Abstract from a paper by Ujvarosi et al. (2019), published in Chemospere :
Microginins (MGs) are bioactive metabolites mainly produced by Microcystis spp., (Cyanobacteria) commonly found in eutrophic environments. In this study, the cytotoxic and genotoxic activities of four MG congeners (MG FR3, MG GH787, cyanostatin B, MGL 402) and a well characterized cyanobacterial extract B-14-01 containing these metabolites were evaluated in the human hepatocellular carcinoma (HepG2) cell line. The cytotoxicity was measured with the MTT assay, while genotoxicity was studied with the comet, γH2AX and cytokinesis block (CBMN) micronucleus assays. The viability of cells after 24 h was significantly affected only by the extract, whereas after 72 h a concentration dependent decrease in cell proliferation was observed for the extract and tested microginins, with MGL 402 being the most potent and MG FR3 the least potent congener. The extract and all tested congeners induced DNA strand breaks after 4 and 24 h exposure. The most potent was the extract, which induced concentration and time dependent increase in DNA damage at concentrations ≥0.01 μg mL−1. Among microginins the most potent was MGL 402 (increase in DNA strand breaks at ≥ 0.01 μg mL−1) and MG FR3 was the least potent (increase in DNA strand breaks at ≥ 1 μg mL−1). However, no induction of DNA double strand breaks was observed after 24 and 72-h exposure to the cyanobacterial extract or MGs. Induction of genomic instability was observed in cells exposed to MG GH787, cyanostatin B and the extract B-14-01. This study is the first to provide the evidence that microginins exert genotoxic activity.
The paper is a product of joined research by groups in Slovenia and Hungary and features CYANOCOST members Bojana Zegura, Gabor Vasas, Klara Hercog, Metka Filipic. The authors acknowledge CYANOCOST.
Andrea Zsuzsanna Ujvárosi, Klara Hercog, Milán Riba, Sándor Gonda, Metka Filipič, Gábor Vasas, Bojana Žegura (2019). “The cyanobacterial oligopeptides microginins induce DNA damage in the human hepatocellular carcinoma (HepG2) cell line”, Chemosphere, Volume 240, https://doi.org/10.1016/j.chemosphere.2019.124880.
A new paper by Konstantinou et al. from Cyanolab AUTH (Head: Dr. Spyros Gkelis), published in Journal of Phycology. The authors propose a novel marine genus Leptothoe gen. nov. and describe three new sponge-associated species: Le. sithoniana, Le. kymatousa, and Le. spongobia, based on a combination of molecular, chemical and morphological approach. The new sponge-associated Leptothoe species show distinct characters compared to other marine Leptolyngbyaceae, reinforcing the investigation of cyanobacterial diversity associated with sponges. Interestingly, Leptothoe spongobia TAU-MAC 1115 isolated from the sponge Acanthella acuta was shown to produce microcystin-RR indicating that microcystin production among marine cyanobacteria could be more widespread than previously determined.
Konstantinou, D., Voultsiadou, E., Panteris, E., Zervou, S. K., Hiskia, A., & Gkelis, S. (2019). Leptothoe, a new genus of marine cyanobacteria (Synechococcales) and three new species associated with sponges from the Aegean Sea. Journal of phycology. https://doi.org/10.1111/jpy.12866
The combination of liquid chromatography with mass spectrometry (LC-MS) is a valuable tool for the determination of algal toxins contained at trace levels in complex matrices thanks to its high sensitivity, selectivity and ability to deal with the structural diversity and labile nature of the toxins. Targeted LC tandem MS (LC-MS/MS) approaches are already efficiently employed worldwide to monitor toxin distribution in the environment and in the food chain. At the same time, untargeted approaches based on high resolution MS (LC-HRMS) have generally disclosed the presence of a much higher number and types of toxins and made straightforward elucidation of the gross structure of the unknowns based on the interpretation of their fragmentation patterns.
In view of the plethora of LC-MS/MS and LC-HRMS methods that have been developed so far, the need exists for critical reviews that, besides summarizing the methodologies for determination of each toxin-group, single out the main challenges to be addressed in the next future for marine, freshwater and fish-killing toxins. Collaborative efforts among scientists are strongly encouraged both in the field of the regulated toxins in EU and the emerging ones to build the rational basis for inter-laboratory validation trials, where needed. Original research articles reporting LC-MS based identification of emerging issues for water and food safety potentially associated with climate change as well as recent advancements in LC-MS data acquisition and treatment (On-line SPE-LC-MS, 2D-LC-MS, Metabolomics, among others) will be also included in this Special Issue.
More information can be found at: https://www.mdpi.com/journal/toxins/special_issues/lcms_Algal
Deadline for manuscript submissions is 31 December 2019
Guest Editors: Carmela Dell’Aversano and Luciana Tartaglione, Department of Pharmacy, University of Napoli Federico II
Cyanobacteria are an ancient lineage of oxygenic photosynthetic bacteria found in a broad range of habitats, from soil to oceans, where they play important roles in the global nitrogen and carbon cycles. They are known for the toxic blooms they form in fresh water bodies around the world and the production of toxins, posing a threat to human and environmental health. Despite the tremendous effort to understand the biosynthesis, toxicity, and occurrence of cyanobacteria secondary metabolites, the biological role of these compounds still remains relatively unknown. Various hypotheses in this regard have been put forward, encompassing both intracellular effects such as nutrient storage, light adaptation, and protection against oxidative stress, and extracellular functions including quorum sensing, allelopathic interactions, nutrient acquisition, colony formation, and grazing defense. The existing evidence on the potential role of cyanotoxins is mostly based on experimental studies and require further confirmation by in-field observations.
This Special Issue is destined to gather reviews, original experimental papers, and short notes reporting findings on experimental and in-field observations that aim to advance our understanding of the biological role of cyanotoxins.
Dr. Spyros Gkelis
Dr. Piotr Rzymski
Deadline for manuscript submissions: 31 December 2019
Special issue webpage.
From the webpage of the Frontiers Research Topic:
A sustainable food system is insecure if toxins are a threat. There are three types of natural non-proteinaceous toxins that compromise reliability of food systems: cyanotoxins for freshwater aquatic products, phycotoxins for seafood, and mycotoxins mainly for cereals (also for other plant-based foods and food-products of animal origin).
This Research Topic aims to focus on several knowledge gaps that require in-depth research, with an emphasis on new or emerging toxins recently appearing due to global warming and international trade. In this context, several important issues related to toxins stand out for which new information and scientific evidence should be provided. These issues include: monitoring and analytical challenges (including the requirement for certified reference materials), the need for better understanding of toxin mode of action and toxicology, as well as the need to improve risk assessment, and the development of novel mitigation strategies.
We invite scientists from these relevant fields to contribute to this exciting area of research that combines pharmacology, analytical chemistry, toxicology, mycology, phycology, and food safety.
Topic Editors : Luis M. Botana, Panagiota Katikou, Maria J. Sainz, Alison Robertson
View details about this Research Topic here.
Freshwater cyanobacteria are known to produce a suite of different chemicals that can be toxic to many organisms. These toxins can have adverse impacts on humans, animals, and even aquatic and terrestrial plants. Further information about cyanobacterial toxins is required to better understand and manage their risks in freshwater environments. This Special Issue aims to bring together papers that provide new information on the monitoring of cyanobacterial toxins and the identification of toxins in freshwater environments. Further, papers are invited that develop our knowledge of how cyanobacterial toxins impact humans, as well as different aquatic and terrestrial organisms. Papers that better develop our understanding of how toxin production by cyanobacteria is regulated are also welcomed.
Assoc. Prof. Simon Mitrovic
Dr. Ambrose Furey
Deadline for manuscript submissions: 30 June 2019.
Visit the Special Issue webpage here.
A new paper by Stern et al., published in Food and Chemical Toxicology, provides evidence for ROS-mediated genotoxic effects of Nodularin. From the abstract:
“The cyanobacterial pentapeptide nodularin (NOD), mainly produced by genus Nodularia, is a potent inhibitor of protein phosphatases PP1 and PP2A, and causes animal mortality. The few studies available indicate that NOD is a potential non-genotoxic carcinogen. In the present study we evaluated NOD (0.01, 0.1 and 1 μg/ml) genotoxic activity in human hepatoma (HepG2) cells with the comet, γH2AX and cytokinesis block micronucleus cytome assays. In addition, induction of oxidative stress was studied. Moreover changes in the expression of selected genes from the P53 pathway, involved in the response to DNA damage (P53, GADD45α, CDKN1A, MDM2), apoptosis (BAX, BCL2) and oxidative stress (GPX1, GSR, GCLC, CAT, SOD1) were determined using qPCR. Non-cytotoxic concentrations induced time and dose dependant increase in reactive oxygen species (ROS) production and substantially increased the formation of oxidative DNA damage. In addition, elevated formation of micronuclei was detected. For the first time it has been shown that NOD deregulated the mRNA level of DNA damage (CDKN1A, GADD45α) and oxidative stress (GPX1, GSR, GCLC, CAT and SOD1) responsive genes and anti-apoptotic gene BCL2. Our results provide new evidence that NOD genotoxic effects are mediated through ROS production, already at low environmentally relevant concentrations.”
The paper acknowledges CYANOCOST.
A. Štern, A. Rotter, M. Novak, M. Filipič, B. Žegura (2019). Genotoxic effects of the cyanobacterial pentapeptide nodularin in HepG2 cells. Food and Chemical Toxicology 124, 349-358. https://doi.org/10.1016/j.fct.2018.12.019
A review paper on occurrence of BMAA and related compounds in cyanobacteria and food supplements by was recently published by Manolidi et al. in Journal of Hazardous Materials.
“The review critically discusses existing reports regarding the occurrence of BMAA, DAB and AEG in cyanobacteria and cyanobacteria-based food supplements. It is shown that inconsistencies in reported results could be attributed to performance of different methods of extraction and analysis applied and in ambiguities regarding determination of soluble and bound fractions of the compounds. The critical aspect of this review aims to grow awareness of human intake of neurotoxic amino acids, while results presented in literature concerning dietary supplements aim to promote further research, quality control as well as development of guidelines for cyanotoxins in food products.”
The review paper acknowledges CYANOCOST.
Korina Manolidi, Theodoros M. Triantis, Triantafyllos Kaloudis, Anastasia Hiskia (2019). Neurotoxin BMAA and its isomeric amino acids in cyanobacteria and cyanobacteria-based food supplements. Journal of Hazardous Materials 365, 346-365. https://doi.org/10.1016/j.jhazmat.2018.10.084
The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. The first product of the European Multi Lake Survey (EMLS) was published by Mantzouki et al. (2018) in Toxins. Following this publication, the dataset of in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, is now published in Scientific Data (Mantzouki et al. 2018). The data can be found and downloaded from the Environmental Data Portal (EDI). EMLS was coordinated by Evi Manzouki and Bas Ibelings from the University of Geneva, and supported by COST Actions Netlake and CYANOCOST.
- E. Mantzouki et al. (2018). A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins. Scientific Data 5, 180226. https://doi.org/10.1038/sdata.2018.226 .
- Data citation: Mantzouki, E. et al. (2018). Environmental Data Initiative https://doi.org/10.6073/pasta/dabc352040fa58284f78883fa9debe37
Harmful algal blooms (HABs) in frehwaters and partly also in brackish, coastal seas are frequently dominated by cyanobateria. Cyanobacterial blooms are well established as indicators of environmental degradation. Beyond the role as indicators, bloom forming Cyanobacteria by themselves are a serious threat to the functioning of aquatic ecosystems and resources and services provided by aquatic ecosystems. Because of their mechanical properties and the toxicity of several of them, harmful Cyanobacteria may seriously inhibit matter and energy transfer through the food webs. Dense aggregations of cyanobacterial biomass lead to chemical alterations of the water, including pH-changes and a subsequent shift from NH+-ions to toxic NH3, and the release of toxins from live cells and after cell lysis. This, in turn, can lead to animal kills and health hazards for humans via drinking water, consumption of fish, and recreational use. The planned Special Issue should summmarize recent advances in the monitoring, analysis, and prevention of harfmul cyanobacteria and their adverse effects on ecosystem functioning, food webs, and water quality. Among others, possible topics include the effects of cyanobacteria on water chemistry, deep water, and sediment anoxia, grazing inhibition, animal kills, biodiversity, ecological status, human health, and analyses of societal costs.
Prof. Dr. Maria Moustaka-Gouni
Prof. Dr. Ulrich Sommer
Deadline for manuscript submissions: 30 June 2020
Link to the webpage of the special issue.