Malondialdehyde-thiobarbituric Acid Reactive Substances Research Articles

Paraoxonase 1 decline and lipid peroxidation rise reflect a degree of brain atrophy and vascular impairment in dementia.

Paraoxonase 1 (PON1) is an enzyme with the capability to protect against lipid oxidation and atherosclerotic lesions formation. Impaired antioxidative capacity and enhanced lipid peroxidation (reflected by malondialdehyde rise) accompany dementias. The aim of this study was to discern the possible differences in the activity and phenotype distribution of PON1, and lipid peroxidation level in dementias of neurodegenerative and vascular pathology, to assess whether they reflect structural changes in the brain, and to evaluate their potential as dementia markers. Paraoxonase 1 arylesterase activity and polymorphisms (dual-substrate method), and malondialdehyde/thiobarbituric acid reactive substances (MDA/TBARS) levels were determined spectrophotometrically in 257 serum samples derived from 136 dementive patients (with Alzheimer's disease (AD; n = 63), vascular dementia (VaD; n = 40) and mixed-type dementia (MD; n = 33), as well as from 121 non-dementive individuals. The results were analyzed with reference to dementia type and severity (assessed with Mini Mental State Examination (MMSE) and Clinical Dementia Rating (CDR) scales), structural brain changes (estimated with magnetic resonance imaging (MRI) - Global Cortical Atrophy (GCA), Medial Temporal lobe Atrophy (MTA) and Fazekas scales)) and brain ischemia (Hachinski Ischemic Scale (HIS) index), and evaluated using receiver operating characteristic (ROC) analysis. Malondialdehyde/thiobarbituric acid reactive substances were increased in dementia (more in VaD than AD). In patients with vascular involvement, MDA/TBARS elevation reflected a degree of global cortical atrophy. Paraoxonase 1 activity was decreased in patients with dementia, especially in patients with severe cognitive deficits. In VaD, a drop in PON1 reflected a degree of MTA and brain ischemia. MDA/TBARS displayed 75% accuracy as a general dementia marker, but, similarly to PON1, were a poor differential marker. Both indices were more associated with vascular involvement and the severity of brain atrophy or ischemia rather than with degree of cognitive decline.

Assessment the alterations of some biochemical parameters in Afshari sheep with possible metabolic disorders

Clinical or subclinical ketosis is a very common metabolic disease in late-pregnancy in sheep, which causes severe economic losses to sheep flocks. Ovine pregnancy toxaemia (OPT), hypocalcaemia and hypomagnesemia together with decreased immune system function are some of the disorders which will occur following hyperketonemia in sheep. To evaluate common metabolic disorders in Afshari sheep, some serum biochemical parameters in late-pregnancy and non-pregnant Afshari sheep were measured. Blood samples were taken from 255 healthy pregnant sheep on their last 4- 6 weeks of pregnancy and in 122 healthy non-pregnant sheep as control group from 18 herds in Semnan, in the central part of Iran. Sera were isolated by centrifugation and kept in freezer until analysis. β-hydroxybutyrate (BHB), glucose, total antioxidant capacity (TAC), malondialdehyde-thiobarbituric acid reactive substances (MDA-TBARS), fibrinogen, total protein, albumin, urea, creatinine, aspartate aminotransferase (AST), alanine transaminase (ALT), triglycerides, cholesterol, total calcium, magnesium and inorganic phosphorus were measured in serum samples with commercial kits. Statistical analysis of the data showed that seventy pregnant ewes were in inadequate energy intake (IEI) and had subclinical OPT (BHB>0.86mmol/l) whereas 181 pregnant ewes were in good energy balance (BHB<0.86mmol/l). Serum concentrations of glucose (P<0.01), calcium (P<0.05), inorganic phosphorus (P<0.05) and sodium (P<0.05) were significantly lower in ewes with subclinical OPT as compared with ewes without OPT. Ewes with subclinical OPT had significantly higher serum concentrations of urea (P<0.05), triglyceride (P<0.05), cholesterol (P<0.05), AST (P<0.05), ALT (P<0.05), TAC (P<0.05) and TBARS (P<0.05) in comparison with in ewes without OPT. Serum biochemical profile in ewes with IEI and pregnant with twins significantly differed from those in ewes without IEI and singleton pregnant. The results proved NEB, IEI, hypocalcaemia and oxidative stress in pregnant Afshari ewes especially in twin are current and expected, that must be managed and controlled to avoid potential economic losses in the sheep farming industry which plays a significant role in rural and nomadic livelihood.

Biomarkers of lipid peroxidation in the aqueous humor of primary open-angle glaucoma patients

ObjectiveTo investigate the lipid peroxidation (PEROX) processes in primary open-angle glaucoma (POAG) patients, and whether this mechanism may be related to disease progression. Material and methodsA prospective, observational, cross-sectional, non-experimental, and analytical study was conducted on a case and a comparison group, consisting of 175 surgical patients divided into: (1) POAG group (GG; n=88) and (2) comparison group of patients with cataracts (CG; n=87). Demographic data, patient characteristics, lifestyle data, as well as ophthalmological examination were registered in an Excel spreadsheet. Biochemical data were obtained by processing the aqueous humor collected at the beginning of surgery. Determination of malondialdehyde/thiobarbituric acid reactive substances (MDA/TBARS) and total antioxidant activity (AAO) was assayed using enzymatic-colorimetric methods in the aqueous humor samples. Statistical analysis was performed using SPSS 15.0 software. ResultsAqueous humor MDA/TBARS levels were significantly higher (p<0.001) and the AAO significantly lower (p<0.001) in the GG than in the GC. The MDA/TBARS directly correlated with intraocular pressure (IOP) values and the cup-to-disk ratio (CDR). Decreased AAO activity correlated inversely with IOP and CDR. Differences between groups were noticeably higher in the GG as regards obesity, alcohol consumption, anxiety, depression, and sedentary lifestyle. In the multivariate analysis, the variables that showed a better predictive ability were: MDA/TBARS, PIO, AAO, CDR, and depression. ConclusionsThe POAG patients have a PEROX background that is reflected in the aqueous humor by variations in MDA/TBARS and AAO. Moreover, both the MDA/TBARS and AAO correlated with IOP values and the CDR. We propose that determination of MDA/TBARS and AAO in the aqueous humor of POAG patients can be used as biomarkers for monitoring the disease, as well the changes in lifestyle and other related risk factors.

Biomarcadores de peroxidación lipídica en el humor acuoso de pacientes con glaucoma primario de ángulo abierto

ObjectiveTo investigate the lipid peroxidation (PEROX) processes in primary open-angle glaucoma (POAG) patients, and whether this mechanism may be related to disease progression. Material and methodsA prospective, observational, cross-sectional, non-experimental, and analytical study was conducted on a case and a comparison group, consisting of 175 surgical patients divided into: 1) POAG group (GG; n=88) and 2) comparison group of patients with cataracts (CG; n=87). Demographic data, patient characteristics, lifestyle data, as well as ophthalmological examination were registered in an Excel spreadsheet. Biochemical data were obtained by processing the aqueous humor collected at the beginning of surgery. Determination of malondialdehyde/thiobarbituric acid reactive substances (MDA/TBARS) and total antioxidant activity (AAO) was assayed using enzymatic-colorimetric methods in the aqueous humor samples. Statistical analysis was performed using SPSS 15.0 software. ResultsAqueous humor MDA/TBARS levels were significantly higher (P<.001) and the AAO significantly lower (P<.001) in the GG than in the GC. The MDA/TBARS directly correlated with intraocular pressure (IOP) values and the cup-to-disc ratio (CDR). Decreased AAO activity correlated inversely with IOP and CDR. Differences between groups were noticeably higher in the GG as regards obesity, alcohol consumption, anxiety, depression, and sedentary lifestyle. In the multivariate analysis, the variables that showed a better predictive ability were: MDA/TBARS, PIO, AAO, CDR, and depression. ConclusionsThe POAG patients have a PEROX background that is reflected in the aqueous humor by variations in MDA/TBARS and AAO. Moreover, both the MDA/TBARS and AAO correlated with IOP values and the CDR. We propose that determination of MDA/TBARS and AAO in the aqueous humor of POAG patients can be used as biomarkers for monitoring the disease, as well the changes in lifestyle and other related risk factors.

Role of adiponectin on antioxidant profile: evaluation during healthy and hypertensive disorders of pregnancy

The study of adipokines and oxidative stress has aided in understanding pre-eclampsia physiopathology. Therefore, our group aimed to evaluate the correlation between the adipokines (adiponectin and leptin) and the oxidative stress marker malondialdehyde–thiobarbituric acid reactive substances (MDA-TBARS) and antioxidant activity of plasma [ferric reducing ability of plasma (FRAP)] in healthy pregnant women and patients with gestational hypertension and pre-eclampsia. We found a significant negative correlation between MDA-TBARS and adiponectin (r = –0.40, p = 0.0042), suggesting a relationship between antioxidant levels and this adipokine in healthy pregnancies which is altered in patients with gestational hypertension or pre-eclampsia.

Inhibitory Effect of Three C-glycosylflavonoids from Cymbopogon citratus (Lemongrass) on Human Low Density Lipoprotein Oxidation

This study assessed the inhibitory effect of three C-glycosylflavonoids from Cymbopogon citratus leaves − isoorientin (1), swertiajaponin (2) and isoorientin 2"-O-rhamnoside (3) − on human LDL oxidation. Isolated LDL was incubated with compounds 1-3 and the kinetics of lipid peroxidation were assessed by conjugated diene and malondialdehyde-thiobarbituric acid reactive substances (MDA-TBARS) formation after addition of copper ions. Significant differences (p < 0.05) between the lag time phase of the control and the lag time phase in the presence of the compounds 1 (0.25 µM) and 2 (0.50 µM) were observed. After five hours of incubation all three compounds showed a significant inhibitory effect on MDA-TBARS formation with respect to the control. After six hours of incubation only compound 1 kept a remarkable antioxidant effect. This study demonstrates that isoorientin (1) is an effective inhibitor of in vitro LDL oxidation. As oxidative damage to LDL is a key event in the formation of atherosclerotic lesions, the use of this natural antioxidant may be beneficial to prevent or attenuate atherosclerosis.

Oxidative Stress in Primary Open-angle Glaucoma

To analyze oxidative stress in primary open-angle glaucoma (POAG). A case-control study including 90 eyes of 90 patients who needed antiglaucomatous surgery in the course of POAG (glaucoma group, n=50) and from patients who were operated of nonpathologic cataracts (cataract group, n=40). Free radical formation via lipid peroxidation by malondialdehyde-thiobarbituric acid reactive substances (MDA-TBARS) test and total antioxidant status in the aqueous humor samples of both groups were determined. Statistical analyses were carried out in relation to MDA-TBARS and total antioxidant status and their correlations with glaucoma risk factors. Significantly higher MDA-TBARS were detected in the POAG with respect to the comparative group of cataract subjects (P<0.001). Antioxidant activity was significantly lower in the POAG than in the cataract group (P<0.001). Aqueous humor samples may be used for determining oxidative and antioxidant status in pathologic processes. Glaucomatous eyes had a significant increase in oxidative status and decreased antioxidant activity in the aqueous humor than the cataract eyes. Oxidative stress may play a pathogenical role in the POAG.

Oxidative damage and phosphatidylserine expression of red blood cells in cattle experimentally infected with Theileria sergenti.

In order to elucidate the mechanism of anemia in Japanese bovine theileriosis, we investigated the oxidative alteration of red blood cells (RBCs) in cattle infected with Theileria sergenti. As an index of RBC oxidation, the levels of 2',7'-dichlorofluorescin-diacetate (DCFH) oxidation and malondialdehyde-thiobarbituric acid reactive substances (MDA-TBARS), and phosphatidylserine (PS) expression accompanying anemia were examined in experimentally infected cattle. Before the development of anemia, the concentrations of DCFH oxidation and MDA-TBARS were low, and PS expression on the surfaces of RBCs was hardly seen. However, during the onset of anemia, these levels began to increase remarkably in proportion to the decrease of packed cell volume and the increase of parasitemia in all infected cattle. During the serious stage of anemia, these oxidative indices reached their maximum values. Our findings indicate that oxidative damage and loss of membrane asymmetry in RBCs are related to the development of anemia in T. sergenti infection. This oxidative damage to the RBCs might play an important role in the pathogenesis of anemia in Japanese bovine theileriosis.

Normothermic liver ischemia and antioxidant treatment during hepatic resections

The purpose of our study was to evaluate the clinical impact of reperfusion injury after normothermic ischemia during major liver resections and the effect of an intraoperative antioxidant infusion.This prospective randomized study comprised 50 patients; half of them (treatment group) were given an antioxidant infusion containing tocopherol and ascorbate immediately prior to reperfusion onset. Venous blood samples for the determination of MDA-TBARS (malondialdehyde-thiobarbituric acid reactive substances) by a HPLC-based test as a marker of lipid peroxidation were taken prior to ischemia, 30 min after reperfusion onset and at the end of the operation.In the control group there was a significant increase of MDA-TBARS (p = 0.001) at 30 min after reperfusion onset. At the end of the operation the values had returned to the initial level. The treatment group showed only a marginal increase (p-value for the difference between the two groups: 0.007). After exclusion of the patients with histologically proven advanced cirrhosis the increase in the control group (p < 0.001) and the difference between the increase in the two groups (p = 0.001) became more significant. Prothrombin time was also significantly better in the treatment group (p = 0.003). Postoperative complications such as prolonged liver failure, bleeding disorders and infections were seen more often in the control group.In our study MDA-TBARS was increased after liver ischemia, but in patients with advanced cirrhosis the effect was smaller or even absent. This increase and possible clinical consequences of reperfusion injury could be reduced by intraoperative administration of an antioxidant infusion.