] Reduced oxidative stress in parallel to improved cardiac performance one year after selective removal of anti-beta 1-adrenoreceptor autoantibodies in patients with idiopathic dilated cardiomyopathy: data of a preliminary study,JOURNAL OF CLINICAL APHERESIS, Issue 3 2005Ingolf Schimke Abstract Patients with idiopathic dilated cardiomyopathy (IDC) were treated with selective immunoadsorption to remove anti-beta 1-adrenoreceptor autoantibodies (anti-beta1A-AB). After one year, the effect on cardiac performance and oxidative stress was tested. Extracorporeal immunoadsorption of the whole IgG class in IDC patients for the removal of anti-beta1A-AB reduced oxidative stress in parallel to an improvement of cardiac performance. However, the non-specificity of IgG adsorption means that these beneficial effects cannot be attributed exclusively to anti-beta1A-AB removal. In an open clinical pilot study enrolling 8 patients with IDC prior to and one year after selective immunoadsorption of anti-beta1A-AB, plasma markers for oxidative stress,thiobarbituric acid-reactive substances (TBARS), lipid peroxides (LPO) and anti-oxidized low-density lipoprotein autoantibodies (anti-oxLDL-AB),were measured in parallel to evaluation of the left ventricular function using conventional echocardiography and wall motion analysis by tissue Doppler imaging. After one year, TBARS (Wilcoxon test with bootstrapping simulation for paired data: 95% confidence interval of the P value 0.020 to 0.029) and anti-oxLDL-AB (P = 0.025 to 0.035) were decreased in parallel to an improvement of the peak systolic wall motion velocity (P = 0.006 to 0.01) and left ventricular ejection fraction (P = 0.002 to 0.02). For changes over the study period, a direct correlation with borderline significance (P = 0.076) was calculated for TBARS to the left ventricular diameter in the diastole. One year after selective immunoadsorption for anti-beta1A-AB removal, patients with ICD show a reduction in oxidative stress and a parallel improvement in cardiac performance. J. Clin. Apheresis © 2005 Wiley-Liss, Inc. [source] GLYCOSIDASE INHIBITORY ACTIVITY AND ANTIOXIDANT PROPERTIES OF A POLYSACCHARIDE FROM THE MUSHROOM INONOTUS OBLIQUUSJOURNAL OF FOOD BIOCHEMISTRY, Issue 2010HAIXIA CHEN ABSTRACT A water-soluble polysaccharide from Inonotus obliquus (IOPS) was isolated from the mushroom Inonotus obliquus (Fr.) Pilat. The chemical compositions, molecular weight and inhibitory activities on glycosidase and antioxidant properties of IOPS were investigated. The results indicated that IOPS was an acid protein-bound polysaccharide, with a molecular weight of 1.7 × 104 Da and the contents of neutral sugar, protein and uronic acids being 42.5, 18.5 and 6.1%, respectively. IOPS exhibited an inhibitory activity against ,-glucosidase with the IC50 value of 93.3 µg/mL, whereas it had no effective inhibition on ,-amylase. Results of antioxidant activity assays revealed that IOPS had inhibitory activity on the concentration-dependent quenching of 1,1-Diphenyl-2-picrylhydrazyl and hydroxyl radicals. Furthermore, IOPS inhibited the formation of thiobarbituric acid-reactive substances in Fe2+/ascorbate-induced lipid peroxidation in rat liver tissue. These results clearly demonstrated that IOPS was one of the main bioactive components of I. obliquus that contributed to hypoglycemic activity and antioxidant activity. PRACTICAL APPLICATIONS Diabetes mellitus is one of the primary threats to human health because of its increasing prevalence, chronic course and disabling complications. Postprandial hyperglycemia plays an important role in the development of type 2 diabetes mellitus and complications associated with the disease. One therapeutic approach to decrease postprandial hyperglycemia is to retard the absorption of glucose through inhibition of carbohydrate-hydrolyzing enzymes in the digestive organs. In this study, a polysaccharide isolated from the mushroom Inonotus obliquus (IOPS) was shown to have notable glycosidase inhibitory effects and antioxidant activities. This research will benefit for the investigation of effective and safe ,-glucosidase inhibitors from natural materials. IOPS could be a good candidate for application in food and medicinal fields. It might be developed for functional food or lead compounds for use in antidiabetes. [source] EFFECTS OF ANTIOXIDANTS ON IRRADIATED BEEF COLORJOURNAL OF FOOD QUALITY, Issue 3 2010LAKSHMANAN RAMAMOORTHI ABSTRACT Fresh beef was dipped into ascorbic acid (AA; 500 ppm), butylated hydroxyanisole (BHA, 150 ppm), butylated hydroxytoluene (BHT, 100 ppm) or propyl gallate (PG; 100 ppm); control samples were dipped in deionized water. Samples were vacuum packaged, then irradiated (0, 1.25 or 2.50 kGy). After irradiation, samples were stored (0, 7 or 14 days) at 4C. Color was assessed instrumentally (L*, a*, b*values, hue angles, chroma) and visually. All antioxidants increased L*value by two units (lighter); however, irradiation dose had no effect. Irradiation increased wet dog and rancid odors of beef; however, it decreased sour odor, a*value, chroma and hue angle, and increased visual green and brown colors, indicating that it reduced redness and color intensity. Antioxidants reduced L*(decreased lightening) and a*values (redness) compared to controls. BHA had the greatest effect on a*value. AA decreased visual green color the most; however, BHA and BHT were also effective. Antioxidants had inconsistent effects on b*value, chroma and hue angle. Storage decreased L*and a*values, and chroma. BHA and PG were most effective at maintaining low thiobarbituric acid-reactive substances when samples were irradiated. PRACTICAL APPLICATIONS Irradiation has the potential to reduce microbial load, increasing both the safety and shelf life of red meat products; however, it has the potential to damage fresh meat color, resulting in unacceptable discoloration. Irradiation can increase off-odors (wet dog, rancid) of beef; however, it can decrease sour odor, instrumental measures of red color, and increase visual green and brown colors. Use of antioxidants including ascorbic acid, butylated hydroxytoluene, butylated hydroxyanisole and propyl gallate can help maintain the color of irradiated beef held in refrigerated storage for up to 2 weeks. [source] Effects of Various Fiber Additions on Lipid Digestion during,In Vitro,Digestion of Beef PattiesJOURNAL OF FOOD SCIENCE, Issue 9 2009S.J. Hur ABSTRACT:, The purpose of this study was to examine the effect of various fiber additions on lipid digestion during the,in vitro,digestion of beef patties. The control patties were prepared with 90.5% lean meat and 9.5% tallow. Treatments consisted of 90% lean meat with 9.5% tallow and either 0.5% cellulose, 0.5% chitosan, or 0.5% pectin. The beef patties were then passed through an,in vitro,digestion model that simulated the composition of the mouth, stomach, and small intestine juices. The change in structure and properties of the lipid droplets was monitored by laser scanning confocal fluorescence microscopy. In general, there was a decrease in lipid droplet diameter as the droplets moved from mouth to stomach to small intestine. The amount of free fatty acid dramatically increased after,in vitro,digestion in all beef patties. The amount of free fatty acid was, however, lower in beef patties containing chitosan and pectin than other beef patties after,in vitro,digestion. Beef patties containing various fibers had lower thiobarbituric acid-reactive substances (TBARS) values than samples with no fibers. Among the samples to which fibers were added, chitosan and pectin had lower TBARS than beef patties with cellulose. The cholesterol content decreased after,in vitro,digestion in all beef patties but was not different among the beef patties before and after,in vitro,digestion. These results enhance our understanding of the physicochemical and structural changes that occur to ground beef within the gastrointestinal tract. [source] Gel Strengthening Effect of Wood Extract on Surimi Produced from Mackerel Stored in IceJOURNAL OF FOOD SCIENCE, Issue 8 2009A.K. Balange ABSTRACT:, The effect of ethanolic kiam wood extract (EKWE) and commercial tannin (CT) on the gel properties of surimi produced from mackerel (Rastrelliger kanagurta) stored in ice for different times (0 to 12 d) was studied. During 12 d of iced storage, pH, total volatile base (TVB), trimethylamine (TMA), and trichloroacetic acid (TCA)-soluble peptide contents as well as thiobarbituric acid-reactive substances (TBARS) of mackerel mince increased while myosin heavy chain (MHC) band intensity decreased continuously (P,< 0.05). The result suggested that deterioration, protein degradation, and lipid oxidation proceeded with increasing storage time. For corresponding surimi, TVB and TMA were almost removed and TBARS and TCA soluble peptide contents were decreased. Conversely, MHC became more concentrated. Decreases in gel-forming ability of surimi were observed when fish used as raw material were stored in ice for a longer time, regardless of EKWE or CT addition. Whiteness of surimi gel decreased and expressible moisture increased especially when the storage time increased. However, superior breaking force and deformation of surimi gel with 0.15% EKWE or 0.30% CT added, compared to those of the control gel were observed during the first 6 d of the storage. Thereafter, EKWE and CT had no gel enhancing effect on surimi. Therefore, freshness was a crucial factor determining gel enhancing ability of EKWE or CT toward mackerel surimi. [source] Effect of Capsicum annuum (Red Sweet and Cayenne) and Piper nigrum (Black and White) Pepper Powders on the Shelf Life of Fresh Pork Sausages Packaged in Modified AtmosphereJOURNAL OF FOOD SCIENCE, Issue 1 2006Luis Martínez ABSTRACTCapsicum annuum (red sweet and hot cayenne) and Piper nigrum (black and white) pepper powders were evaluated for inhibition of oxidative reactions and extension of the shelf life of fresh pork sausages packaged in a modified atmosphere. Sausages containing either red sweet pepper or cayenne pepper (0.1%, 0.5%, or 2%) or black or white pepper (0.1%, 0.5%, or 1%) were packaged in a modified atmosphere of 80% O2+ 20% CO2, stored for 16 d in the dark at 2 °C, and analyzed each 4 d for pH, CIE L*, a*, and b*, 2-thiobarbituric acid-reactive substances (TBARS), psychrotrophic aerobes, sensory discoloration, and off-odor. Results demonstrated that Capsicum peppers (sweet red and hot cayenne) enhanced red color but failed to prevent discoloration, whereas they were very effective in inhibiting lipid oxidation, chiefly at the highest concentration used (2%), which resulted in a delay of off-odor formation. Piper peppers (black and white) significantly delayed discoloration with small modification of sausage color; furthermore, they also inhibited lipid oxidation, which led to a delay of off-odor formation, particularly in the form of black pepper. Besides this, all those spices inhibited microbial growth when added at the highest concentration (1%Piper and 2%Capsicum). [source] Development of Shelf-stable Intermediate-moisture Meat Products Using Active Edible ChitosanCoating and IrradiationJOURNAL OF FOOD SCIENCE, Issue 7 2005M. Shobita Rao ABSTRACT Shelf-stable intermediate-moisture (IM) meat products were developed using a combination of hurdles such as reduced aw, active edible coating of chitosan, and irradiation. Chitosan prepared from chitin had a viscosity of 16 c P, molecular weight of 17.54 kDa, and a degree of deacetylation (DD) of 74%. The nitrogen content of the chitosan was estimated to be 7.56%. The antioxidant activity of chitosan increased upon irradiation without significantly affecting its antimicrobial property. The effect of irradiated chitosan coating in terms of its antimicrobial and antioxidant properties in IM meat products immediately after irradiation and during storage was assessed. The aw of meat products such as mutton sheek kababs and streaky bacon was first reduced to 0.85 ± 0.02. The products were then coated with chitosan and irradiated (4 kGy). No viable bacteria or fungi were detected in chitosan-coated, irradiated products. In contrast, IM meat products that were not subjected to gamma radiation showed visible fungal growth within 2 wk. The chitosan-coated products showed lower thiobarbituric acid-reactive substances (TBARS) than the noncoated samples for up to 4 wk of storage at ambient temperature. The studies thus clearly indicated the potential use of chitosan coating for the preparation of safe and stable meat products. [source] Mortadella Sausage Formulations with Partial and Total Replacement of Beef and Pork Backfat with Mechanically Separated Meat from Spent Layer HensJOURNAL OF FOOD SCIENCE, Issue 3 2005Marco A. Trindade ABSTRACT: Mortadella sausages were formulated with 0%, 20%, 40%, 60%, 80%, and 100% mechanically separated layer hen meat (MSLM) replacing the beef and pork backfat as raw materials. Treatments were compared by determination of shear force, sensory acceptance, and stability during cold storage (microbial analysis, thiobarbituric acid-reactive substances [TBARS], color, and descriptive sensory analysis). Mortadella with higher MSLM presented lower shear force values. TBARS index and sensory rancidity were not affected. The greater the amounts of MSLM used, the paler was the pink color observed in the sensory evaluations and the lower were the CIE a* values. All treatments presented minimal increase in the microbiological counts evaluated during storage. The limiting factor in the acceptance of the product was the perception of bone particles in mortadella containing 60% or more MSLM. [source] Antioxidant Properties of Natural Plant Extracts Containing Polyphenolic Compounds in Cooked Ground BeefJOURNAL OF FOOD SCIENCE, Issue 4 2002J. Ahn ABSTRACT Thiobarbituric acid-reactive substances (TBARS) values, hexanal content, and sensory analysis were used to evaluate the effectiveness of selected natural antioxidants to reduce warmed-over flavor (WOF) development in cooked ground beef. The control without added antioxidant showed the highest TBARS value, hexanal content, and WOF scores. Grape seed extract (ActiVinTM) and pine bark extract (Pycnogenol®) significantly improved the oxidative stability of cooked beef. Compared to the control, ActiVinTM, Pycnogenol®, and oleoresin rosemary reduced the hexanal content by 97%, 94% and 73% after 3 d of refrigerated storage, respectively. WOF scores showed a similar pattern as TBARS values and hexanal contents. TBARS values, WOF scores, and hexanal contents were all well correlated. [source] Chronic fatigue syndrome: assessment of increased oxidative stress and altered muscle excitability in response to incremental exerciseJOURNAL OF INTERNAL MEDICINE, Issue 3 2005Y. JAMMES Abstract. Objectives., Because the muscle response to incremental exercise is not well documented in patients suffering from chronic fatigue syndrome (CFS), we combined electrophysiological (compound-evoked muscle action potential, M wave), and biochemical (lactic acid production, oxidative stress) measurements to assess any muscle dysfunction in response to a routine cycling exercise. Design., This case,control study compared 15 CFS patients to a gender-, age- and weight-matched control group (n = 11) of healthy subjects. Interventions., All subjects performed an incre-mental cycling exercise continued until exhaustion. Main outcome measures., We measured the oxygen uptake (Vo2), heart rate (HR), systemic blood pressure, percutaneous O2 saturation (SpO2), M-wave recording from vastus lateralis, and venous blood sampling allowing measurements of pH (pHv), PO2 (PvO2), lactic acid (LA), and three markers of the oxidative stress (thiobarbituric acid-reactive substances, TBARS, reduced glutathione, GSH, and ascorbic acid, RAA). Results., Compared with control, in CFS patients (i) the slope of Vo2 versus work load relationship did not differ from control subjects and there was a tendency for an accentuated PvO2 fall at the same exercise intensity, indicating an increased oxygen uptake by the exercising muscles; (ii) the HR and blood pressure responses to exercise did not vary; (iii) the anaerobic pathways were not accentuated; (iv) the exercise-induced oxidative stress was enhanced with early changes in TBARS and RAA and enhanced maximal RAA consumption; and (v) the M-wave duration markedly increased during the recovery period. Conclusions., The response of CFS patients to incremental exercise associates a lengthened and accentuated oxidative stress together with marked alterations of the muscle membrane excitability. These two objective signs of muscle dysfunction are sufficient to explain muscle pain and postexertional malaise reported by our patients. [source] Pregnenolone Sulfate, a Naturally Occurring Excitotoxin Involved in Delayed Retinal Cell DeathJOURNAL OF NEUROCHEMISTRY, Issue 6 2000C. Cascio Abstract: The present study was designed to investigate the neurosteroid pregnenolone sulfate (PS), known for its ability to modulate NMDA receptors and interfere with acute excitotoxicity, in delayed retinal cell death. Three hours after exposure of the isolated and intact retina to a 30-min PS pulse, DNA fragmentation as assessed by genomic DNA gel electrophoresis and a modified in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method appeared concurrently with an increase in superoxide dismutase (SOD) activity and thiobarbituric acid-reactive substances (TBARS) levels. At 7 h, the increased amount of DNA laddering was accompanied by a higher number of TUNEL-positive cells in the inner nuclear and ganglion cell layers. Necrotic signs were characterized by DNA smear migration, lactate dehydrogenase (LDH) release, and damage mainly in the inner nuclear layer. PS-induced delayed cell death was markedly reduced by the NMDA receptor antagonists 4-(3-phosphonopropyl)-2-piperazinecarboxylic acid and 3,-hydroxy-5,-pregnan-20-one sulfate but completely blocked after concomitant addition of the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione. Steroids with antioxidant properties (progesterone, dehydroepiandrosterone and its sulfate ester, and 17,-estradiol) differently prevented PS-induced delayed cell death. Cycloheximide treatment protected against DNA fragmentation and LDH release but failed to prevent the rise in SOD activity and TBARS level. We conclude that a brief PS pulse causes delayed cell death in a slowly evolving apoptotic fashion characterized by a cycloheximide-sensitive death program downstream of reactive oxygen species generation and lipid peroxidation, turning into secondary necrosis in a retinal cell subset. [source] Evidence that 3-hydroxy-3-methylglutaric acid promotes lipid and protein oxidative damage and reduces the nonenzymatic antioxidant defenses in rat cerebral cortexJOURNAL OF NEUROSCIENCE RESEARCH, Issue 3 2008Guilhian Leipnitz Abstract In the present work we investigated the in vitro effect of 3-hydroxy-3-methylglutarate (HMG) that accumulates in 3-hydroxy-3-methylglutaryl-CoA lyase deficiency (HMGLD) on important parameters of oxidative stress in rat cerebral cortex. It was observed that HMG induced lipid peroxidation by significantly increasing chemiluminescence and levels of thiobarbituric acid-reactive substances (TBA-RS). This effect was prevented by the antioxidants ,-tocopherol, melatonin, N-acetylcysteine, and superoxide dismutase plus catalase, suggesting that free radicals were involved in the lipid oxidative damage. On the other hand, HMG did not change TBA-RS levels in intact or disrupted mitochondrial preparations, indicating that generation of oxidants by this organic acid was dependent on cytosolic mechanisms. HMG also induced protein oxidative damage in cortical supernatants, which was reflected by increased carbonyl content and sulfhydryl oxidation. Furthermore, HMG significantly reduced the nonenzymatic antioxidant defenses total-radical trapping antioxidant potential, total antioxidant reactivity, and reduced glutathione (GSH) levels in rat cerebral cortex. HMG-induced GSH reduction was totally blocked by melatonin pretreatment. We also verified that the decrease of GSH levels provoked by HMG in cortical supernatants was not due to a direct oxidative effect of this organic acid, because exposition of commercial GSH and purified membrane protein-bound thiol groups to HMG in the absence of cortical supernatants did not decrease the reduced sulfhydryl groups. Finally, the activities of the main antioxidant enzymes were not altered by HMG exposure. Our data indicate that oxidative stress elicited in vitro by HMG may possibly contribute at least in part to the pathophysiology of the brain injury in HMGLD. © 2007 Wiley-Liss, Inc. [source] Activity of the Chinese prescription Hachimi-jio-gan against renal damage in the Otsuka Long-Evans Tokushima Fatty rat: a model of human type 2 diabetes mellitusJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 4 2006Noriko Yamabe Currently, in Japan, approximately 95% of patients with diabetes mellitus have non-insulin-dependent (type 2) diabetes mellitus (NIDDM), and diabetic nephropathy is a major cause of patients requiring chronic haemodialysis. A previous study showed that Hachimi-jio-gan has a protective effect in rats subjected to subtotal nephrectomy plus streptozotocin injection, a model of insulin-dependent (type 1) diabetic nephropathy. In this study, we used the Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model of human NIDDM, to investigate whether long-term administration of Hachimi-jio-gan affects glycaemic control and renal function in NIDDM. Male OLETF rats, aged 22 weeks, were divided into 4 groups of 10 and given Hachimi-jio-gan (50, 100 or 200 mg kg,1 daily) orally or no treatment for 32 weeks. Male Long-Evans Tokushima Otsuka (LETO) rats (n = 6) were used as non-diabetic normal controls. Hachimi-jio-gan reduced hyperglycaemia dose-dependently from 16 weeks of the administration period. Urinary protein excretion decreased significantly from an early stage, and creatinine clearance levels improved at 32 weeks. In addition, the levels of serum glycosylated protein and renal advanced glycation end-products were effectively reduced. Hachimi-jio-gan also significantly reduced the levels of thiobarbituric acid-reactive substances in renal mitochondria, although it showed only a tendency to reduce these in serum. Furthermore, long-term administration of Hachimi-jio-gan reduced renal cortical expression of proteins, such as transforming growth factor-,1 (TGF-,1), fibronectin, inducible nitric oxide synthase and cyclooxygenase-2. The 100- and 200-mg kg,1 daily doses of Hachimi-jio-gan significantly reduced TGF-,1 and fibronectin protein expression to levels below those of LETO rats. These data suggest that Hachimi-jio-gan may have a beneficial effect on the progression of diabetic nephropathy in OLETF rats by attenuating glucose toxicity and renal damage. [source] Protective effects of melatonin against oxidative stress in Fmr1 knockout mice: a therapeutic research model for the fragile X syndromeJOURNAL OF PINEAL RESEARCH, Issue 2 2009Yanina Romero-Zerbo Abstract:, Fragile X syndrome is the most common form of inherited mental retardation. It is typically caused by a mutation of the Fragile X mental-retardation 1 (Fmr1) gene. To better understand the role of the Fmr1 gene and its gene product, the fragile X mental-retardation protein in central nervous system functions, an fmr1 knockout mouse that is deficient in the fragile X mental-retardation protein was bred. In the present study, fragile X mental retardation 1-knockout and wild-type mice are used to determine behaviour and oxidative stress alterations, including reduced glutathione, oxidized glutathione and thiobarbituric acid-reactive substances, before and after chronic treatment with melatonin or tianeptine. Reduced glutathione levels were reduced in the brain of fmr1-knockout mice and chronic melatonin treatment normalized the glutathione levels compared with the control group. Lipid peroxidation was elevated in brain and testes of fmr1-knockout mice and chronic melatonin treatment prevents lipid peroxidation in both tissues. Interestingly, chronic treatment with melatonin alleviated the altered parameters in the fmr1-knockout mice, including abnormal context-dependent exploratory and anxiety behaviours and learning abnormalities. Chronic treatment with tianeptine (a serotonin reuptake enhancer) did not normalize the behaviour in fmr1-knockout mice. The prevention of oxidative stress in the fragile X mouse model, by an antioxidant compound such as melatonin, emerges as a new and promising approach for further investigation on treatment trials for the disease. [source] Melatonin protects hepatic mitochondrial respiratory chain activity in senescence-accelerated miceJOURNAL OF PINEAL RESEARCH, Issue 3 2002Yuji Okatani Mitochondrial oxidative damage from free radicals may be a factor underlying aging, and melatonin, a powerful free radical scavenger, may participate in mitochondrial metabolism. We measured respiratory chain complex I and IV activities in liver mitochondria from a strain of senescence-accelerated prone mice (SAMP8) and a strain of senescence-accelerated resistant mice (SAMR1) at age 3, 6, and 12 months. No age-associated effects were found in either complex I and IV activities, thiobarbituric acid-reactive substances (TBARS), or glutathione peroxidase (GPx) activity in SAMR1. In contrast, SAMP8 showed significant age-associated decreases in complex I and IV activities. While no age effect was found in TBARS in SAMP8, TBARS levels in SAMP8 were significantly more abundant than in SAMR1. GPx activity in SAMP8 decreased significantly by 12 months. Daily oral melatonin administration (2 ,g/mL of drinking fluid) beginning when the mice were 7 months old significantly increased complex I and IV activity, decreased TBARS, and increased GPx activities in both SAMR1 and SAMP8 at 12 months. The implication of the findings is that melatonin may be beneficial during aging as it reduced the deteriorative oxidative changes in mitochondria and other portions of the cell associated with advanced age. [source] The protective effects of melatonin from oxidative damage induced by amyloid beta-peptide 25,35 in middle-aged ratsJOURNAL OF PINEAL RESEARCH, Issue 2 2002Y. X. Shen This work investigated the ability of melatonin to prevent oxidative damage in brain tissue induced by injection of beta-amyloid peptide 25,35 (A,25,35) in middle-aged rats. The Morris water maze was used to evaluate the cognitive function of the rats. Thiobarbituric acid-reactive substances and antioxidative enzymes (superoxide dismutase and glutathione peroxidase) activities were measured. It was found that injection of (A,25,35) (20 ,g) into the rat hippocampus caused an increase in the latency (the time to find the platform), the total swimming distance to the platform, and the starting angles in (A,25,35)-treated rats. Furthermore, a significant rise in lipid peroxidation and decrease in antioxidative enzyme activities in brain tissue were found. Melatonin (0.1, 1, and 10 mg/kg, i.g. × 10 days) improved the spatial resolution of amnesic rats in the Morris water maze test. Meanwhile, melatonin antagonized the lipid peroxidation in both the mitochondria (P < 0.01) at the doses of 0.1, 1.0, and 10 mg/kg and in the cytoplasm at the doses of 0.1 and 1.0 mg/kg. Also in the amnesic rats, melatonin (0.1, 1.0, and 10 mg/kg, i.g. × 10 days) stimulated the antioxidative enzyme activities. The results show that melatonin effectively reduced lipid peroxidation and enhanced the antioxidative enzyme activities in A,25,35 -treated rats, which may contribute to the improvement of rats' learning and memory impaired by A,25,35. [source] Antioxidative capacity produced by Bifidobacterium - and Lactobacillus acidophilus -mediated fermentations of konjac glucomannan and glucomannan oligosaccharidesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2008Cheng-Hsin Wang Abstract BACKGROUND: Konjac glucomannan (KGM) has been shown to stimulate the growth of bifidobacteria and lactobacilli in the human and rat colon. This study investigated the antioxidative effects produced after 48 h in vitro fermentation of unhydrolysed KGM and two hydrolysed KGM fractions (KH1 and KH2 with degree of polymerisation 10 and 5 respectively) by Bifidobacterium adolescentis, B. bifidum, B. breve, B. longum and Lactobacillus acidophilus respectively. The inhibitory effect on conjugated diene formation, ferric-chelating capacity, ,,,-diphenyl-,-picrylhydrazyl (DPPH) radical-scavenging ability and thiobarbituric acid-reactive substances (TBARS) concentration produced by these fermentations were compared with those of oligofructose (OF) fermentation. RESULTS: The fermentation of KGM by each bacterial strain produced higher ferric-chelating capacity of the culture supernatant compared with KH2 or OF fermentation. In contrast, the fermentation of KGM by each bacterial strain led to lower inhibition of conjugated diene formation and lower radical-scavenging ability compared with KH2 fermentation. The fermentation of KH2 produced the lowest amount of TBARS. CONCLUSION: The fermentation of unhydrolysed KGM by colonic lactic acid bacteria in vitro produced antioxidative capacity mainly by preventing the initiation of ferrous ion-induced peroxidation, whereas the fermentation of konjac oligosaccahrides did so by increasing the radical-scavenging ability and eliminating lipid peroxide formation. Copyright © 2008 Society of Chemical Industry [source] Effect of hot air treatments on senescence and quality parameters of harvested broccoli (Brassica oleracea L var Italica) headsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2005María L Costa Abstract Treatments with hot air were applied to broccoli (Brassica oleracea L) florets to investigate the effect on several quality and senescence parameters. To select the optimum treatment, florets were treated with different combinations of time/temperature ranging from 1 to 3 h and 37 to 50 °C and then placed in darkness at 20 °C. Most treatments delayed yellowing and loss of chlorophylls, except those performed at 37 °C, which accelerated senescence. Treatment at 48 °C for 3 h caused the highest delay in chlorophyll loss and was chosen to analyse its effect on quality and senescence. Non-treated florets showed yellowing and reduced their chlorophyll content during storage. Heat treatment delayed the onset of chlorophyll catabolism by 1 day and slowed down the rate of degradation. Treated florets also showed lower losses of total sugars and proteins and an inhibition of protein solubilisation. Control heads showed an increment in CO2 production, which was not detected in heat-treated florets. Total antioxidants decreased and thiobarbituric acid-reactive substances (TBARS) increased during storage. The treatment delayed the decrease in antioxidant content and inhibited the increment in TBARS. In conclusion, treatment at 48 °C for 3 h delayed broccoli senescence at 20 °C and contributed to maintaining an overall better quality of the product. Copyright © 2005 Society of Chemical Industry [source] Inhibitory effects of Hibiscus sabdariffa L extract on low-density lipoprotein oxidation and anti-hyperlipidemia in fructose-fed and cholesterol-fed ratsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2004Chang-Che Chen Abstract Hibiscus sabdariffa L extract (HSE) is an aqueous extract of Hibiscus sabdariffa L flowers that is used as a local soft drink and medical herb in Taiwan. Oxidation of low-density lipoprotein (LDL) has been shown to increase the incidence of atherosclerosis. In this study, we determined the antioxidative activity of HSE on LDL oxidation by examining relative electrophoretic mobilities (REM) and thiobarbituric acid-reactive substances (TBARS). The data revealed an inhibitory effect of HSE on Cu2+ -mediated REM and TBARS. HSE exhibited a remarkable ability to reduce cholesterol degradation and ApoB fragmentation. Overall, HSE showed a high potency to inhibit the production of oxidized LDL induced by copper and, specifically, to reduce serum triglycerides in high-fructose diet (HFD) fed rats and serum cholesterol in high-cholesterol diet (HCD) fed animals. The levels of LDL and the ratio of LDL-cholesterol (LDL-C) to HDL-cholesterol (HDL-C) were reduced by HSE in both hyperlipidaemia models. Based on these findings, we suggest that HSE may be used to inhibit LDL oxidation and to prevent various types of hyperlipidaemia in HFD- or HCD-fed rats. Copyright © 2004 Society of Chemical Industry [source] Effect of lipid oxidation and frozen storage on muscle proteins of Atlantic mackerel (Scomber scombrus)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2002Suhur Saeed Abstract The effect of storage on the lipids and proteins in Atlantic mackerel stored for up to 24 months at ,20 and ,30,°C was studied. Traditional methods including the peroxide value, thiobarbituric acid-reactive substances (TBARS) and a reverse phase HPLC method were used to determine the primary and secondary lipid oxidation products. All tests showed an increase in lipid oxidation products with storage time and at a higher storage temperature of ,20,°C compared with samples stored at ,30,°C. Antioxidants had a significant effect (P,<,0.01) on the inhibition of lipid oxidation, as shown by the reduction in peroxide value and hydroxides, and malondialdehyde formation. Similarly, deterioration of protein structure and functionality in mackerel stored for 3, 6, 12 and 24 months was greater at ,20 than ,30,°C. ATPase activity in the myosin extract of Atlantic mackerel showed a significant decrease (P,<,0.01) with progressive frozen storage. Protein solubility in high salt concentration (0.6,M NaCl) decreased (P,<,0.01) during storage at both ,20 and ,30,°C but was greater at ,20,°C. Interestingly, antioxidants BHT, vitamin C and vitamin E protected the proteins against complete loss of ATPase activity and protein solubility to a significant level (P,<,0.01) for up to 1 year at ,20,°C compared with samples stored without antioxidants. This study confirms the deleterious effect of lipid oxidation products on protein structure and function in frozen fatty fish. © 2002 Society of Chemical Industry [source] Advanced oxidative protein products are independently associated with endothelial function in peritoneal dialysis patientsNEPHROLOGY, Issue 3 2009HUSEYIN KOCAK SUMMARY Aim: Oxidative stress (OS) and asymmetric dimethylarginine (ADMA) are accepted as non-classical cardiovascular risk factors in end-stage renal disease patients. To clarify the role of these factors in the atherosclerotic process, we investigated if OS and ADMA are associated with endothelial function (EF) in peritoneal dialysis (PD) patients. Methods: Fifty-two non-diabetic PD patients without known atherosclerotic disease as well as 30 age- and sex-matched healthy individuals were included. We measured serum thiobarbituric acid-reactive substances (TBARS), malondialdehyde (MDA), advanced glycation end-product (AGE), pentosidine, advanced oxidation protein products (AOPP), ADMA and EF as described by Celermejer et al. in all subjects. Results: TBARS, MDA, AOPP, AGE, pentosidine and ADMA levels were significantly higher in PD patients than in controls (P < 0.001). Flow-mediated dilatation (FMD)% and nitrate mediated dilatation (NMD)% in PD patients were lower than in the control group (7.7 ± 4.0% vs 11.70 ± 5.50%, P < 0.01 and 17.6 ± 8.3% vs 26.4 ± 4.6%, P < 0.01). Additionally, it was found that AOPP are independently correlated with FMD% and NMD% in PD patients (, = ,463, P < 0.01 and , = ,420, P < 0.05). Conclusion: This study shows that PD patients without known atherosclerotic disease can also be characterized by endothelial dysfunction and AOPP levels independently predict endothelial function level in PD patients. [source] Modified atmosphere packaging affects lipid oxidation, myofibrillar fragmentation index and eating quality of beefPACKAGING TECHNOLOGY AND SCIENCE, Issue 2 2009Ina Clausen Abstract The objective of this study was to evaluate the effects of different modified atmosphere packaging (MAP) systems applied during ageing and retail display on the quality of beef longissimus dorsi. The quality of the steaks was measured by sensory analysis, thiobarbituric acid-reactive substances (TBARS), myofibrillar fragmentation index (MFI), protein oxidation, weight loss, cooking loss and vitamin E content. The study included 11 different packaging systems investigated in two separate trials, using O2, CO2, N2 gas and vacuum in combination or alone during ageing and retail display. In some systems, loins were sliced into steaks before packaging, and in other systems, loins were vacuum packed and aged for 14,18 days, and thereafter were sliced and repacked in different atmospheres. Systems including high O2 MAP resulted in a large increase in warmed-over flavour and in TBARS as well as a decrease in juiciness, tenderness and vitamin E content, compared to anaerobic systems. Also, MFI was lower in high O2 MAP steaks, and an increase in protein oxidation was seen, suggesting that the decrease in meat tenderness was due to reduced proteolysis and/or protein oxidation. In addition, the cooked steaks of high O2 MAP looked well done, although the internal temperature was only 62°C, indicating premature browning. Ageing of steaks in N2 did not affect any measured parameter compared to vacuum thermoforming packed muscle. Steaks stored in vacuum skin pack for 20 days were less tender than steaks stored in 100% N2 for 18 days followed by 2 days in atmospheric air. In conclusion, packaging in high O2 concentrations compromises several aspects of meat quality. Copyright © 2008 John Wiley & Sons, Ltd. [source] Renal carcinogenesis induced by ferric nitrilotriacetate in mice, and protection from it by Brazilian propolis and Artepillin CPATHOLOGY INTERNATIONAL, Issue 9 2000Tetsuo Kimoto The protective effect of Brazilian propolis and its extract Artepillin C against ferric nitrilotriacetate (Fe-NTA)-induced renal lipid peroxidation and carcinogenesis was studied in male ddY mice. Fe-NTA-induced renal lipid peroxidation leads to a high incidence of renal cell carcinoma (RCC) in mice. Administration of propolis by gastric intubation 2 h before or Artepillin C at either the same time, 2 h, or 5 h before the intraperitoneal injection of Fe-NTA (7 mg Fe/kg) effectively inhibited renal lipid peroxidation. This was evaluated from the measurement of renal thiobarbituric acid-reactive substances (TBARS) or histochemical findings of 4-hydroxy-2-nonenal (4-HNE)-modified proteins and 8-hydroxy-2, -deoxyguanosine (8-OHdG). Repeated injection of Fe-NTA (10 mg Fe/kg per day, twice a week for a total of 16 times in 8 weeks) caused subacute nephrotoxicity as revealed by necrosis and pleomorphic large nuclear cells in the renal proximal tubules, and gave rise to RCC 12 months later. A protective effect from carcinogenicity was observed in mice given propolis or Artepillin C. Furthermore, the mice given Fe-NTA only developed multiple cysts composed of precancerous lesions with multilayered and proliferating large atypical cells. Mice treated with propolis and Artepillin C also had cysts, but these were dilated and composed of flat cells. These results suggest that propolis and Artepillin C prevent oxidative renal damage and the carcinogenesis induced by Fe-NTA in mice. [source] Protective effect of green tea polyphenol (-)-epigallocatechin gallate and other antioxidants on lipid peroxidation in gerbil brain homogenatesPHYTOTHERAPY RESEARCH, Issue 3 2003Seong-Ryong Lee Abstract The aim of this study was to compare the protective effects of green tea polyphenol (-)-epigallocatechin gallate (EGCG) and other well-known antioxidants on the lipid peroxidation in gerbil brain homogenates. Oxidative stress was induced by H2O2 (10 mM) or ferrous ammonium sulfate (5 µM) and lipid peroxidation was studied. Hydrogen peroxide and ferrous ions are capable of oxidizing a wide range of substrates and causing biological damage. The reaction, referred to as the Fenton process, is complex and can generate both hydroxyl radicals and higher oxidation states of the iron. Thiobarbituric acid-reactive substances (TBA-RS) were used as a marker of lipid peroxidation. EGCG, trolox, lipoic acid, and melatonin reduced H2O2 - or ferrous ion-induced lipid peroxidation in a concentration-dependant manner. In reducing the H2O2 -induced lipid peroxidation, IC50 values of antioxidants were as follows: EGCG (0.66 µM), trolox (37.08 µM), lipoic acid (7.88 mM), and melatonin (19.11 mM). In reducing the ferrous ion-induced lipid peroxidation, IC50 values of antioxidants were as follows: EGCG (3.32 µM), trolox (75.65 µM), lipoic acid (7.63 mM), and melatonin (15.48 mM). Under the in vitro conditions of this experiment, EGCG was the most potent antioxidant in inhibiting H2O2 or ferrous ion-induced lipid peroxidation in the gerbil brain homogenates. Copyright © 2003 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||