Indices Of Antioxidant Status Research Articles

Antioxidant status and oxidative stress in organophosphate pesticide poisoning

Objective: To study the antioxidant status and the extent of oxidative stress in patients with organophosphate poisoning before and after specific treatment. Material and methods : The study was conducted in 50 OP poisoned patients. Superoxide dimutase (SOD), catalase (CAT) and malonalaldehyde levels were estimated as an index of antioxidant status and oxidative stress respectively and comparisons were made(a) healthy control subjects& sprayer poisoned patients(b) between pretreated &post treated patients, after specific treatment . Results : There were significantly increase in superoxide dismutase(SOD)& catalase in the exposed sprayer groups, comparative to normal healthy control subjects .The increase in lipid peroxidation as reflected by elevated levels of malonalaldehyde (MDA) in the pesticide exposed group, indicates oxidative stress. There were progressive improvement observed in the both SOD&CAT levels after specific therapy in post treated patients, comparative to pretreated patients. Significant compensatory level of malonalaldehyde(MDA)were observed in post treated patients in comparison to pretreated patients. The level of improvement in post treated patients also depends on the severity grade of poisoning. . Conclusion: The increased level of MDA in OPP patients who failed to survive was probably reflective of accelerated lipid peroxidation, cell damage &death(oxidative stress).significant improvement was noticed in the SOD&CAT levels with specific treatment (atropine plus pralidoxime (PAM) therapy).

Absence of Blood Oxidative Stress in Trained Men after Strenuous Exercise

Exercise has been noted in some, but not all, studies to elicit an oxidative stress. The discrepancy in findings may be related to differences in exercise intensity across protocols, as well as to differences in training status of participants. We compared blood oxidative stress biomarkers in exercise-trained men after three different bouts of exercise of varying intensity and duration, as well as a nonexercise condition. On different days, men (n = 12, 21-35 yr) performed aerobic cycle exercise (60 min at 70% HR reserve) and cycle sprints (five 60-s sprints at 100% maximum wattage obtained during graded exercise testing and ten 15-s sprints at 200% maximum wattage obtained during graded exercise testing). Blood was collected before and 0, 30, and 60 min after exercise and analyzed for malondialdehyde, hydrogen peroxide (H(2)O(2)), advanced oxidation protein products, and nitrate/nitrite (NO(x)). As indicators of antioxidant status, Trolox equivalent antioxidant capacity, superoxide dismutase, catalase, and glutathione peroxidase were measured. No differences were noted in malondialdehyde, H(2)O(2), advanced oxidation protein product, or NO(x) between conditions or across time (P > 0.05). Antioxidant capacity was generally highest at 30 and 60 min after exercise and lowest at 0 min after exercise. In trained men, and considering the limitations of the current design (e.g., inclusion of selected oxidative stress and antioxidant biomarkers measured in blood only), strenuous bouts of exercise do not result in a significant increase in blood oxidative stress during the 1-h postexercise period. These findings may be related to attenuation in reactive oxygen species production as an adaptation to chronic exercise training and/or a protective effect of the antioxidant system in response to acute strenuous exercise.

Assessment of plasma and salivary antioxidant status in patients with recurrent aphthous stomatitis

Objective: The purpose of this study was to evaluate the antioxidant levels in plasma and saliva of patients with recurrent aphthous stomatitis (RAS) and healthy controls. Material and methods: Forty patients with RAS and 40 health controls were included into the study. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx) activities and uric acid (UA) levels were measured in plasma and saliva. Chi-square and Student’s t-test was used to estimate the significance between parameters. P value less than 0.05 was considered statistically significant.Results: Plasma analysis showed significantly decreased SOD and CAT activities, and UA level in RAS patients compared to control group. Plasma GSHPx activity was significantly higher in RAS patients. In saliva, SOD and CAT activities, and UA levels were significantly higher in RAS patients, while GSHPx activity was lower compared to control. Conclusion: Plasma and saliva antioxidant system is affected in RAS patients and both may be considered as an appropriate indicator of antioxidant status of body.

Antioxidant Status and Oxidative Stress in Primary Open Angle Glaucoma and Pseudoexfoliative Glaucoma

Purpose: The aim of this study was to establish the antioxidant status and oxidative stress in patients with primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEG).Methods: Serum levels of total antioxidant capacity (TAC) and superoxide dismutase (SOD) as indicators of antioxidant status; and total oxidant status (TOS), nitric oxide (NO), protein carbonyl (PC), and malondialdehyde (MDA) as indicators of oxidative stress were measured from the blood samples of patients with POAG (n = 23), PEG (n = 24) and healthy control subjects (n = 19) by spectrophotometry.Results: Mean TAC level was 0.6 ± 0.1 mmol/L in the POAG group; 0.5 ± 0.1 mmol/L in the PEG group and 1.2 ± 0.3 mmol/L in the control group (p = 0.001). Mean SOD level was 13 ± 0.5 mg/L in the POAG group, 11.6 ± 0.2 mg/L in the PEG group and 9.4 ± 0.6 mg/L in the control group (p = 0.001). Mean TOS level was 19.6 ± 2.6 μmol/L in the POAG group, 21.2 ± 4.2 μmol/L in the PEG group and 15.1 ± 7 μmol/L in the control group (p = 0.001). Mean NO level was 74.3 ± 14.4 µmol/L in the POAG group, 66.1 ± 8.1 µmol/L in the PEG group and 62.3 ± 13.5 µmol/L in the control group (p = 0.005). Mean PC level was 641.5 ± 102.5 nmol/mg in the POAG group, 988.3 ± 214.7 nmol/mg in the PEG group and 654.4 ± 150.7 nmol/mg in the control group (p = 0.001). Mean MDA level was 1.9 ± 0.2 µmol/L in the POAG group, 1.7 ± 0.4 µmol/L in the PEG group and 1.1 ± 0.2 µmol/L in the control group (p = 0.001).Conclusion: The findings of the present study are potentially of significance and add to the growing body of evidence for oxidative stress in POAG and PEG. Decreased antioxidant defense and increased oxidative stress system may play an important role in the pathogenesis of POAG and PEG.

Effects of postharvest processes on quality of Australian sardines (Sardinops sagax) and redbait (Emmelichthys nitidus nitidus) for feeding aquacultured southern bluefin tuna (Thunnus maccoyii)

Feed nutritional quality impacts on the performance of aquacultured species. This study was undertaken to assess the consequences of existing postharvest handling practices on nutritional quality of local baitfish (Australian sardines, Sardinops sagax and redbait, Emmelichthys nitidus nitidus) used to feed farmed southern bluefin tuna (Thunnus maccoyii). Controlled experiments were then undertaken to determine the most appropriate postharvest treatments to maintain baitfish nutritional quality, assessed through measurement of vitamins C and E, histamine, K value and TBARS. During frozen storage (−18 °C) vitamins and fish freshness decreased significantly and rancidity increased; after approximately 3 months baitfish were of questionable utility, particularly as a source of antioxidants. On-land freezing method [i.e. block or individually quick frozen (IQF)] affected vitamin E loss with IQF sardines losing vitamin E faster than block-frozen baitfish. Block-frozen baitfish, particularly sardines, should be thawed in seawater, not air or freshwater, to minimize vitamin losses. Thawing time should be no more than 2 days, and baitfish storage less than 3 months. Thiobarbituric acid reactive substances (TBARS) correlated well with remaining vitamin E, indicating its usefulness as an indicator of antioxidant status. TBARS analysis is methodologically simpler, faster and cheaper than that for vitamins, and is therefore recommended for determination of baitfish nutritional quality.

Effect of Atiko (<i>Aframomum sceptrum</i>) and African nutmeg (<i>Monodora myristica</i>) on reduced glutathione, uric acid levels and liver marker enzymes in streptozotocin-induced diabetic rats

This study investigated the effect of the methanolic extract ofAframomum sceptrum and Monodora myristica on the reducedglutathione (GSH) and uric acid levels in the plasma and liver ofstreptozotocin (STZ)-induced-diabetic rats. The possible hepaticdamage resulting from the administration of the spices was alsoexamined.(Thirty-two Wistar albino rats (males and females),weighing between 160g -200g were divided into eight groups ( n=4).Four groups were made diabetic by the administration of STZ(50mg/kg body wt.) intraperiotoneally.Results obtained indicatedecreased levels of blood reduced glutathione and uric acid (indices ofantioxidant status) in the plasma and liver of diabetic rats, but therewere significant increases in the activities of alanine and aspartatetransaminases (ALT and AST) (indices of liver dysfunction).However, oral administration of the methanolic extract of M.myristica as well as A. sceptrum significantly increased blood GSHcontent of diabetic rats. Uric acid levels were elevated in plasma andliver of diabetic rats treated with both spices as compared with thecontrol rats. Similarly, ALT and AST activities decreased significantlyin the plasma and liver of diabetic rats administered with themethanolic extracts. These results suggest that the methanolic extracts of A. sceptrum and M. myristica may contribute to the protection against oxidative damage in STZ induced-diabetic rats without any adverse effect on the liver. The potency of the spices as effective antioxidants is comparable to that of vitamin E, a well known and acceptable antioxidant. Further studies on the phytochemical andtoxicological properties are required to fully document the benefits ofthese extracts as antioxidants.Key words: Atiko(Aframomum sceptrum, African nutmeg(Mondoramyristica), Reduced glutathione, uric acid and antioxidant.

Oxidative stress responses of rats exposed to Roundup and its active ingredient glyphosate

Glyphosate is the active ingredient and polyoxyethyleneamine, the major component, is the surfactant present in the herbicide Roundup formulation. The objective of this study was to analyze potential cytotoxicity of the Roundup and its fundamental substance (glyphosate). Albino male rats were intraperitoneally treated with sub-lethal concentration of Roundup (269.9 mg/kg) or glyphosate (134.95 mg/kg) each 2 days, during 2 weeks. Hepatotoxicity was monitored by quantitative analysis of the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) activities, total protein, albumin, triglyceride and cholesterol. Creatinine and urea were used as the biochemical markers of kidney damages. The second aim of this study to investigate how glyphosate alone or included in herbicide Roundup affected hepatic reduced glutathione (GSH) and lipid peroxidation (LPO) levels of animals as an index of antioxidant status and oxidative stress, respectively, as well as the serum nitric oxide (NO) and alpha tumour necrosis factor (TNF-α) were measured. Treatment of animals with Roundup induced the leakage of hepatic intracellular enzymes, ALT, AST and ALP suggesting irreversible damage in hepatocytes starting from the first week. It was found that the effects were different on the enzymes in Roundup and glyphosate-treated groups. Significant time-dependent depletion of GSH levels and induction of oxidative stress in liver by the elevated levels of LPO, further confirmed the potential of Roundup to induce oxidative stress in hepatic tissue. However, glyphosate caused significant increases in NO levels more than Roundup after 2 weeks of treatment. Both treatments increased the level of TNF-α by the same manner. The results suggest that excessive antioxidant disruptor and oxidative stress is induced with Roundup than glyphosate.

The anti-atherosclerotic effect of olive leaf extract is related to suppressed inflammatory response in rabbits with experimental atherosclerosis

The anti-atherogenic effect of olive leaf extract is supposed to be related to its activities of anti-oxidation and anti-inflammation. To prove the effect of anti-atherosclerosis by olive leaf extract (OLE) and to elucidate the mechanism behind. Twenty-four rabbits were assigned to the control, high lipid diet (HLD) and OLE group that were fed with standard diet, HLD and HLD supplemented with OLE, respectively. Serum levels of atherosclerosis related markers, triglyceride (TG), total cholesterol (T-CHO), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and malondialdehyde (MDA) were detected at the ends of week 2, 4 and 6. Surface lesions and thickness of intimas were measured at the end of week6. The protein and/or mRNA expressions of inflammation factors, monocyte chemoattractant protein (MCP)-1, vascular cell adhesion molecule (VCAM)-1, nuclear factor-kappa B (NF-kappaB) and tumor necrosis factor alpha (TNF-alpha) were investigated by immunohistochemistry and RT-PCR. Atherosclerotic lesions were found in the HLD and OLE groups but not in the control group. In comparison with that in the HLD group, reduced size and thickness of intima (0.31 +/- 0.26 in the HLD group versus 0.10 +/- 0.03 mm in the OLE group) were found in the OLE group. The MDA level, an indicator of antioxidant status, was 35.27 +/- 15.37 in the HLD group and 20.63 +/- 11.52 nmol/ml in the OLE group. The level of CHO, TG and LDL-C were 104.46 +/- 30.34, 2.48 +/- 1.11, 82.83 +/- 28.44 mmol/l in the HLD group versus 83.03 +/- 27.23, 1.84 +/- 0.44, 59.51 +/- 23.72 mmol/l in the OLE group. Down-regulated expressions of MCP-1, VCAM-1, NF-kappaB and TNF-alpha at both protein and mRNA level (P < 0.05) were also found with the administration of OLE. This study proved the effect of OLE on inhibition of atherosclerosis, which is related to the suppressed inflammatory response.

Effects of vitamin E, age and sex on performance of Japanese quail. 1. Haematological indices and liver function

1. A trial was conducted to examine the effects of dietary vitamin E content, age and sex on haematological indices and liver enzymes of Japanese quails. A total of 800 1-d-old quail chicks were assigned at random into 4 equal groups and fed on starter and layer diets containing 0, 1, 5 or 10 times the NRC recommended supplements of vitamin E. No selenium was added to the basal deficient diets; the other diets were supplied with 0·2 mg selenium/kg diet. 2. The investigation covered the age span of 3 to 12 weeks in female and male birds. Blood samples were collected at 3-week intervals and tested for haematological indices (erythrocyte count; leucocyte count; susceptibility of erythrocytes to haemolysis; haemoglobin concentration (Hb); packed cell volume (PCV); and mean corpuscular volume (MCV)) and liver enzymes (aspartate transaminase, AST, and glutathione peroxidase, GSH-Px). 3. The significant differences between the 4 dietary treatments indicated that as the levels of selenium and/or vitamin E increased, the percentage of erythrocytes haemolysed and AST activity decreased, whereas Hb and GSH-Px concentrations increased. 4. Differences between age groups showed that older quails had higher erythrocyte susceptibility to haemolysis, higher AST levels and but lower erythrocyte count and PCV. 5. Females had lower erythrocyte haemolysis and higher Hb concentrations than males. 6. The interaction between dietary groups and age groups revealed that the differences between age groups were reduced as the level of selenium and/or vitamin E increased, leading to similar group means over the age period of study. 7. In conclusion, NRC recommended supplements of vitamin E (12 and 25 mg/kg diet) were not adequate. Doses equal to, at least, 5 times that recommended were advised to improve GSH-Px (index of antioxidant status) and Hb concentrations.

Geldanamycin (GA) sustainment of antioxidant status in skeletal muscle from rats subjected to tourniquet (TK)‐induced ischemia/reperfusion (I/R).

The present study investigated whether HSP70 induction by GA protected skeletal muscle against TK-induced I/R. Rats (n= 8–10/gp) were pretreated with GA (2.5 mcg/g bw ip) or normal saline (vehicle controls) 12 hr prior to TK application. TKs were then randomly applied to the right or left leg for 3 hr and rats were euthanized 6 hr after reperfusion. Lateral and medial gastrocnemius muscles were collected for analysis. Muscle from the contralateral leg served as controls. GA treatment induced a 2–3 fold increase in muscle HSP70 levels. TK-induced I/R of the lateral gastrocnemius muscle resulted in over a 30% decrease (p< 0.05) in indices of antioxidant status and antioxidant enzyme activity (glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT)) compared to the levels and activity in control muscle. GA-pretreatment in rats subjected to TK-induced I/R, fully maintained muscle antioxidant potential (p<0.05 from vehicle controls), but only maintained GR, SOD and CAT activity to about 85% of enzyme activities in control muscles. GPx activity was not maintained by GA-pretreatment in these animals. Myeloperoxidase activity was undetectable in any group and no significant differences were observed in muscle nitric oxide levels among groups. Similar results were obtained from the medial gastrocnemius muscle. These data suggest that geldanamycin pre-treatment provided partial pharmacological protection of muscle antioxidant defense systems against tourniquet-induced ischemia reperfusion after 3 hr TK use and 6 hr of reperfusion.

Zinc and antioxidant vitamin deficiency in patients with severe sickle cell anemia

BACKGROUNDPatients with severe sickle cell anemia (SCA) have a higher potential for oxidative damage due to chronic redox imbalance in red blood cells that often leads to hemolysis, endothelial injury and recurrent vaso-occlusive episodes. This study evaluated the plasma levels of vitamins A, C and E as indicators of antioxidant status. In addition, serum levels of zinc and copper were also estimated.PATIENTS AND METHODSTwenty-five adult patients with severe sickle cell anemia (12 males and 13 females aged 29.72±12.94 years) and 25 matched controls were studied. Plasma levels of vitamins A, C and E were measured by HPLC technique. Serum zinc and copper levels were measured by atomic absorption spectrometry.RESULTSThere was a significant decrease in plasma levels of vitamins A, C and E and in serum levels of zinc in patients with SCA as compared with controls (P<0.0001). Serum copper levels were signficantly elevated compared with controls (P<0.0001).CONCLUSIONThese findings emphasize the significant deficiencies of the antioxidant vitamins A, C and E and the trace element zinc along with the significant elevation of serum copper in patients with severe sickle cell disease. Further studies are needed to find out whether supplementation of antioxidant vitamins and zinc may ameliorate some sickle cell disease complications.

HIGH-DOSE VITAMIN C INFUSION REDUCES FLUID REQUIREMENTS IN THE RESUSCITATION OF BURN-INJURED SHEEP

Fluid resuscitation to maintain adequate tissue perfusion while reducing edema in the severely burned patient remains a challenge. Recent studies suggest that reactive oxygen species generated by thermal injury are involved in edema formation associated with burn. The present study tested the hypothesis that adding a free radical scavenger to the resuscitation fluid would reduce total fluid requirements in the treatment of severe thermal injury. Anesthetized chronically instrumented sheep received a 40% total body surface area full-thickness flame burn. At 1 h after injury, animals were resuscitated with lactated Ringer's (LR, n = 14) as control, LR containing high doses of vitamin C (VC, n = 6), 1000 mOsM hypertonic saline (HS, n = 7), or 1000 HS containing VC (HS/VC, n = 7) in coded bags so that investigators were blinded to the treatment. Fluids were infused at an initial Parkland rate of 10 mL/kg/h, adjusted hourly to restore and maintain urine output at 1 to 2 mL/kg/h. Sheep in the VC or HS/VC group received 250 mg/kg VC in the first 500 mL of LR or HS, and then 15 mg/kg/h thereafter. Hemodynamic variables and indices of antioxidant status were measured. At 48 h postburn, sheep were euthanized, and heart, liver, lung, skeletal muscle, and ileum were evaluated for antioxidant status. All fluid resuscitation regimens were equally effective in restoring cardiac output to near baseline levels; no treatment effects were apparent on arterial pressure or heart rate. VC infusion significantly reduced fluid requirements and, therefore, net fluid balance (fluid in, urine out) by about 30% at 6 h and about 50% at 48 h in comparison with the LR group (P < 0.05). HS and HS/VC reduced fluid requirements by 30% and 65%, respectively, at 6 h, but the volume-sparing effect of HS was not observed after 36 h and that of HS/VC was lost after 12 h. Plasma total antioxidant potential increased about 25-fold (P < 0.05) at 2 and 3 h in response to VC infusion compared with the LR and HS groups, and remained about 5- to 10-fold higher throughout the rest of the study. VC infusion also prevented the 4-fold increase in plasma thiobarbituric acid reactive substances seen in the LR group early after burn (P < 0.05). Tissue antioxidant status was similar between groups. In this sheep burn model, continuous high-dose VC infusion reduced net fluid balance, reduced indices of plasma lipid peroxidation, and maintained overall antioxidant status in comparison with standard-of-care LR treatment.

Assessment Of The Relationship Between Oxidative Stress, Antioxidant Status, Inflammation And Cardiorespiratory Fitness In The Obese

Purpose Increasing evidence from epidemiological studies suggest that measures of chronic inflammation are associated with an increased risk of cardiovascular disorders, including ischemic heart disease, stroke and other thromboembolism. Oxidative stress may play a role in the development of the inflamed state, and previous studies have shown a possible protective effect of high levels of cardiorespiratory fitness. The purpose of this study was to examine the relationship between oxidative stress, markers of inflammation and cardiorespiratory fitness (VO2max) in the obese. Methods A total of four hundred eighty three obese individuals (mean age 43.34 ± 8.32) were assessed for VO2max, oxidative stress as measured photometrically in the blood with a Free Radical Analysis System (FRAS), C-Reactive protein (CRP), which was used as a measure of inflammation and Body Defense Score (BDS), which was used as an indicator of antioxidant status and measured non-invasively using Raman Spectroscopy (Biophotonic Scanner, Pharmanex. Descriptive data is shown below in table 1Table 1Reults Body weight was negatively correlated with FRAS (r=−0.199, p=0.009) and BDS (r=−0.171, p=0.002), but not CRP. Additionally CRP was positively correlated with FRAS (r=0.551, p<0.001) and negatively with VO2max (r=−0.260, p<0.001). No other associations among these variables were observed. Conclusions These data support the concept that obesity stimulates an inflammatory response. Part of the inflammatory response may be due to oxidative stress. The strong negative correlation between body weight and BDS suggests that a diet rich in fruits and vegetables or antioxidant supplementation may be particularly important in obese individuals. Increased fitness may also protect against inflammation in these individuals. Work Supported by: Pharmanex

Oxidative stress and antioxidant status in patients with alcoholic liver disease

Backround Alcoholic liver diseases (ALD) are very common in lower socio-economical strata due to heavy drinking habits and multiple nutritional deficiencies. Ethanol causes liver damage by many mechanisms. The generation of lipid peroxidation by free radicals has been proposed as a mechanism for ethanol induced hepatotoxicity. These free radicals are destroyed by anti-oxidants. Many anti-oxidants are present in the diet, e.g., vitamin E, vitamin C etc. However, poor nutrition or malabsorption leads to deficiency of these vitamins. This may impair the anti-oxidative defense leading to ethanol induced oxidative stress and then to liver damage. Methods Oxidative stress and antioxidant defense were assessed in patients with alcoholic liver disease. Serum malondialdehyde (MDA) concentrations were measured as an index of lipid peroxidation, i.e., oxidative stress; and serum vitamins E and C concentrations were measured as an index of antioxidant status. Results Serum MDA concentrations were increased with the increase in severity of the disease. Concentrations of serum vitamins E and C were decreased in patients with alcoholic liver disease as compared to controls. Conclusions Our observations may be due to increased demands of the same or increased utilization.

Plasma Antioxidants Changes after Acute Cadmium Intoxication in Rats

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Resonance Raman detection of carotenoid antioxidants in living human tissue.

Increasing evidence points to the beneficial effects of carotenoid antioxidants in the human body. Several studies, for example, support the protective role of lutein and zeaxanthin in the prevention of age-related eye diseases. If present in high concentrations in the macular region of the retina, lutein and zeaxanthin provide pigmentation in this most light sensitive retinal spot, and as a result of light filtering and/or antioxidant action, delay the onset of macular degeneration with increasing age. Other carotenoids, such as lycopene and beta-carotene, play an important role as well in the protection of skin from UV and short-wavelength visible radiation. Lutein and lycopene may also have protective function for cardiovascular health, and lycopene may play a role in the prevention of prostate cancer. Motivated by the growing importance of carotenoids in health and disease, and recognizing the lack of any accepted noninvasive technology for the detection of carotenoids in living human tissue, we explore resonance Raman spectroscopy as a novel approach for noninvasive, laser optical carotenoid detection. We review the main results achieved recently with the Raman detection approach. Initially we applied the method to the detection of macular carotenoid pigments, and more recently to the detection of carotenoids in human skin and mucosal tissues. Using skin carotenoid Raman instruments, we measure the carotenoid response from the stratum corneum layer of the palm of the hand for a population of 1375 subjects and develop a portable skin Raman scanner for field studies. These experiments reveal that carotenoids are a good indicator of antioxidant status. They show that people with high oxidative stress, like smokers, and subjects with high sunlight exposure, in general, have reduced skin carotenoid levels, independent of their dietary carotenoid consumption. We find the Raman technique to be precise, specific, sensitive, and well suitable for clinical as well as field studies. The noninvasive laser technique may become a useful method for the correlation between tissue carotenoid levels and risk for malignancies or other degenerative diseases associated with oxidative stress.

Antioxidant status and muscle cell leakage during endurance exercise.

Antioxidant status of 35 endurance horses was studied during an 80 (OD80) or 160 km (OD160) race. Packed cell volume (PCV), total plasma protein (TPP), plasma ascorbic acid (VIT C), plasma alpha-tocopherol (VIT E) and erythrocyte glutathione (GSH) concentrations, erythrocyte glutathione peroxidase (GPX), plasma aspartate aminotransferase (AST) and plasma creatine kinase (CK) activities were measured at 0, 40, 80 km and 60 min of recovery (REC) at OD80, and 0, 64, 106, 142, 160 km and REC at OD160. In both races, no changes were found in plasma VIT E concentration, but VIT C and GSH concentrations decreased (P<0.05), and mean GPX, AST and CK activities increased from 0 km (P<0.05). Indices of muscle cell leakage (plasma AST and CK) were correlated (r = 0.36 to 0.67; P<0.03) with indices of antioxidant status (VIT C, GSH and GPX). Associations between increased muscle leakage and decreased antioxidant status may, in part, reflect oxidative stress and suggest the testing of antioxidant supplements in endurance horses to improve performance and welfare.

A longitudinal study of biochemical variables in women at risk of preeclampsia

Objective: The purpose of this study was to characterize gestational profiles of biochemical markers that are associated with preeclampsia in the blood of pregnant women in whom preeclampsia developed later and to compare these markers with the markers of women who were delivered of small-for-gestational-age infants without preeclampsia and with women who were at low risk for the development of preeclampsia. Study Design: This was a prospective case control study. The subjects were women at risk of preeclampsia who were enrolled in the placebo arm of a clinical trial. Indices of antioxidant status, oxidative stress, placental and endothelial function, and serum lipid concentrations were evaluated from 20 weeks of gestation until delivery in 21 women in whom preeclampsia developed later, in 17 women without preeclampsia who were delivered of small-for-gestational-age infants, and in 27 women who were at low risk for the development of preeclampsia. Results: Ascorbic acid was reduced early in preeclampsia and small-for-gestational-age pregnancies. Leptin, placenta growth factor, the plasminogen activator inhibitor (PAI-1)/PAI-2 ratio, and uric acid were predictive of the development of preeclampsia. Conclusion: Gestational profiles of several markers were abnormal in the group with preeclampsia, and some of the markers that may prove useful in the selective prediction of preeclampsia were identified. (Am J Obstet Gynecol 2002;187:127-36.)

Indices of antioxidant status in rats subjected to wood smoke inhalation and/or thermal injury

The present study investigated antioxidant status in lavage fluid, lung, liver, heart and kidney in a rat model to simulate an inhalation injury as might be encountered by firefighters and burn victims. Anesthetized rats received either a 20% total body surface area (TBSA) full thickness scald or a sham burn. After a 5 h recovery period, half of the animals in the burn or sham burn groups were exposed to cooled western bark (fir and pine) smoke for 16.25 min. The remaining rats in each group breathed room air. At 1, 12, 24, 48 and 96 h after exposure to the smoke, five rats from each of the four groups were euthanatized and lungs were lavaged by infusing three 5 ml aliquots of normal saline for evaluation of airway cellular content and lung wet to dry weight ratios to estimate lung water content. A second series of five rats/group per time point were euthanatized at the above times and lung, liver, kidney and heart were removed for evaluation of tissue antioxidant enzyme activities and for thiobarbituric acid reactive substances (TBARS) concentrations, as well as for lung histology. Smoke exposure resulted in average plasma carboxyhemoglobin (COHb) of 19±2% in the two smoke exposed groups and produced areas of erosion of the tracheal surface, resulting in loss of epithelium and exposed basement membrane. Lung water content was not significantly different among the four groups during the 96-h experimental period. Lung TBARS levels were 2–3-fold higher at 12 h in smoke exposed rats compared with controls. These levels peaked at 24 h and remained significantly elevated at 48 h compared to controls. TBARS were also elevated in liver, but not in heart or kidney in response to burn or combined injury. Minor effects on lung antioxidant enzyme activities were observed after smoke inhalation. These data suggest that smoke inhalation, independent of burn injury, induces an oxidant stress that persists for at least the first 48 h after smoke exposure.

Effects of cigarette smoking with different tar content on erythrocyte oxidant/antioxidant status

In this study, the effects of cigarettes with differing tar content on erythrocyte oxidant/antioxidant status was investigated. Malondialdehyde (MDA) as an indicator of oxidant status and superoxide radical scavenger activity (SSA) as an indicator of antioxidant status were measured in erythrocytes from 20 smokers and 10 non-smoker controls. Ten of the 20 smoking subjects smoked five cigarettes with full flavour low tar (FFLT with 12 mg tar) and the others smoked five cigarettes with full flavour high tar (FF with 23 mg tar) over 1 hour. Initial blood samples from both groups at fasting, followed by further samples from smokers at 1.5 hours and 3 hours after smoking. Initial erythrocyte MDA level and SSA activity were found to be higher in the smoking groups compared to non-smokers. Furthermore, both parameters were significantly higher at the 1.5-hour and 3-hour erythrocyte samples when compared to initial values in the FFLT group. However, there were no statistically significant differences between SSA values established at different times in FF group. Results suggest that smoking causes oxidant load in the erythrocytes. Although a compensatory mechanism (i.e. increased SSA activities) develops in the FFLT group after smoking, this cannot prevent peroxidation reactions (i.e. increased MDA levels) in the erythrocytes. As to the types of cigarettes, both seem to have oxidant potential, but oxidation degree in the FFLT group is higher than that of FF group. These results suggest that antioxidant supplementation to smokers might be beneficial to decrease cellular oxidation damages.