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
- biologické markery analýza MeSH
- biomasa MeSH
- glutathion analýza MeSH
- glutathiontransferasa analýza MeSH
- mikrocystiny škodlivé účinky MeSH
- oxidační stres účinky léků MeSH
- peroxidace lipidů účinky léků MeSH
- ryby metabolismus MeSH
- sinice metabolismus MeSH
- škodlivý vodní květ MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
The aim of this study was to evaluate the influence of toxic cyanobacterial water blooms on blood indices in the Nile tilapia (Oreochromis niloticus). Experimental fish were exposed to natural cyanobacterial water blooms (consisting mainly of Microcystis aeruginosa and M. ichthyoblabe) which contained microcystins (total concentration 1187 - 1211 μg g-1 of dry weight and 17.4 - 25.4 μg l-1 of water) for 28 days without additional feeding. Control groups of fish were kept in another pond without apparent cyanobacterial bloom formation. Experimental and control rearing ponds had the same water source. After exposure, fish were placed in dechlorinated potable water for the same period. Statistical evaluation of the influence of cyanobacterial water bloom on biochemical indices of experimental fish showed a distinct increase of alkaline phosphatase (p ⪬ 0.05), total bilirubin (p ⪬ 0.001), creatinine (p ⪬ 0.01), lactate (p ⪬ 0.01) and urea (p ⪬ 0.01) when compared to controls. After transfer to the dechlorinated potable water the experimental group showed significantly lower values of phosphorus (p ⪬ 0.001), urea (p ⪬ 0.01) and cholinesterase (p ⪬ 0.05) and higher values of lactate (p ⪬ 0.05) and iron (p ⪬ 0.05) compared to controls. It may be concluded that the exposure of the Nile tilapia to the environment containing cyanobacterial water bloom influenced only some biochemical indices. However, this modulation is to a much lower degree compared to the common carp and silver carp.
- MeSH
- alkalická fosfatasa krev MeSH
- bilirubin krev MeSH
- biologické markery * krev MeSH
- cholinesterasy krev MeSH
- fosfor krev MeSH
- hematologické testy * MeSH
- kreatinin krev MeSH
- laktasa krev MeSH
- laktáty krev MeSH
- Microcystis * metabolismus patogenita MeSH
- mikrocystiny farmakologie škodlivé účinky MeSH
- močovina krev MeSH
- rybníky MeSH
- sinice klasifikace patogenita MeSH
- Tilapia MeSH
- železo krev MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- srovnávací studie MeSH