Pectinatella magnifica, an invasive bryozoan, might significantly affect ecosystem balance due to its massive occurrence in many areas in Europe and other parts of the world. Biological and chemical analyses are needed to get complete information about the impact of the animal on the environment. In this paper, we aimed to evaluate in vitro cytotoxic effects of five extracts prepared from P. magnifica using LDH assay on THP-1 cell line. Antimicrobial activities of extracts against 22 different bacterial strains were tested by microdilution method. Our study showed that all extracts tested, except aqueous portion, demonstrated LD50 values below 100 μg/mL, which indicates potential toxicity. The water extract of P. magnifica with LD50 value of 250 μg/mL also shows potentially harmful effects. Also, an environmental risk resulting from the presence and increasing biomass of potentially toxic benthic cyanobacteria in old colonies should not be underestimated. Toxicity of Pectinatella extracts could be partially caused by presence of Aeromonas species in material, since we found members of these genera as most abundant bacteria associated with P. magnifica. Furthermore, P. magnifica seems to be a promising source of certain antimicrobial agents. Its methanolic extract, hexane, and chloroform fractions possessed selective inhibitory effect on some potential pathogens and food spoiling bacteria in the range of MIC 0.5-10 mg/mL. Future effort should be made to isolate and characterize the content compounds derived from P. magnifica, which could help to identify the substance(s) responsible for the toxic effects of P. magnifica extracts.

• Keywords
• Aeromonas, Bryozoa, Pectinatella magnifica, antimicrobial activity, bacteria, cyanobacteria, invasive species, toxicity,
• MeSH
• Aeromonas chemistry   MeSH
• Anti-Bacterial Agents chemistry   pharmacology   MeSH
• Bacteria drug effects   MeSH
• Bacterial Toxins pharmacology   MeSH
• Bryozoa chemistry   microbiology   MeSH
• Cell Line MeSH
• Chloroform pharmacology   MeSH
• Hexanes pharmacology   MeSH
• Humans MeSH
• Methanol pharmacology   MeSH
• Microbial Sensitivity Tests MeSH
• Toxicity Tests MeSH
• Cell Survival drug effects   MeSH
• Introduced Species MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Bacterial Toxins MeSH
• Chloroform MeSH
• Hexanes MeSH
• Methanol MeSH

The aim of this study is to summarise the determination of concentrations of microcystins (MCs) in muscle and liver of freshwater fish species caught in stagnant waters of the Czech Republic. Within the years 2007-2009, 351 muscle samples and 291 liver samples of 16 freshwater fish species derived from four fishponds, and four water reservoirs were analysed. MCs were detected in 53 liver samples. The highest concentrations of microcystins were determined in liver samples of carnivorous fish species; 50.3 ng/g of fresh weight (FW) in perch (Perca fluviatilis) and 22.7 ng/g FW in pikeperch (Sander lucioperca). MCs in liver were detected in other five fish species; asp (Aspius aspius), pike (Esox lucius), common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idella) and European eel (Anguilla anguilla). Concentrations of MCs in liver of nine fish species (European bream, whitefish, tench, silver carp, European catfish, roach, chub, crucian carp and rudd) were below the detection limit of 1.2-5.4 ng/g FW for different MC congeners. However, the concentrations of MCs in all muscle samples were below the detection limit. The assessment of MCs concentrations might be influenced by the detection method used. Due to the concentrations of MCs being below the detection limit in muscle samples of all fish species analysed, it seems that there might be a low potential threat for human health in case of fish muscle consumption.

• MeSH
• Water Pollutants, Chemical metabolism   MeSH
• Liver metabolism   MeSH
• Microcystins metabolism   MeSH
• Environmental Monitoring * MeSH
• Fishes metabolism   MeSH
• Fresh Water chemistry   MeSH
• Muscles metabolism   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Czech Republic MeSH
• Names of Substances
• Water Pollutants, Chemical MeSH
• Microcystins MeSH

Toxicity and liver tumor promotion of cyanotoxins microcystins have been extensively studied. However, recent studies document that other metabolites present in the complex cyanobacterial water blooms may also have adverse health effects. In this study we used rat liver epithelial stem-like cells (WB-F344) to examine the effects of cyanobacterial extracts on two established markers of tumor promotion, inhibition of gap-junctional intercellular communication (GJIC) and activation of mitogen-activated protein kinases (MAPKs) - ERK1/2. Extracts of cyanobacteria (laboratory cultures of Microcystis aeruginosa and Aphanizomenon flos-aquae and water blooms dominated by these species) inhibited GJIC and activated MAPKs in a dose-dependent manner (effective concentrations ranging 0.5-5mgd.w./mL). Effects were independent of the microcystin content and the strongest responses were elicited by the extracts of Aphanizomenon sp. Neither pure microcystin-LR nor cylindrospermopsin inhibited GJIC or activated MAPKs. Modulations of GJIC and MAPKs appeared to be specific to cyanobacterial extracts since extracts from green alga Chlamydomonas reinhardtii, heterotrophic bacterium Klebsiella terrigena, and isolated bacterial lipopolysaccharides had no comparable effects. Our study provides the first evidence on the existence of unknown cyanobacterial toxic metabolites that affect in vitro biomarkers of tumor promotion, i.e. inhibition of GJIC and activation of MAPKs.

• MeSH
• Enzyme Activation drug effects   MeSH
• Alkaloids MeSH
• Aphanizomenon chemistry   isolation & purification   MeSH
• Bacterial Toxins MeSH
• Cell Line MeSH
• Time Factors MeSH
• Extracellular Signal-Regulated MAP Kinases metabolism   MeSH
• Phosphorylation drug effects   MeSH
• Carcinogens chemistry   toxicity   MeSH
• Complex Mixtures chemistry   toxicity   MeSH
• Rats MeSH
• Gap Junctions drug effects   MeSH
• Cell Communication drug effects   MeSH
• Microcystis chemistry   isolation & purification   MeSH
• Microcystins analysis   toxicity   MeSH
• Mitogen-Activated Protein Kinases metabolism   MeSH
• Cyanobacteria chemistry   isolation & purification   MeSH
• Fresh Water microbiology   MeSH
• Cyanobacteria Toxins MeSH
• Uracil analogs & derivatives   toxicity   MeSH
• Dose-Response Relationship, Drug MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, N.I.H., Extramural MeSH
• Comparative Study MeSH
• Geographicals
• Czech Republic MeSH
• Names of Substances
• Alkaloids MeSH
• Bacterial Toxins MeSH
• cylindrospermopsin MeSH Browser
• Extracellular Signal-Regulated MAP Kinases MeSH
• Carcinogens MeSH
• Complex Mixtures MeSH
• Microcystins MeSH
• Mitogen-Activated Protein Kinases MeSH
• Cyanobacteria Toxins MeSH
• Uracil MeSH