Vania Lucia Loro

Anesthesia of silver catfish with eugenol: time of induction, cortisol response and sensory analysis of fillet

O objetivo deste estudo foi identificar o tempo de inducao e recuperacao anestesica de jundias (Rhamdia quelen) expostos ao eugenol, bem como a eficacia desse anestesico na inibicao do estresse e realizar analise sensorial dos files dos peixes expostos a essa substância. Os jundias foram expostos ao ar por um minuto para realizacao da biometria, e o sangue foi coletado zero, uma e quatro horas depois. O eugenol pode ser usado na faixa de 20-50mg L-1 para a inducao da anestesia em jundias, e o tempo de recuperacao da anestesia nao foi afetado pela concentracao do eugenol. O grupo de controle mostrou niveis significativamente mais elevados do cortisol quatro horas apos a biometria que no tempo zero. Os peixes anestesiados com eugenol (50mg L-1) apresentaram niveis significativamente mais baixos do cortisol plasmatico do que peixes do grupo de controle do mesmo tempo. Esses dados indicam que o eugenol inibe o aumento do cortisol no sangue. O teste sensorial demonstrou que o eugenol modifica o sabor dos files e consequentemente e contra-indicado para a anestesia do jundia quando o file for destinado ao consumo humano.

Association between thyroid hormones, lipids and oxidative stress biomarkers in overt hypothyroidism

Abstract Background: The aim of this study was to investigate the effect of hypothyroidism on lipid peroxidation and the antioxidant profile, as well as to evaluate the interaction between thyroid hormones and biomarkers of oxidative stress in patients with overt hypothyroidism. We also evaluated the influence of cholesterol concentrations on biomarkers of oxidative stress in these same patients. Methods: Total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and vitamin E were measured in 20 subjects with overt hypothyroidism (OH) and 20 controls. Results: TC, LDL cholesterol, triglycerides, TBARS, SOD, CAT, and vitamin E were significantly higher in the OH group. Significant correlation was observed for TSH and SOD, CAT, vitamin E and TBARS. Correlation was observed for triiodothyronine (T3) and SOD, CAT, vitamin E and TBARS. Significant correlation was also observed for free thyroxine and vitamin E and TBARS. However, correlation between T3 and CAT remained significant after controlling for TC concentrations. Conclusions: Overt hypothyroidism is associated with an increase in oxidative stress, and hypercholesterolemia has a stronger influence on development of oxidative stress in hypothyroid conditions compared with thyroid hormones. Clin Chem Lab Med 2010;48:1635–9.

Effects of the commercial formulation containing fipronil on the non-target organism Cyprinus carpio: implications for rice-fish cultivation.

The aim of this research was to evaluate possible toxic effects of commercial formulation containing fipronil on Cyprinus carpio tissues under rice field conditions. Antioxidant profile (SOD, catalase, glutathione S-transferase), oxidative stress parameters (thiobarbituric acid-reactive substances, protein carbonyl), and growth were investigated in carp exposed to fipronil under rice field conditions for 7, 30, and 90 days. Waterborne insecticide concentrations were measured and the detectable concentration of fipronil was observed up to 45 day after application. Common carp survival and growth was not affected by fipronil. Liver superoxide dismutase activity was enhanced while liver catalase activity was inhibited at 7, 30, and 90 days. Alterations were not observed in the glutathione S-transferase activity in any experimental periods. Protein carbonyl increased only after 30 and 90 days of exposure. The thiobarbituric acid-reactive substances levels were enhanced in all analyzed tissues (liver, muscle, and brain) and periods of exposure. This study demonstrates that fipronil insecticides cause alterations in the biochemical parameters in different tissues of carp without affecting the growth or the survival of the fish.

Toxicological responses of Cyprinus carpio after exposure to a commercial herbicide containing imazethapyr and imazapic

Cyprinus carpio was exposed to imazethapyr and imazapic at laboratory and at field conditions. The laboratory experiment was carried out for 7 days and at rice field for 7, 30 and 90 days. Oxidative stress parameters and antioxidant profile were studied as well as metabolic parameters. After 7 days, brain AChE activity increases in laboratory and field, but in muscle, reduction was observed only in laboratory. At the same period, brain and muscle TBARS and liver CAT increase in the laboratory. Metabolic parameters showed changes in both conditions and exposure periods. After 30 days in rice field, brain AChE activity decreases and in muscle it was enhanced. After 90 days in field, only muscle AChE activity was reduced. The disorders in oxidative stress parameters and metabolism remained, indicating mainly a protein catabolism. This study pointed out short- and long-term effects of rice herbicides at environmentally relevant concentrations on toxicological parameters in tissues of C. carpio.

Effects of the acute exposition to glyphosate-based herbicide on oxidative stress parameters and antioxidant responses in a hybrid Amazon fish surubim (Pseudoplatystoma sp).

The aim of this study was to investigate the effects of acute glyphosate (active ingredient) exposure on the oxidative stress biomarkers and antioxidant defenses of a hybrid surubim (Pseudoplatystoma sp). The fish were exposed to different herbicide concentrations for 96 h. The thiobarbituric acid-reactive substances (TBARS), protein carbonyls and antioxidant responses were verified. The 15 mg a.pL(-1) of herbicide resulted in the death of 50% of the fish after 96 h. An increase in liver and muscle TBARS levels was observed when fish were exposed to the herbicide. The protein carbonyl content was also increased in the liver (4.5mg a.pL(-1) concentration) and brain (2.25 mg a.pL(-1) concentration). The antioxidant activities decreased in the liver and brain after exposure to herbicide. Levels of ascorbic acid in the liver (2.25 mg a.pL(-1) and 4.5 mg a.pL(-1) concentrations) and brain (2.25 mg a.pL(-1) concentration) were increased post-treatment. Levels of total thiols were increased in the liver and brain (2.25 mg L(-1) and 7.5mg a.pL(-1), respectively). Glyphosate exposure, at the tested concentrations affects surubim health by promoting changes that can affect their survival in natural environment. Some parameters as TBARS and protein carbonyl could be early biomarkers for Roundup exposure in this fish species.

Commercial formulation containing quinclorac and metsulfuron-methyl herbicides inhibit acetylcholinesterase and induce biochemical alterations in tissues of Leporinus obtusidens.

The effects of commercial formulation containing quinclorac and metsulfuron-methyl herbicides on acetylcholinesterase (AChE), antioxidant profile and metabolic parameters in teleost fish (Leporinus obtusidens) were studied. The fish were exposed during 90 days to commercial formulation containing quinclorac (204 μg L(-1)) and metsulfuron-methyl (5.8 μg L(-1)) herbicides in rice field irrigated condition. AChE activity in the brain and muscle decreased after exposure to both commercial formulations. The same response was observed for the TBARS levels in brain, liver and muscle. Liver catalase activity reduced after exposure to commercial formulation containing quinclorac and metsulfuron-methyl herbicides. Metabolic parameters in the liver and white muscle (glycogen, lactate, protein and glucose) were determined. These parameters showed different changes after exposure to both commercial formulations. This study pointed out long-term effects of exposure to commercial formulations containing herbicides used in rice on metabolic and enzymatic parameters in tissues of L. obtusidens.

Oxidative stress biomarkers in Cyprinus carpio exposed to commercial herbicide bispyribac-sodium.

Cyprinus carpio were exposed under field conditions to 20.87 µg l−1 of commercial herbicide bispyribac‐sodium (Nominee®, SC), during 7, 21 and 72 days. Enzymatic parameters such as catalase (CAT), glutathione S‐transferase (GST) and acetylcholinesterase (AChE) activities, as well as thiobarbituric acid‐reactive substances (TBARS) and protein carbonyl contents were studied in different tissues. After 7 days of exposure, GST activity decreased. At the same period, brain AChE activity increased, but a reduction of activity was observed in muscle tissue. Brain TBARS levels increased at 7 days. After 21 days of exposure liver CAT levels and muscle AChE activities decreased. In the same period, liver protein carbonyl and muscle TBARS increased. After 72 days of exposure in the field, AChE activity was reduced in both brain and muscle. Protein carbonyl contents in liver and brain TBARS levels increased. Muscle AChE activity, TBARS and protein carbonyl can be used as biomarkers of exposure to the herbicide bispyribac‐sodium. This study demonstrates effects of exposure to bispyribac‐sodium under rice field conditions on oxidative stress parameters in tissues of Cyprinus carpio. Copyright

Pesticide contamination of water alters the metabolism of juvenile silver catfish, Rhamdia quelen

We investigated how pesticide contamination of water affects the metabolism of the silver catfish, Rhamdia quelen, by studying fish maintained at two sites with low and high anthropic activity (Lino Creek, southern Brazil). Several pesticides were found at both stream sites. After 30 days plasma glucose levels were higher in fish exposed to water in the low anthropic activity site than those exposed to water in the high anthropic activity site. Plasma K+ levels, however, were lower after exposure to low anthropic water than after exposure to high anthropic water. Moreover, values of hepatic glycogen, muscle lactate and protein were higher, but glycogen and protein of the kidney were lower in fish exposed to water at the high anthropic activity site. Our results show that these fish can be used as pesticide toxicity indicators in streams near agricultural fields.

Assessment of oxidative stress and metabolic changes in common carp (Cyprinus carpio) acutely exposed to different concentrations of the fungicide tebuconazole.

The aim of this research is to determine the lethal concentration (LC(50-96 h)) of fungicide tebuconazole for common carp (Cyprinus carpio) and to investigate the occurrence of oxidative stress and metabolic changes after acute exposure to different concentrations of tebuconazole. For this purpose, several parameters were assessed as whole-body levels of thiobarbituric acid-reactive substance (TBARS), protein carbonyl, catalase, superoxide dismutase, glutathione S-transferase, nonprotein thiols, ascorbic acid, glycogen, glucose, lactate, protein, amino acids and ammonia in tebuconazole-exposed fish. The calculated LC(50-96 h) was 2.37 mg L(-1). Fish exhibited significant increase in TBARS levels in all concentrations used while the enzymatic and nonenzymatic antioxidants were decreased. Among the metabolic parameters, glycogen and glucose increased at 1.19 mg L(-1) and protein levels decreased at 1.78 and 2.37 mg L(-1). In conclusion, the fish health was adversely affected by exposure to tebuconazole, and those changes can compromise animal survival in the natural environment. The results indicate that the some of the parameters measured like a possible biomarkers of exposure to tebuconazole for this species of fish.

Bioaccumulation and oxidative stress parameters in silver catfish (Rhamdia quelen) exposed to different thorium concentrations

The objective of this study was to evaluate the effect of chronic thorium (Th) exposure on bioaccumulation, metabolism (through biochemical parameters of the muscle) and oxidative parameters (lipidic peroxidation levels and antioxidant enzymes in the gills and in the hepatic and muscular tissues) of silver catfish (Rhamdia quelen). Silver catfish juveniles were exposed to different waterborne Th levels (in microg L(-1)): 0 (control), 25.3+/-3.2, 80.6+/-12.0, 242.4+/-35.6, and 747.2+/-59.1 for 30 d. The gills and skin were the organs that accumulated the highest Th levels. The increase in the waterborne Th concentration corresponded to a progressive increase in the Th levels in the gills and kidney. Chronic Th exposure causes alterations in the oxidative parameters of silver catfish gills, which are correlated with the Th accumulation in this organ. The levels of GST decreased in the gills of fish exposed to 747.2 microg L(-1) Th and SOD activity decreased in silver catfish exposed to 242.4 and 747.2 microg L(-1) Th. In addition, the increase in the LPO in the gills exposed to 242.4 and 747.2 microg L(-1) Th suggests that higher oxidative damage occurred in the gills. However, in the liver and muscle, these alterations occurred mainly in the lowest waterborne Th level. Metabolic intermediates in the muscle were altered by Th exposure, but no clear relationship was found.