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1.
Emerg Med Clin North Am ; 40(1): 119-133, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34782083

RESUMO

Scombroid poisoning, systemic mastocytosis, and hereditary alpha tryptasemia all present with episodes that resemble allergic reactions. Knowledge regarding systemic mastocytosis and hereditary alpha tryptasemia is quickly evolving. Epidemiology, pathophysiology, and strategies to identify and diagnose are discussed. Evidence-based management in the emergency setting and beyond is also explored and summarized. Key differences are described between these events and allergic reactions.


Assuntos
Angioedema/diagnóstico , Hipersensibilidade/diagnóstico , Toxinas Marinhas/biossíntese , Angioedema/fisiopatologia , Mimetismo Biológico , Humanos , Hipersensibilidade/fisiopatologia , Toxinas Marinhas/metabolismo , Triptases/análise , Triptases/deficiência
2.
Toxins (Basel) ; 13(5)2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-34069292

RESUMO

In this study, Karenia brevis 165 (K. brevis 165), a Chinese strain, was used to research brevetoxin (BTX) metabolites. The sample pretreatment method for the enrichment of BTX metabolites in an algal culture medium was improved here. The method for screening and identifying intracellular and extracellular BTX metabolites was established based on liquid chromatography-time-of-flight mass spectrometry (LC-ToF-MS) and liquid chromatography triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS). The results show that the recovery rates for BTX toxins enriched by a hydrophilic-lipophilic balance (HLB) extraction column were higher than those with a C18 extraction column. This method was used to analyze the profiles of extracellular and intracellular BTX metabolites at different growth stages of K. brevis 165. This is the first time a Chinese strain of K. brevis has been reported that can produce toxic BTX metabolites. Five and eight kinds of BTX toxin metabolites were detected in the cell and culture media of K. brevis 165, respectively. Brevenal, a toxic BTX metabolite antagonist, was found for the first time in the culture media. The toxic BTX metabolites and brevenal in the K. brevis 165 cell and culture media were found to be fully proven in terms of the necessity of establishing a method for screening and identifying toxic BTX metabolites. The results found by qualitatively and quantitatively analyzing BTX metabolites produced by K. brevis 165 at different growth stages show that the total toxic BTX metabolite contents in single cells ranged between 6.78 and 21.53 pg/cell, and the total toxin concentration in culture media ranged between 10.27 and 449.11 µg/L. There were significant differences in the types and contents of toxic BTX metabolites with varying growth stages. Therefore, when harmful algal blooms occur, the accurate determination of BTX metabolite types and concentrations will be helpful to assess the ecological disaster risk in order to avoid hazards and provide appropriate disaster warnings.


Assuntos
Cromatografia Líquida/métodos , Dinoflagelados/metabolismo , Toxinas Marinhas/metabolismo , Oxocinas/metabolismo , Espectrometria de Massas em Tandem/métodos , Proliferação Nociva de Algas , Toxinas Marinhas/análise , Oxocinas/análise
3.
Toxins (Basel) ; 13(4)2021 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-33924256

RESUMO

Microplastics (MP) widely distributed in aquatic environments have adverse effects on aquatic organisms. Currently, the impact of MP on toxigenic red tide microalgae is poorly understood. In this study, the strain of Alexandrium pacificum ATHK, typically producing paralytic shellfish toxins (PST), was selected as the target. Effects of 1 and 0.1 µm polystyrene MP with three concentration gradients (5 mg L-1, 25 mg L-1 and 100 mg L-1) on the growth, chlorophyll a (Chl a), photosynthetic activity (Fv/Fm) and PST production of ATHK were explored. Results showed that the high concentration (100 mg L-1) of 1 µm and 0.1 µm MP significantly inhibited the growth of ATHK, and the inhibition depended on the size and concentration of MP. Contents of Chl a showed an increase with various degrees after MP exposure in all cases. The photosynthesis indicator Fv/Fm of ATHK was significantly inhibited in the first 11 days, then gradually returned to the level of control group at day 13, and finally was gradually inhibited in the 1 µm MP treatments, and promotion or inhibition to some degree also occurred at different periods after exposure to 0.1 µm MP. Overall, both particle sizes of MP at 5 and 25 mg L-1 had no significant effect on cell toxin quota, and the high concentration 100 mg L-1 significantly promoted the PST biosynthesis on the day 7, 11 and 15. No significant difference occurred in the cell toxin quota and the total toxin content in all treatments at the end of the experiment (day 21). All MP treatments did not change the toxin profiles of ATHK, nor did the relative molar percentage of main PST components. The growth of ATHK, Chl a content, Fv/Fm and toxin production were not affected by MP shading. This is the first report on the effects of MP on the PST-producing microalgae, which will improve the understanding of the adverse impact of MP on the growth and toxin production of A. pacificum.


Assuntos
Dinoflagelados/efeitos dos fármacos , Toxinas Marinhas/metabolismo , Microalgas/efeitos dos fármacos , Microplásticos/toxicidade , Fotossíntese/efeitos dos fármacos , Poliestirenos/toxicidade , Intoxicação por Frutos do Mar , Poluentes Químicos da Água/toxicidade , Clorofila A/metabolismo , Dinoflagelados/crescimento & desenvolvimento , Dinoflagelados/metabolismo , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Fatores de Tempo
4.
Toxins (Basel) ; 13(3)2021 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-33673481

RESUMO

Microcystins (MCs) are toxins produced by several cyanobacterial species found worldwide. While MCs have a common structure, the variation of two amino acids in their structure affects their toxicity. As toxicodynamics are very similar between the MC variants, their differential toxicity could rather be explained by toxicokinetic parameters. Microcystin-RR (MC-RR) is the second most abundant congener and induces toxicity through oral exposure. As intestinal permeability is a key parameter of oral toxicokinetics, the apparent permeability of MC-RR across a differentiated intestinal Caco-2 cell monolayer was investigated. We observed a rapid and large decrease of MC-RR levels in the donor compartment. However, irrespective of the loaded concentration and exposure time, the permeabilities were very low from apical to basolateral compartments (from 4 to 15 × 10-8 cm·s-1) and from basolateral to apical compartments (from 2 to 37 × 10-8 cm·s-1). Our results suggested that MC-RR would be poorly absorbed orally. As similar low permeability was reported for the most abundant congener microcystin-LR, and this variant presented a greater acute oral toxicity than MC-RR, we concluded that the intestinal permeability was probably not involved in the differential toxicity between them, in contrast to the hepatic uptake and metabolism.


Assuntos
Absorção Intestinal , Mucosa Intestinal/metabolismo , Toxinas Marinhas/metabolismo , Microcistinas/metabolismo , Células CACO-2 , Humanos , Fígado/metabolismo , Toxinas Marinhas/toxicidade , Microcistinas/toxicidade , Permeabilidade , Toxicocinética
5.
Toxicon ; 196: 1-7, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33716070

RESUMO

Economic bivalve ingested toxic algae causes frequent human poisoning events. To explore new compounds that can accelerate the depuration of toxins in shellfish, we investigated the detoxification of the paralytic shellfish toxins (PSTs) and the biotransformation pathway of PSTs during detoxification by the application of three treatments to a toxic bloom, Alexandrium minutum (A. minutum). The detoxification effect of Platymonas subcordiformis (PS) mixed with carboxymethyl chitosan (CMC) group is significantly better than the starving group in each oyster tissues. The toxicity of viscera which occupied 78.95% of total toxicity reduced to 155 MU/100g after 13 days' depuration experiment. And adding CMC could significantly achieve rapid detoxification and effectively reduce the STX to 0.07 µmol/100 g in viscera. Meanwhile, PSTs underwent biotransformation during the depuration process, which mainly manifested as GTX1/4→GTX2/3→STX, GTX2→dcGTX2. This study explored a new strategy for toxin depuration in shellfish.


Assuntos
Quitosana , Dinoflagelados , Ostrea , Intoxicação por Frutos do Mar , Animais , Biotransformação , Dinoflagelados/metabolismo , Humanos , Toxinas Marinhas/metabolismo , Ostrea/metabolismo , Frutos do Mar/análise
7.
Toxins (Basel) ; 13(2)2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33671640

RESUMO

Shellfish toxin monitoring programs often use mussels as the sentinel species to represent risk in other bivalve shellfish species. Studies have examined accumulation and depuration rates in various species, but little information is available to compare multiple species from the same harvest area. A 2-year research project was performed to validate the use of mussels as the sentinel species to represent other relevant eastern Canadian shellfish species (clams, scallops, and oysters). Samples were collected simultaneously from Deadmans Harbour, NB, and were tested for paralytic shellfish toxins (PSTs) and amnesic shellfish toxin (AST). Phytoplankton was also monitored at this site. Scallops accumulated PSTs and AST sooner, at higher concentrations, and retained toxins longer than mussels. Data from monitoring program samples in Mahone Bay, NS, are presented as a real-world validation of findings. Simultaneous sampling of mussels and scallops showed significant differences between shellfish toxin results in these species. These data suggest more consideration should be given to situations where multiple species are present, especially scallops.


Assuntos
Monitoramento Biológico , Toxinas Marinhas/metabolismo , Moluscos/metabolismo , Espécies Sentinelas/metabolismo , Intoxicação por Frutos do Mar , Frutos do Mar/análise , Animais , Oceano Atlântico , Biotransformação , Avaliação de Programas e Projetos de Saúde , Reprodutibilidade dos Testes , Especificidade da Espécie , Fatores de Tempo
8.
Ecotoxicol Environ Saf ; 208: 111748, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396074

RESUMO

Microcystin-leucine arginine (MC-LR) is a kind of toxin produced by cyanobacterial, resulting in decrease of testosterone levels in serum and leading to impaired spermatogenesis. Gonadotropin-releasing hormone (GnRH) neurons play crucial roles in the regulation of testosterone release. Meanwhile, it has been demonstrated that MC-LR is capable of entering the GnRH neurons and inducing apoptosis. Nevertheless, the molecular mechanism of MC-LR induced apoptosis of GnRH neurons remains elusive. In present study, we found that MC-LR inhibited the cell viability of GT1-7 cells. In addition, we discovered apoptosis of GnRH neurons and GT1-7 cells treated with MC-LR. And increased intracellular ROS production and the release of intracellular Ca2+ were all observed following exposure to MC-LR. Furthermore, we also found the endoplasmic reticulum stress (ERs) and autophagy were activated by MC-LR. Additionally, pretreatment of the ERs inhibitor (4-Phenyl butyric acid) reduced the apoptotic rate of GT1-7 cells comparing with MC-LR exposure alone. Comparing with MC-LR treatment alone, apoptotic cell death was increased by pretreatment of GT1-7 cells with an autophagy inhibitor (3-methyladenine). Together, our data implicated that the treatment of MC-LR induced the apoptosis of GnRH neurons by activating the ERs resulting in a decrease of serum testosterone level in mice. Autophagy is a protective cellular process which was activated by ER stress and thus protected cells from apoptosis upon MC-LR exposure.


Assuntos
Estresse do Retículo Endoplasmático , Microcistinas/toxicidade , Testosterona/sangue , Animais , Apoptose , Arginina/metabolismo , Bioensaio , Sobrevivência Celular , Cianobactérias/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Leucina/metabolismo , Masculino , Toxinas Marinhas/metabolismo , Camundongos , Microcistinas/metabolismo , Neurônios/metabolismo , Testosterona/metabolismo
9.
Mar Drugs ; 19(2)2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33513729

RESUMO

Diarrhetic shellfish toxins (DSTs), some of the most important phycotoxins, are distributed almost all over the world, posing a great threat to human health through the food chain. Therefore, it is of great significance to find effective methods to reduce toxin accumulation in shellfish. In this paper, we observed the effects of four phytochemicals including cinnamaldehyde (CA), quercetin, oridonin and allicin on the accumulation of DSTs in the digestive gland of Perna viridis after exposure to the DSTs-producing Prorocentrum lima. We found that, among the four phytochemicals, CA could effectively decrease the accumulation of DSTs (okadaic acid-eq) in the digestive gland of P. viridis. Further evidence demonstrated that CA could reduce the histological alterations of the digestive gland of a mussel caused by DSTs. RT-qPCR showed that CA could suppress the CYP3A4 induction by DSTs, suggesting that the DSTs' decrease induced by CA might be related to the inhibition of CYP3A4 transcription induction. However, further studies on the underlying mechanism, optimal treatment time, ecological safety and cost should be addressed before cinnamaldehyde is used to decrease the accumulation of DSTs in field.


Assuntos
Acroleína/análogos & derivados , Diarreia/tratamento farmacológico , Sistema Digestório/efeitos dos fármacos , Toxinas Marinhas/antagonistas & inibidores , Perna (Organismo)/efeitos dos fármacos , Intoxicação por Frutos do Mar/tratamento farmacológico , Acroleína/farmacologia , Acroleína/uso terapêutico , Animais , Diarreia/metabolismo , Diarreia/patologia , Sistema Digestório/metabolismo , Sistema Digestório/patologia , Toxinas Marinhas/metabolismo , Perna (Organismo)/metabolismo , Frutos do Mar , Intoxicação por Frutos do Mar/metabolismo , Intoxicação por Frutos do Mar/patologia
10.
Food Chem ; 344: 128729, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33277122

RESUMO

Reduced pesticides use, alongside increased organic farming, has created a need for new biological products, such as thiocyclam, to control pests. Thiocyclam has scarcely been studied, making the study of its degradation in fruits and vegetables, such as tomatoes, an urgent requirement. To monitor thiocyclam metabolites in tomato, dissipation studies were carried out using a liquid chromatography-Orbitrap mass spectrometry (UHPLC-Orbitrap MS) method for 60-days after foliar application. Thiocyclam was not persistent (DT50 < 15 days), but nereistoxin - its primary metabolite - remained present in the tomatoes for >60 days. Four nereistoxin metabolites, detected at low concentrations (<100 µg/kg), were also monitored. This is the first time a study has provided dissipation patterns for thiocyclam and nereistoxin. The results obtained suggest revising the legislation concerning these compounds is required. Toxicological studies must also be carried out because there is no toxicity data currently for thiocyclam or nereistoxin.


Assuntos
Cromatografia Líquida de Alta Pressão , Compostos Heterocíclicos com 1 Anel/análise , Laboratórios , Lycopersicon esculentum/química , Espectrometria de Massas , Praguicidas/análise , Frutas/química , Compostos Heterocíclicos com 1 Anel/metabolismo , Lycopersicon esculentum/metabolismo , Toxinas Marinhas/análise , Toxinas Marinhas/metabolismo , Praguicidas/metabolismo , Medição de Risco
11.
Toxins (Basel) ; 12(11)2020 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-33228063

RESUMO

Cyanotoxins are the underlying cause of the threat that globally pervasive Cyanobacteria Harmful algal blooms (CyanoHABs) pose to humans. Major attention has been focused on the cyanobacterial hepatotoxin microcystins (MCs); however, there is a dearth of studies on cyanobacterial neurotoxin anatoxins. In this study, we explored how an anatoxin-producing Cuspidothrix issatschenkoi strain responded to culture with inorganic and organic nitrogen sources in terms of growth and anatoxins production. The results of our study revealed that ʟ- alanine could greatly boost cell growth, and was associated with the highest cell productivity, while urea significantly stimulated anatoxin production with the maximum anatoxin yield reaching 25.86 µg/mg dry weight, which was 1.56-fold higher than that in the control group (BG11). To further understand whether the carbon/nitrogen balance in C. issatschenkoi would affect anatoxin production, we explored growth and toxin production in response to different carbon/nitrogen ratios (C/N). Anatoxin production was mildly promoted when the C/N ratio was within low range, and significantly inhibited when the C/N ratio was within high range, showing approximately a three-fold difference. Furthermore, the transcriptional profile revealed that anaC gene expression was significantly up-regulated over 2-24 h when the C/N ratio was increased, and was significantly down-regulated after 96 h. Overall, our results further enriched the evidence that urea can stimulate cyanotoxin production, and ʟ-alanine could boost C. issatschenkoi proliferation, thus providing information for better management of aquatic systems. Moreover, by focusing on the intracellular C/N metabolic balance, this study explained the anatoxin production dynamics in C. issatschenkoi in response to different N sources.


Assuntos
Toxinas Bacterianas/metabolismo , Carbono/farmacologia , Cianobactérias/efeitos dos fármacos , Toxinas Marinhas/metabolismo , Nitrogênio/farmacologia , Tropanos/metabolismo , Alanina/farmacologia , Compostos de Amônio/farmacologia , Cianobactérias/crescimento & desenvolvimento , Cianobactérias/metabolismo , Nitratos/farmacologia , Prolina/farmacologia , Ureia/farmacologia
12.
Mar Drugs ; 18(11)2020 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-33147725

RESUMO

Marine habitats harbour a large variety of organisms that belong to diverse taxa; from bacteria and unicellular eukaryotes to fungi, animals, and plants. Although we have only started to understand the diversity and structure of marine communities, it is clear that numerous marine species have or might have an impact on human health. Some are a source of natural products with potential or actual medical applications, others are toxic and harmful to humans, and some are used in biomedical research to help understand the molecular basis of human diseases. New molecular genetics and genomic methods provide powerful and ever more indispensable tools for studying marine organisms and all aspects of their influence on human health. Herein, we present work using the latest research, which mostly uses genomics, to tackle the questions related with the topic of the issue.


Assuntos
Organismos Aquáticos/genética , Produtos Biológicos/uso terapêutico , Genoma , Toxinas Marinhas/efeitos adversos , Animais , Organismos Aquáticos/classificação , Organismos Aquáticos/metabolismo , Produtos Biológicos/isolamento & purificação , Nível de Saúde , Humanos , Toxinas Marinhas/metabolismo , Medição de Risco
13.
Toxins (Basel) ; 12(11)2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33153112

RESUMO

Domoic acid (DA), the main toxin responsible for Amnesic Shellfish Poisoning, frequently affects the marine resources of Chile and other countries across the South Pacific, thus becoming a risk for human health. One of the affected resources is the scallop Argopecten purpuratus. Even though this species has a high commercial importance in Northern Chile and Peru, the characteristics of its DA depuration are not known. In this work, the DA depuration was studied by means of two experiments: one in controlled (laboratory) and another in natural conditions. All organs of A. purpuratus depurated the toxin very quickly in both experiments. In some organs, an increase or a very small decrease of toxin was detected in the early depuration steps. Several models were used to describe this kinetics. The one that included toxin transfer between organs and independent depuration from each organ was the model that best fit the data. It seems, therefore, that the DA in this species is quickly transferred from the digestive gland to all other organs, which release it into the environment. Physiological differences in the two experiments have been shown to have some effect on the depuration from each organ but the actual reasons are still unknown.


Assuntos
Sistema Digestório/metabolismo , Ácido Caínico/análogos & derivados , Toxinas Marinhas/metabolismo , Pectinidae/metabolismo , Alimentos Marinhos , Intoxicação por Frutos do Mar , Animais , Carga Corporal (Radioterapia) , Ácido Caínico/metabolismo , Ácido Caínico/toxicidade , Cinética , Toxinas Marinhas/toxicidade , Alimentos Marinhos/efeitos adversos , Distribuição Tecidual , Toxicocinética
14.
Toxins (Basel) ; 12(10)2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33019550

RESUMO

Toxin-producing cyanobacteria in aquatic, terrestrial, and aerial environments can occur alongside a wide range of additional health hazards including biological agents and synthetic materials. Cases of intoxications involving cyanobacteria and cyanotoxins, with exposure to additional hazards, are discussed. Examples of the co-occurrence of cyanobacteria in such combinations are reviewed, including cyanobacteria and cyanotoxins plus algal toxins, microbial pathogens and fecal indicator bacteria, metals, pesticides, and microplastics. Toxicity assessments of cyanobacteria, cyanotoxins, and these additional agents, where investigated in bioassays and in defined combinations, are discussed and further research needs are identified.


Assuntos
Toxinas Bacterianas/toxicidade , Cianobactérias/metabolismo , Exposição Ambiental , Poluentes Ambientais/toxicidade , Toxinas Marinhas/toxicidade , Microcistinas/toxicidade , Animais , Toxinas Bacterianas/metabolismo , Cianobactérias/crescimento & desenvolvimento , Monitoramento Ambiental , Proliferação Nociva de Algas , Humanos , Toxinas Marinhas/metabolismo , Microcistinas/metabolismo , Medição de Risco , Fatores de Risco , Microbiologia da Água
15.
Aquat Toxicol ; 228: 105619, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32937230

RESUMO

Commonly affected by changes in climate and environmental conditions, coastal areas are very dynamic environments where shellfish play an important ecological role. In this study, the oxidative stress and genotoxic responses of mussels (Mytilus galloprovincialis) exposed to paralytic shellfish toxin (PST) - producing dinoflagellates Gymnodinium catenatum were evaluated under i) current conditions (CC: 19 °C; pH 8.0), ii) warming (W: 24 °C; pH 8.0), iii) acidification (A:19 °C; pH 7.6) and iv) combined effect of warming and acidification (WA: 24 °C; pH 7.6). Mussels were fed with G. catenatum for 5 days, and to a non-toxic diet during the following 10 days. A battery of oxidative stress biomarkers and comet assay was performed at the peak of toxin accumulation and at the end of the post-exposure phase. Under CC, gills and hepatopancreas displayed different responses/vulnerabilities and mechanisms to cope with PST. While gills presented a tendency for lipid peroxidation (LPO) and genetic damage (expressed by the Genetic Damage Indicator - GDI), hepatopancreas seems to better cope with the toxins, as no LPO was observed. However, the mechanisms involved in hepatopancreas protection were not enough to maintain DNA integrity. The absence of LPO, and the antioxidant system low responsiveness, suggests DNA damage was not oxidative. When exposed to toxic algae under W, toxin-modulated antioxidant responses were observed in both gills and hepatopancreas. Simultaneous exposure to the stressors highlighted gills susceptibility with a synergistic interaction increasing DNA damage. Exposure to toxic algae under A led to genotoxicity potentiation in both organs. The combined effect of WA did not cause relevant interactions in gills antioxidant responses, but stressors interactions impacted LPO and GDI. Antioxidant responses and LPO pointed out to be modulated by the environmental conditions in hepatopancreas, while GDI results support the dominance of toxin-triggered process. Overall, these results reveal that simultaneous exposure to warming, acidification and PSTs impairs mussel DNA integrity, compromising the genetic information due to the synergetic effects. Finally, this study highlights the increasing ecological risk of harmful algal blooms to Mytilus galloprovinciallis populations.


Assuntos
Dano ao DNA , Toxinas Marinhas/toxicidade , Mytilus/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Ensaio Cometa , Dinoflagelados/metabolismo , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Hepatopâncreas/efeitos dos fármacos , Hepatopâncreas/metabolismo , Concentração de Íons de Hidrogênio , Peroxidação de Lipídeos/efeitos dos fármacos , Toxinas Marinhas/metabolismo , Mytilus/genética , Mytilus/metabolismo , Temperatura
16.
Ecotoxicol Environ Saf ; 206: 111223, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32891913

RESUMO

Bivalve mollusks accumulate diarrhetic shellfish toxins (DSTs) from toxigenic microalgae, thus posing a threat to human health by acting as a vector of toxins to consumers. In bivalves, free forms of DSTs can be esterified with fatty acids at the C-7 site to form acyl esters (DTX3), presumably a detoxification mechanism for bivalves. However, the effects of esterification of DSTs on fatty acid metabolism in mollusks remain poorly understood. In this study, mussels (Mytilus galloprovincialis) were fed the DST-producing dinoflagellate Prorocentrum lima for 10 days followed by an additional 10-days depuration in filtered seawater to track the variation in quantity and composition of DST acyl esters and fatty acids. A variety of esters of okadaic acid (OA) and dinophysistoxin-1 (DTX1) were mainly formed in the digestive gland (DG), although trace amounts of esters also appeared in muscle tissue. A large relative amount of OA (60%-84%) and DTX1 (80%-92%) was esterified to DTX3 in the visceral mass (referred to as digestive gland, DG), and the major ester acyl chains were C16:0, C16:1, C18:0, C18:1, C20:1 and C20:2. The DG and muscle tissues showed pronounced differences in fatty acid content and composition during both feeding and depuration periods. In the DG, fatty acid content gradually decreased in parallel with increasing accumulation and esterification of DSTs. The decline in fatty acids was accelerated during depuration without food. This reduction in the content of important polyunsaturated fatty acids, especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), would lead to a reduction in the nutritional value of mussels. Enzymes involved in lipid metabolism, including acetyl-coenzyme A carboxylase (ACC), fatty acid synthase (FAS), lipoprotein lipase (LPL) and hepatic lipase (HL), were actively involved in the metabolism of fatty acids in the DG, whereas their activities were weak in muscle tissue during the feeding period. This study helps to improve the understanding of interactions between the esterification of DSTs and fatty acid dynamics in bivalve mollusks.


Assuntos
Dinoflagelados/metabolismo , Ácidos Graxos/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Toxinas Marinhas/toxicidade , Mytilus/metabolismo , Ácido Okadáico/análogos & derivados , Ácido Okadáico/toxicidade , Animais , Esterificação , Ésteres , Cadeia Alimentar , Toxinas Marinhas/metabolismo , Microalgas/metabolismo , Mytilus/efeitos dos fármacos , Mytilus/enzimologia , Ácido Okadáico/metabolismo , Alimentos Marinhos , Frutos do Mar , Intoxicação por Frutos do Mar
17.
Mar Drugs ; 18(8)2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32752210

RESUMO

Nemerteans (ribbon worms) employ toxins to subdue their prey, but research thus far has focused on the small-molecule components of mucus secretions and few protein toxins have been characterized. We carried out a preliminary proteotranscriptomic analysis of putative toxins produced by the hoplonemertean Amphiporus lactifloreus (Hoplonemertea, Amphiporidae). No variants were found of known nemertean-specific toxin proteins (neurotoxins, cytotoxins, parbolysins or nemertides) but several toxin-like transcripts were discovered, expressed strongly in the proboscis, including putative metalloproteinases and sequences resembling sea anemone actitoxins, crown-of-thorn sea star plancitoxins, and multiple classes of inhibitor cystine knot/knottin family proteins. Some of these products were also directly identified in the mucus proteome, supporting their preliminary identification as secreted toxin components. Two new nemertean-typical toxin candidates could be described and were named U-nemertotoxin-1 and U-nemertotoxin-2. Our findings provide insight into the largely overlooked venom system of nemerteans and support a hypothesis in which the nemertean proboscis evolved in several steps from a flesh-melting organ in scavenging nemerteans to a flesh-melting and toxin-secreting venom apparatus in hunting hoplonemerteans.


Assuntos
Perfilação da Expressão Gênica , Invertebrados/genética , Invertebrados/metabolismo , Toxinas Marinhas/genética , Toxinas Marinhas/metabolismo , Proteoma , Proteômica , Transcriptoma , Animais , Bases de Dados Genéticas
18.
Photochem Photobiol Sci ; 19(10): 1470-1477, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-32857084

RESUMO

Of all cyanobacteria, Microcystis aeruginosa is the most commonly found species in bloom episodes all over the world. This species is known to produce cyanopeptides with hepatotoxic effects, namely microcystins (MCs). In this regard, Advanced Oxidation Processes (AOPs) have been widely studied for cyanotoxin degradation, but very few studies focused on cyanobacteria inactivation combined with toxin removal. To our knowledge, this is the first report of the photo-Fenton process application focusing on M. aeruginosa inactivation and microcystin-LR (MC-LR) degradation. This research work aimed to evaluate the photo-Fenton process under three different conditions with regard to Fe2+/H2O2 ratios (0.6/10, 5/50, and 20/100 mg L-1) at the initial near-neutral pH. Process efficiency was measured by immediate cell density reduction, growth inhibition, effect on MC-LR concentrations, and scanning electron microscopy (SEM) to analyze any alterations in cell morphology. Growth inhibition test (GIT) results pointed to cell inactivation under all conditions tested, and MC-LR concentrations were reduced below WHO's maximum limit at medium and higher concentrations of reagents. The possible mechanisms of cell inactivation by oxidative species are discussed.


Assuntos
Toxinas Marinhas/metabolismo , Microcistinas/metabolismo , Microcystis/metabolismo , Compostos Ferrosos/análise , Compostos Ferrosos/farmacologia , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/farmacologia , Concentração de Íons de Hidrogênio , Microcystis/citologia , Microcystis/efeitos dos fármacos , Oxirredução
19.
Toxins (Basel) ; 12(8)2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32823916

RESUMO

Microcystin-LR (MC-LR) is prevalent in water and can be translocated into soil-crop ecosystem via irrigation, overflow (pollution accident), and cyanobacterial manure applications, threatening agricultural production and human health. However, the effects of various input pathways on the bioaccumulation and toxicity of MCs in terrestrial plants have been hardly reported so far. In the present study, pot experiments were performed to compare the bioaccumulation, toxicity, and health risk of MC-LR as well as its degradation in soils among various treatments with the same total amount of added MC-LR (150 µg/kg). The treatments included irrigation with polluted water (IPW), cultivation with polluted soil (CPS), and application of cyanobacterial manure (ACM). Three common leaf-vegetables in southern China were used in the pot experiments, including Ipomoea batatas L., Brassica juncea L., and Brassica alboglabra L. All leaf vegetables could bioaccumulate MC-LR under the three treatments, with much higher MC-LR bioaccumulation, especially root bioconcentration observed in ACM treatment than IPW and CPS treatments. An opposite trend in MC-LR degradation in soils of these treatments indicated that ACM could limit MC-LR degradation in soils and thus promote its bioaccumulation in the vegetables. MC-LR bioaccumulation could cause toxicity to the vegetables, with the highest toxic effects observed in ACM treatment. Similarly, bioaccumulation of MC-LR in the edible parts of the leaf-vegetables posed 1.1~4.8 fold higher human health risks in ACM treatment than in IPW and CPS treatments. The findings of this study highlighted a great concern on applications of cyanobacterial manure.


Assuntos
Bioacumulação , Toxinas Marinhas/análise , Toxinas Marinhas/metabolismo , Microcistinas/análise , Microcistinas/metabolismo , Verduras/química , Verduras/toxicidade , Toxinas Bacterianas/análise , Toxinas Bacterianas/metabolismo , Biodegradação Ambiental , China , Produtos Agrícolas/química , Produtos Agrícolas/toxicidade , Cianobactérias/metabolismo , Ecossistema , Contaminação de Alimentos , Humanos , Medição de Risco , Microbiologia do Solo
20.
Toxins (Basel) ; 12(8)2020 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-32727048

RESUMO

To investigate the mechanism for the production of paralytic shellfish toxins (PST) in toxic dinoflagellates, with a 2D-gel based approach, we had made two sets of proteomic comparisons: (a) between a toxic Alexandrium catenella (AC-T) and a phylogenetically closely related non-toxic strain (AC-N), (b) between toxic AC-T grown in a medium with 10% normal amount of phosphate (AC-T-10%P) known to induce higher toxicity and AC-T grown in normal medium. We found that photosynthesis and energy production related proteins were up-regulated in AC-T when compared to AC-N. However, the same group of proteins was down-regulated in AC-T-10%P when compared to normal AC-T. Examining the relationship of photosynthesis and toxin content of AC-T upon continuous photoperiod experiment revealed that while growth and associated toxin content increased after 8 days of continuous light, toxin content maintained constant when cells were shifted from continuous light to continuous dark for 3 days. This emphasized the cruciality of light availability on toxin biosynthesis in AC-T, while another light-independent mechanism may be responsible for higher toxicity in AC-T-10%P compared to normal AC-T. Taken all together, it is believed that the interplay between "illumination", "photosynthesis", "phosphate availability", and "toxin production" is much more complicated than what we had previously anticipated.


Assuntos
Dinoflagelados/metabolismo , Metabolismo Energético , Toxinas Marinhas/metabolismo , Fotossíntese , Dinoflagelados/genética , Dinoflagelados/crescimento & desenvolvimento , Luz , Fosfatos/metabolismo , Fotoperíodo , Filogenia , Proteômica , Intoxicação por Frutos do Mar
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