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The thiobarbituric acid reactive substances (TBARS) assay is a commonly used method for the detection of lipid peroxidation. Malondialdehyde is formed as a result of lipid peroxidation and reacts with thiobarbituric acid to form a pink pigment that has an absorption maximum at 532 nm. Other compounds also react with thiobarbituric acid to form colored species that can interfere with this assay, but little is known about these interfering species. This is the first investigation using LC-MS and MS-MS to study the structures of the pink adduct as well as a common unstable yellow interference compound, which absorbs at 455 nm. Also, the presence of barbituric acid impurities in the thiobarbituric acid reagent was found to produce 1:1:1 thiobarbituric acid/malondialdehyde/barbituric acid and 2:1 barbituric acid/malondialdehyde adducts that absorbed at 513 and 490 nm, respectively, indicating that thiobarbituric acid should be purified before use.
Serum copper, ceruloplasmin and thiobarbituric acid reactive substances (TBARS) were estimated in 30 patients of ovarian cancer. The copper to ceruloplasmin ratio was moderately increased (P<0.05) but the copper (P<0.01( and ceruloplasmin (P<0.001) levels were significantly increased in ovarian cancer patients as compared to controls. TBARS levels were also found to be highly significant (P<0.001). Trace elements and free radicals have been implicated in the etiology of cancer. Hence the estimation of antioxidants like ceruloplasmin and TBARS along with the trace element like copper may be of value in the early diagnosis of cancer.
Increased levels of lipid peroxidation products (thiobarbituric acid reactive substances [TBARS]) are reported in plasma/serum from patients with schizophrenia. CSF TBARS levels were assessed in 10 neuroleptic-free patients with schizophrenia and in 9 normal controls. Controlling for duration of storage, CSF TBARS content was significantly lower in patients with schizophrenia vs. controls (p<0.002). No significant correlations were found between CSF TBARS and patients' age, gender, or duration of illness. The likely source of reported elevated plasma/serum TBARS in schizophrenia is therefore in the periphery. Degeneration of central neuronal membranes in schizophrenia is not supported by the present study.
The serum concentration of thiobarbituric acid reactive substances (TBARS), which can be used in the characterization of O2-radical metabolism, was analyzed in patients with myocardial infarction in the acute phase, 10-14 days, 1 month, and 6 months after infarction, and compared with the TBARS concentration of a healthy group and a group with atherosclerosis. After myocardial infarction we found increased TBARS concentration at all moments of investigation in comparison with the healthy and atherosclerosis groups. Maximum concentration was found 10-14 days after infarction, afterwards the TBARS concentration decreased, without however attaining the values which we found in the comparison groups. The increased TBARS concentration 6 months after myocardial infarction demonstrates a manifestation of disturbances in the O2-radical metabolism. Such disturbances may be regarded as a high-risk factor to the cardiovascular system.
In this study we investigated the output of thiobarbituric acid reactive substances (TBARS) and malondialdehyde (MDA), as thiobarbituric acid (TBA)-MDA adduct, in the urine from subjects eating a diet in which the only source of n-3 long-chain, polyunsaturated fatty acids was fresh salmon. Nine healthy men, ages 30-65, were confined in the United States Department of Agriculture Western Human Nutrition Research Center, San Francisco, CA, for 100 d; food intake and exercise levels were controlled. All subjects were placed on a stabilization diet (StD) for 20 d, then six were fed the salmon diet for 40 d. The others remained on the StD. The groups switched diets for the last 40 d. Both diets were isocaloric (16% protein, 54% CHO and 30% fat by energy %). The salmon diet contained 7.5% of calories from n-6 fatty acids (FAs) and 2% from n-3 FAs, primarily eicosapentaenoic acid and docosahexaenoic acid in a 50:60 ratio, while the StD contained 7.5% from n-6 FAs and < 0.3% n-3 FAs (with presumably no significant amounts of C20 or C22 n-3 FAs). Twenty-four hour urinary output was collected, and 2% 3-d pool samples prepared for analysis of urinary TBARS and the TBA-MDA adduct. The total urinary output of each individual varied considerably, and on a daily basis the concentration of autoxidation products in an individual's urine varied also.(ABSTRACT TRUNCATED AT 250 WORDS)
The effect of irradiation on thiobarbituric acid reactive substances (TBARS) and volatile compounds in raw and cooked nonirradiated and irradiated chicken breast meat infused with green tea and grape seed extracts was investigated. Chicken breast meat was vacuum infused with green tea extract (3,000 ppm), grape seed extract (3,000 ppm), or their combination (at a total of 6,000 ppm), irradiated with an electron beam, and stored at 5 degrees C for 12 d. The targeted irradiation dosage was 3.0 kGy and the average absorbed dosage was 3.12 kGy. Values of TBARS and volatile compound contents of raw and cooked chicken meat were determined during the 12-d storage period. Thiobarbituric acid reactive substances values ranged from 15.5 to 71.4 mg of malondialdehyde/kg for nonirradiated raw chicken and 17.3 to 80.1 mg of malondialdehyde/kg for irradiated raw chicken. Values for cooked chicken ranged from 31.4 to 386.2 and 38.4 to 504.1 mg of malondialdehyde/kg for nonirradiated and irradiated chicken, respectively. Irradiation increased TBARS and hexanal values of controls and meat infused with plant extracts. Hexanal had the highest intensity of volatiles followed by pentanal and other volatiles. Cooking the samples significantly (P < 0.05) increased the amounts of TBARS and volatiles. Addition of plant extracts decreased the amount of TBARS as well as hexanal and pentanal values. Although irradiation increases lipid oxidation, infusion of chicken meat with plant extracts could reduce lipid oxidation caused by irradiation.
Serum thiobarbituric acid reactive substances (TBARS), Zn, Cu, and Se concentrations were determined in 47 healthy adults and in patients with diseases, such as renal insufficiency, insulin-dependent diabetes mellitus, chronic pancreatitis, liver cirrhosis, or cancer, in order to clarify the relationship between this indicator of lipid peroxidation and antioxidative trace element status. TBARS levels were higher than control values in all pathological cases, except in cancer patients. Cu levels in patients highly correlated with ferroxidase ceruloplasmin activity (r = 0.86), but were only statistically different from controls in diabetics. Zn levels were lower than normal in dialysis, liver cirrhosis, and cancer patients. Se levels were significantly decreased in all pathological cases. Half of the subjects with liver cirrhosis or renal insufficiency and 3/4 of chronic pancreatitis or cancer patients had an active inflammatory process. Despite intense modifications in determined indicators, no clear correlation could be demonstrated between the different parameters. Basic antioxidative trace element status and inflammation are therefore not major determinants of TBARS levels in normal and in pathological conditions, despite of the frequent association of low serum Zn and mainly low serum Se with high TBARS levels.
PURPOSE: To investigate whether serum levels of lipid peroxides measured as thiobarbituric-acid-reactive substances (TBARS) differ in type I and type II diabetic patients, whether serum levels correlate with late sequelae of diabetes, and whether serum levels of free vitamin E correlate with levels of lipid peroxidation by-products. PATIENTS AND METHODS: The relationship among lipids, glycosylated hemoglobin A1c (HbA1c), lipid peroxides measured as TBARS, and free vitamin E was determined in 158 patients. Fifteen of the 77 patients with type I diabetes and 39 of the 81 patients with type II diabetes had clinically apparent peripheral vascular disease or coronary artery disease, or both. RESULTS: Compared with control subjects, serum levels of TBARS were found to be significantly elevated (P < 0.001) in diabetic patients, and type II diabetic patients had significantly higher levels (P < 0.001) than type I patients. Both type I and type II diabetic patients with good metabolic control (HbA1c < 6.5%) had significantly lower (P < 0.005) TBARS levels than patients with poor metabolic control, but all groups had higher levels than the control group. Type II patients with angiopathy had significantly higher levels of TBARS than patients without angiopathy. Free vitamin E levels in control subjects and diabetic patients did not differ statistically. CONCLUSION: Serum levels of TBARS were significantly increased in all patients suffering from diabetes mellitus, whereby TBARS levels did not depend on the total amount of circulating lipids. It can be suggested that the enhanced lipidperoxidation is contributed to an increased formation of free radicals in diabetes mellitus.
The purpose of this study was to measure the level of thiobarbituric acid reactive substances (TBARS), which are products of lipid peroxidation, as a reflection of oxidative status in 30 patients with laryngeal cancer. The TBARS were measured 1 day before surgery and 3 weeks after laryngectomy compared to 30 normal control subjects by the thiobarbituric acid (TBA) test using spectrophotometry. The TBARS levels were significantly elevated in patients with laryngeal cancer compared to the controls (18.4 +/- 3.13 mumol/l versus 7.75 +/- 1.9 mumol/l; P < 0.05). There were no differences in the TBARS levels in relation to T staging, N staging, or degree of differentiation. Among patients with laryngeal cancer smokers had slightly higher TBARS levels. Comparison of the paired observations of laryngeal cancer larynx before and after operation revealed a significant rise in the TBARS levels after laryngectomy. Tissue damage resulting from surgery is the most probable explanation for this rise. The state of altered lipid peroxidation detected in our patients might be related to a deficient antioxidant status. The role of antioxidants in the prevention of laryngeal cancer among high risk patients is worth studying.
BACKGROUND: Patients with end-stage renal disease are thought to be in a highly peroxidative state, based on studies showing decreased serum antioxidant activity and increased peroxidative products. In this study we confirm these findings by examining lipid peroxidation in subcutaneous fat tissue in uraemia. SUBJECTS AND METHODS: Twenty-seven subcutaneous fat samples were taken from patients with end-stage renal disease when they underwent intervention for arteriovenous fistula for haemodialyis or for catheter insertion for continuous ambulatory peritoneal dialysis. The control samples were taken from 11 patients with normal renal function and without any history of renal disease who had surgical interventions. Lipid peroxides were measured as thiobarbituric acid reactive substance. RESULTS: The concentration of thiobarbituric acid reactive substances in subcutaneous fat tissue in the patients with end-stage renal disease is 1.223 +/- 0.636 nmol/mg fat tissue (mean +/- SD) whereas the level in the control group is 0.097 +/- 0.054 nmol/mg fat tissue. A comparison of the two groups by Student's t test revealed a highly significant difference (P < 0.001). CONCLUSIONS: This study supports the finding of a severe peroxidative state in patients with end-stage renal disease.
Four nonsteroidal antiinflammatory drugs--namely, acetylsalicylic acid, naproxen, nimesulide, and dipyrone--were assayed to search their capability in preventing the hepatic increase of triacylglycerols and thiobarbituric acid reactive substances, as an indication of lipid peroxidation, resulting from the acute intoxication of rats with ethanol. The four antiinflammatory compounds inhibited the ethanol-mediated increase in triacylglycerols and thiobarbituric acid reactive substances. Furthermore, each one of these antiinflammatory drugs produced distinctive actions on blood ethanol levels: a temporal diminution with aspirin and naproxen, no changes with nimesulide, and an increase with dipyrone. It is concluded that the nonsteroidal antiinflammatory drugs contributed to controlling hepatic lipid peroxidation, and hence the oxidative stress promoted by ethanol intoxication.
In this study we examined superoxide dismutase (SOD) activity and thiobarbituric acid reactive substances (TBARS) concentration in liver and muscles of four fish species: the carp, the brown trout, the white cod and the flounder. Higher SOD activity and higher TBARS concentration was revealed in the tissues of marine fish in comparison to freshwater fish. The highest SOD activity was observed in the cod while the highest TBARS concentration was in the flounder. The observed differences are probably an effect of the different living mode of the compared fish.
Serum copper, ceruloplasmin, protein thiols and thiobarbituric acid reactive substances (TEARS) were estimated in 25 patients of liver cancer. The copper to ceruloplasmin ratio was moderately increased (P<0.05) but the copper (P<0.001) and ceruloplasmin (P<0.001) levels were significantly increased in liver cancer patients when compared to controls. Protein thiols levels were found to be highly significant (P<0.001). Where as the TEARS levels were not found to be significant. Trace elements and free radicals have been implicated in the etiology of cancer. Hence the estimation of ceruloplasmin and protein thiols along with the copper may be of high value in the early diagnosis of cancer.
The aim of the present study is to evaluate tissue nitric oxide (NO) and thiobarbituric acid reactive substance (TBARS) levels in testicular tissue, and to determine their relationship with seminal parameters in order to explain possible effects on varicocele pathophysiology. Ten adult male Wistar rats at 8 weeks old underwent partial left renal vein ligation. A sham operation was performed on control rats in a second group of another ten rats. All animals were killed 4 weeks after surgery. The testes were removed and histological changes were observed by light microscopy with haematoxylin and eosin stain on half of each testis. The rest of testis was used for the evaluation of testicular tissue NO and TBARS levels. Epididymal aspirated seminal plasma was used for semen analysis and morphological analysis was carried out according to Kruger's criteria. Statistical analysis was performed by using Mann-Whitney U-tests and Spearman rank correlations between the two groups for NO and TBARS levels and for seminal parameters. Testicular tissue NO and TBARS levels (mean+/-SEM) were 62.8+/-10.1 micromol/g protein and 4.7+/-0.3 nmol/g protein in group 1. These parameters were 16.9+/-2.2 micromol/g protein and 3.1+/-0.2 nmol/g protein in the group 2 controls. There were significant differences between these parameters ( P(NO)=0.000, P(TBARS)=0.001). Although a positive and significant correlation between testicular tissue NO and TBARS levels was found ( r(s)=0.739, P=0.014), there was only a strong negative correlation between NO levels and sperm motility in group 1 ( r(s)=-0.815, P=0.004). We found that this effect of NO on sperm motility was independent from TBARS levels after regression analysis ( r(2)=-0.687, beta=0.825, P=0.034). Although there were statistically significant differences in seminal parameters between the two groups, there was no difference between them in the histopathological examination. We found that sperm motility was significantly related to testicular tissue NO levels only. Thus, we suggest that NO is an important mediator in the pathogenesis of varicocele. TBARS and other substances have been effective via NO pathways.
The level of urinary thiobarbituric acid reactive substances (TBARS) consisting of bound forms of malonaldehyde and, to a lesser extent, other aldehydes is one of the indices of lipid peroxidation status. Levels of urinary TBARS in healthy subjects before and after supplementation with a high dose of d-alpha-tocopherol were measured using high performance liquid chromatography. Four healthy Japanese were given a supplement of 300 mg d-alpha-tocopherol/d, about 40-fold higher than the normal intake recommended, for a period of 50 d. Levels of urinary TBARS (nmol/kg body weight.h) within-day, before and after supplementation with d-alpha-tocopherol, exhibited similar behavior and levels of daily urinary TBARS (nmol/kg body weight.d) were unchanged by d-alpha-tocopherol supplementation. These results indicate that supplementation with a high dose of d-alpha-tocopherol does not affect the level of urinary TBARS.
The relationships between 4-hydroxy-2-nonenal (HNE), 2-thiobarbituric acid reactive substances (TBARS) and n-6 polyunsaturated fatty acids (n-6 PUFAs) were investigated for pork stored at 0, -20 and -80 degrees C. A significant linear correlation was apparent between HNE and TBARS for the pork stored at each temperature. However, the n-6 PUFA content remained unchanged during storage.
OBJECTIVE: The aim of the study is to evaluate the levels of nitrite/nitrate and thiobarbituric acid reactive substances (TBARS) and their relationship with seminal parameters in experimental obstructive azoospermic rats to explain the possible mechanism of impaired sperm quality in obstructive azoospermia. METHODS: A total of 10 male Spraque-Dawley rats underwent bilateral vas resection and ligation (Group-1 = vasectomy group). The findings were compared with control group (Group-2 = sham group, n = 10). Animals were sacrificed 8 weeks after surgery. Testes were removed and used for the evaluation of nitrate/nitrite and TBARS levels and for histology. Epididymal-aspirated seminal plasma was used for semen count and morphological analysis according to the Kruger criteria. RESULTS: Testicular tissue nitrate/nitrite and TBARS levels were 35.7 +/- 3.1 micromol/g protein and 3.7 +/- 0.1 nmol/g protein in Group-1, and 19.3 +/- 0.7 micromol/g protein and 3.1 +/- 0.1 nmol/g protein in Group-2, respectively. Both parameters showed statistical differences between the two groups. Testicular tissue nitrate/nitrite and TBARS levels showed negative and statistically significant correlations with sperm motility and morphology. CONCLUSIONS: The present study showed that testicular nitrate/nitrite and TBARS levels were increased in obstructive azoospermia. For that reason, we concluded that antioxidant treatment can be recommended to patients before sperm extraction for artificial reproduction due to obstructive infertility after vasectomy reversal.