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1.
Environ Res ; 226: 115671, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36907345

RESUMO

Potential endocrine-disrupting properties of cyanotoxins, such as microcystin-LR (MC-LR) and cylindrospermopsin (CYN) are of concern due to their increasing occurrence, the scarcity of reports on the topic (particularly for CYN) and the impact of human's health at different levels. Thus, this work performed for the first time the uterotrophic bioassay in rats, following the Organization for Economic Cooperation and Development (OECD) Test Guideline 440, to explore the oestrogenic properties of CYN and MC-LR (75, 150, 300 µg/kg b.w./day) in ovariectomized (OVX) rats. Results revealed neither changes in the wet and blotted uterus weights nor in the morphometric study of uteri. Moreover, among the steroid hormones analysed in serum, the most remarkable effect was the dose-dependent increase in progesterone (P) levels in rats exposed to MC-LR. Additionally, a histopathology study of thyroids and serum levels of thyroids hormones were determined. Tissue affectation (follicular hypertrophy, exfoliated epithelium, hyperplasia) was observed, as well as increased T3 and T4 levels in rats exposed to both toxins. Taken together, these results point out that CYN and MC-LR are not oestrogenic compounds at the conditions tested in the uterotrophic assay in OVX rats, but, however, thyroid disruption effects cannot be discarded.


Assuntos
Toxinas Bacterianas , Glândula Tireoide , Humanos , Animais , Ratos , Organização para a Cooperação e Desenvolvimento Econômico , Estrogênios/toxicidade , Toxinas Bacterianas/toxicidade , Toxinas de Cianobactérias , Microcistinas/toxicidade , Microcistinas/análise
2.
Travel Med Infect Dis ; 49: 102415, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35934309

RESUMO

BACKGROUND: Lower eosinophil counts observed during acute malaria episodes could hide helminth-related eosinophilia. METHOD: Retrospective observational study with sub-Saharan migrants with imported malaria from May-2007 to May-2020. Absolute eosinophil count was determined upon diagnosis at hospital admission and at least once after clearance of parasitemia. Helminthic co-infections were investigated by searching for stool and urine parasites, serology for Strongyloides spp. and Schistosoma spp., and Knott and/or saponin tests for blood microfilariae. RESULTS: A total of 259 patients were included. Most of them were male (n = 237; 91.5%) and VFR travelers (n = 241; 93.1%). 131 patients (50.6%) were diagnosed with probable schistosomiasis, 15 (5.8%) with confirmed schistosomiasis, 16 (6.2%) with strongyloidiasis, 4 (1.6%) with soil-transmitted helminthiasis, and 4 (1.6%) with filariasis (Mansonella perstans). Prevalence of eosinophilia increased from 2.7% on admission to 32.5% during outpatient follow-up. Eosinophilia did not appear until several weeks after hospital discharge in up to 24% of the confirmed helminthic co-infections and in 61.1% of patients with probable schistosomiasis. Eosinophilia was associated with confirmed schistosomiasis and mansonellosis while 56.2% and 75% of cases with strongyloidiasis and soil-transmitted worms did not present eosinophilia at any time, respectively. CONCLUSIONS: Regardless of the absence of eosinophilia, patients hospitalized because of acute imported malaria might benefit from the screening of the main parasitic diseases, allowing for earlier diagnosis and treatment.


Assuntos
Coinfecção , Eosinofilia , Malária , Esquistossomose , Estrongiloidíase , Coinfecção/epidemiologia , Eosinofilia/etiologia , Eosinófilos , Feminino , Humanos , Malária/complicações , Malária/epidemiologia , Masculino , Esquistossomose/complicações , Esquistossomose/diagnóstico , Esquistossomose/epidemiologia , Solo , Estrongiloidíase/complicações , Estrongiloidíase/diagnóstico , Estrongiloidíase/epidemiologia
3.
Int J Mol Sci ; 23(3)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35163089

RESUMO

Lipopolysaccharide (LPS)-induced endotoxemia induces an acute systemic inflammatory response that mimics some important features of sepsis, the disease with the highest mortality rate worldwide. In this work, we have analyzed a murine model of endotoxemia based on a single intraperitoneal injection of 5 mg/kg of LPS. We took advantage of galectin-3 (Gal3) knockout mice and found that the absence of Gal3 decreased the mortality rate oflethal endotoxemia in the first 80 h after the administration of LPS, along with a reduction in the tissular damage in several organs measured by electron microscopy. Using flow cytometry, we demonstrated that, in control conditions, peripheral immune cells, especially monocytes, exhibited high levels of Gal3, which were early depleted in response to LPS injection, thus suggesting Gal3 release under endotoxemia conditions. However, serum levels of Gal3 early decreased in response to LPS challenge (1 h), an indication that Gal3 may be extravasated to peripheral organs. Indeed, analysis of Gal3 in peripheral organs revealed a robust up-regulation of Gal3 36 h after LPS injection. Taken together, these results demonstrate the important role that Gal3 could play in the development of systemic inflammation, a well-established feature of sepsis, thus opening new and promising therapeutic options for these harmful conditions.


Assuntos
Modelos Animais de Doenças , Endotoxemia/patologia , Galectina 3/fisiologia , Inflamação/patologia , Lipopolissacarídeos/toxicidade , Macrófagos Peritoneais/imunologia , Animais , Endotoxemia/etiologia , Endotoxemia/metabolismo , Inflamação/etiologia , Inflamação/metabolismo , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Macrófagos Peritoneais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
4.
Food Chem Toxicol ; 161: 112827, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35077829

RESUMO

The organosulfur compounds (OSC) extracted from Allium spp. exhibit antibacterial, antifungal, and antioxidant properties. The agri-food industry is taking advantage of these properties by using them as natural feed and food additives. In the present work, an acute and a subchronic 90-days toxicity studies have been conducted for the first time to assess the safety of the OSC propyl-propane-thiosulfinate (PTS). Both studies were carried out following the Organization for Economic Co-operation and Development test guidelines (425 and 408, respectively). The acute study provided a maximum tolerated dose (MTD) of 175 mg/kg and the subchronic study established the Non Observed Adverse Effect Level (NOAEL) ≥ 55 mg/kg body weight (b.w.)/day in both sexes. In addition, the subchronic study performed on rats exposed to 14, 28 and 55 mg/kg b.w./day PTS, revealed no changes in any of the hematological parameters measured as well as no differences in body weight and water/food consumption. However, biochemical parameters were altered in some groups, although they were not biologically significant (Ca2+ in female rats, and the thyroids hormones T3 and T4 in rat males). Furthermore, the histopathological assessment evidenced no abnormality on the gastrointestinal, respiratory, lymphoid, urinary, circulatory, nervous, musculoskeletal, and reproductive systems.


Assuntos
Allium/química , Extratos Vegetais/farmacologia , Ácidos Tiossulfônicos/toxicidade , Animais , Relação Dose-Resposta a Droga , Feminino , Dose Letal Mediana , Masculino , Extratos Vegetais/química , Ratos , Testes de Toxicidade
5.
Foods ; 10(5)2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062736

RESUMO

Propyl-propanethiosulfinate (PTS) is a component of Allium essential oils. This organosulfur molecule can be used as a feed additive to decrease the appearance of bacterial resistances caused by the residues of antibiotics. In previous in vitro genotoxicity studies, contradictory results were reported for PTS. In this work, the in vivo genotoxicity of PTS in male and female rats was assessed for the first time, following OECD (Organisation for Economic Co-operation and Development) guidelines. After oral administration (doses: 5.5, 17.4, and 55.0 mg/kg PTS body weight), a combination of the micronucleus (MN) assay (OECD 474) in bone marrow and the standard and enzyme-modified comet assay (OECD 489) was performed. After necropsy, histopathological studies were also carried out. The results did not show the in vivo genotoxicity of PTS at any doses assayed, revealed by the absence of increased MN, and DNA strand breaks or oxidative DNA damage in the standard and enzyme-modified comet assays. The histopathological study revealed that only the highest dose tested (55.0 mg/kg) in the liver and all dose groups in the stomach presented minimal pathological lesions in the organs studied. Consequently, the present work confirms that PTS is not genotoxic at the doses assayed, and it is a promising natural alternative to synthetic preservatives and antibiotics in animal feed.

6.
Food Chem Toxicol ; 151: 112108, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33741479

RESUMO

Cylindrospermopsin (CYN) is a toxin with a world-wide increasing occurrence. It can induce toxic effects both in humans and the environment, and toxicity studies are needed to complete its toxicological profile. In this sense, in vivo oral toxicity studies with pure CYN are scarce. The aim of this work was to perform a repeated dose 28-day oral study in rats following the OECD guideline 407 to provide information on health hazard likely to arise from this kind of exposure. Male and female Sprague-Dawley rats were dosed with 18.75, 37.5 and 75 µg CYN/kg b.w./day. After the study period, no clinical signs or mortality and no significant differences in final body weight, body weight gain and total feed intake in both sexes were observed. Only in females some biochemical parameters (triglycerides (TRIG) levels and aspartate aminotransferase (AST) activity) as well as changes in the weight of organs (absolute liver weight values, relative kidney/body weight ratios or relative liver weight/brain weight ratios) were altered, but without toxicological relevance. Histopathological analysis revealed a very mild affectation of liver and kidney in rats. These results suggest the need to perform longer oral toxicity studies to define the potential consequences of long term CYN exposure.


Assuntos
Alcaloides/toxicidade , Administração Oral , Alcaloides/administração & dosagem , Animais , Peso Corporal/efeitos dos fármacos , Testes de Química Clínica , Toxinas de Cianobactérias , Relação Dose-Resposta a Droga , Comportamento de Ingestão de Líquido/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Feminino , Testes Hematológicos , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
7.
Food Chem Toxicol ; 144: 111612, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32738370

RESUMO

Propyl-propane-thiosulfonate (PTSO) is one of the main organosulfur compounds present in Allium essentials oil. Different applications in the food sector have been proposed for PTSO, such as food and feed additive and as active packaging. However, the authorization of its use depends on its toxicity profile. Thus, as a part of its safety assessment, in this work a repeated dose 90-day oral toxicity study has been conducted for the first time in rats following the OECD guideline 408. PTSO was administered to groups of 10 male and 10 female rats at dose levels of 0, 14, 28, and 55 mg/kg/day. No clinical signs or mortality and no changes in body weight, food consumption and feed conversion efficiency were detected through the study. Moreover, no treatment-related changes in hematological and biochemical parameters were observed, for either sex or dose groups. The histopathology study performed revealed no differences in organ weights, and no morphological and histopathological changes were observed. Based on these results, the no-observed-adverse-effect level (NOAEL) of PTSO was judged to be ≥ 55 mg/kg/day for both sexes.


Assuntos
Testes de Toxicidade Subcrônica , Administração Oral , Animais , Peso Corporal/efeitos dos fármacos , Testes de Química Clínica , Relação Dose-Resposta a Droga , Comportamento de Ingestão de Líquido/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Feminino , Testes Hematológicos , Masculino , Nível de Efeito Adverso não Observado , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Aumento de Peso/efeitos dos fármacos
8.
Toxins (Basel) ; 12(6)2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32466519

RESUMO

Cylindrospermopsin (CYN) and microcystins (MC) are cyanotoxins that can occur simultaneously in contaminated water and food. CYN/MC-LR mixtures previously investigated in vitro showed an induction of micronucleus (MN) formation only in the presence of the metabolic fraction S9. When this is the case, the European Food Safety Authority recommends a follow up to in vivo testing. Thus, rats were orally exposed to 7.5 + 75, 23.7 + 237, and 75 + 750 µg CYN/MC-LR/kg body weight (b.w.). The MN test in bone marrow was performed, and the standard and modified comet assays were carried out to measure DNA strand breaks or oxidative DNA damage in stomach, liver, and blood cells. The results revealed an increase in MN formation in bone marrow, at all the assayed doses. However, no DNA strand breaks nor oxidative DNA damage were induced, as shown in the comet assays. The histopathological study indicated alterations only in the highest dose group. Liver was the target organ showing fatty degeneration and necrotic hepatocytes in centrilobular areas, as well as a light mononuclear inflammatory periportal infiltrate. Additionally, the stomach had flaking epithelium and mild necrosis of epithelial cells. Therefore, the combined exposure to cyanotoxins may induce genotoxic and histopathological damage in vivo.


Assuntos
Alcaloides/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Fígado Gorduroso/induzido quimicamente , Hepatócitos/efeitos dos fármacos , Toxinas Marinhas/toxicidade , Microcistinas/toxicidade , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Animais , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Ensaio Cometa , Toxinas de Cianobactérias , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Feminino , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/patologia , Hepatócitos/metabolismo , Hepatócitos/patologia , Masculino , Testes para Micronúcleos , Necrose , Ratos Wistar
9.
Food Chem Toxicol ; 132: 110664, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31279043

RESUMO

Cylindrospermopsin (CYN) is a potent cyanotoxin recognized as an emerging human threat due to its cytotoxicity and potential carcinogenicity. Although the genotoxicity of CYN has been extensively studied in vitro, limited data are available on its in vivo genotoxicity. The aim of this study was to evaluate the in vivo genotoxicity of pure CYN (7.5-75 µg/kg body weight) after oral exposure of rats through a combined assay of the micronucleus test (MN) in bone marrow, and the standard and modified comet assay in stomach, liver and blood. Also, histopathological changes in stomach and liver were evaluated. Positive results in the MN test were observed in bone marrow in the exposed rats at all the tested concentrations. However, the comet assay revealed that CYN did not induce DNA strand breaks nor oxidative DNA damage in any of the tissues investigated. Finally, histopathological changes were observed in stomach and liver (7.5-75 µg/kg) in intoxicated rats. These results could indicate that CYN is able to induce irritation in stomach before its biotransformation in rats orally exposed, and genotoxicity in bone marrow.


Assuntos
Toxinas Bacterianas/toxicidade , Ensaio Cometa , Testes para Micronúcleos , Mutagênicos/toxicidade , Uracila/análogos & derivados , Alcaloides , Animais , Medula Óssea/efeitos dos fármacos , Toxinas de Cianobactérias , Dano ao DNA , Fígado/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Estômago/efeitos dos fármacos , Uracila/toxicidade
10.
Ecotoxicol Environ Saf ; 156: 116-124, 2018 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-29549734

RESUMO

Thousands of safety-related studies have been published on bisphenol A (BPA), an ubiquitous environmental pollutant with estrogenic activity and many other potential biological effects. In recent years, BPA exposure has been shown to cause anovulation and infertility through irreversible alteration of the hypothalamic-pituitary-gonadal axis in several organisms, including fish and mammals. Recently, the European Chemical Agency classified BPA as a "substance of very high concern" because of its endocrine-disrupting properties, which have serious effects on human health. Given the risk of exposure to BPA as a pollutant in the environment, food, and drinking water, the objective of our study was to assess the effects of this compound on the adeno-hypophysis by means of a histopathological and morphometric study of the gonadotroph cells. In addition, using quantitative real-time PCR (qRT-PCR) assays, we analyzed the changes in the expression of Cyp19b (an aromatase gene). Zebrafish were randomly distributed into five groups: a control group and 4 treated groups which were exposed to different BPA concentrations (1, 10, 100 and 1000 µg/L). The effects of the different doses on Cyp19b mRNA molecules followed a non-monotonic curve, with the 1 and 1000 µg/L doses causing dramatic decreases in the number of Cyp19b transcripts while the doses of 10 and 100 µg/L caused important increases. The consequences might be deregulation of gonadotropic hormones causing degeneration of gonadotropic cells, as observed in BPA treated animals. This is the first study in which the gonadotroph cells have been evaluated using histomorphological endpoints after BPA exposure in zebrafish.


Assuntos
Compostos Benzidrílicos/toxicidade , Hipotálamo/efeitos dos fármacos , Ovário/efeitos dos fármacos , Fenóis/toxicidade , Reprodução/efeitos dos fármacos , Peixe-Zebra/metabolismo , Animais , Aromatase/genética , Aromatase/metabolismo , Biomarcadores/metabolismo , Relação Dose-Resposta a Droga , Disruptores Endócrinos/toxicidade , Determinação de Ponto Final , Feminino , Gonadotrofos/citologia , Gonadotrofos/efeitos dos fármacos , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
11.
Food Chem Toxicol ; 112: 19-25, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29258955

RESUMO

Given the importance of bisphenol A (BPA) as a xenoestrogen and its potential effects on human and animal health, we evaluated BPA exposure's short-term effects on follicular development, yolk protein vitellogenin (VTG) production and aromatase expression in female zebrafish. Histological modifications were observed along with increased presence of atretic follicles. Whole-body VTG concentration increased with the dose of BPA exposure. In contrast, expression of Cyp19a mRNA in the ovaries of BPA-exposed fish exhibited an apparent non-monotonic response curve, marked by downregulation at 1 µg/L BPA, upregulation at 10 µg/L BPA, and a return to downregulation at 100 µg/L BPA and higher doses. Ovaries only exhibited significant increases in follicular atresia and VTG concentration after exposure to 100 µg/L BPA and higher doses. Ovarian histopathology, aromatase Cyp19a transcript levels and whole-body VTG protein abundance may be good biomarkers for early detection of environmental BPA exposure.


Assuntos
Compostos Benzidrílicos/toxicidade , Disruptores Endócrinos/toxicidade , Atresia Folicular/efeitos dos fármacos , Ovário/efeitos dos fármacos , Fenóis/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Animais , Aromatase/genética , Biomarcadores/metabolismo , Relação Dose-Resposta a Droga , Regulação para Baixo , Monitoramento Ambiental/métodos , Estradiol/metabolismo , Feminino , Ovário/enzimologia , Ovário/patologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Regulação para Cima , Vitelogeninas/metabolismo , Proteínas de Peixe-Zebra/genética
12.
Am J Trop Med Hyg ; 96(6): 1427-1429, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28719260

RESUMO

AbstractWe report the case of a patient from Mali who, after 10 years of living in Spain, presented with symptomatic Plasmodium falciparum malaria without having visited an endemic area during that time. We cannot completely rule out the possibility of indigenous transmission, but this case most likely represents recrudescence of an infection acquired over 10 years earlier.


Assuntos
Malária Falciparum/diagnóstico , Adulto , Antimaláricos/uso terapêutico , Emigrantes e Imigrantes , Humanos , Malária Falciparum/tratamento farmacológico , Masculino , Mali , Plasmodium falciparum/isolamento & purificação , Recidiva , Espanha
13.
Environ Toxicol ; 32(4): 1318-1332, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27463828

RESUMO

Cylindrospermopsin (CYN) is a highly water-soluble cytotoxin produced by several species of freshwater cyanobacteria and it is considered the second most studied cyanotoxin worldwide. CYN acts as a potent protein and glutathione synthesis inhibitor, as well as inducing genotoxicity, oxidative stress and histopathological alterations. Studies concerning the depuration of cyanobacterial toxins in aquatic organisms, especially in fish, are of great interest for fish economy and public health, but are scarce in the case of CYN. This is the first study reporting the ability of depuration (3 - 7 days) in reversing or ameliorating the histopathological lesions induced in liver, kidney, heart, intestines, and gills of tilapia (Oreochromis niloticus) due to exposure by immersion to repeated doses of a CYN-containing culture of A. ovalisporum for 14 days. The main histopathological changes induced by CYN were glucogenic degeneration and loss of the normal hepatic cord-structure (liver), hyperemia, dilated Bowman's capsule and cellular tumefaction (kidney), myofibrolysis, hemorrhages and edema (heart), necrosis and partial loss of microvilli (gastrointestinal tract), and hyperemia and inflammatory cells infiltrates (gills). After 3 days of depuration, gills were totally recovered, while the liver, kidney, and gastrointestinal tract required 7 days, and longer depuration periods may be needed for a full recovery of the heart. In addition, the morphometric study indicated that depuration managed to reverse the affectation in the hepatocytes nuclear diameters and cross sections of the proximal and distal convoluted tubules induced in CYN-exposed fish. In general, these results validate depuration as an effective practice for detoxification of fish contaminated with CYN. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1318-1332, 2017.


Assuntos
Toxinas Bacterianas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Uracila/análogos & derivados , Alcaloides , Animais , Cianobactérias/metabolismo , Toxinas de Cianobactérias , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Brânquias/patologia , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Intestinos/efeitos dos fármacos , Intestinos/patologia , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Tilápia , Uracila/toxicidade
14.
Environ Toxicol ; 32(1): 241-254, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26714798

RESUMO

Cylindrospermopsin (CYN) is a cytotoxin highly water-soluble, which is easily taken up by several aquatic organisms. CYN acts as a potent protein and glutathione synthesis inhibitor, as well as inducing genotoxicity, oxidative stress, and histopathological alterations. This is the first study reporting the protective effect of a l-carnitine (LC) pretreatment (400 or 880 mg LC/kg bw fish/day, for 21 days) on the histopathological alterations induced by pure CYN or Aphanizomenon ovalisporum lyophilized cells (400 µg CYN/kg bw fish) in liver, kidney, heart, intestines, and gills of tilapia (Oreochromis niloticus) acutely exposed to the toxin by oral route. The main histopathological changes induced by CYN were disorganized parenchyma with presence of glycogen and lipids in the cytoplasm (liver), glomerulonephritis, glomerular atrophy, and dilatation of Bowman's capsule (kidney), myofibrolysis, loss of myofibrils, with edema and hemorrhage (heart), intestinal villi with necrotic enterocytes and partial loss of microvilli (gastrointestinal tract), and hyperemia and hemorrhage (gills). LC pretreatment was able to totally prevent those CYN-induced alterations from 400 mg LC/kg bw fish/day in almost all organs, except in the heart, where 880 mg LC/kg bw fish/day were needed. In addition, the morphometric study indicated that LC managed to recover totally the affectation in the cross sections of the proximal and distal convoluted tubules in CYN-exposed fish. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 241-254, 2017.


Assuntos
Toxinas Bacterianas/toxicidade , Carnitina/farmacologia , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Uracila/análogos & derivados , Poluentes da Água/toxicidade , Alcaloides , Animais , Aphanizomenon/metabolismo , Toxinas Bacterianas/metabolismo , Ciclídeos/metabolismo , Toxinas de Cianobactérias , Dieta , Brânquias/efeitos dos fármacos , Brânquias/patologia , Coração/efeitos dos fármacos , Rim/patologia , Fígado/patologia , Microscopia Eletrônica , Miocárdio/patologia , Estresse Oxidativo/efeitos dos fármacos , Uracila/toxicidade
15.
Food Chem Toxicol ; 98(Pt B): 240-250, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27829163

RESUMO

Genotoxic data of substances which could be incorporated into food packaging are required by the European Food Safety Authority. Due to its antioxidant and antibacterial properties carvacrol is one of these compounds. This work aims to study for the first time the in vivo genotoxic effects produced in rats orally exposed to 81, 256 or 810 mg cavacrol/kg body weight (bw) at 0, 24 and 45 h. A combination of the micronucleus assay (OECD 474) in bone marrow and the standard (OECD 489) and enzyme-modified comet assay was used to determine the genotoxicity on cells isolated from stomach and liver of exposed animals. In addition, a histopathological study was performed on the assayed tissues, and also in the lungs due to the volatility of carvacrol. Direct analytical pyrolysis was used to search for carvacrol in viscera and to ensure that the compound reaches stomach and liver cells. Results from MN-comet assay revealed that carvacrol (81-810 mg/kg bw) did not induce in vivo genotoxicity or oxidative DNA damage in any of the tissues investigated. Moreover, no histopathological changes were observed. Altogether, these results suggest lack of genotoxicity of carvacrol and therefore its good profile for its potential application as food preservative.


Assuntos
Ensaio Cometa/métodos , Dano ao DNA/efeitos dos fármacos , Testes para Micronúcleos/métodos , Monoterpenos/toxicidade , Animais , Medula Óssea/efeitos dos fármacos , Cimenos , Relação Dose-Resposta a Droga , Feminino , Fígado/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Estômago/efeitos dos fármacos
16.
Artigo em Inglês | MEDLINE | ID: mdl-27085469

RESUMO

Components of Allium species have antimicrobial and antioxidant properties. A commercial Allium sp. extract (Proallium AP(®)), of which the main constituent is propyl thiosulphinate oxide (PTSO), is being used in the development of active food packaging. In previous in vitro genotoxicity studies, PTSO, in the presence of metabolic activation, increased the appearance of micronuclei (MN). We assessed the genotoxicity PTSO in rats following oral administration (doses: 5.5, 17.4, and 55mg/kg). The comet assay in liver and stomach (OECD 489) and the MN assay in bone marrow (OECD 474) were carried out. After necropsy, histopathological examinations of the liver and the stomach were performed. The results revealed no in vivo genotoxicity and the histopathological analysis showed only slight modifications, such as increased glycogen storage in the liver and a degenerative process in stomach, with vacuolization of cell membranes, only at the highest dose. Therefore, the present work confirms that this compound is not genotoxic and could be considered as a natural alternative to synthetic preservatives used in the food packaging industry.


Assuntos
Allium/química , Ensaio Cometa/métodos , Testes para Micronúcleos/métodos , Ácidos Sulfínicos/toxicidade , Animais , Feminino , Embalagem de Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Mucosa Gástrica/ultraestrutura , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/ultraestrutura , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Microscopia Eletrônica de Transmissão , Testes de Mutagenicidade , Ratos Wistar , Estômago/efeitos dos fármacos , Estômago/patologia , Ácidos Sulfínicos/sangue , Ácidos Sulfínicos/metabolismo
17.
Environ Toxicol ; 31(11): 1469-1485, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26011011

RESUMO

Cylindrospermopsin (CYN) is a cyanotoxin frequently involved in blooms with a predominantly extracellular availability, which makes it easily taken up by a variety of aquatic organisms. CYN is a potent protein and glutathione synthesis inhibitor, and also induces genotoxicity, oxidative stress and several histopathological lesions. The present study investigates the protective role of a vitamin E pretreatment (700 mg vit E/kg fish bw/day, for 7 days) on the histopathological alterations induced in different organs of tilapia (Oreochromis niloticus) acutely exposed to a single oral dose of 400 µg pure CYN/kg bw fish. The major histological changes observed were degenerative glucogenic process and loss of the hepatic structure in the liver, glomerulopathy and tubular tumefaction in the kidney, myofibrolysis and edema in the heart, catarrhal enteritis and necrosis in the gastrointestinal tract, hyperemic processes in the gill lamellae, and high basophilia, degeneration and tumefaction of granular neurons in the brain. Vitamin E pretreatment was effective in preventing or ameliorating the abovementioned alterations induced by CYN. In addition, a morphometric study indicated that the average nuclear diameter of hepatocytes, and cross-sections of proximal and distal convoluted tubules, together with the cardiac fiber and capillaries diameters represent a useful tool to evaluate the damage induced by CYN. This is the first study reporting vitamin E prevention of histopathological damage in tissues (liver, kidney, heart, gastrointestinal tract, gills and brain) of fish intoxicated with CYN. Therefore, vitamin E can be considered a useful chemoprotectant in the treatment of histopathological changes induced in CYN-intoxicated fish. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1469-1485, 2016.


Assuntos
Toxinas Bacterianas/antagonistas & inibidores , Ciclídeos , Citoproteção , Hepatócitos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Uracila/análogos & derivados , Vitamina E/farmacologia , Alcaloides , Animais , Toxinas Bacterianas/toxicidade , Ciclídeos/anatomia & histologia , Ciclídeos/metabolismo , Toxinas de Cianobactérias , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Hepatócitos/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Fígado/metabolismo , Masculino , Estresse Oxidativo/efeitos dos fármacos , Fatores de Tempo , Testes de Toxicidade , Uracila/antagonistas & inibidores , Uracila/toxicidade
18.
Aquat Toxicol ; 161: 17-24, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25661706

RESUMO

Cylindrospermopsin (CYN) is a cytotoxic cyanotoxin produced by several species of freshwater cyanobacteria, such as Aphanizomenon ovalisporum. CYN is a tricyclic alkaloid known for its ability to inhibit both protein and glutathione synthesis, and the alteration of different oxidative stress biomarkers in mammals and vertebrates. Although the liver and kidney appear to be the main CYN targets for this toxin, it also affects other organs. In fish, there is no evidence about the neurotoxicity of CYN yet. In the present study, we aimed to study the potential neurotoxicity of CYN, based on the measure of Acetylcholinesterase (AChE) activity, lipid peroxidation (LPO) levels and histopathological studies in brain of tilapia (Oreochromis niloticus) subchronically exposed to repeated concentrations of 10µg CYN/L by immersion in an A.ovalisporum culture for 14 days. The results showed significant inhibition of AChE activity and increases in LPO levels, as well as relevant histopathological alterations in the brain of fish (O. niloticus) subchronically exposed to the toxin. Moreover, we also investigated the potential recovery of these parameters by subjecting the fish to two depuration periods (3 and 7 days) in clean uncontaminated water, showing a recovery of the biochemical parameters since 3 days of depuration, and being necessary 7 days to recover the histopathological changes. In order to support these results, CYN was detected and quantified by enzyme-linked immunosorbent assay (ELISA) in brain of all the exposed fish and the effects of the depuration periods were also observed. Based on these results, it was demonstrated for the first time the neurotoxicity of CYN and its presence in brain of tilapia fish subchronically exposed to CYN.


Assuntos
Aphanizomenon/fisiologia , Encéfalo/efeitos dos fármacos , Ciclídeos/fisiologia , Uracila/análogos & derivados , Acetilcolinesterase/metabolismo , Alcaloides , Animais , Aphanizomenon/química , Toxinas Bacterianas , Biomarcadores/metabolismo , Toxinas de Cianobactérias , Ativação Enzimática/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Uracila/toxicidade , Poluentes Químicos da Água/toxicidade
19.
Environ Toxicol ; 30(3): 261-77, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24000190

RESUMO

The acute toxicity of cylindrospermopsin (CYN) has been established in rodents, based on diverse intraperitoneal an oral exposure studies and more recently in fish. But no data have been reported in fish after subchronic exposure to cyanobacterial cells containing this cyanotoxin, so far. In this work, tilapia (Oreochromis niloticus) were exposed by immersion to lyophilized Aphanizomenon ovalisporum cells added to the aquaria using two concentration levels of CYN (10 or 100 µg CYN L(-1)) and deoxy-cylindrospermopsin (deoxy-CYN) (0.46 or 4.6 µg deoxy-CYN L(-1)), during two different exposure times: 7 or 14 d. This is the first study showing damage in the liver, kidney, hearth, intestines, and gills of tilapia after subchronic exposure to cyanobacterial cells at environmental relevant concentrations. The major histological changes observed were degenerative processes and steatosis in the liver, membranous glomerulopathy in the kidney, myofibrolysis and edema in the heart, necrotic enteritis in the gastrointestinal tract, and hyperemic processes in gill lamellae and microhemorrhages. Moreover, these histopathological findings confirm that the extent of damage is related to the CYN concentration and length of exposure. Results from the morphometric study indicated that the average of nuclear diameter of hepatocytes and cross-sections of proximal and distal convoluted tubules are useful to evaluate the damage induced by CYN in the main targets of toxicity.


Assuntos
Ciclídeos/fisiologia , Cianobactérias/metabolismo , Uracila/análogos & derivados , Alcaloides/metabolismo , Animais , Aphanizomenon/metabolismo , Toxinas Bacterianas , Toxinas de Cianobactérias , Brânquias/metabolismo , Brânquias/patologia , Hepatócitos/metabolismo , Hepatócitos/patologia , Rim/metabolismo , Rim/patologia , Túbulos Renais Distais/metabolismo , Túbulos Renais Distais/patologia , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Fígado/metabolismo , Fígado/patologia , Masculino , Miocárdio/metabolismo , Miocárdio/patologia , Uracila/metabolismo , Uracila/toxicidade
20.
J Toxicol Environ Health A ; 77(13): 731-46, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24839927

RESUMO

The food packaging industry is in continuous development in order to obtain more secure and stable food and beverages. The incorporation of inorganic and organic materials with plastic polymers leads to polymer composites. Among the inorganic compounds, clays such as montmorillonite (MTT) and its derivatives are of great interest due to their advantageous properties. The Technological Institute of Packaging, Transport,and Logistics (ITENE) developed a novel nanocomposite based on a poly(lactic) acid (PLA) polymer using an MMT derivative, named Clay1, as filler, to be used in the beverage industry. The improvement of the technological properties of this new material was demonstrated, but safety issues are also of concern. In the present study, a histopathological examination by optical and electron microscopy of organs from Wistar rats exposed for 90 d to a migration extract of PLA-Clay1 nanocomposite was carried out. Moreover, different clinical biochemistry, inflammation,and oxidative stress biomarkers were determined. Results showed no apparent evidence of damage, indicating that this nanocomposite has a good profile to be used in the food packaging industry, although further research is still needed.


Assuntos
Bentonita/toxicidade , Ácido Láctico/toxicidade , Nanocompostos/química , Nanocompostos/toxicidade , Polímeros/toxicidade , Animais , Bentonita/química , Biomarcadores , Fracionamento Químico/métodos , Armazenamento de Alimentos , Regulação da Expressão Gênica/efeitos dos fármacos , Interleucina-6/genética , Interleucina-6/metabolismo , Ácido Láctico/química , Masculino , Estresse Oxidativo/efeitos dos fármacos , Poliésteres , Polímeros/química , Ratos , Ratos Wistar
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