Biochemical and genetic alterations in the freshwater neotropical fish Prochilodus lineatus after acute exposure to Microcystis aeruginosa

Abstract

Microcystins are secondary metabolites produced by different species of cyanobacteria, such as Microcystis aeruginosa (MA). In this study, the biochemical and genetic effects of lyophilized MA were evaluated in the neotropical fish Prochilodus lineatus exposed to 1 or 2 mg L -1 lyophilized MA (treated group) or only water (control group) in static toxicity tests for 24 and 96 h. The gills and liver were used in the analysis of biotransformation enzymes and antioxidant defenses, blood and gill cells in genetic analysis and in brain and muscle it was determined the activity of acetylcholinesterase (AChE). The results showed the biotransformation pathway activation due to the increase in hepatic CYP1A and in branchial and hepatic glutathione Stransferase (GST). The antioxidant defense proved to be greatly affected by MA exposure leading to changes, both in gills and liver, in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and in the content of tripeptide glutathione (GSH). Lipid peroxidation was not detected, but damage to DNA molecule was observed in blood cells. In conclusion, it can be state the lyophilized MA is able to promote changes in the biochemical and genetic parameters of P. lineatus.As microcistinas são metabólitos secundários produzidos por diferentes espécies de cianobactérias, como a Microcystis aeruginosa (MA). Neste estudo, os efeitos bioquímicos e genéticos de liofilizado de MA foram avaliados para juvenis da espécie de peixe Neotropical Prochilodus lineatus expostos a 1 ou 2 mg L -1 de liofilizado de MA (grupo tratado) ou apenas à água (grupo controle), em testes de toxicidade estáticos, durante 24 e 96 h. As brânquias e o fígado foram usados para as análises das enzimas de biotransformação e defesas antioxidantes, células do sangue e das brânquias para análises genéticas e no cérebro e músculo foi determinada a atividade da acetilcolinesterase (AChE). Os resultados mostraram ativação da via de biotransformação devido ao aumento da atividade da CYP1A hepática e da atividade da glutationa S-transferase (GST) hepática e branquial. As defesas antioxidantes foram muito afetadas pela exposição a MA levando a alterações, tanto no fígado como nas brânquias, na atividade da superóxido dismutase (SOD), da catalase (CAT), da glutationa peroxidase (GPx), glutationa redutase (GR) e no conteúdo do tripeptídeo glutationa (GSH). Apesar dessas alterações a peroxidação lipídica não foi detectada em nenhum dos tecidos, mas danos na molécula de DNA foram observados nas células do sangue. Em conclusão, pode-se afirmar que o liofilizado de MA é capaz de promover alterações em parâmetros bioquímicos e genéticos de P. lineatus.

Antioxidative responses in zebrafish liver exposed to sublethal doses Aphanizomenon flos-aquae DC-1 aphantoxins

“…It is inferred that scavenging by toxin-induced antioxidant enzymes at early timepoints is sufficient to maintain hepatic redox balance, in accordance with other reports Garcia and Martinez, 2012).…”

Lipid peroxidation and antioxidant responses in zebrafish brain induced by Aphanizomenon flos-aquae DC-1 aphantoxins

“…Recently, several studies have reported increased CAT and GPx activities in fish brain induced by atrazine, ethanol and other chemicals (Garcia and Martinez, 2012;Xing et al, 2012). We showed increased CAT and GPx activities in zebrafish brain induced by toxins, suggesting increased production of H 2 O 2 with accumulated toxicity, which is similar to previous studies (Correia et al, 2007;Garcia and Martinez, 2012).…”

“…Previous studies have demonstrated that many toxins or toxicants, such as cyanobacterial toxins, heavy metals and insecticides, can cause elevation of CAT and GPx activities in the liver, kidneys and gills of fish (Xu et al, 2009;Jin et al, 2010). Recently, several studies have reported increased CAT and GPx activities in fish brain induced by atrazine, ethanol and other chemicals (Garcia and Martinez, 2012;Xing et al, 2012). We showed increased CAT and GPx activities in zebrafish brain induced by toxins, suggesting increased production of H 2 O 2 with accumulated toxicity, which is similar to previous studies (Correia et al, 2007;Garcia and Martinez, 2012).…”

Physiological effects of gasoline on the freshwater fish Prochilodus lineatus(Characiformes: Prochilodontidae)

“…In addition to its ecological value, it is also economically important for the region (Cazenave et al, 2009). Several studies have demonstrated that this species is highly sensitive to different contaminants (Camargo et al, 2009;Modesto & Martinez, 2010;Garcia & Martinez, 2012;Santos & Martinez, 2012;Pereira et al, 2013), including petroleum derivatives (Simonato et al, 2006(Simonato et al, , 2008(Simonato et al, , 2011. All these features make the P. lineatus a suitable biological model for environmental monitoring.…”