title: In vitro modulation of intracellular receptor signaling and cytotoxicity induced by extracts of cyanobacteria, complex water blooms and their fractions.
abstract: The biological activity of cyanobacteria and their chemical components have been widely studied due to their blooms in eutrophic waters worldwide. The primary goal of this study was to determine if individual cyanobacterial species and mixtures of cyanobacteria collected from the environment contain compounds with the potential for interaction with signaling pathways of the aryl hydrocarbon receptor (AhR), androgen receptor (AR), estrogen receptor (ER), glucocorticoid receptor (GR) and retinoid acid receptor (RAR). Cytotoxicity and specific toxic potencies of products of freshwater cyanobacteria were determined by use of in vitro reporter gene trans-activation assays. The testing included samples prepared from five selected single cyanobacterial species cultivated in laboratory and five complex cyanobacterial biomasses collected from blooms in surface waters in the Czech Republic. The results demonstrate estrogenic potencies of extracts of cyanobacterial biomasses. Among the laboratory single species, the extract of Planktothrix agardhii (intracellular metabolites) had a potency of estrogenic equivalents (EEQ) of 3.8 ng 17β-estradiol/g dw. The estimates of EEQs of samples prepared from complex cyanobacterial biomasses collected from freshwaters in the Czech Republic ranged from 19 to 2200 ng 17β-estradiol/g dw. Several samples prepared from the environmental cyanobacterial biomasses potentiated the androgenic potency of dihydrotestosterone. There was no dioxin-like, glucocorticoid or anti/retinoic activity observed for any of the extracts studied. Extracts of natural complex cyanobacterial biomasses exhibited greater and more frequent presence of compounds with specific modes of action, mainly estrogenic, and also greater cytotoxicity than extracts of single cyanobacterial species. The demonstrated estrogenic potency of the compounds present in complex cyanobacterial biomasses is of environmental relevance, and could potentially contribute to endocrine disruptive effects in aquatic ecosystems in case of great bloom densities.
authors: Research Centre for Toxic Compounds in the Environment (RECETOX), Faculty of Science, Masaryk University, Kamenice 126/3, 625 00 Brno, Czech Republic.
authors: T
authors: T
authors: Stěpánková
authors: L
authors: L
authors: Ambrožová
authors: L
authors: L
authors: Bláha
authors: J P
authors: JP
authors: Giesy
authors: K
authors: K
authors: Hilscherová
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000633:toxicity; D001681:Biological Assay; D018533:Biomass; D002460:Cell Line; D045744:Cell Line, Tumor; D045424:Complex Mixtures / Q000633:toxicity*; D000458:Cyanobacteria / Q000737:chemistry*; D003603:Cytotoxins / Q000633:toxicity*; D052244:Endocrine Disruptors / Q000633:toxicity*; D004967:Estrogens / Q000633:toxicity*; D006801:Humans; D066298:In Vitro Techniques; D052998:Microcystins / Q000633:toxicity; D051381:Rats; D011944:Receptors, Androgen / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D001427:Bacterial Toxins; D045424:Complex Mixtures; D003603:Cytotoxins; D052244:Endocrine Disruptors; D004967:Estrogens; D052998:Microcystins; D011944:Receptors, Androgen; D018336:Receptors, Aryl Hydrocarbon; D011960:Receptors, Estrogen; D011965:Receptors, Glucocorticoid; D018168:Receptors, Retinoic Acid; C078588:microcystin