Massive toxic blooms of cyanobacteria represent a major threat to water supplies worldwide. Here, the biological activities of lipopolysaccharide (LPS) isolated from Microcystis aeruginosa, the most prominent cyanobacteria in water bloom, were studied. LPS was isolated from complex environmental water bloom samples dominated by M. aeruginosa, and from laboratory cultures of non-axenic as well as axenic M. aeruginosa strains PCC7806 and HAMBI/UHCC130. Employing human blood-based in vitro tests, the LPS isolated from complex water bloom revealed the priming of both major blood phagocyte population monocytes and polymorphonuclear leukocytes documented by the increased surface expression of CD11b and CD66b. This was accompanied by a water bloom LPS-mediated dose-dependent induction of tumor necrosis factor α, interleukin-1β, and interleukin-6 production. In accordance with its priming effects, water bloom LPS induced significant activation of p38 and ERK1/2 kinases, as well as NF-κB phosphorylation, in isolated polymorphonuclear leukocytes. Interestingly, the pro-inflammatory potential of LPS from the axenic strain of M. aeruginosa was not lower compared to that of LPS isolated from non-axenic strains. In contrast to the biological activity, water bloom LPS revealed almost twice higher pyrogenicity levels compared to Escherichia coli LPS, as analyzed by the PyroGene test. Moreover, LPS from the non-axenic culture exhibited higher endotoxin activity in comparison to LPS from axenic strains. Taking the above findings together, M. aeruginosa LPS can contribute to the health risks associated with contamination by complex water bloom mass.

• Keywords
• cyanobacteria, endotoxin, inflammation, leukocytes, lipopolysaccharide, water bloom,
• MeSH
• CD11b Antigen metabolism   MeSH
• Antigens, CD metabolism   MeSH
• Cytokines blood   MeSH
• Eutrophication MeSH
• GPI-Linked Proteins metabolism   MeSH
• Cells, Cultured MeSH
• Laboratories MeSH
• Leukocytes, Mononuclear drug effects   metabolism   MeSH
• Humans MeSH
• Lipopolysaccharides toxicity   MeSH
• Microcystis * MeSH
• Cell Adhesion Molecules metabolism   MeSH
• Immunity, Innate drug effects   MeSH
• Pyrogens toxicity   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• CD11b Antigen MeSH
• Antigens, CD MeSH
• CEACAM8 protein, human MeSH Browser
• Cytokines MeSH
• GPI-Linked Proteins MeSH
• ITGAM protein, human MeSH Browser
• Lipopolysaccharides MeSH
• Cell Adhesion Molecules MeSH
• Pyrogens MeSH

The aim of the study was to assess the effects of a cyanobacterial extract containing microcystins (MCs) on selected hematological and biochemical parameters in common carp (Cyprinus carpio L.), as well as to determine the accumulation of toxins in fish tissues. The fish were immersed for 5 days in water containing toxins at a final concentration of 12 μg/L of microcystin LR equivalent. Microcystin LR residues were detected in fish liver, reaching 207, 238 and 260 ng/g f.w. of the tissues taken 24 h, 72 h and 5 days after the end of intoxication, respectively. The most substantial changes were found in fish plasma, including increases in creatine kinase, lactate dehydrogenase, ammonia, glucose, aspartate aminotransferase and alanine aminotransferase levels. A decline of about 50% in lysozyme activity was observed by the end of the experimental period. Moreover, a marked increase in ceruloplasmin activity was detected 24 h after the end of intoxication with a subsequent decrease in its activity after 72 h and 5 days. This study concludes that not only consumption of food containing toxins but also MCs dissolved in water may pose a threat to fish health. Additionally, detected changes in lysozyme and ceruloplasmin activity may have distinct effects in fish resistance against pathogens or oxidative stress, which should be taken into account in the future studies.

• MeSH
• Ceruloplasmin metabolism   MeSH
• Carps blood   immunology   MeSH
• Microcystis chemistry   MeSH
• Microcystins analysis   toxicity   MeSH
• Muramidase metabolism   MeSH
• Immunity, Innate MeSH
• Toxicity Tests MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Ceruloplasmin MeSH
• Microcystins MeSH
• Muramidase MeSH

Cyanobacterial blooms represent a serious threat to the aquatic environment. Among other effects, biochemical markers have been studied in aquatic vertebrates after exposures to toxic cyanobacteria. Some parameters such as protein phosphatases may serve as selective markers of exposure to microcystins, but under natural conditions, fish are exposed to complex mixtures, which affect the overall biomarker response. This review aims to provide a critical summary of biomarker responses in aquatic vertebrates (mostly fish) to toxic cyanobacteria with a special focus on detoxification and oxidative stress. Detoxification biomarkers such as glutathione (GSH) and glutathione-S-transferase (GST) showed very high variability with poor general trends. Often, stimulations and/or inhibitions and/or no effects at GSH or GST have been reported, even within a single study, depending on many variables, including time, dose, tissue, species, etc. Most of the oxidative stress biomarkers (e.g., superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) provided more consistent responses, but only lipid peroxidation (LPO) seemed to fulfill the criteria needed for biomarkers, i.e., a sufficiently long half-life and systematic response. Indeed, reviewed papers demonstrated that toxic cyanobacteria systematically elevate levels of LPO, which indicates the important role of oxidative damage in cyanobacterial toxicity. In summary, the measurement of biochemical changes under laboratory conditions may provide information on the mode of toxic action. However, comparison of different studies is very difficult, and the practical use of detoxification or oxidative stress biomarkers as diagnostic tools or early warnings of cyanobacterial toxicity is questionable.

• MeSH
• Biomarkers analysis   MeSH
• Biomass MeSH
• Glutathione analysis   MeSH
• Glutathione Transferase analysis   MeSH
• Microcystins adverse effects   MeSH
• Oxidative Stress drug effects   MeSH
• Lipid Peroxidation drug effects   MeSH
• Fishes metabolism   MeSH
• Cyanobacteria metabolism   MeSH
• Harmful Algal Bloom MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Biomarkers MeSH
• Glutathione MeSH
• Glutathione Transferase MeSH
• Microcystins MeSH