Exposure to pesticides used in rice farming (bentazone, chlorantraniliprole and tebuconazole) affects biochemical biomarkers and hepatic histopathological parameters of hammertoad tadpoles (Boana faber).

Pesticides used in rice cultivation can cause negative health effects to non-target organisms representative of natural biodiversity. In this context, the present study aimed to investigate the occurrence of pesticides in surface waters from a river that flows in the middle of a rice farming-dominated area. We were also interested in evaluate biochemical and histological effects caused by exposure (16 d) to the lower and higher concentrations of the main found herbicide (bentazone, BTZ), insecticide (chlorantraniliprole, CTP) and fungicide (tebuconazole, TBZ), isolated or mixed, in Boana faber tadpoles. No significant differences were observed in the development of the animals. Tadpoles exposed to the herbicide BTZ showed higher hepatic levels of malondialdehyde (MDA). In animals exposed to CTP, MDA levels were lower than controls. Animals exposed to the fungicide TBZ showed higher hepatic activity of glutathione S-transferase and carboxylesterase (CbE), as well as higher levels of carbonyl proteins and MDA. Animals exposed to Mix showed higher activity in CbE and glucose-6-phosphate dehydrogenase activity in the liver, as well as higher levels of MDA. In the brain and muscle of tadpoles exposed to Mix, acetylcholinesterase activity was higher. Histological changes were also observed in pesticide-exposed animals, such as increased occurrence of melanomacrophages, inflammatory infiltrates and congestion. Our data evidences the contamination of natural aquatic environments by rice pesticides, and the adverse effects of main ones in B. faber tadpoles, which suggests the contribution of pesticides derived from rice cultivation to the degradation of local biodiversity health.

Prednisone and prednisolone effects on development, blood, biochemical and histopathological markers of Aquarana catesbeianus tadpoles.

Synthetic glucocorticoids are often found in surface waters and can cause harmful effects to aquatic organisms such as amphibians. In this work we evaluated the effects of the drugs prednisone (PD) and prednisolone (PL) on developmental, molecular, blood, biochemical and histological markers. Aquarana catesbeianus tadpoles were exposed for 16 days to environmentally relevant concentrations of 0, 0.1, 1 and 10 µg/L of both drugs. PD increased the transcript levels of the enzyme deiodinase III (Dio3), the hormones cortisol and T4 and delayed development. Changes in the thyroid gland occurred after tadpoles were exposed to both drugs, with a reduction in the diameter and number of follicles and an increase/or decrease in area. Also, both drugs caused a decrease in lymphocytes (L) and an increase in neutrophils (N), thrombocytes, the N:L ratio and lobed and notched erythrocytes. Increased activity of the enzymes superoxide dismutase, glutathione S-transferase and glucose 6-phosphate dehydrogenase was observed after exposure to PD. Furthermore, both drugs caused an increase in the activity of the enzymes catalase and glutathione peroxidase. However, only PD caused oxidative stress in exposed tadpoles, evidenced by increased levels of malondialdehyde and carbonyl proteins. Both drugs caused an increase in inflammatory infiltrates, blood cells and melanomacrophages in the liver. Our results indicate that PD was more toxic than PL, affecting development and causing oxidative stress.

Combined effects of diesel and air exposure on oxidative stress parameters of mussels Perna perna (Mytilidae, Bivalvia).

This study aimed to assess the combined effect of hypoxia and exposure to diesel on biochemical parameters of Perna perna mussels. Mussels previously kept for 48 h in clean seawater were submitted to hypoxia for 24 h followed by reoxygenation in clean seawater for 48 h. The same procedure was done but using seawater containing 0.01 mL/L of diesel, before and after hypoxia. Antioxidant enzymes as well as levels of glutathione and lipid peroxidation were measured in gills and digestive glands. The neutral red retention time assay was also evaluated in hemocytes. Results showed that cycles of air exposure and reoxygenation caused oxidative stress and antioxidant modulation in both the gills and digestive glands. The presence of diesel in water triggered additional modulation of antioxidants under hypoxia and reoxygenation stress, apparently enhancing the capacity of mussels to avoid lipid peroxidation.

Potential Cytoprotective and Regulatory Effects of Ergothioneine on Gene Expression of Proteins Involved in Erythroid Adaptation Mechanisms and Redox Pathways in K562 Cells.

This study aimed to establish the importance of ergothioneine (ERT) in the erythroid adaptation mechanisms by appraising the expression levels of redox-related genes associated with the PI3K/AKT/FoxO3 and Nrf2-ARE pathways using K562 cells induced to erythroid differentiation and H2O2-oxidative stress. Cell viability and gene expression were evaluated. Two concentrations of ERT were assessed, 1 nM (C1) and 100 µM (C2), with and without stress induction (100 µM H2O2). Assessments were made in three periods of the cellular differentiation process (D0, D2, and D4). The C1 treatment promoted the induction of FOXO3 (D0 and 2), PSMB5, and 6 expressions (D4); C1 + H2O2 treatment showed the highest levels of NRF2 transcripts, KEAP1 (D0), YWHAQ (D2 and 4), PSMB5 (D2) and PSMB6 (D4); and C2 + H2O2 (D2) an increase in FOXO3 and MST1 expression, with a decrease of YWHAQ and NRF2 was observed. in C2 + H2O2 (D2) an increase in FOXO3 and MST1, with a decrease in YWHAQ and NRF2 was observed All ERT treatments increased gamma-globin expression. Statistical multivariate analyzes highlighted that the Nrf2-ARE pathway presented a greater contribution in the production of PRDX1, SOD1, CAT, and PSBM5 mRNAs, whereas the PI3K/AKT/FoxO3 pathway was associated with the PRDX2 and TRX transcripts. In conclusion, ERT presented a cytoprotective action through Nrf2 and FoxO3, with the latter seeming to contribute to erythroid proliferation/differentiation.

Oxidative stress biomarkers in treatment-responsive and treatment-resistant schizophrenia patients.

INTRODUCTION: Schizophrenia is a complex psychiatric disorder that affects approximately twenty million people worldwide. Various factors have been associated with the physiopathology of this disease such as oxidative stress, which is an imbalance between pro-oxidant and antioxidant molecules. OBJECTIVE: This study evaluated the association between biomarkers of oxidative stress and response to pharmacological treatment among patients with schizophrenia in the context of their clinical information, demographic data, and lifestyle. METHODS: A total of 89 subjects were included, 26 of whom were treatment-responsive schizophrenia patients (Group 1), 27 treatment-resistant schizophrenia patients (Group 2), and 36 healthy controls (Group 3). All of the subjects completed a questionnaire to provide clinical and demographic data, and all provided peripheral blood samples. The oxidative stress markers analyzed using spectrophotometry were catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), total glutathione (GSH-t), malondialdehyde (MDA), and Trolox-equivalent antioxidant capacity (TEAC; p < 0.05). RESULTS: When all schizophrenia patients (G1 + G2) were compared to the control group, SOD levels were found to be lower among schizophrenia patients (p < 0.0001), while MDA and CAT levels were higher (p < 0.0001 and p = 0.0191, respectively). GPx, GSH-t, and TEAC levels were similar in all three groups (p > 0.05). CONCLUSION: Lower SOD levels and higher MDA and CAT levels indicate oxidative damage in schizophrenia patients, regardless of their response to pharmacological treatment. Smoking is associated with oxidative stress, in addition, a family history of the disease was also found to be correlated with cases of schizophrenia, which reflects the relevance of genetics in disease development.

Oxidative stress, biotransformation enzymes and histopathological alterations in Nile tilapia (Oreochromis niloticus) exposed to new and used automotive lubricant oil.

Lubricant oils are among oil-based products that are not fully consumed during its use, thereby producing non-biodegradable residues which can cause contamination of natural systems. This study evaluated the toxicity of new and used lubricating oil (0.01 and 0.1 mL L-1) in adult Nile tilapia (Oreochromis niloticus), by assessing the effects on oxidative stress, biotransformation enzymes (liver and gills), and histopathological alterations on hepatic and pancreatic tissues after 3 and 7 days of exposure. Results showed that 3-days exposure to 0.1 mL L-1 of used and new lubricating oil increased the activity of superoxide dismutase (SOD) and malondialdehyde (MDA) levels in liver of O. niloticus, respectively. In gills, catalase (CAT) was decreased in fish exposed to 0.1 mL L-1 of non-used oil after 3 days, but pronounced increases in CAT was detected after 7 days-exposure to both new and used oil. Shorter exposure to both concentrations of new and used oil also raised glutathione-S-transferase activity (GST) in gills. Ethoxyresorufin-O-deethylase (EROD) was induced in liver of fish exposed to 0.1 mL L-1of used oil after 3 and 7 days, however a reduced response of this enzyme was detected in gills of animals from both oil treatments. In vitro analysis showed that hepatic EROD was inhibited by lubricating oil exposures, with more pronounced responses in treatments containing used oil. Hepatic lesions, such as cytoplasmic vacuolization, nuclei abnormally, changes in hepatocytes shape, steatosis, cholestasis, eosinophilic inclusions and necrosis were mainly increased by 7 days exposure to used lubricating oil at higher concentration.

Decreased malondialdehyde levels in fish (Astyanax altiparanae) exposed to diesel: Evidence of metabolism by aldehyde dehydrogenase in the liver and excretion in water.

Increased malondialdehyde (MDA) levels are commonly considered an indicator of lipid peroxidation derived from oxidative stress insults promoted by exposure of fish to pollutants. However, a decrease in MDA levels after xenobiotic exposure has been also reported, an effect that is mostly attributed to enhanced antioxidant defenses. In this study, we assessed whether pollutant-mediated MDA decrease would be associated with antioxidant enhancement or with its metabolism by aldehyde dehydrogenase (ALDH) in the liver and gills of lambari (Astyanax altiparanae) exposed to diesel oil (0.001, 0.01, and 0.1 mL/L). MDA levels were decreased in the liver of lambari exposed to diesel. The activities of the antioxidant enzymes, catalase (CAT) and glutathione peroxidase (GPx), were unchanged in the liver, while that of glucose-6-phosphate dehydrogenase (G6PDH) was decreased. In contrast, levels of total glutathione (tGSH) and the activity of glutathione S-transferase (GST) were increased in the liver, which partly support antioxidant protection against lipid peroxidation. More importantly, ALDH activity increased in a concentration-dependent manner, being negatively correlated with MDA levels, indicating MDA metabolism by ALDH. In the gills, diesel exposure increased MDA and lipid hydroperoxide levels, and promoted increases in antioxidant defenses, indicating oxidative stress. Curiously, ALDH activity was undetectable in the gills, supporting the possibility of direct MDA excretion in the water by the gills. Analyses of MDA in the water revealed increased levels of MDA in the aquaria in which the fish were exposed to diesel, compared to control aquaria. A second experiment was carried out in which the fish were intraperitoneally injected with MDA (10 mg/kg) and analyzed after 1, 6, and 12 h. MDA injection caused a time-dependent decrease in hepatic MDA levels, did not alter ALDH, CAT, GPx, and GST activities, and decreased G6PDH activity and tGSH levels. In the gills, MDA injection caused a slight increase in MDA levels after 1 h, but did not alter GPx, G6PDH, and GST activities. MDA injection also enhanced CAT activity and tGSH levels in the gills. MDA concentration in water increased progressively after 1, 6, and 12 h, supporting the hypothesis of direct MDA excretion as an alternative route for MDA elimination in fish. Our results suggest that the decreased MDA levels after exposure of lambari to diesel oil pollutant probably reflects an association between enhanced antioxidant protection, MDA metabolism, and MDA excretion in water.

Fish biomarker responses to perturbation by drought in streams

Drought can be viewd as a perturbation in running waters and fish are often trapped in isolated pools, where deterioration of water quality may be stressful. We investigated how this extreme condition influences response of oxidative stress biomarkers. The response of the characid Astyanax elachylepis was assessed during the dry and rainy seasons in intermittent and perennial (control) sites in streams from Brazilian savannah (Cerrado). We predicted that the biomarkers would be enhanced in the dry season in intermittent streams only due the environmentally harsh conditions in the few isolated pools that remain filled with water. As predicted, fish from the intermittent stream in the dry season presented higher gill MDA values, indicating greater stress. In the liver, MDA values were higher in the dry season for both intermittent and perennial streams, suggesting a generalized seasonal response. As expected, some antioxidant response enzymes changed in the intermittent sites during the dry season. Therefore, oxidative stress biomarkers vary seasonally, with greater increase in intermittent sites. These evidences contribute for the understanding of the spatio-temporal variation of the fish responses and fish resistance to perturbations by drought in tropical environments.(AU)

A seca pode ser vista como uma perturbação em ambientes aquáticos lóticos e, em alguns casos, os peixes podem ser aprisionados em trechos lênticos (poços), onde a perda da qualidade da água pode causar estresse. Investigamos como esta condição extrema influencia biomarcadores bioquímicos de estresse oxidativo. Para isso, a resposta do caracídeo Astyanax elachylepis foi avaliada durante as estações seca e chuvosa em trechos intermitentes e perenes (controle) de riachos da savana brasileira (Cerrado). Predizemos que os biomarcadores seriam aumentados somente em peixes dos trechos intermitentes durante a estação seca, devido as condições restritivas dos poucos poços isolados que contém água. Como predito, os peixes do riacho intermitente apresentaram altos valores de MDA nas brânquias durante a estação seca, indicando maior estresse oxidativo. No fígado, os valores de MDA foram maiores na estação seca em ambos riachos, intermitente e perene, sugerindo uma resposta sazonal generalizada. Como esperado, algumas enzimas antioxidantes foram alteradas em peixes de trechos intermitentes durante a estação seca. Portanto, os biomarcadores de estresse oxidativo variam sazonalmente e essa variação é maior em trechos intermitentes. Essas evidências contribuem para a compreensão da variação espaço-temporal da resposta dos peixes e da sua resistência às perturbações por seca em ambientes tropicais.(AU)

Evaluation of melatonin and AFMK levels in women with breast cancer.

PURPOSE: Changes in the circadian rhythm may contribute to the development of cancer and are correlated with the high risk of breast cancer (BC) in night workers. Melatonin is a hormone synthesized by the pineal gland at night in the absence of light. Levels of melatonin and the metabolite of oxidative metabolism AFMK (acetyl-N-formyl-5-methoxykynurenamine), are suggested as potential biomarkers of BC risk. The aims of this study were to evaluate levels of melatonin and AFMK in women recently diagnosed with BC, women under adjuvant chemotherapy, and night-shift nurses, and compare them with healthy women to evaluate the relation of these compounds with BC risk. METHODS: Blood samples were collected from 47 women with BC, 9 healthy women, 10 healthy night shift nurses, and 6 patients under adjuvant chemotherapy. Compound levels were measured by mass spectrometry. RESULTS AND CONCLUSIONS: Our results showed that women with BC had lower levels of melatonin compared to control group women, and even lower in night-shift nurses and in patients under adjuvant chemotherapy. There was no significant difference of AFMK levels between the groups. In addition to this, high levels of melatonin and AFMK were related to patients with metastasis, and high levels of AFMK were related to the presence of lymph node-positive, tumor > 20 mm and patients who sleep with light at night. Our results showed a reduction of melatonin levels in BC patients, suggesting a relation with the disease, and in addition, point to the importance of melatonin supplementation in women that work at night to reduce the BC risk.

Estrogenic and anti-androgenic effects of the herbicide tebuthiuron in male Nile tilapia (Oreochromis niloticus).

Tebuthiuron is a phenylurea herbicide widely used in agriculture that can reach the aquatic environments, possibly posing negative effects to the aquatic biota. Phenylurea herbicides, such as diuron, are known to cause estrogenic and anti-androgenic effects in fish, but no such effects were yet reported for tebuthiuron exposure. Thus, the aim of this study was to evaluate if tebuthiuron, at environmentally relevant concentrations (100 and 200ng/L) and after 25days of exposure have estrogenic and/or anti-androgenic effects on male of Nile tilapia (Oreochromis niloticus), through the evaluation of plasmatic testosterone (T) and estradiol (E2) levels, brain aromatase (CYP19) levels (western-blot), and by evaluating the histology of the testicles. When compared to the control group, plasmatic T levels decreased about 76% in the animals exposed to 200ng/L of tebuthiuron, while E2 levels increased about 94%, which could be related to a significant increase (77%) in CYP19A1 levels, an enzyme that catalyzes the conversion of androgens into estrogens. Histological analyses of the testicles also demonstrated that tebuthiuron at both tested concentrations caused a decrease in the diameter of the seminiferous tubules and in the diameter of the lumen. Therefore, the gonadosomatic index (GSI) was reduced by 36% % in the animals exposed 200ng/L to tebuthiuron. Indeed, the relative frequency of spermatocytes and spermatids increased respectively 73% (200ng/L) and 61% (100ng/L) in the tebuthiuron exposed animals, possibly due to the impairment of sperm release into the lumen, that was decreased 93% (200ng/L) in the treated animals compared to the control. These results confirm that tebuthiuron causes estrogenic and anti-androgenic effects in Nile tilapias at environmentally relevant concentrations.

Hypoxia effects on oxidative stress and immunocompetence biomarkers in the mussel Perna perna (Mytilidae, Bivalvia).

This study investigated the effects of hypoxia on oxidative stress response and immune function in mussels Perna perna exposed to air for 6, 12, 24 and 48 h. In air-exposed mussels, the antioxidant enzymes superoxide dismutase (SOD), catalase, and glutathione reductase (GR) activities were lower in gill tissues (24-48 h) and digestive gland (12 h), while the glutathione peroxidase and GR activities were increased in the digestive gland (48 h). In both tissues, aerial exposure promoted a rapid (6 h) and persistent (up to 48 h) increase of glutathione levels. Decreased hemocyte count and viability, as well as increased phagocytic activity and cellular adhesion capacity were detected after prolonged aerial exposure (>12 h). In summary, induction of thiol pools, altered antioxidant enzyme activities, and activation of immune responses were detected in hypoxia exposed brown mussels, indicating hypoxia induced tissue-specific responses in both antioxidant and immune systems.

Estrogenic activities of diuron metabolites in female Nile tilapia (Oreochromis niloticus).

Some endocrine disrupting chemicals (EDCs) can alter the estrogenic activities of the organism by directly interacting with estrogen receptors (ER) or indirectly through the hypothalamus-pituitary-gonadal axis. Recent studies in male Nile tilapia (Oreochromis niloticus) indicated that diuron may have anti-androgenic activity augmented by biotransformation. In this study, the effects of diuron and three of its metabolites were evaluated in female tilapia. Sexually mature female fish were exposed for 25 days to diuron, as well as to its metabolites 3,4-dichloroaniline (DCA), 3,4-dichlorophenylurea (DCPU) and 3,4-dichlorophenyl-N-methylurea (DCPMU), at concentrations of 100 ng/L. Diuron metabolites caused increases in E2 plasma levels, gonadosomatic indices and in the percentage of final vitellogenic oocytes. Moreover, diuron and its metabolites caused a decrease in germinative cells. Significant differences in plasma concentrations of the estrogen precursor and gonadal regulator17α-hydroxyprogesterone (17α-OHP) were not observed. These results show that diuron metabolites had estrogenic effects potentially mediated through enhanced estradiol biosynthesis and accelerated the ovarian development of O. niloticus females.

Effects of ammonia stress in the Amazon river shrimp Macrobrachium amazonicum (Decapoda, Palaemonidae).

We evaluate the effects of total ammonia nitrogen-N (TAN) exposure for 72h on (Na(+),K(+))- and V(H(+))-ATPase activities and on their subunit expressions in gills of the diadromous freshwater shrimp Macrobrachium amazonicum. Specific (Na(+),K(+))- and V(H(+))-ATPase activities increased roughly 1.5- to 2-fold, respectively, after exposure to 2.0mmolL(-1) TAN. Quantitative RT-PCR analyses revealed a 2.5-fold increase in V(H(+))-ATPase B subunit mRNA expression while (Na(+),K(+))-ATPase α-subunit expression was unchanged. Immunohistochemical analyses of the gill lamellae located the (Na(+),K(+))-ATPase throughout the intralamellar septal cells, independently of TAN concentration, while the V(H(+))-ATPase was located in both the apical pillar cell flanges and pillar cell bodies. Systemic stress parameters like total hemocyte count decreased by 30% after exposure to 2.0mmolL(-1) TAN, accompanied by increased activities of the oxidative stress enzymes superoxide dismutase, glutathione reductase and glucose-6-phosphate dehydrogenase in the gills. The stress responses of M. amazonicum to elevated TAN include increases in gill (Na(+),K(+))- and V(H(+))-ATPase activities that are accompanied by changes in oxidative stress enzyme activities, immune system effects and an increase in gill V(H(+))-ATPase gene expression. These findings likely underpin physiological effects in a crustacean like M. amazonicum that exploits multiple ecosystems during its life cycle, as well as under culture conditions that may significantly impact shrimp production by the aquaculture industry.

Biochemical responses in mussels Perna perna exposed to diesel B5.

In Brazil B5 blend (5% biodiesel and 95% diesel oil) has been adopted as mandatory fuel since 2010 for automotive vehicles. Since little is known about the effects of B5 exposure can promote on antioxidant system of marine biota this study aimed to assess if B5 can generate modifications in antioxidant parameters of mussels Perna perna. To address this question mussels were exposed to two concentrations of B5 (0.01 mL L(-1) and 0.1 mL L(-1)) for 6h, 12h, 48 h and 168 h. Then the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) were evaluated in gills and digestive gland as well as the contents of glutathione (GSH) and lipid peroxidation by measuring the malondialdehyde concentration (MDA). In the gills, GST activity decreased after 48 h and GR after 12h of exposure to B5. In digestive glands, the activities of SOD, GPx and GR were changed due to treatments. GSH concentration increased in digestive gland after 6h and 12h and in gills after 48 h for B5 0.1 mL L(-1) and after 168 h in the digestive gland for B5 0.01 mL L(-1) treatment. No lipid peroxidation was detected. The integrated biomarker response index (IBR) evidenced a B5 effect in the digestive gland after 168 h of exposure. Regarding the experimental conditions and species used in this study, long-term exposure to B5 is apparently more likely to affect the parameters tested in P. perna mussels.

Potential utility of melatonin as an antioxidant therapy in the management of sickle cell anemia.

This study aimed to assess antioxidant effects of melatonin treatment compared to N-acetylcysteine (NAC) and to their combination in a sickle cell suspension. Sickle erythrocytes were suspended in phosphate-buffered saline, pH 7.4, composing external control group. They were also suspended and incubated at 37°C either in the absence (experimental control group) or in the presence of NAC, melatonin and their combination at concentrations of 100 pm, 100 nm and 100 µm for 1 hr (treatment groups). The melatonin influences were evaluated by spectrophotometric [hemolysis degree, catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PDH), and superoxide dismutase (SOD) activities] and chromatographic methods [glutathione (GSH) and malondialdehyde (MDA) levels]. Incubation period was able to cause a rise about 64% on hemolysis degree as well as practically doubled the lipid peroxidation levels (P < 0.01). However, almost all antioxidants tested treatments neutralized this incubation effect observed in MDA levels. Among the antioxidant biomarkers evaluated, we observed a modulating effect of combined treatment on GPx and SOD activities (P < 0.01), which showed ~25% decrease in their activities. In addition, we found an antioxidant dose-dependent effect for melatonin on lipid peroxidation (r = -0.29; P = 0.03) and for combined antioxidant treatments also on MDA levels (r = -0.37; P = 0.01) and on SOD activity (r = -0.54; P < 0.01). Hence, these findings contribute with important insight that melatonin individually or in combination with NAC may be useful for sickle cell anemia management.

Prostate hyperplasia caused by long-term obesity is characterized by high deposition of extracellular matrix and increased content of MMP-9 and VEGF.

Recent studies have shown a positive association of cancer and obesity, but the morphological and molecular mechanisms involved in this relationship are still unknown. This study analysed the impact of long-term obesity on rat prostate, focusing on stromal changes. Male adult Wistar rats were treated with high-fat diet to induce obesity, while the control group received a balanced diet. After 30 weeks of feeding, the ventral prostate was analysed by immunohistochemistry for cell proliferation, smooth muscle α-actin, vimentin, chondroitin sulphate and metalloproteinases (MMP-2 and 9). The content of androgen receptor (AR), oestrogen receptors (ERs) and vascular endothelial growth factor (VEGF) was measured by Western blotting, and activity of catalase and Glutathione-S-Transferase (GST) were quantified by enzymatic assay. Long-term obesity decreased testosterone plasma levels by 70% and resulted in stromal prostate hyperplasia, as evidenced by increased collagen fibres. Such stromal hyperplasia was associated with increased number of blood vessels and raised VEGF content, and increased expression of chondroitin sulphate, vimentin, α-actin and MMP-9. In spite of the high cell density in prostate, the proliferative activity was lower in the prostates of obese rats, indicating that hyperplasia was established during the early phases in this obesity model. AR levels increased significantly, whereas the ERα decreased in this group. Moreover, the levels of catalase and GST were changed considerably. These findings indicate that long-term obesity, besides disturbing the antioxidant control, causes intense stromal remodelling and release of factors that create an environment that can promote proliferative disorders in the gland, culminating with diffuse hyperplasia.

E2 potentializes benzo(a)pyrene-induced hepatic cytochrome P450 enzyme activities in Nile tilapia at high concentrations.

In the aquatic environment, biotransformation enzymes are established biomarkers for assessing PAH exposure in fish, but little is known about the effect of 17ß-estradiol (E2) on these enzymes during exposure to benzo(a)pyrene (BaP). In this study, Nile tilapia (Oreochromis niloticus) were exposed for 3, 5, and 10 days to BaP (300 µg L(-1)) and E2 (5 µg L(-1)). These substances were applied isolated or mixed. In the mixture experiment, fish were analyzed pre- and postexposure in order to better understand whether preexposure to the hormone masks the responses activated by PAH or vice versa. Phase I enzymes ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-O-depenthylase (PROD), and benzyloxyresorufin-O-debenzylase (BROD) activities as well as the phase II enzyme glutathione S-transferase (GST) were analyzed. Isolated E2 treatment decreased EROD activity after 3 days, but this enzyme activity returned to control values after 5 and 10 days of exposure. Isolated BaP treatment significantly induced EROD activity after 3 and 5 days, and the activity returned to control levels after ten exposure days. Combined treatment (E2 + Bap) significantly increased EROD activity, both in the pre- and postexposure. This increase was even higher than in the isolated BaP treatment, suggesting a synergism between these two compounds. When E2 and BaP were used singly, they did not change BROD and PROD activities. However, combined treatment (E2 + Bap) significantly increased PROD activity. Isolated BaP treatment increased GST activity after 10 days. However, this response was not observed in the mixture treatment, suggesting that E2 suppressed the GST induction modulated by BaP. The results put together indicated that E2 altered the biotransformation pathway regarding enzymes activated by BaP in Nile tilapia.

Efeito da mistura de diazinon e benzo[a]pireno naS-transferase da Glutationa em Tilápias do Nilo / Effect of mixture of diazinon and benzo[a]pyrenein Glutathione S-transferase of Nile tilapia

Atualmente, com a crescente contaminação dos ecossistemas aquáticos, muitos compostos, como pesticidas e hidrocarbonetos,são lançados de forma indevida em corpos d’água. Estudos relacionando a exposição de poluentes, individualmente,com variações bioquímicas são abundantes na literatura. Entretanto, ainda são poucos os voltados às misturas complexas.Sendo assim, o objetivo do presente estudo foi analisar se a mistura diazinon e benzo[a]pireno pode afetar as atividadesbioquímicas de biomarcadores clássicos, tais como acetilcolinesterase (AChE), carboxilesterase (CbE), catalase (CAT), glutationaperoxidase (GPx) e glutationa S-transferase (GST) em Tilápias do Nilo (Oreochromis niloticus) e comparar os efeitosnos sistemas enzimáticos quando estão expostos à mistura e aos compostos separadamente. Foi medida a atividade dasenzimas em brânquias e fígados de Tilápia do Nilo após 2 e 7 dias de exposição ao Diazinon (0,5 mg/L) e ao benzo[a]pireno (1,0 mg/L) individualmente e em mistura. Os resultados mostraram que no grupo mistura do fígado após 7 dias deexposição, o benzo[a]pireno aumentou a ação inibidora do Diazinon na atividade da enzima GST. Isso indica que a toxicidadedas interações ambientais entre pesticida e hidrocarboneto policíclico aromático pode apresentar efeito sinérgico.Desse modo, é importante levar em conta esse fator, pois irá auxiliar na compreensão de resultados obtidos em estudosde campo, como em um monitoramento ambiental.

Currently, with the growing contamination of aquatic ecosystems, many compounds, such as pesticides and hydrocarbons,are improperly released into rivers and lakes. Studies about the exposure of single pollutants causing biochemical variationsare abundant in the literature. However, there are few studies focused on the biological effects of complex mixtures.The aim of this investigation was to evaluate whether mixture diazinon and benzo[a]pyrene can affect the biochemicalactivities of classic biomarkers such as acetylcholinesterase (AChE), carboxylesterase (CbE), catalase (CAT), glutathioneperoxidase (GPx) and glutathione S-transferase (GST) in Nile tilapia and compare the effects on enzymatic systems of theexposure to a mixture of compounds and the effects observed when they are exposed separately. We measured the activityof enzymes in gills and liver of Nile Tilapia (Oreochromis niloticus) after 2 and 7 days of exposure to Diazinon (0.5 mg/L)and benzo[a]pyrene (1.0 mg/L) individually and in mixture. The results showed that in the mixture group after 7 days ofexposure, the benzo[a]pyrene increased the inhibitory action of Diazinon in GST enzyme activity, in liver tissue. This indicatesthat the toxicity of the interactions between pesticide and polycyclic aromatic hydrocarbon may show synergisticeffect. These results suggest the importance of studies with mixture of compounds, because these data will help to understandthe results obtained in field studies, such as those from environmental monitoring.

Genetic and biochemical markers of hydroxyurea therapeutic response in sickle cell anemia.

BACKGROUND: Sickle cell anemia (SCA) presents a complex pathophysiology which can be affected by a number of modifying factors, including genetic and biochemical ones. In Brazil, there have been no studies verifying ßS-haplotypes effect on oxidative stress parameters. This study evaluated ßS-haplotypes and Hb F levels effects on oxidative stress markers and their relationship with hydroxyurea (HU) treatment in SCA patients. METHODS: The studied group was composed by 28 SCA patients. Thirteen of these patients were treated with HU and 15 of them were not. We used molecular methodology (PCR-RFLP) for hemoglobin S genotype confirmation and haplotypes identification. Biochemical parameters were measured using spectrophotometric methods (Thiobarbituric-acid-reactive substances and Trolox equivalent antioxidant capacity levels, catalase and GST activities) and plasma glutathione levels by High-performance liquid chromatography coupled to electrochemical detection. RESULTS: We found the highest frequency of Bantu haplotype (48.2%) which was followed by Benin (32.1%). We observed also the presence of Cameroon haplotype, rare in Brazilian population and 19.7% of atypical haplotypes. The protective Hb F effect was confirmed in SCA patients because these patients showed an increase in Hb F levels that resulted in a 41.3% decrease on the lipid peroxidation levels (r =-0.74, p=0.01). Other biochemical parameters have not shown differential expression according to patient's haplotypes. Bantu haplotype presence was related to the highest lipid peroxidation levels in patients (p < 0,01), but it also conferred a differential response to HU treatment, raising Hb F levels in 52.6% (p = 0.03) when compared with the group with the same molecular profile without HU usage. CONCLUSIONS: SCA patients with Bantu haplotype showed the worst oxidative status. However these patients also demonstrated a better response to the treatment with HU. Such treatment seems to have presented a "haplotype-dependent" pharmacological effect.

Biochemical responses in armored catfish (Pterygoplichthys anisitsi) after short-term exposure to diesel oil, pure biodiesel and biodiesel blends.

Biodiesel fuel is gradually replacing petroleum-based diesel oil use. Despite the biodiesel being considered friendlier to the environment, little is known about its effects in aquatic organisms. In this work we evaluated whether biodiesel exposure can affect oxidative stress parameters and biotransformation enzymes in armored catfish (Pterygoplichthys anisitsi, Loricariidae), a South American endemic species. Thus, fish were exposed for 2 and 7d to 0.01mLL(-1) and 0.1mLL(-1) of pure diesel, pure biodiesel (B100) and blends of diesel with 5% (B5) and 20% (B20) biodiesel. Lipid peroxidation (malondialdehyde) levels and the activities of the enzymes glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase were measured in liver and gills. Also, DNA damage (8-oxo-7, 8-dihydro-2'-deoxyguanosine) levels in gills and 7-ethoxyresorufin-O-deethylase activity in liver were assessed. Pure diesel, B5 and B20 blends changed most of the enzymes tested and in some cases, B5 and B20 induced a higher enzyme activity than pure diesel. Antioxidant system activation in P. anisitsi was effective to counteract reactive oxygen species effects, since DNA damage and lipid peroxidation levels were maintained at basal levels after all treatments. However, fish gills exposed to B20 and B100 presented increased lipid peroxidation. Despite biodiesel being more biodegradable fuel that emits less greenhouse gases, the increased lipid peroxidation showed that biofuel and its blends also represent hazards to aquatic biota.