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Journal of Hazardous Materials Jan 2022Domoic acid (DA) is a major marine neurotoxin, occurs frequently in most of the world's coastlines and seriously threatens ecosystem and public health. However,...
Domoic acid (DA) is a major marine neurotoxin, occurs frequently in most of the world's coastlines and seriously threatens ecosystem and public health. However, information on its biotransformation process in coastal anaerobic environments remains unclear. In this study, the underlying mechanism of anaerobic biotransformation of DA by marine consortium GLY was investigated using the combination of liquid chromatography-high-resolution Orbitrap mass spectrometry and comparative metatranscriptomics analysis. The results demonstrated that DA could be cometabolically biotransformed under anaerobic conditions with pseudo-first-order reaction. Anaerobic biotransformation pathway of DA was clarified, including decarboxylation, dehydrogenation, carboxylation activation with CoA and multiple β-oxidation steps occurring at aliphatic side chain, which facilitated DA detoxification. Furthermore, anaerobic cometabolic biotransformation mechanism of glycine-DA by consortium GLY was established for the first time, a number of genes related to the metabolic pathways of glycine fermentation, fatty acid synthesis and β-oxidation were responded in the consortium GLY transcriptome and involved in the anaerobic biotransformation of DA. This study could deepen understanding of interaction mechanism between toxin DA and marine microorganisms, which provides a new insight into the DA fate and its effects on benthic microbial community in marine environments.
Topics: Anaerobiosis; Biotransformation; Ecosystem; Kainic Acid; Marine Toxins
PubMed: 34388926
DOI: 10.1016/j.jhazmat.2021.126798 -
Toxicology Mar 2022Domoic acid (DA) is a marine neurotoxin produced as a defence compound by diatom Pseudo-nitzschia. Although its toxicity is well known in marine mammals and fish, data...
Domoic acid (DA) is a marine neurotoxin produced as a defence compound by diatom Pseudo-nitzschia. Although its toxicity is well known in marine mammals and fish, data on DA cyto/genotoxicity in human non-target cells is still limited. Hence, we aimed to study the effect of DA (0.001-10 µg/mL) on cell viability and proliferation kinetics of human hepatocellular carcinoma (HepG2) cells as well as DNA damage induction after 4, 24 and 72 h of exposure. The results revealed that DA up to 10 µg/mL did not elicit significant changes in HepG2 cell viability, proliferation and cell cycle at applied conditions. DA did not generate DNA double-strand breaks, while it exhibited significant dose- and time-dependent increase of DNA damage in the form of either DNA single-strand breaks or alkali labile sites. Additionally, increased malondialdehyde level after DA treatment indicated oxidative damage to lipids. Altogether, the results showed that neurotoxin DA induced only minor adverse genotoxic effects in non-target HepG2 cells that most probably occurred resulting from the oxidative stress. However, additional research is needed to further elucidate the mechanisms of DA toxicity, particularly in terms of chronic exposure, as well as to understand its potential influence on human non-target cells.
Topics: Animals; DNA; Diatoms; Hep G2 Cells; Humans; Kainic Acid; Mammals; Marine Toxins; Neurotoxins
PubMed: 35307467
DOI: 10.1016/j.tox.2022.153157 -
Current Opinion in Chemical Biology Dec 2020Throughout history, humans have encountered natural toxic chemicals from the ocean environment, often through contaminated seafood. Although marine toxins can be harmful... (Review)
Review
Throughout history, humans have encountered natural toxic chemicals from the ocean environment, often through contaminated seafood. Although marine toxins can be harmful to human health and devastate local environments when they are produced during algal bloom events, they are also important biochemical research reagents and drug leads in medicine. In spite of their long history, the biosynthetic origin of many well-known marine toxins has remained elusive. New biosynthetic insights have shed light on the chemical transformations that create the complex structures of several iconic oceanic toxins. To that end, this review highlights advances made in the biosynthetic understanding of five important environmental toxins of marine origin: domoic acid, kainic acid, saxitoxin, tetrodotoxin, and polyether polyketides such as brevetoxin.
Topics: Animals; Aquatic Organisms; Biosynthetic Pathways; Kainic Acid; Marine Toxins; Saxitoxin; Tetrodotoxin
PubMed: 32731193
DOI: 10.1016/j.cbpa.2020.06.009 -
Analytical and Bioanalytical Chemistry Jul 2010The presence of marine toxins in seafood poses a health risk to human consumers which has prompted the regulation of the maximum content of marine toxins in seafood in... (Review)
Review
The presence of marine toxins in seafood poses a health risk to human consumers which has prompted the regulation of the maximum content of marine toxins in seafood in the legislations of many countries. Most marine toxin groups are detected by animal bioassays worldwide. Although this method has well known ethical and technical drawbacks, it is the official detection method for all regulated phycotoxins except domoic acid. Much effort by the scientific and regulatory communities has been focused on the development of alternative techniques that enable the substitution or reduction of bioassays; some of these have recently been included in the official detection method list. During the last two decades several biological methods including use of biosensors have been adapted for detection of marine toxins. The main advances in marine toxin detection using this kind of technique are reviewed. Biological methods offer interesting possibilities for reduction of the number of biosassays and a very promising future of new developments.
Topics: Animals; Biological Assay; Humans; Marine Toxins; Seafood
PubMed: 20458470
DOI: 10.1007/s00216-010-3782-9 -
Archives of Toxicology Jan 2018Palytoxin, isolated from a zoanthid of the genus Palythoa, is the most potent marine toxin known. Intoxication by palytoxin leads to vasoconstriction, hemorrhage,... (Review)
Review
Palytoxin, isolated from a zoanthid of the genus Palythoa, is the most potent marine toxin known. Intoxication by palytoxin leads to vasoconstriction, hemorrhage, ataxia, muscle weakness, ventricular fibrillation, pulmonary hypertension, ischemia and death. Palytoxin and its numerous derivatives (congeners) may enter the food chain and accumulate mainly in fishes and crabs, causing severe human intoxication and death following ingestion of contaminated products. Furthermore, toxic effects in individuals exposed via inhalation or skin contact to marine aerosol in coincidence with Ostreopsis blooms, have been reported. Blooms of the benthic dinoflagellate Ostreopsis cf. ovata are a concern in the Mediterranean Sea, since this species produces a wide range of palytoxin-like compounds listed among the most potent marine toxins. Thus, the formerly unsuspected broad distribution of the benthic dinoflagellate Ostreopsis spp. has recently posed a problem of risk assessment for human health. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide. This review summarized and discussed the pharmacology and toxicology data of palytoxin and its congeners, including their cytotoxicity, human and animal toxicities. Moreover, the risk assessment and their control strategies including prevention and treatment assays were evaluated.
Topics: Acrylamides; Animals; Bridged Bicyclo Compounds, Heterocyclic; Cnidarian Venoms; Humans; Marine Toxins; Pyrans; Risk Assessment
PubMed: 29110038
DOI: 10.1007/s00204-017-2105-8 -
Toxicon : Official Journal of the... Apr 2019Marine toxins are known among several causes of toxin induced renal injury. Enzymatic mechanism by phospholipase A is responsible for acute kidney injury (AKI) in sea... (Review)
Review
Marine toxins are known among several causes of toxin induced renal injury. Enzymatic mechanism by phospholipase A is responsible for acute kidney injury (AKI) in sea snake envenoming without any change in cardiac output and systemic vascular resistance. Cnidarian toxins form pores in the cell membrane with Ca influx storm resulting in cell death. Among plankton toxins domoic acid, palytoxin and maitotoxin cause renal injury by ion transport into the cell through ion channels resulting in renal cell swelling and lysis. Okadaic acid, calyculin A, microcystin LR and nodularin cause AKI by serine threonine phosphatase inhibition and hyperphosphorylation with increased activity of Ca/calmodulin - dependent protein kinase II, increased cytosolic Ca, reactive oxygen species, caspase and P53. Renal injury by plankons is mostly subclinical and requires sensitive biomarker for diagnosis. In this respect repeated consumption of plankton toxin contaminated seafood is a risk of developing chronic renal disease. The subject deserves more clinical study and scientific attention.
Topics: Acute Kidney Injury; Animals; Humans; Marine Toxins
PubMed: 30826470
DOI: 10.1016/j.toxicon.2019.02.012 -
Marine Drugs Jan 2022Palytoxin (PLTX) is a highly toxic polyether identified in various marine organisms, such as soft corals, dinoflagellates, and cyanobacteria. In addition to adverse...
Palytoxin (PLTX) is a highly toxic polyether identified in various marine organisms, such as soft corals, dinoflagellates, and cyanobacteria. In addition to adverse effects in humans, negative impacts on different marine organisms have been often described during blooms and the concomitant presence of PLTX and its analogues. Considering the increasing frequency of blooms due to global warming, PLTX was investigated for its effects on a crustacean commonly used as a model organism for ecotoxicological studies. At concentrations comparable to those detected in culture media of cf. (1.0-10.0 nM), PLTX significantly reduced cysts hatching and induced significant mortality of the organisms, both at larval and adult stages. Adults appeared to be the most sensitive developmental stage to PLTX: significant mortality was recorded after only 12 h of exposure to PLTX concentrations > 1.0 nM, with a 50% lethal concentration (LC) of 2.3 nM (95% confidence interval = 1.2-4.7 nM). The toxic effects of PLTX toward adults seem to involve oxidative stress induction. Indeed, the toxin significantly increased ROS levels and altered the activity of the major antioxidant enzymes, in particular catalase and peroxidase, and marginally glutathione-S-transferase and superoxide dismutase. On the whole, these results indicate that environmentally relevant concentrations of PLTX could have a negative effect on population, suggesting its potential ecotoxicological impact at the marine level.
Topics: Acrylamides; Animals; Artemia; Cnidarian Venoms; Dose-Response Relationship, Drug; Ecotoxicology; Lethal Dose 50; Life Cycle Stages; Marine Toxins; Oxidative Stress; Reactive Oxygen Species; Time Factors
PubMed: 35200611
DOI: 10.3390/md20020081 -
Toxins Aug 2017Rex Munday was a scientist working for AgResearch Ltd. in New Zealand. He was a leading figure in the area of marine toxin toxicity. His passing in July 2017 marked a...
Rex Munday was a scientist working for AgResearch Ltd. in New Zealand. He was a leading figure in the area of marine toxin toxicity. His passing in July 2017 marked a loss for his family, as well as for colleagues who knew him as a dedicated professional, and a lively scientist with a great sense of humor.
Topics: History, 20th Century; History, 21st Century; Marine Toxins; New Zealand; Toxicology
PubMed: 28837074
DOI: 10.3390/toxins9090257 -
Toxicology Feb 1994Four homologous Cerebratulus lacteus A toxins are the first and as yet only protein cytolysins to be isolated from an ancient phylum of marine worms, the nemertines. The... (Review)
Review
Four homologous Cerebratulus lacteus A toxins are the first and as yet only protein cytolysins to be isolated from an ancient phylum of marine worms, the nemertines. The most abundant and toxic variant, toxin A-III, has been sequenced and its mechanisms of action studied in the most detail. It consists of a single basic polypeptide chain of 95 amino acid residues cross-linked by three disulfide bonds, and possesses a predominantly alpha-helical secondary structure. The C-terminal third of the toxin sequence is postulated to be a helical 'hairpin' structure involved in pore formation. Toxin A-III permeabilizes a variety of cells as well as liposomes made from a variety of phospholipids; apparently large pores are formed, as large proteins are released almost as rapidly as small organic molecules and inorganic ions. At sublytic concentrations, the toxin also inhibits protein kinase C and endogenous voltage-gated cation selective (sodium, calcium) channels occurring in the nervous and cardiovascular systems. A curious observation, also reported for colicins and some other protein cytolysins, was the conservation of toxin secondary structure upon insertion into phospholipid liposomes, despite the strong likelihood that significant changes in tertiary structure occur to provide a hydrophobic surface for interaction with membrane lipids. Because of its small size and presumed single helical hairpin secondary structure, Cl toxin A-III is an excellent molecular subject for investigating protein insertion into biological membranes and mechanisms of pore formation.
Topics: Amino Acid Sequence; Cell Membrane; Cytotoxins; Marine Toxins; Molecular Sequence Data; Structure-Activity Relationship
PubMed: 8160185
DOI: 10.1016/0300-483x(94)90251-8 -
Critical Reviews in Food Science and... 2022With harmful algal blooms, marine food poisoning caused by marine biotoxins frequently occurs and is life-threatening if severe. However, the conventional detection... (Review)
Review
With harmful algal blooms, marine food poisoning caused by marine biotoxins frequently occurs and is life-threatening if severe. However, the conventional detection methods of marine toxins have a few limitations: low sensitivity and high-cost. Therefore, it is necessary to establish a fast and sensitive on-site detection method for real seafood sample. Biosensors based on aptamers, antibodies, and cells have been applied in marine toxins monitoring. This review presents the classification and toxic effects of marine toxins, and recent biosensor for marine toxin detection. In addition, we have compared the superiority and limitation of these biosensors. Finally, challenges and opportunities of biosensors in food safety detection were discussed. Considering the excellent results achieved by the aptasensor in the field of detection, it seems ready to be put into practical applications.
Topics: Biosensing Techniques; Food Safety; Foodborne Diseases; Humans; Marine Toxins; Seafood
PubMed: 33287557
DOI: 10.1080/10408398.2020.1854170