The aim of this study was to determine oxidative stress parameters in the liver and gill of Brazilian flounder juveniles (307.0 ± 16.0 g and 30.0 ± 4.0 cm) submitted to different water temperature ...(17.1, 23.0 and 28.8ºC) for 72 h and maintained at salinity 25‰. After the acclimation of 7 days, in 23ºC, fish were transferred to 200 L tanks containing seawater (salinity 25‰) at 28.8ºC (heat shock), 17.1ºC (cold shock) or 23.0ºC (control), five replicates (five fish tank-1). The sampled collection occurred in 0 (pre-challenge), 3, 24, 48 and 72 h after temperature shock. Flounder exposed to 17.1ºC and 28.8ºC showed significantly higher TBARS levels and GST activity in the liver post-exposition (PE) in relation to the control (23ºC). CAT activity in liver present a significantly increase at 17.1ºC, in first 48 h, and subsequently decrease in 72 h PE in relation to 28.8ºC. The gills of flounder showed significantly higher TBARS levels, GST and CAT activity when submitted at 17.1 and 28.8ºC in relation to 23.0ºC. There were observed changes in lipid peroxidation levels (LPO), CAT and GST activities in the liver and gill of Brazilian flounder in response to reactive oxygen species (ROS) produced by thermal shocks.
O objetivo deste estudo foi determinar os parâmetros de estresse oxidativo no fígado e brânquias de juvenis de linguado (307,0 ± 16,0 g e 30,0 ± 4,0 cm) submetidos a diferentes temperaturas da água (17,1, 23,0 e 28,8ºC) por 72 h e mantidos na salinidade de 25‰. Após uma aclimatação de sete dias, em 23ºC, os peixes foram transferidos para tanques de 200 L contendo água do mar (salinidade 25‰) em 28,8ºC (choque quente), 17,1ºC (choque frio) ou 23,0ºC (controle), cinco repetições (cinco peixes/tanque). A coleta de amostras ocorreu em 0 (pré-exposição), 3, 24, 48 e 72 h após o choque térmico. O linguado exposto a 17,1ºC e 28,8ºC apresentaram um significante aumento dos níveis de TBARS e atividade da GST no fígado pós-exposição (PE) em relação ao controle (23ºC). A atividade da CAT no fígado apresentou um aumento significativo em 17,1ºC, nas primeiras 48 h, e subsequente diminuição em 72 h PE em relação a 28,8ºC. As brânquias do linguado apresentaram significante aumento dos níveis de TBARS e atividade da GST e CAT quando submetidos a 17,1ºC e 28,8ºC em relação a 23,0ºC. Foram observadas alterações nos níveis de peroxidação lipídica (LPO) e atividade de GST e CAT no fígado e brânquias de linguado em resposta as espécies reativas de oxigênio (ROS) produzidas pelo choque térmico.
Protective or ameliorative effects of quercetin on the oxytetracycline (OTC) induced oxidative stress and presence of OTC residues in the muscle of silver catfish (Rhamdia quelen) were assessed. Fish ...were divided into four different experimental groups and received the following experimental diets for 14 or 21days: (i)-control; (ii)-quercetin; (iii)-OTC; or (iv)-quercetin plus OTC. Muscle samples were collected at the end of the experiment and analyzed for the oxidant/antioxidant status and presence of OTC residues. The OTC values in muscle of fish were lower than the quantification limit. There was a significant increase on lipid peroxidation and protein carbonyl content in the muscle of OTC-treated fish at 14 and 21days. Treatment with quercetin avoided this increase in the groups that received diet with quercetin plus OTC. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities decreased in the muscle of OTC-treated fish at 14days. Quercetin was able to avoid the decrease of GPx activity in the group that fed diet with quercetin plus OTC. After 21days of treatment there was a decrease of SOD, GPx and glutathione S-transferase activities in the muscle of OTC-treated fish. Quercetin was able prevent the decrease of SOD activity in the group that received diet with quercetin plus OTC. The glutathione reductase activity was higher in quercetin group at 14 and 21days of treatment. Ascorbic acid (AA) content increased in quercetin and quercetin plus OTC groups after 14days of treatment. After 21days of treatment, the AA and non-protein thiols content decreased in the muscle of OTC-treated fish. Thus, the present study demonstrates that quercetin protects the muscle from the OTC-induced oxidative stress, suggesting that it may be a useful compound to minimize the adverse effects in fish requiring treatment with OTC.
•Oxytetracycline led to oxidative stress in the muscle of fish in the different time of administration.•Quercetin demonstrated to be able to protect the tissue from oxidative stress caused by oxytetracycline in different time of administration.•Values of oxytetracycline residues in the muscle were lower than the limit of quantification.
The current work investigated whether the long transport could impact the water quality, the response to stress, the antioxidant defense system in cururu stingray (Potamotrygon wallacei) liver, and ...how a recovery process could affect them. Furthermore, it also examined the effects of the Lippia alba essential oil (EOLA) on these transport-induced changes. For this purpose, the cururu stingray (n = 30) were transported in plastic bags (from 3 to 4 specimens, each bag) in the absence or presence of EOLA at 10 μL/L from Manaus (Amazonas, Brazil) to Santa Maria (Rio Grande do Sul, Brazil) for about 32 h. A set of cururu stingray was sampled immediately at the arrival (n = 5 for each condition, without or with EOLA). The remaining individuals were kept for 24 h (n = 5 for each condition, without or with EOLA) and 48 h (n = 5 for each condition, without or with EOLA) to assess their recovery from the trip. After it, they were anesthetized for blood collection, and then, euthanized for liver removal. A set of cururu stingray was sampled before starting the transport protocol (n = 5). Water samples were collected during all steps for monitoring its quality. First of all, when the transport was carried out in the absence of EOLA, it resulted in higher ammonia levels in water linked to a hyperglycemic response, and an impairment in the glutathione-related antioxidant system characterized by decreased total glutathione, and catalytic subunit of glutamate cysteine ligase levels as well as glutathione S-transferase, and glucose-6-phosphate-dehydrogenase activities, thus leading the cururu stingray liver to lipid peroxidation at its arrival. The EOLA, in turn, avoided most transport-induced changes at the arrival. Furthermore, it also helped the antioxidant system to retrieve its optimal function in the liver after 48 h recovery, speeding up the recovery process that could take more than 48 h when transport was completed in the absence of this additive. Therefore, the addition of EOLA to the transport water at 10 μL/L is highly advisable when transporting cururu stingray for more than 30 h.
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•Cururu stingray transport increases ammonia levels in water.•Transport triggers an hyperglycemic response, an stress index.•The glutathione-related antioxidant system in the liver is affected by transport.•Lippia alba essential oil improves water quality during transport.•Lippia alba accelerates the recovery from the transported-induced stress.
The effect of parboiled rice (PR) and white rice (WR) diets on oxidative stress (OS) parameters was investigated in the kidneys of rats with streptozotocin-induced diabetes (40 mg kg(-1), iv). The ...experimental groups (n=8) were control fed with PR (CPR), control fed with WR, diabetic fed with PR, and diabetic fed with WR. After 30 days of treatment, all animals were anesthetized and exsanguinated before removal of kidneys, which were used to determine thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides, carbonyl protein, superoxide dismutase, catalase, glutathione peroxidase (GPx), glutathione reductase, glutathione-S-transferase activities, and levels of glutathione (GSH). Total phenolic compounds were determined in WR and PR grains. Our data indicated that diabetes induced increase in TBARS and lipid hydroperoxides levels. Although PR has not prevented the rise in the levels of these measurements, its consumption by our animals resulted in higher GPx activity and GSH content than that of the CPR. Moreover, PR also presented concentration of total phenolic compounds 127% higher than WR grains. Thus, its consumption in this diabetic condition is suggested because this seems to confer greater protection against OS in the renal tissue of diabetic animals.
Aquatic animals are naturally exposed simultaneously to environments with different concentrations of humic acid (HA) and seasonal or daily variations of dissolved oxygen (DO) levels. This study ...investigated the effects of simultaneous exposure to different HA and DO levels on plasma ion levels and some hematological and oxidative parameters in different tissues of silver catfish (
Rhamdia quelen
). The fish were exposed to 0, 2.5 or 5 mg L
−1
HA for 120 h. After this period, each group was divided into two groups: normoxia and hypoxia. Exposure to the different DO levels lasted 96 h, totaling 216 h of experimentation. At the end of the experimental period, blood sampling was performed, and the fish were euthanized prior to the excision of the gills and the brain to evaluate hematological and oxidative parameters. To verify the antioxidant capacity of HA, total phenolic compounds were measured. In general, all tissues of silver catfish exposed simultaneously to hypoxia and different HA concentrations showed a reduction in lipid peroxidation levels, as well as a modulation of the antioxidant system. These effects occurred in an HA concentration-dependent manner. Thus, HA is beneficial to silver catfish exposed to hypoxia. These beneficial effects can be attributed, most likely, to the action of the different HA constituents and functional groups, including phenolic compounds, which have antioxidant properties.
Purpose:
To assess the contribution of Italian radiation oncologists in the current management of recurrent high-grade gliomas (HGG), focusing on a reirradiation (reRT) approach.
Methods:
In 2015, ...the Reirradiation and the Central Nervous System Study Groups on behalf of the Italian Association of Radiation Oncology (AIRO) proposed a survey. All Italian radiation oncologists were individually invited to complete an online questionnaire regarding their clinical management of recurrent HGG, focusing on a reRT approach.
Results:
A total of 37 of 210 questionnaires were returned (18% of all centers): 16 (43%) from nonacademic hospitals, 14 (38%) from academic hospitals, 5 (13%) from private institutions, and 2 (6%) from hadron therapy centers. The majority of responding centers (59%) treated ≤5 cases per year. Performance status at the time of recurrence, along with a target diameter <5 cm and an interval from primary radiation ≥6 months, were the prevalent predictive factors considered for reRT. Sixty percent of reirradiated patients had already received a salvage therapy, either chemotherapy (40%) or reoperation (20%). The most common approach for reRT was fractionated stereotactic radiotherapy to a mean (photon) dose of 41.6 Gy.
Conclusions:
Although there were wide variations in the clinical practice of reRT across the 37 centers, the core activities were reasonably consistent. These findings provide a basis for encouraging a national collaborative study to develop, implement, and monitor the use of reRT in this challenging clinical setting.
The objective of this study was to evaluate the effect of thorium (Th) bioaccumulation on the metabolism of silver catfish (
Rhamdia quelen) through biochemical parameters of the muscle (glycogen, ...glucose, lactate, protein, and ammonia). In addition, lipidic peroxidation levels (TBARS), catalase (CAT) and glutathione-
S-transferase (GST) in the gills and in hepatic and muscular tissues were also analyzed. Cytogenetic parameters were studied through the evaluation of nuclear abnormalities in red blood cells. Silver catfish juveniles were exposed to different waterborne Th levels (in μg
L
−1): 0 (control), 25.3
±
3.2, 69.2
±
2.73, 209.5
±
17.6, and 608.7
±
61.1 for 15 days. The organs that accumulated the highest Th levels were the gills and skin. The increase of waterborne Th concentration corresponded to a progressive increase of Th levels in the gills, liver, skin and kidneys, with the highest accumulation in the gills and skin. Metabolic intermediates in the muscle were altered by Th exposure, but no clear relationship was found. CAT and GST activities in the hepatic and muscular tissues of this species suggest that the enzymatic activities can be stimulated at the lowest Th levels and inhibited at the higher levels (mainly in 608.7
μg
L
−1). The results of the cytogenetic assay contribute to this hypothesis because the higher toxicity in blood samples was found in juveniles exposed to 69.2 and 209.5
μg
L
−1 Th.
The growing increase in the fish farming sector has favored the establishment of bacterial outbreaks caused by Aeromonas hydrophila in several species. The hexane extract of Hesperozygis ringens ...(HEHR) (Lamiaceae) leaves increased the survival rate of silver catfish (Rhamdia quelen) experimentally infected by A. hydrophila. However, it is noteworthy that no reports have been found on the possible mechanisms of action of this extract in infected fish. This study aimed to evaluate the effect of the HEHR, administered through single immersion bath, on lipid peroxidation and antioxidant defenses in muscle and liver tissue of silver catfish challenged with A. hydrophila. The results showed that the oxidative status of silver catfish was altered, although oxidative stress was not triggered during the experiment. HEHR at 30 mg/L (HEHR30) was not characterized as a pro-oxidant agent in the presence of infection, unlike florfenicol and HEHR at 15 mg/L treatments in some cases. In short, HEHR30 provided an important increase in hepatic catalase activity, characterizing one of the possible mechanisms involved in the greater survival of fish experimentally infected by A. hydrophila. Additionally, HEHR30 did not induce lipid peroxidation, nor reduced antioxidant defenses of silver catfish infected or not by A. hydrophila.
This study aimed to verify whether dietary quercetin protects against the detrimental effects induced by oxytetracycline (OTC) administration in silver catfish (Rhamdia quelen). Fish were divided ...into different experimental groups that received OTC and/or quercetin, either during 14 or 21 days. To determine the endocrine system stress response, we have measured the brain mRNA expression levels of corticotropin-releasing hormone (crh), proopiomelanocortins (pomca and pomcb) and some of the pituitary hormones (growth hormone gh, somatolactin sl, and prolactin prl). We have also quantified the levels of cortisol as well as some metabolites (glucose, glycogen, lactate, and triglycerides) in the plasma. Moreover, the enzymatic activity of hexokinase, phosphorylase (active GPase), fructose-biphosphatase (FBP), glycerol-3-phosphate dehydrogenase, glucose-6-phosphate dehydrogenase, and glutamate dehydrogenase (GDH) and gill Na+/K+-ATPase were measured. The results demonstrated that OTC activates the silver catfish stress response by increasing the plasma cortisol and decreasing the glucose levels at 14 and 21 days. Additionally, OTC also altered the fish hepatic metabolic status as demonstrated by an increase in triglycerides levels and the enzymatic activity of both FBP and GDH after 14 days. OTC also stimulated Na+/K+-ATPase activity in the gill after 14 days and altered the hypophyseal expression of gh (at 14 and 21 days) and prl (at 14 days). The co-treatment with 1.5 g of quercetin could prevent most of the alterations caused by OTC, strongly suggesting quercetin as a beneficial compound when added to the fish diet.
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•Quercetin reduced the levels of cortisol altered by OTC in the silver catfish.•Quercetin reduced hepatic triglycerides and hepatic FBP and GDH activities.•Quercetin reduced gill Na+/K+-ATPase activity altered by OTC in the 14 days.•Quercetin increased hypophyseal expression of gh altered by OTC.•Quercetin reduced hypophyseal expression of prl altered by OTC in the 14 days.
Responses to anaesthesia with essential oil (EO) of Aloysia triphylla (135 and 180 mg L⁻¹) and tricaine methanesulfonate (MS222) (150 and 300 mg L⁻¹) were assessed in silver catfish. Exposure to the ...anaesthetics elicited a stress response in the species. In the case of MS222, it was displayed as a release of cortisol into bloodstream, elevation in hematocrit and plasma ion loss. The EO presented cortisol‐blocking properties, but increased haematocrit and disturbances of hydromineral balance were observed. Liver antioxidant/oxidant status of EO and MS222‐anaesthetized silver catfish was also estimated. The synthetic anaesthetic induced lipoperoxidation, notwithstanding increased catalase contents, whereas the naturally occurring product was capable of preventing the formation of lipid peroxides, possibly due to combined actions of catalase and glutathione‐S‐transferase. Anaesthetic efficacy was also tested via induction and recovery times. Overall, the promising results obtained for the physiological parameters of the EO‐treated fish counterbalanced the slight prolonged induction time observed for 180 mg L⁻¹. As for 135 mg L⁻¹, both induction and recovery times were lengthy; despite that, the EO was able to promote oxidative protection and mitigate stress. None of the MS222 concentrations prompted such responses concomitantly.
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