Estrogenic and retinoid-like activity in stagnant waters with mass occurrence of water blooms.

Stagnant freshwaters can be affected by anthropogenic pollution and eutrophication that leads to massive growth of cyanobacteria and microalgae forming complex water blooms. These can produce various types of bioactive compounds, some of which may cause embryotoxicity, teratogenicity, endocrine disruption and impair animal or human health. This study focused on potential co-occurrence of estrogenic and retinoid-like activities in diverse stagnant freshwaters affected by phytoplankton blooms with varying taxonomic composition.

Variability in retinoid-like activity of extracellular compound mixtures produced by wide spectra of phytoplankton species and contributing metabolites.

Some phytoplankton species were shown to produce teratogenic retinoids. This study assessed the variability in the extracellular production of compounds with retinoid-like activity for 50 independent cultivations of wide spectra of species including 12 cyanobacteria (15 strains) and 4 algae of different orders. Extracellular retinoid-like activity was detected for repeated cultivations of six cyanobacteria.

Neurobehavioral effects of cyanobacterial biomass field extracts on zebrafish embryos and potential role of retinoids.

Cyanobacteria are known for their ability to produce and release mixtures of up to thousands of compounds into the environment. Recently, the production of novel metabolites, retinoids, was reported for some cyanobacterial species along with teratogenic effects of samples containing these compounds. Retinoids are natural endogenous substances derived from vitamin A that play a crucial role in early vertebrate development.

Field cyanobacterial blooms producing retinoid compounds cause teratogenicity in zebrafish embryos.

Cyanobacteria routinely release potentially harmful bioactive compounds into the aquatic environment. Several recent studies suggested a potential link between the teratogenicity of effects caused by cyanobacteria and production of retinoids. To investigate this relationship, we analysed the teratogenicity of field-collected cyanobacterial bloom samples by means of an in vivo zebrafish embryo test, an in vitro reporter gene bioassay and by the chemical analysis of retinoids.

Intracellular and extracellular retinoid-like activity of widespread cyanobacterial species.

Cyanobacterial species produce wide range of bioactive compounds. This study characterized production of retinoid-like compounds with embryotoxic and teratogenic potential by commonly occurring cyanobacterial species with tendency to form massive water blooms. The major goal was to simultaneously assess the intracellular and extracellular retinoid-like activity from several independent cultivations of one coccal (Microcystis aeruginosa) and four filamentous cyanobacteria (Aphanizomenon gracile, Cylindrospermopsis raciborskii, Limnothrix redekeii, and Planktothrix agardhii) and characterize the variability in its production among cultivations.