Biochemical Markers of Oxidative Stress in Saudi Women with Recurrent Miscarriage

This study was undertaken to investigate the antioxidant/oxidant status in recurrent miscarriage patients. Antioxidants including glutathione peroxidase (GPx), catalase (CAT), glutathione reductase (GR), reduced glutathione (GSH) and selenium (Se), as well as the oxidants hydrogen peroxide (H2O2), oxidised glutathione (GSSG) and lipid peroxidation were assayed in plasma, whole blood and placental tissue of non-pregnant women (NP), healthy pregnant women (HP), and recurrent miscarriage (RM) patients. Results indicated that all antioxidant activities and levels in plasma and whole blood of HP women were consistently moderately lower, and much more significantly lower in RM patients when both were compared to those seen in NP women (P<0.05 and P<0.001, respectively). Furthermore, whereas plasma antioxidant activities and levels were significantly lower in RM patients, those of whole blood and placental tissue were much more significantly lower when compared with HP women (P<0.001). Concurrent with these findings there were consistent increases of equal statistical significance and magnitude in the levels of all investigated oxidants assayed in all samples when compared in between subjects of the study as indicated above. Data thus illustrated a distinct shift in favor of oxidative reactions and reactive oxygen species (ROS) generation, and very significant decreases in the GSH/GSSG ratios in whole blood and placental tissue of RM patients when compared to HP and NP women (P<0.001). The above noted oxidative stress could have been a major causative factor of recurrent miscarriage.

The effect of weight reduction on antioxidant enzymes and their association with dietary intake of vitamins A, C and E / Efeito da redução de peso sobre as enzimas antioxidantes e associação destas com a ingestão de vitaminas A, C e E

Objective Our goal was to assess the effects of weight loss on antioxidant enzymes of red blood cells and it’s relation with vitamins A, E and C intake in 30 obese women. Subjects and methods General information, anthropometric measurements, 3-day food recall, and fasting blood samples were collected from 30 obese women at the beginning of the study and after 3 months intervention. Weight loss was set at about 10% of their weight before the intervention. Results Glutathione reductase and catalase activities showed a significant increase (P < 0.01) after weight reduction, but no significant changes were seen in the superoxide dismutase and glutathione peroxidase activities. There was a positive linear correlation between daily vitamin C intake with superoxide dismutase enzyme after intervention (P = 0.004, r = 0.507). There was a negative linear correlation between vitamin E intake and glutathione peroxidase activity before intervention (P = 0.005, r = -0.5). A negative correlation was found between daily vitamin A intake and glutathione reductase enzyme before and after intervention (r = -0.385, r = -0.397, P < 0.05) respectively. No significant correlation was observed between vitamins A, C, E amounts and catalase activity. Conclusions Ten percent weight reduction can have a significant role in increasing antioxidant enzymes activities, especially glutathione reductase, and catalase enzymes in obese women. However, it is important to take into consideration a balanced amount of certain nutrients while administering a diet with limited energy. .

Objetivo Nosso objetivo foi avaliar os efeitos da perda de peso sobre as enzimas antioxidantes de eritrócitos, e a relação destas com a ingestão das vitaminas A, E e C. Sujeitos e métodos Foram coletadas informações gerais e medidas antropométricas, registro alimentar de três dias e amostras de sangue em jejum de 30 mulheres obesas no início do estudo e depois de três meses da intervenção. A perda de peso determinada antes da intervenção foi de 10% do peso. Resultados As atividades da glutationa redutase e da catalase mostraram aumento significativo (P < 0,01) depois da perda de peso, mas não houve mudanças significativas nas atividades da superóxido dismutase e da glutationa peroxidase. Foi observada uma correlação linear positiva entre a ingestão diária de vitamina C e a enzima superóxido dismutase após a intervenção (P = 0,004, r = 0,507). Houve uma correlação linear negativa entre a ingestão de vitamina E e a atividade da glutationa peroxidase antes da intervenção (P = 0,005, r = -0,5). Foi observada uma correlação negativa entre a ingestão diária de vitamina A e a enzima glutationa redutase antes e depois da intervenção (r = -0,385, r = -0,397, P < 0,05), respectivamente. Não foram observadas correlações significativas entre as vitaminas A, C, E e os níveis e a atividade da catalase. Conclusões Uma redução de 10% no peso pode ter um papel significativo no aumento da atividade das enzimas antioxidantes, especialmente na glutationa redutase e catalase em mulheres obesas. Entretanto, é importante levar em consideração uma ingestão equilibrada de certos nutrientes ao se recomendar uma dieta com níveis de energia restritos. .

Beta-carotene, vitamin E, MDA, glutathione reductase and arylesterase activity levels in patients with active rheumatoid arthritis

Many studies have investigated the possible role of reactive oxygen species in the etiology and pathogenesis of Rheumatoid Arthritis [RA]. The aim of this study was to investigate the activities of some antioxidants in RA patients. In this case-control study, 59 RA patients and 60 healthy sex and age-matched controls were selected. Vitamin E and Beta-carotene were determined using HPLC. Erythrocytes glutathione reductase [GR] activity was measured spectrophotometrically, and malondialdehyde [MDA] was determined by colorimetric method. Arylesterase activity [AEA] was measured by Phenylacetate. The clinical data were determined by a rheumatologist, medical history and filling the questionnaire by interview. Statistical analyses were carried out using the SPSS software. In patients with RA, serum MDA level was significantly higher and plasma concentration of vitamin E, Beta-carotene and GR activity, were significantly lower than healthy control [P<0.001]. AEA activity differences between two groups were non-significant. Oxidative stress may play an important role in the inflammation and pathogenesis of RA

Antidiabetic and antioxidant activity of Terminalia belerica. Roxb.

Effect of continuous administration of dried 75% methanolic extract of fruits of Terminalia belerica (Combretaceae) suspended in water was studied in alloxan induced hyperglycemia and antioxidant defense mechanism in rats. T. belerica prevented alloxan-induced hyperglycaemia significantly from 6th day of administration and there was 54% reduction on 12th day. Oxidative stress produced by alloxan was found to be significantly lowered by the administration of T. belerica extract. This was evident from a significant decrease in thiobarbituric acid reactive substances, conjugated dienes and hydroperoxides in blood and liver respectively. Similarly, decreased glutathione level produced by alloxan was increased by the administration of the extract in blood and liver. However the increase was not significant. Superoxide dismutase which was decreased by alloxan was significantly increased from 9th day in blood and liver of drug treated group. Similarly there was significant increase in the activity of catalase in blood and liver. Decrease in glutathione peroxidase by alloxan administration was found to be increased significantly in the blood and liver from 9th day by extract treatment. Glutathione reductase also was found to be increased in blood and liver. These results suggested that T. belerica fruit extract possessed anti-diabetic and anti-oxidant activity and these activities may be interrelated.

Time-dependent effects of ethanol on blood oxidative stress parameters and cytokines.

Alcohol consumption is implicated in the genesis of a spectrum of liver abnormalities, which are associated with a number of factors. In the present study, time-dependent effects of ethanol on cytokines (TNF-alpha, IL-2, IL-4, IL-10, IFN-gamma, VEGF-A and TGF-beta1) in serum, and blood oxidative stress parameters such as reduced glutathione content, TBARS level and activities of GPx, GR, GST, catalase and SOD in 8-10 weeks-old male BALB/c mice have been investigated. Ethanol administered @ 1.6 g/kg body wt/day significantly increased the activities of liver marker enzymes AST, ALT and ALP. Serum nitrite levels and haemolysate TBARS level also increased, while total antioxidant status in serum and GSH content in whole blood hemolysate decreased from 4th week onwards of exposure. In spite of the increased serum nitrite level and GST activity in the haemolysate, albumin level in serum, GPx and GR activities in haemolysate decreased after 12 weeks of exposure. Chronic ethanol treatment did not show any effect on IL-2, but IL-4 level was reduced and other cytokines such as IL-10, TNF-alpha, IFN-gamma, TGF-beta1 and VEGF-A levels were increased significantly after 12 weeks. The study indicates a relationship between free radical generation and immune response, and suggests that ethanol-induced liver damage is associated with oxidative stress and immunological alterations in a time-dependent manner.

Antioxidant status and lipid peroxidation activity in evaluating hepatocellular damage in children

Serum levels of glutathione reductase [GR], glutathione S-transferase-alpha [GST-alpha] and malondialdehyde [MDA] were determined to evaluate their use in diagnosing hepatocellular damage in 75 children with liver disease. Except for level of GR in patients with HBV, GR, GST-alpha and MDA were raised significantly in patients compared with controls. At 100% specificity, the sensitivity of the 3 markers for detecting hepatitis B virus, hepatitis C virus and schistosomiasis infection respectively were: 16.7%, 100.0% and 17.7% for GR; 33.3%, 62.1% and 38.2% for GST-alpha; and 25.0%, 10.3% and 29.4% for MDA. GR was more sensitive in hepatitis C infection, while MDA reflected changes in liver ultrasound and GST-alpha was the best indicator for histopathological changes

Implication of glutathione S-transferase M1 and T1 polymorphisms in the development of senile cataract among Egyptians

Cataract, or opacification of the lens, is one of the most common causes of loss of useful vision among Egyptians. Currently, surgery is the only approach for the treatment of cataract and the etiology of age-related changes in the lens is not fully understood. Oxidative damage and genetic factors have a major role in the development of age related cataract. Glutathione is the most abundant non-protein intracellular thiol, with multiple roles as antioxidant agent, and the glutathione S-transferases [GSTs] are group of polymorphic enzymes that are important in protection against oxidative damage, as they dethiolate protein-S-S-glutathione in the human lens. The study aimed to determine the effect of genetic polyorphisms of Glutathione S-transferases M1 and T1 on the risk of senile cataract in Egyptian population. Using a multiplex polymerase chain reaction [PCR], the GSTM1 and GSTT1 gene polymorphisms were evaluated in 53 Egyptian patients with senile cataract and in 73 otherwise healthy control group with matched age and sex distribution. Serum GST activity, the level of Malondiableyde [a lipid peroxidation product] and the blood level of reduced glutathione [GSH] were estimated. The frequency of the GSTM1 positive individuals among the senile cataract group was significantly higher than in controls [57 vs 37%] with odds ratio 2.22 95% CI:1.08-4.573; p=0.029]. The risk among the GSTM1 positive individuals of developing senile caaract was even higher in female subjects: 68% of females were GSTM1 positive in the cataract group while only 38% of females had GSTM1 positive genotype in controls [OR=3.4; 95% CI: 1.284-9.067; p=0.012]. combination of "GSTM1 positive and GSTT1 positive" genotypes [OR = 2.16; 95% CI: 0998-4.68; P=0.049]. However the combination of "GSTM1 null, GSTT1 positive" was found to be protective from the development of senile cataract [OR=0.47; 95% CI: 0.22-0.99; p=0.045]. The study also showed significantly deceased serum level of GST and reduced glutathione [GSH] and increased level of malondialdehyde [MDA] in senile cataract patients relative to controls [p>0.001]. The present study suggests that the GSTM1 positive genotype and the combined "GSTM1 positive/GSTT1 positive" genotype may be associated with increased risk of development of senile cataract. However the "GSTM1 null/GSTT1 positive" genotype was found to be protective from the development of cataract in the Egyptian population. The correlation between polymorphic GSTs with the other cataractogenic genetic and environmental factors is highly complicated so, the study also, suggests that when evaluating the role of a particular GST gene in any disease susceptibility, the whole pattern of different biotransformation enzymes should be taken into account as much as possible. The importance to further evaluate this matter is related to the possibility of developing diagnostic tool for predicting, by non-invasive genotype analysis, the inter-individual susceptibility to the disease

Role of tomato against lead induced hepatic and kideny toxicty in rats

Lead is toxic even in low dose, causes both chronic and acute intoxication. Therefore this study aimed to investigate the effect of plants, tomato [Lycopersium esculentum] against lead toxicity in male rats. Five groups of animals was used in this study, the first group received a basal diet and served as negative control, the second group received basal diet supplemented with lead acetate [0.05mg/kg] as positive control. The other three groups received basal diet supplemented with lead acetate [0.05mg/kg] and 1%, 3% and 5% tomatoes for 30 days. The results revealed that positive control gave a significant increase in alanine aminotransferase [ALT], aspartate minotransferase [AST], glutathione-S-transferase [GST], alkaline phosphatase [ALP] activities, creatinine and urea; significantly depleted glutathione content [GSH], total protein [TP] and albumin. These results indicate the toxicity of lead on liver and kidney. However tomatoe supplemented to lead treated group significantly alleviated GSH, TP and albumin depletion and the elevation of ALT, AST, GST, ALP, creatinine and urea. These results indicate the protective action of tomato as a potential protective agent against lead toxicity. This may be due to multiple defense powerful antioxidants, fiber and glutathione which present in high levels in tested plant

plasma level of selenium and tumor necrosis factor-alpha and the activities of glutathione peroxidase lsoenzymes in colorectal cancer patients

Colorectal cancer represents a significant cause of morbidity and mortality worldwide. It is known that reactive oxygen species [ROS] are formed in excess in chronic diseases of the colon but the precise mechanisms of oxidative stress being induced in cancer cell and the role of ROS in colorectal cancer progression are still not exactly understood. The present study aimed to investigate the oxidative status of plasma as lipid peroxidation end products and the level of glutathione [GSH] in colorectal patients. The level of Selenium was also assessed by atomic absorption in association with the activities of GSH peroxidase isoenzymes [total, Se-dependent and non-Se-dependent]. Also the level of tumor necrosis factor-alpha [TNF-alpha] in plasma was assessed. The study was carried out on 30 colorectal cancer patients at different stages and grades and 10 healthy control subjects of matched age and sex. The results demonstrate that, colorectal cancer patients suffer from oxidative stress which is dependent on the grade and stage of the disease as indicated by elevated levels of lipid peroxidation end products, TNF-alpha and oxidized glutathione and by decreased levels of total and reduced GSH. Also, Se was significantly decreased in patients compared to control with the lowest level observed in grade III patients. This decrease in Se was associated with inhibited activities of total and Se-dependent GSH peroxidase while no change was observed in the activity of non-Se-dependent isoenzyme. Colorectal carcinogenesis is associated with serious oxidative stress and depletion of Selenium

[ evaluation of total antioxidant capacity and related markers in patients with chronic peritoneal dialysis]

Oxidative stress due to overproduction of reactive oxygen species and impairment in antioxidant defense mechanisms have been suggested as possible factors contributing to the pathogenesis of atherosclerosis in patients with end- stage renal disease. The aim of this study was to evaluate antioxidant markers of oxidative stress including glutathione and glutathione related enzymes [i.e. glutathione peroxidase [GPx] and glutathione reductase [GR]] as well as total antioxidant capacity in peritoneal dialysis [PD] patients. Twelve PD patients and 17 healthy controls [age range: 25-60 and 22-53 years respectively] were selected. Erythrocyte glutathione levels and plasma activities of GPx, GR and total antioxidant capacity were determined spectrophtometrically. Glutathione levels and GPx activity were significantly lower in the patients group than in controls [1.17 +/- 0.28 vs. 1.42 +/- 0.25 micro mol/ml and 57.1 +/- 21.8 vs. 142.5 +/- 31.7 U/L; p<0.05, respectively]. Higher levels of GR activity and total antioxidant capacity were noted in patient group [57.5 +/- 16.4 U/L and 0.60 +/- 0.09 micro mol/ml; respectively] in comparison to control group [32 +/- 9.4 U/L and 0.47 +/- 0.11 micro mol/ml; p<0.05, respectively]. Decreased glutathione levels and alteration in the activities of its related enzymes imply increased oxidative stress and disturbances of antioxidant defense systems in peritoneal dialysis patients. This condition may contribute to the development of accelerated cardiovascular disease and its morbidity and mortality in these patients

Radical scavenging activity of Trianthema triquetra in male albino rats intoxicated with CCl4.

Radical scavenging activity of ethanolic extract of Trianthema triquetra root was investigated against CCl4 in rats. The rats were treated with T. triquetra (100 mg, 200 mg/kg b.w.) for a period of 7 days. Antihepatotoxic effect was studied by assaying the activities of thiobarbituric acid (TBARS), reduced glutathione (GSH), glutathione peroxidase (GPx),catalase (CAT), super oxide dismutase (SOD) and vitamin C (Vit. C). Lipid peroxidation is evidenced by an increase in the value of TBARS and also a distinct diminution in the level of GSH, Vit. C at 200 mg/kg b.w. The activity of antioxidant enzymes, such as GPx, CAT SOD and Vit. E is significantly recovered towards an almost normal level in animals coadministrated with T. triquetra. The maximum protection against CCl4 induced hepatic injury was afforded by the dose of 200 mg/kg b.w. of Trianthema triquetra.

Effect of alpha-lipoic acid on oxidative stress status in rat kidney subjected to ischemia/reperfusion injury

Renal ischemia/reperfusion [I/R] injury is a major cause of acute renal failure in both native kidneys and renal allografts. There is increasing evidence to suggest that reactive oxygen species [ROS] play a role in the pathogenesis of I/R injury in the kidney. This study was designed to investigate the effect of alpha-lipoic acid [LA] on the alterations of oxidative stress status in rat kidney subjected to I/R injury. Wistar albino rats were allocated into Three groups; [1] sham operated control; [2] I/R group in which ischemia was induced by a right renal pedicle occlusion for 30 min followed by 10 min of reperfusion with contralateral nephrectomy; [3] LA + I/R group in which animals were pretreated with LA [100 mg/kg i.p.] for 7 days before I/R insult. At the end of the reperfusion period, animals were sacrificed. Kidneys were isolated for histological examination or determination of the renal malondialdehyde [MDA], glutathione [GSH], glutathione peroxidase [GPx] and glutathione reductase [GR] levels/activities as oxidative stress markers. Kidney myeloperoxidase [MPO] activity and nitrite/nitrate [NO[x] content were assessed as indices of neutrophil infiltration and nitric oxide metabolism respectively. In addition renal lactate content, serum urea and creatinine levels were also measured. I/R injury caused marked increases in renal MDA level, lactate content and MPO activity, associated with significant decreases in GSH level, GPx and GR activities as well as NO[x] content. This biochemical derangement was accompanied by severe histological lesions. Pretreatment with LA significantly reduced the enhanced oxidative stress, neutrophil infiltration and increased lactate content in the ischemic rat kidney. It also improved the histological alterations induced by renal I/R injury. So, It could be concluded that LA pretreatment effectively improved the antioxidant/oxidant imbalance associated with renal I/R injury in rats

Impact of oral vitamin E supplementation on oxidative stress & lipid peroxidation in patients with polymorphous light eruption.

BACKGROUND & OBJECTIVES: Polymorphous light eruption (PMLE) is a photo-induced disease which clinically manifests in the form of pruritic eruptions on sun/light exposed parts. Little is known about lipid peroxidation and free radical scavengers in patients during PMLE. The present study was therefore undertaken to evaluate oxidative stress and levels of antioxidant enzymes in patients of PMLE. METHODS: The PMLE was diagnosed clinically by a consultant dermatologist and validated independently by another and through histopathologic findings. Blood samples were collected on day 1 and patients were given oral vitamin E supplementation (400 mg OD) along with topical sunscreen and advice for photo-protection. Samples were collected again after one week. The blood samples were evaluated for lipid peroxidation, oxygen free radical (OFR) scavenging enzymes, glutathione (GSH) and related enzymes such as glutathione reductase (GR), glutathione peroxidase (GPx), gamma glutamyl transpeptidase (GGT) and glutathione- S-transferase (GST) in erythrocytes and compared with healthy controls. RESULTS: The serum malondialdehyde (MDA) level was higher and GSH level was lower in PMLE cases as compared to controls. There was a significant decrease in superoxide dismutase (SOD) activity while activities of catalase (CAT) and glutathione related enzymes were increased in PMLE cases. Administration of oral vitamin E for one week, along with photoprotection resulted in a significant decrease in MDA levels and activities of all others enzymes except SOD. The GSH was replenished and returned to normal. INTERPRETATION & CONCLUSION: Oxidative stress and differential modulation of antioxidant enzymes in PMLE might play a pathogenic role in humans, which supports the incorporation of antioxidant drugs in the treatment protocol of the disease.

Effect of 50 Hz magnetic field with different intensities on some blood biochemical and hematological parameters

The present study has been undertaken to evaluate the biological changes that could be encountered in response to extremely low frequency [50 Hz] magnetic field with different intensities. The effect of magnetic field on oxidative stress [reduced glutathione [GSH] and total lipid peroxide [LPO]], hematological indices, total and differential leukocytes count, cardiac functions [creatinine phosphokinase [CPK] and lactate dehydrogenase [LDH]], level of calcium ions concentrations [Ca[++]] and total protein content have been investigated in this work. Sprague-Dawley rats were exposed to the magnetic field for two hours. The blood samples were collected before and after exposure. The level of serum total lipid peroxide showed a significant increase while the level of blood reduced glutathione content and hematological indices showed a significant decrease at the level of p<0.05 after exposure to magnetic field. The total leukocyte differentiation showed a small reduction but with no significance. The reduction in neutrophils obtained after exposure was significant. The decrease in the counts of lymphocytes, monocytes, eosinophils and basophils was not regular as the magnetic field changes. The work also records that creatinine phosphokinase [CPK] and lactate dehydrogenase [LDH] activities, the Level of serum calcium ion concentration [Ca[+2]] and serum total protein showed significant increases as a result of exposure to magnetic field

Evaluation of zinc against salinomycin toxicity in broilers.

Salinomycin was studied for its toxicity and zinc (80 mg/kg) was assessed for prophylactic and therapeutic management in broiler chicks. Male broiler chicks were randomly divided into 7 groups consisting of 6 chicks in each. Group 1, 2 and 3 were maintained as control, therapeutic dose control (60 mg/kg feed) and toxic dose control (120 mg/kg feed), respectively. Group 4 was fed on feed containing salinomycin therapeutic dose and zinc. Group 5 received feed containing toxic dose of salinomycin. Group 6 and 7 were fed on feed containing toxic dose of salinomycin for the first 4 weeks for induction of ionophore toxicity and for the subsequent 2 weeks, group 6 received zinc and group 7 was fed on feed containing toxic dose of salinomycin along with zinc. Weekly body weights revealed a significant (P<0.01) decrease in toxic controls as compared to group 1, 2, 4 and 5. The activity of glutathione peroxidase, glutathione reductase and catalase, and the values of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total proteins, total cholesterol, triglycerides, low density lipoproteins (LDL), urea, creatinine and blood urea nitrogen (BUN) were significantly (P<0.01) elevated in toxic controls, whereas glutathione (GSH) and high density lipoproteins (HDL) were significantly (P<0.01) lowered as compared to group 1, 2, 4 and 5. Following toxicity, zinc supplementation in group 6 and 7, all serobiochemical parameters were revived to normal. Thus, it is enunciated that salinomycin toxicity is due to oxidative damage and use of zinc in feed tends to cure and avoid any accidental toxicity.

Interactions among indicators of B1, B2, B6 and vitamin C status in university students

In 209 young university students (109 males and 80 females) with body mass index within the normal range, the activation coefficient of the erythrocyte transketolase (ETKAC) glutathione reductase (EGRAC) and aspartate amino transferase (EASTAC) as well as the circulating levels of vitamin C were determined. Using the usual cutoff points for ETKAC and serum vitamin C and higher than usual cutoff points for EASTAC and EGRAC 99, 95, 92, and 87 per cent of the study subjects exhibited activation coefficients which were compatible with an acceptable status for vitamin B2, B6, C and B1 respectively. A correlation analysis showed a high correlation (r = 0.81) between erythrocyte indicators of B1 and B2 status a lower correlation between indicators of the status of these vitamins and B6 and no correlation between the indicators of B1, B2, and B6 status and serum vitamin C. This study indicated that in this largely nutritionally adequate population, the activation coefficient of the erythrocyte enzymes used here as markers of the nutritional status of B1, B2, and B6 were related between themselves and varied in the same direction. These changes, however, were not associated with circulating levels of vitamin C.

Skin diseases and enzymatic antioxidant activity among workers exposed to pesticides

In this study, 150 workers exposed to pesticides and 50 healthy control subjects were given clinical and dermatological examinations, patch tests, tests of liver and renal function, complete blood count, blood sugar and urinalysis. Activity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase and glutathione reductase was also evaluated. Dermatological findings were positive in 78%, 76% and 54% of workers exposed to organophosphates, pyrethroids and carbamate pesticides respectively. The patch test was positive in 70% of workers exposed to pyrethroids and 64% exposed to carbamate pesticides. Liver enzyme levels were generally increased in workers while antioxidant enzyme activity was significantly decreased in all workers compared with the controls

cardioprotective effect of urea against acute doxorubicin induced cardiotoxicity in rats

Recently, urea is considered one of the endogenous antioxidant substances that have a potential antioxidant cardioprotective effect against ex vivo post-ischemic reperfusion and oxidative stress induced cardiac injury in rats. A single injection of doxorubicin, 15 mg Kg[-1], intrapeirtoneal [i.p] in rats induced cardiac toxicity manifested biochemically by the significant increase [P<0.01] of serum creatine phosphokinase [CPK] and lactate dehydrogenase [LDH] after 48 hours and significant decrease [P<0.01] of heart homogenate superoxide dismutase [SOD] and reduced glutathione [GSH] compared to normal control rats. Administration of urea [500 mg Kg[-1] day[-1] i.p] for 2 successive days improved doxorubicin induced cardiotoxicity in rats represented by the significant decrease [P<0.01] of serum CPK and LDH in comparison to rats injected with doxorubicin only. The cardioprotective effect of urea could be explained by the observed significant reduction [P<0.01] of heart homogenate lipid peroxidation, expressed as thiobarbituric acid reacting substances [TBARS], and significant increase [P<0.01] of SOD and GSH compared to doxorubicin-induced cardiotoxicity rats. In conclusion, urea could have antioxidant cardioprotective effect in vivo against acute doxorubicin-induced cardiotoxicity. This newly observed effect of urea might have broad applications towards many oxidative stress-related pathophysiological situations

Lipid peroxidation and antioxidant enzyme activities in children with type I diabetes mellitus

To asses free radical activation products and antioxidant status in children with 1DDM, serum levels of lipid peroxides [LP], selenium and red blood cell glutathione peroxidase [GSH-Px] were measured in 26 diabetic children : they were 17 with micro albuminuria and 9 without micro albuminuria. Ten apparently healthy children of matched age and sex represented the control group. Diabetic children had significantly higher levels of LP [3.49 +/- 0.64] versus [2.65 +/- 33] and lower levels of serum selenium [118.27 +/- 28.7] versus [174.90 +/- 31.06] and red blood cell GSH-Px [19.70 +/- 5.48] versus [37.37 +/- 6.04] as compared with the control group. Diabetic children with micro-albuminuria had significantly higher levels of LP [3.82 +/- 0.45] versus [2.85 +/- 0.43] and non significant lower levels of serum selenium [113.29 +/- 30.21] versus [127.67 +/- 24.45] and red blood cell GSH - Px [18.39 +/- 5.88] versus [22.17 +/- 3.76] when compared with the levels of diabetic children without micro albuminuria. Positive significant correlation was found between levels of LP and levels of fasting blood sugar while negative significant correlation was found with the levels of red blood cell GSH. Px. We concluded that the imbalance between generation of free radicals and antioxidant status is act uncommon in diabetic children and this imbalance may have a role in early microvascular disorders occurring in the disease

Thiamin and riboflavin status of medical inpatients.

Thiamin status was assessed by erythrocyte transketolase activity (ETKA) and thiamin pyrophosphate effect (TPPE) and riboflavin status by erythrocyte glutathione reductase activity (EGRA) and activity coefficient (AC) in 165 medical inpatients in Ramathibodi Hospital. Based on TPPE > 15 per cent, 9 per cent of the medical inpatients had thiamin depletion. Most of them were patients with renal, cardiovascular, hematological and infectious diseases. Based on AC > or = 1.2, 17 per cent of these inpatients had riboflavin depletion. Most of them were patients with pulmonary, cardiovascular and hematological diseases. Only one patient with pulmonary disease had both thiamin and riboflavin depletion. The proportion of thiamin depletion (2/37) in subjects with thiamin supplementation (mean 32.4, median 6, mode 2 md/d) tended to be less than those without (9/98). But, subjects with riboflavin supplementation (mean 3.3, median 4, mode 1 md/d) had the proportion of riboflavin depletion (0/31) significantly (Z-test, p < 0.005) lower than without supplementation (23/104). The data suggested that although the usual dose of vitamin supplementation in medical inpatients is beneficial thiamin depletion can still be present in catabolic patients.