Higher Levels Of Catalase Research Articles

Abstract B47: Modulating the NQO1-dependent ‘kiss of death’ mechanism of action of NQO1 bioactivatable drugs

Abstract Metabolic adaptations in tumors are necessary to balance the need for cellular energy supply, macromoleclar biosynthesis and maintenance of redox balance. A critical molecule produced as a result of this altered metabolism is nicotinamide adenine dinucleotide phosphate (NADPH). NADPH is a critical co-factor that provides reducing power to maintain cytoprotective concentrations of reduced glutathione against reactive oxygen species (ROS) that are produced during rapid growth and proliferation. In pancreatic cancers, NADPH can be formed by the NAD+ salvage pathway through the enzyme, Nicotinamide phosphoribosyltransferase (NamPT), as well as through the non-canonical metabolism of glutamine through glutaminase-1 (GLS1). While NamPT and GLS1 inhibitors have shown some anti-tumor activity in vitro and in vivo, these inhibitors lack tumor specificity and can have an extensive toxicity profile due to the requirement of NADPH synthesis in proliferating normal cells/tissue. We recently discovered that NAD(P)H:quinone oxidoreductase 1 (NQO1) levels were elevated 5- to 40-fold in >80% of pancreatic tumors vs associated normal tissue. As important, we noted that catalase levels were inversely expressed comparatively, elevated in normal and suppressed in tumor tissue. Thus, NQO1 represents a unique target to exploit for the therapeutic elimination of pancreatic cancers. While NQO1 is normally a detoxifying (Phase II) enzyme, we have discovered two unique classes of compounds that are ‘bioactivated’ in a futile redox cycle by the enzyme. NQO1 bioactivatable drugs, such as β-lapachone (β-lap) and deoxynyboquinone (DNQ), generate hydrogen peroxide as a mechanism to hyperactivate poly(ADP-ribose) polymerase 1 (PARP1), and to rapidly deplete NAD+ and ATP in a selective manner to kill tumors. Normal cells are protected due to low NQO1 and relatively high Catalase levels. We found that the tumor specificity and efficacy of NamPT or GLS1 inhibition can be greatly increased when small molecule NamPT inhibitors (e.g., FK866) or GLS1 inhibitors (e.g., BPTES) are used in combination with NQO1-bioactivatable drugs. With combination treatment, cells are primed for ROS-mediated damage due to reduced glutathione and NADPH levels; they are unable to recover ATP, NAD+, and NADPH synthesis even after only a 2 h exposure to NQO1 bioactivatable drugs, and they rapidly die through a caspase-independent, parthanatos (programmed necrosis) mechanism. Our findings indicate that NQO1-bioactivatable drugs may improve the sensitivities of clinical grade GLS1 and NamPT inhibitors in pancreatic cancer patients. This work was supported by an AACR/Pancreatic Cancer Action Network - George and June Block Foundation - Innovator Award and an NIH/NCI R01 CA102971 grant to DAB. Citation Format: Zachary Moore, Gaurab Chakrabarti, Costas Lyssiotis, Ralph Deberardinis, Boothman A. David. Modulating the NQO1-dependent ‘kiss of death’ mechanism of action of NQO1 bioactivatable drugs. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B47.

Oxidative Stress–Associated Senescence in Dermal Papilla Cells of Men with Androgenetic Alopecia

Dermal papilla cells (DPCs) taken from male androgenetic alopecia (AGA) patients undergo premature senescence in vitro in association with the expression of p16(INK4a), suggesting that DPCs from balding scalp are more sensitive to environmental stress than nonbalding cells. As one of the major triggers of senescence in vitro stems from the cell "culture shock" owing to oxidative stress, we have further investigated the effects of oxidative stress on balding and occipital scalp DPCs. Patient-matched DPCs from balding and occipital scalp were cultured at atmospheric (21%) or physiologically normal (2%) O2. At 21% O2, DPCs showed flattened morphology and a significant reduction in mobility, population doubling, increased levels of reactive oxygen species and senescence-associated β-Gal activity, and increased expression of p16(INK4a) and pRB. Balding DPCs secreted higher levels of the negative hair growth regulators transforming growth factor beta 1 and 2 in response to H2O2 but not cell culture-associated oxidative stress. Balding DPCs had higher levels of catalase and total glutathione but appear to be less able to handle oxidative stress compared with occipital DPCs. These in vitro findings suggest that there may be a role for oxidative stress in the pathogenesis of AGA both in relation to cell senescence and migration but also secretion of known hair follicle inhibitory factors.

Abstract P6-02-02: Exploiting Isobutyl-deoxynyboquinone-induced DNA damage responses and metabolic changes for breast cancer therapy

Abstract During oncogenic or cellular stress new genes are frequently (over)-expressed that could be exploited for targeted cancer therapy. The enzyme, NAD(P)H:quinone oxidoreductase-1 (NQO1) is over-expressed in most solid cancers, including 60% of primary and metastatic breast cancers regardless of subtype. Normally, NQO1 detoxifies quinones resulting in the formation of stable hydroquinones that are subsequently excreted from the cell. However, NQO1 bioreduction can turn certain rare quinones, such as β-lapachone and deoxynyboquinone (DNQ), into potent cell death-inducing compounds. These agents cause severe DNA damage, poly(ADP-ribose)polymerase-1 (PARP1) hyperactivation, NAD+/ATP loss, and programmed necrosis of NQO1-expressing cancer cells. Although ß-lapachone (ARQ761) is in current clinical trials at UTSW, more potent tumor-selective NQO1 compounds are needed. Based on its structure and mode of action, isobutyl-DNQ (IB-DNQ) was recently added to the spectrum of NQO1 substrates as a more selective and potent anti-cancer agent whose mechanism of action remains to be elucidated. Although NQO1 expression is a major determinant of IB-DNQ-induced lethality, previously published results from our group showed that increased catalase expression could cause marked cytoprotection. We conducted a screen for NQO1:Catalase ratios in 266 breast tumor samples, and 143 normal breast samples, for a total of 409 specimens. We found that NQO1 expression was significantly elevated in breast tumors compared to normal tissue. In contrast, catalase expression was suppressed in breast tumors versus adjacent normal tissue. These results predict that normal tissue, which typically has higher catalase levels than cancer cells, could be selectively spared from IB-DNQ-induced toxicity. Thus, NQO1:Catalase ratios favor use of IB-DNQ in breast cancers to exploit this large therapeutic window. Since NQO1 bioactivatable drugs synergize with agents that damage DNA, we hypothesized that certain cancer vulnerabilities (e.g., BRCA1-deficient breast cancers) that have elevated endogenous DNA damage would synergize with IB-DNQ. Exposure of breast cancer cells with IB-DNQ induced DNA damage, PARP1 hyperactivation, dramatic loss of essential nucleotides (NAD+/ATP), and µ-calpain-mediated programmed necrosis with 10X greater potency than ß-lapachone. IB-DNQ-induced DNA double-strand breaks (DSBs) that occurred in cells in S/G2 phases were mainly repaired by error-free homologous recombination (HR), and therefore BRCA1-deficient cancers, being HR defective, would be particularly vulnerable to IB-DNQ treatment. Indeed, HCC1937 breast cancer cells, deficient in BRCA1, were extremely sensitive to low dose IB-DNQ due to the overwhelming levels of IB-DNQ-induced DNA damage and their inability to repair it due to their compromised HR. In fact, IB-DNQ was far superior to PARP inhibitors in targeting BRCA1-deficient cells. Studies in vivo showed equivalent antitumor efficacy of IB-DNQ to β-lapachone and DNQ, but with much greater potency at lower doses. These findings offer preclinical ‘proof-of-concept’ for IB-DNQ as a potent chemotherapeutic agent for the treatment of breast cancers, especially those deficient in BRCA1. This research was supported by grant CA102972 to DAB. Citation Format: Mariya Ilcheva, Lifen Cao, Sandeep Burma, David Boothman. Exploiting Isobutyl-deoxynyboquinone-induced DNA damage responses and metabolic changes for breast cancer therapy [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-02-02.

The renaissance of acetaldehyde as a psychoactive compound: decades in the making.

The renaissance of acetaldehyde as a psychoactive compound: decades in the making.

Postpartum development of endothelial dysfunction and oxidative stress markers in women with previous gestational diabetes mellitus

Relationships between adhesion molecules (AM), oxidative stress, gestational diabetes mellitus (GDM) and future development of type 2 diabetes mellitus are unclear. We investigated AM and oxidant/antioxidant markers in women with previous history of GDM. Postpartum women with GDM (cases; n = 41) and healthy women (controls; n = 21) had clinical and laboratory variables measured, including indicators of vascular damage (ICAM-1, VCAM-1 and E-selectin), oxidative stress (LPO, GSH and GST) and antioxidant markers (catalase, SOD, GPX and TAC). Previous GDM versus control women presented higher body mass index: 27.4 ± 5.6 versus 23.9 ± 3.6 (p = 0.013); waist circumference: 85.2 ± 12.9 versus 77.5 ± 9.0 (p = 0.017); MetS (WHO definition): 14.6 versus 0 % (p = 0.012); MetS (NCEP-ATPIII definition): 22 versus 0 % (p = 0.002); low HDL: 36.6 versus 9.5 % (p = 0.024); fasting glucose (mmol/L): 5.4 ± 0.6 versus 4.9 ± 0.2 (p < 0.001); glucose 120 min (mg/dL): 105.0 ± 30.2 versus 85.1 ± 14.2 (p = 0.007); fasting insulin (μU/mL): 13.4 ± 8.1 versus 8.4 ± 4.3 (p = 0.004); HOMA index: 3.3 ± 2.3 versus 1.8 ± 1.0 (p = 0.002); HbA1c (%/mmol/mol): 5.4 ± 0.2 versus 5.2 ± 0.2/36 ± 1.4 versus 33 ± 1.4 (p = 0.021); uric acid (mg/dL): 4.1 ± 1 versus 3.5 ± 0.6 (p = 0.009); catalase (nmol/min/mL): 38.7 ± 15.6 versus 28.9 ± 11.1 (p = 0.013). There were no significant differences in hypertension prevalence, lipid fractions, albumin/creatinine ratio and AM. Women with previous GDM have high catalase levels which correlate positively with glucose intolerance, indicating the potential effect of oxidative stress on postpartum dysglycemic status.

Transferability of oxytetracycline (OTC) from feed to carp muscle and evaluation of the antibiotic effects on antioxidant systems in liver and kidney

Oxytetracycline (OTC) is employed in fish farms to contest or prevent bacterial infections. We simulated an OTC treatment at therapeutic level (75mgkg(-1)) and at higher doses (150, 300mgkg(-1)) for 10days. A withdrawal period of 10days was considered for treated carp, carrying out the same chemical and biochemical analyses (total glutathione, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase and malondialdehyde). The aim was to obtain data related to the carryover in muscle and on variations in the antioxidant indicators in liver and kidney. The OTC residual levels in muscle showed a dose-response relationship. After 10days of treatment at the recommended dose (75mgkg(-1)), the mean value in muscle was 295μgkg(-1). After 10 withdrawal days, residues in all treated groups were not entirely eliminated by fish. Residues of recommended 75mgkg(-1) OTC dose were lower than the maximum permitted by EEC regulation: 100μgkg(-1). Disturbance in the antioxidant systems in liver and kidney was recorded in (150, 300mgkg(-1)) carp, as well as during the withdrawal period. A lowered superoxide dismutase activity and higher levels of catalase, glutathione peroxidase, glutathione reductase and glutathione were evaluated in liver, while in kidney only higher malondialdehyde and glutathione S-transferase concentrations were recorded for 300mgkg(-1) dose. The therapeutic OTC dose exerted lower effects, and only in liver, enhancement of GPx and GR activities was recorded. After the withdrawal period, altered antioxidant responses in tissues were restored for all three OTC doses.

Copper chloride induces antioxidant gene expression but reduces ability to mediate H2O2 toxicity in Xanthomonas campestris

Copper (Cu)-based biocides are currently used as control measures for both fungal and bacterial diseases in agricultural fields. In this communication, we show that exposure of the bacterial plant pathogen Xanthomonas campestris to nonlethal concentrations of Cu(2+) ions (75 µM) enhanced expression of genes in OxyR, OhrR and IscR regulons. High levels of catalase, Ohr peroxidase and superoxide dismutase diminished Cu(2+)-induced gene expression, suggesting that the production of hydrogen peroxide (H2O2) and organic hydroperoxides is responsible for Cu(2+)-induced gene expression. Despite high expression of antioxidant genes, the CuCl2-treated cells were more susceptible to H2O2 killing treatment than the uninduced cells. This phenotype arose from lowered catalase activity in the CuCl2-pretreated cells. Thus, exposure to a nonlethal dose of Cu(2+) renders X. campestris vulnerable to H2O2, even when various genes for peroxide-metabolizing enzymes are highly expressed. Moreover, CuCl2-pretreated cells are sensitive to treatment with the redox cycling drug, menadione. No physiological cross-protection response was observed in CuCl2-treated cells in a subsequent challenge with killing concentrations of an organic hydroperoxide. As H2O2 production is an important initial plant immune response, defects in H2O2 protection are likely to reduce bacterial survival in plant hosts and enhance the usefulness of copper biocides in controlling bacterial pathogens.

Oxidative stress and antioxidant enzyme activity in South Indian male smokers with chronic obstructive pulmonary disease

Oxidative stress resulting from tobacco smoking has been suggested to play a role in the pathogenesis of chronic obstructive pulmonary disease (COPD). The aim of the present study was to evaluate the oxidant and antioxidant levels in smokers with and without COPD. Two hundred thirty-six patients with COPD and 150 smokers with no respiratory problems were selected. COPD diagnosis and staging was done based on the Global Initiative for Chronic Obstructive Lung Disease criteria. Plasma malondialdehyde (MDA) and erythrocyte glutathione (GSH) concentrations and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-s-transferase (GST) activities were assessed. COPD patients had higher levels of MDA and lower levels of antioxidants when compared with controls (P < 0.01). Analysis of variance revealed increase in MDA (P < 0.05) and decrease in CAT activity (P < 0.01) and GSH (P < 0.05) level with the progression of the disease. In patients, lung function positively correlated with CAT and SOD activities and negatively correlated with MDA levels (P < 0.01). Smoking history showed negative relation with forced expiratory volume in 1 s (FEV1 )/forced vital capacity (P < 0.05) and positive correlation with CAT activity (P < 0.01). MDA levels negatively correlated with SOD (r = -0.239; P < 0.01). In controls, MDA levels showed significant positive correlation with FEV1 and GPx (P < 0.05) and negative correlation with GSH (P < 0.01). Logistic regression showed association of higher MDA levels with increased risk and higher levels of CAT and GSH with decreased risk of progressing in the disease (odds ratio = 2.938, 2.538, 7.860). Our study demonstrates that there is an oxidant antioxidant imbalance in COPD patients and suggests the importance of GPx in maintaining lung function.

Association between Machado–Joseph disease and oxidative stress biomarkers

Spinocerebellar ataxia type 3, also called Machado–Joseph disease (MJD), is an hereditary autosomal dominant neurodegenerative disease that affects the cerebellum and its afferent and efferent connections. Since the mechanism by which mutant ataxin-3 eventually leads to neuronal death is poorly understood, additional investigations to clarify the biological alterations related to Machado–Joseph disease are necessary. Recent investigations suggest that oxidative stress may contribute significantly to Machado–Joseph disease. We compared markers of oxidative stress between Machado–Joseph disease and healthy control subjects. The results showed that Machado–Joseph patients have higher catalase levels and lower thiol protein levels compared to control subjects. The peripheral blood lymphocyes of MJD patients also showed higher levels of DNA damage by the comet assay than control subjects. Our results corroborate the hypothesis that the oxidative stress is associated with MJD patients. However, whether strategies to increase cellular antioxidative capacity may be effective therapies for the treatment of Machado–Joseph disease is an open question.

Elevated p66Shc is associated with intracellular redox imbalance in developmentally compromised bovine embryos

The in vitro production of mammalian embryos suffers from low efficiency, with 50-70% of all fertilized oocytes failing to develop to the blastocyst stage. This high rate of developmental failure is due, in part, to the effects of oxidative stress generated by reactive oxygen species (ROS). The p66Shc adaptor protein controls oxidative stress response by regulating intracellular ROS levels through multiple pathways, including mitochondrial ROS generation and the repression of antioxidants. This study explored the relationship between p66Shc levels, redox state, and developmental potential in early bovine embryos. Embryo developmental potential was established based on observing their time of first cleavage. P66Shc, catalase, and mitochondrial-specific, manganese-superoxide dismutate (MnSOD) levels were compared between embryos with high and low developmental potentials. Additionally, p66Shc, catalase, and MnSOD content were assayed following a variety of oxidative stress-inducing and-alleviating conditions. Increased developmental potential correlated with significantly lower p66Shc content, significantly higher levels of catalase and MnSOD, and significantly lower intracellular ROS levels (MitoSOX staining) and reduced DNA damage (γ-H2A.X(phospho S139) immunostaining). p66Shc content was increased by either high (20%) O(2) culture or H(2)O(2) treatment, and significantly decreased by supplementing culture media with the antioxidant polyethylene glycol-conjugated catalase. While the abundance of p66Shc varied according to pro/anti-oxidant culture conditions, antioxidant content varied only according to developmental potential. This discrepancy has important implications regarding ongoing efforts towards maximizing in vitro embryo production.

Oxidative stress responses and biological indices in the giant clam Tridacna maxima and the reef fish Epinephelus merra from the French Polynesian Moorea Island

Responses of biological indices and oxidative stress biomarkers were studied in the giant clam Tridacna maxima and in the fish Epinephelus merra collected from two sites differing by their level of contamination in the French Polynesian Moorea island. Higher levels of catalase (CAT), glutathione-S-transferases (GST) and thiobarbituric acid reactive substances (TBARs) were observed in the hepatopancreas of T. maxima and in the liver of E. merra compared to muscle. CAT and TBARs levels were significantly higher in the hepatopancreas of clams collected from the impacted site (Vaiare) compared to the reference site (bay of Cook). The same pattern was observed for TBARs levels in the liver of E. merra. These results indicate that both organisms from the impacted site were exposed to contaminants leading to an oxidative stress and demonstrate, for the first time, the usefulness of T. maxima and E. merra as sentinel species for biomonitoring reef environments.

Characterization of partially purified catalase from camel ( Camelus dromedarius ) liver

The liver of camel has high level of catalase (32,225 units/g tissue) as commercially used bovine liver catalase. For the establishment of the enzyme, the rate of catalase activity was linearly increased with increase of the catalase concentration and incubation time. The procedure of partial purification of catalase from camel liver included preparation of crude extract, ammonium sulphate precipitation and chromatography on diethylaminoethyl cellulose (DEAE)-Sepharose. One peak catalase activity was obtained from the chromatography. The enzyme had optimum pH of 7.0. Camel liver catalase had broad optimum temperature between 25 and 40°C and was stable up to 25°C. The Km and Vmax values were found to be 22.7 mM H2O2/ml and 7.9 units/ml, respectively. All metal cations partially inhibited camel liver catalase with the exception of Hg 2+ which had strong inhibitory effect, whereas 95% of its activity was lost at 1.0 mM. In conclusion, camel liver catalase can be used as an alternative commercial bovine liver catalase.

The effects of immunosuppressants on vascular function, systemic oxidative stress and inflammation in rats

Immunosuppressants have been associated with increased cardiovascular disease risk. We determined the effects of calcineurin and mammalian target of rapamycin (mTOR) inhibitor administration on endothelial dysfunction and associated inflammation and oxidative stress in adult rats. Cyclosporine A (low and high dose), sirolimus, tacrolimus, everolimus and placebo were administered to 8-week-old male Wistar rats for 10 consecutive days. Aortic vascular endothelial and smooth muscle function were assessed ex vivo in organ baths. Maximal aortic contraction to noradrenaline in sirolimus-treated rats was significantly greater than cyclosporine groups, everolimus and placebo, whereas endothelial-dependent relaxation was significantly impaired with cyclosporine and tacrolimus compared with everolimus. Endothelial-independent relaxation was impaired in tacrolimus-treated rats compared with low dose cyclosporine, everolimus and sirolimus. Sirolimus was associated with a reduction in plasma interleukin (IL)-1β and tumour necrosis factor (TNF)-α and higher levels of catalase and total antioxidant status. In nontransplanted rats, vascular dysfunction was evident following administration of cyclosporine A, sirolimus and tacrolimus, whereas everolimus did not compromise aortic endothelial or smooth muscle function. At the doses administered in this model, the immunosuppressants exerted varying effects on vascular function.

Mammary gene expression and activity of antioxidant enzymes and concentration of the mammalian lignan enterolactone in milk and plasma of dairy cows fed flax lignans and infused with flax oil in the abomasum

The objectives of the study were to investigate the effects of dietary supplementation of flax hulls and/or flax oil on the activity of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX)) in plasma and the mammary gland and the relative mRNA abundance of antioxidant genes in the mammary gland of dairy cows. A total of eight dairy cows were used in a replicated 4 × 4 Latin square design. There were four treatments: control with no flax hulls (CONT), 9·88% flax hulls in the DM (HULL), control with 500 g flax oil/d infused in the abomasum (COFO), 9·88% flax hulls in the DM and 500 g flax oil/d infused in the abomasum (HUFO). Plasma GPX activity tended to decrease with flax oil supplementation. Cows fed HULL had higher levels of CAT, GPX1 and SOD1 mRNA in the mammary gland and lower mRNA abundance of GPX3, SOD2 and SOD3 compared with those fed CONT. Abundance of CAT, GPX1, GPX3, SOD2 and SOD3 mRNA was down-regulated in the mammary gland of cows fed HUFO compared to those fed CONT. The mRNA abundance of CAT, GPX1, GPX3 and SOD3 was lower in the mammary gland of cows fed COFO than in the mammary gland of cows fed CONT. The present study demonstrates that flax hulls contribute to increasing the abundance of some antioxidant genes, which can contribute to protecting against oxidative stress damage occurring in the mammary gland and other tissues of dairy cows.

Abnormal levels of antioxidant defenses in a large sample of patients with hypertensive disorders of pregnancy

Increased levels of oxidative stress have been demonstrated in Preeclampsia in previous studies, but this finding has not been established in other hypertensive disorders in pregnancy (HDP). We measured different markers of lipid peroxidation and antioxidant defenses by spectrophotometry or enzymoimmunoanalysis in 339 pregnant women: 85 with gestational hypertension (GH), 88 chronic hypertension (CH), 104 Preeclampsia and 62 healthy pregnant control women (PCW). Lower activity of superoxide dismutase and higher levels of catalase were found in GH, CH and preeclampsia compared with PCW (964.4±116.5, 970.0±120.4, 971.2±137.5 and 1063.4±133.7 U g(-1) Hb, P<0.001; and 313.0±71.7, 292.2±45.3, 297.1±47.2, 215.5±26.2 U mg(-1) Hb, P<0.0001; respectively). Regarding the glutathione REDOX cycle, we found the following in GH, CH and preeclampsia compared with PCW: a decrease in its reduced form (2.6±0.6, 2.7±0.8, 2.7±0.9, 3.3±1.3 μmol l(-1), P<0.003), a parallel increase in the oxidized form (185.6±68.9, 194.7±75.0, 184.3±78.3, 85.1±27.5 μmol l(-1), P<0.0001) and an increment in glutathione peroxidase (85.9±22.0, 86.4±20.9, 82.1±23.5 and 77.2±19.7 U g(-1) Hb, P<0.04) and glutathione reductase (6384.3±1261.9, 6724.6±1154.1, 6287.9±1399.9 and 6044.4±1208.4 mU g(-1) Hb, P<0.01, respectively). Nitrites/nitrates were higher in patients with preeclampsia than in PCW (31.50±15.08, 26.80±8.39 μmol l(-1), P<0.002). Although malondialdehyde and oxidized-LDL levels were similar among groups, free fatty acids were increased in every HDP (GH 514.6±194.6, CH 501.3±197.4, preeclampsia 555.2±230.1 μmol l(-1)) compared with PCW (351.4±146.1 μmol l(-1)), P<0.0001. Our results show an oxidation/reduction imbalance with an increase in oxidative stress coupled with a decreased capacity of antioxidant systems, not only in preeclampsia but also in every HDP.

Plant allocation to defensive compounds of transgenic Bt cotton in response to infestation by cotton bollworm under conditions of elevated CO2

Allocation of defensive compounds of transgenic Bt cotton grown under conditions of elevated CO2 in response to infestation by cotton bollworm, Helicoverpa armigera (Hübner) was studied in two successive years (2004 and 2005). Both CO2 levels and bollworm infestation affected allocation of defensive compounds of non-transgenic cotton and transgenic Bt cotton. Both significantly higher foliar condensed tannin and a higher carbon/nitrogen ratio for non-transgenic cotton and transgenic Bt cotton were recorded under elevated CO2 compared to ambient CO2. This result accords with the Carbon Nutrient Balance hypothesis linking limiting nitrogen and excess carbon in cotton plants in response to elevated CO2. Furthermore, significantly higher levels of catalase (CAT) and superoxide dismutase (SOD) and a significantly lower level of true choline esterase (TChE) were also observed in H. armigera fed on transgenic Bt cotton compared with those fed on non-transgenic cotton. Also, there were significant interactions between cotton variety and bollworm infestation time on CAT and SOD activities. Our results indicate that plant allocation to defensive compounds will be affected sufficiently to affect plant–herbivore populations interactions.

Oxidative Stress Biomarkers in Liver and Gill Tissues of Spotted Barb (Capoeta Barroisi Lortet, 1894) Living in Ceyhan River, Adana-Turkey

This study was carried out in an agricultural, industrial, domestic, and slaughterhouse area that is also a discharging region of the river Ceyhan just under the crest of the Aslantaş dam. Levels of pollution indicator parameters of the water were observed and their effects on various oxidative stress biomarkers in gill and liver tissues of spotted barb (Capoeta barroisi Lortet, 1894) were investigated. The oxidative stress biomarkers analyzed included superoxide dismutase (SOD), catalase (CAT), and glucose-6-phosphate dehydrogenase (G6PD). Levels of reduced glutathione (GSH) and lipid peroxidation (LPO) were also evaluated. High levels of CAT, G6PD, GST, and GSH activity were found in the liver tissues of fish collected from the river Ceyhan discharging region; it was determined that the region was polluted. Substantially high levels of SOD and LPO (P < 0.05 in gill and liver) were observed. The findings of the present investigation will provide a rational use for oxidative stress biomarkers in aquatic ecosystem pollution biomonitoring.

Ecophysiological determinations of antioxidant enzymes and lipoperoxidation in the blood of White Stork Ciconia ciconia from Poland

The aim of this study was to investigate the activity of antioxidant enzymes in the blood of White Stork Ciconia ciconia chicks (aged 19–54 days) in Poland in 2006. We took under consideration superoxide dismutase (SOD), catalase (CAT), ceruloplasmine (CP), glutathione peroxidase (GPx), glutathione reductase (GR) and the content of thiobarbituric acid-reactive substances (malondialdehyde) in polluted (copper manufacture), suburban areas, at the Odra meadows, and at swamps near Baltic Sea in the Pomeranian region. We examined the levels of Na, K, Ca, Mg, Fe, Zn, Cu, Mn, Co, Cd, and Pb and compared ecophysiological determinations for developing storks. Blood samples of wing venous were collected from 91 chicks from 33 nests. The degree of activity of antioxidant enzymes studied has been different in White Stork chicks’ blood from Poland regions, as a rule. We have stated a relatively high level of CAT, GPx, SOD, and GR activity and malondialdehyde (MDA) content in chicks from polluted areas. However, relative value for GR in storks from Odra meadows was considerably higher (about 112 nmol NADPH 2/min ml) than those in chicks from other environments (56–84 nmol on average). Relatively high levels of CAT, CP, and GPx (2.7 mkM/min l, 22.2 mg/l, and 3.8 nmol GSH/min ml, respectively) were also stated in chicks nested in swamps near Baltic Sea. Simultaneously, we have stated differences ( p<0.02– p<0.001) in the level of elements (besides Ca) in blood of young storks from the studied areas. We found a high level of toxic metals, e.g. Cd, either from swamps near Baltic Sea (2.7 mg/kg) or from Głogów smelter (2.2 mg/kg), whilst Pb concentration was high in chicks from Głogów (7.2 mg/kg). Cd and Pb levels in blood of chicks were different in individuals from each region ( p<0.001). Birds from a smelter have the highest level of these elements, whereas the lowest one was stated in chicks from Odra meadows (Cd: 1.45, Pb: 0.84 mg/kg). Thus, Cd could be a useful marker of response for polluted stress. We also observed a relatively high level of Mg in chicks from both Pomeranian (7000 mg/kg) and polluted (about 6000 mg/kg) areas. Potassium, zinc, and cobalt levels were highest in chicks from suburbs (4.65, 10.1, and 2.7 mg/kg, respectively) and polluted regions (3.8, 9.7, and 5.6 mg/kg, respectively), whilst Cu and Mn were highest in those from polluted (10.9 and 47.6 mg/kg, respectively) and Pomeranian regions (11 and 42.2 mg/kg, respectively). Concentrations of Na, K, and Ca in chicks from Głogów smelter (143.2, 3.8, and 115.9 mg/kg, respectively) were often similar to those from Odra meadows (147.8, 3.6, and 112.5 mg/kg, respectively). This was probably due to a similar degree of homeostatic regulations of an organism. The levels of Mg, Fe, Zn, and Cu were often different ( p<0.02– p<0.001) in the blood of White Stork chicks from the studied areas. Co, Pb, and Cd levels were higher ( p<0.001) in chicks from Głogów smelter than in those from Odra meadows. It is evidence for importance of anthropopression, which influenced the course of biogeochemical processes and the bioaccumulation of toxic metals locally. This takes place also in chicks from swamps near Baltic Sea, in which the level of Cd was high (2.7 mg/kg); so we can state the high intensity of intoxication in this region. We can conclude that the use of hematological research assesses the condition of birds and might give a positive association with miscellaneous environmental loads. The high concentration of toxic heavy metals involved greater intensity of antioxidant enzymes’ activity. Environmental intoxication causes an increase of lipoperoxidation intensity in growing chicks and changes the response of their immunological system.

Antioxidant enzymatic system in neuronal and glial cells enriched fractions of rat brain after aluminum exposure.

The aim of this work was to investigate as to how neurons and glial cells separated from the brain cortex respond to oxidative stress induced by aluminum. Female SD rats were exposed to aluminum at the dose level of 100 mg/kg b.w. for 8 weeks. Neuronal and glial cell-enriched fractions were obtained from rat cerebral cortex by sieving the trypsinated homogenate through a series of nylon meshes, followed by centrifugation on ficoll density gradient. Total glutathione content, glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-s-transferase (GST) along with antioxidant enzymes superoxide dismutase (SOD), catalase were estimated in neuronal and glial-enriched fractions in both control (N-c and G-c) and aluminum exposed animals (N-a and G-a). Secondary products of lipid peroxidation that is MDA levels were estimated by measuring the (TBARS) levels. Our results indicate that TBARS levels were significantly higher in glial cell fraction of unexposed controls (Gc) than the neuronal cells (Nc). Correspondingly the glial cells had higher levels of GSH, GSSG, GPx and GST where as neurons had higher levels of catalase, SOD and GR. Following aluminum exposures significant increase in the TBARS levels was observed in neurons as compared to glial cells which also showed a significant decrease in SOD and catalase activity. The decrease in the TBARS levels in the glial cells could be related to the increase in the GSH levels, GR activity, and GST activity which were found to be increased in glial enriched fractions following aluminum exposure. The increase in activity of various enzymes viz GR, GST in glial cells as compared to neurons suggests that glial cells are actively involved in glutathione homeostasis. Our conclusion is that glial and neurons isolated from rat cerebral cortex show a varied pattern of important antioxidant enzymes and glial cells are more capable of handling the oxidative stress conditions.

Efficiency of antioxidant response in Spartina densiflora: An adaptative success in a polluted environment

The effects of different culture conditions, unpolluted and polluted substrates, on an antioxidative system – antioxidant enzymes, such as catalase, ascorbate peroxidase and guaiacol peroxidase, and ascorbic acid – were investigated to establish its relationship with the acclimatization success of Spartina densiflora. Plants of this species growing in the polluted Odiel marshes (Huelva, Spain) showed high levels of catalase, ascorbate and guaiacol peroxidase activities and ascorbate concentration (reduced and oxidized ascorbate). In addition, we found significant oxidation of the ascorbate pool, since only 40% of ascorbate was reduced, and low levels of photosynthetic pigments, suggesting that an oxidative stress was impairing S. densiflora. Transplantation to an unpolluted substrate in the laboratory led to a gradual change in all tested parameters: antioxidative activities and total ascorbate concentration decreased while the percentage of reduced ascorbate and pigment concentrations increased; these data agreed with the hypothesis that oxidative stress conditions in S. densiflora habitat were due to a polluted substrate. After 28 days, the plants were transplanted for a second time to polluted conditions, equivalent to those in their habitats, and a rapid alteration of the antioxidative system was observed. In the first 24 h, catalase and guaiacol peroxidase activities and ascorbate concentration increased greatly and the percentage of reduced ascorbate fell drastically. Regardless of this fact, ascorbate peroxidase activity did not change until the end of the first week, while photosynthetic pigments declined at a constant rate during the whole culture period. Subsequently, we found that the antioxidative system improved its reductive capacity gradually and slowly – over weeks – but this reductive power was rapidly lost within days or even hours. It may be concluded that S. densiflora undergoes oxidative stress in its natural environment and is able to modulate its antioxidative system, based on the degree of pollution, in order to acclimatize successfully to its fluctuating environment.