Effects of manganese on fat snook Centropomus parallelus (Carangaria: Centropomidae) exposed to different temperatures

Abstract

This study evaluates the effects of exposure to manganese (Mn 2+ ) for 96 hours at two different temperatures (24 and 27°C) on juveniles of Centropomus parallelus through the activities of glutathione S-transferase (GST) and catalase (CAT), micronuclei test (MN) and comet assay. The GST activity did not show any significant difference between the groups exposed to Mn 2+ and the respective control groups; in contrast, a major increase in the CAT activity was observed at 27°C in the group exposed to Mn 2+ compared to the control group. The genotoxic analyses showed that in all animals exposed to Mn 2+, the number of red cells with micronuclei increased significantly compared to the respective control groups. There was also a significant increase in the incidence of DNA damage in the groups exposed to Mn 2+. At a temperature of 24ºC, animals exposed to Mn 2+ had more DNA damage than those at 27°C. It is likely that the increase in temperature can also induce oxidative stress. Thus, we conclude that manganese is toxic to the fat snook juveniles, causing genotoxic damage, and when associated with an increase in temperature, manganese can also provoke an increase in oxidative stress.Keywords: Biomarkers, DNA damage, Enzymes, Genotoxicity, Metal, Micronuclei.Este estudo avaliou os efeitos da exposição ao manganês (Mn 2+ ), após 96 horas, a duas temperaturas (24 e 27°C) em juvenis de Centropomus parallelus por meio de análises bioquímicas (atividade das enzimas glutationa S-transferase (GST) e catalase (CAT)) e genotóxicas (teste do micronúcleo e ensaio cometa). A atividade da GST não mostrou diferença significativa entre os grupos expostos ao Mn 2+ e os seus respectivos grupos controle, enquanto que um aumento significativo na atividade da CAT foi observado a 27°C no grupo exposto ao Mn 2+ , quando comparado ao grupo controle. As análises genotóxicas mostraram que os animais expostos ao Mn 2+ tiveram aumento significativo na quantidade de células com micronúcleo em relação aos seus grupos de controles. Houve também aumento significativo na incidência de danos ao DNA nos grupos expostos a esse contaminante. Na temperatura de 24°C, os animais expostos ao Mn 2+ tiveram maior quantidade de danos no DNA em relação a 27°C. É provável que o aumento da temperatura também possa induzir o estresse oxidativo. Assim, concluímos que o manganês é tóxico para os juvenis de robalo, causando dano genotóxico, e quando associado a um aumento da temperatura, também pode provocar um aumento no estresse oxidativo.

Iron and Manganese Retention of Juvenile Zebrafish (Danio rerio) Exposed to Contaminated Dietary Zooplankton (Daphnia pulex)—a Model Experiment

“…In that study ten times lower level of the two elements were applied in a very similar experimental setup; thus, we can conclude that the elevated dose of Fe and Mn supplementation in present investigation reached the value where it affects the growth performance. The negative influence of Mn in fish is mainly due to the increased oxidative stress it provokes [55][56][57][58]. Gabriel et al described the toxicity of Mn exposed to juvenile Colossoma macropomum by evaluating oxidative stress parameters and found that biomarkers changed significantly in the tissues of the studied fish individuals proving specific toxicity of Mn to the different organs [58].…”

Bioaccumulation of metals and genotoxic effects in females of Colomesus asellus collected in an Amazon River estuary, Amapá, Brazil

“…Excess metals in the environment, even those essential to aquatic life, can have genotoxic effects. Current legislation correctly forbids such excess to protect aquatic life from damage to genetic material or, in some cases, apoptosis of affected cells, such as that which occurs with nonessential toxic metals (Palermo et al, 2015, Tuzuki et al, 2017Murray & Carr, 2018, Guo et al, 2021. Palermo et al (2015) observed damage to the genome of Prochilodus lineatus after exposure to Ni.…”

“…Palermo et al (2015) observed damage to the genome of Prochilodus lineatus after exposure to Ni. Tuzuki et al (2017) reported that Mn induced genotoxic effects, including DNA strand breaks, in fish erythrocytes. For nonessential metals, such as Pb, Hg, Cd and Cr, several studies have reported their genotoxic potential in fish, even when present in low concentrations in the aquatic environment (Pereira et al, 2016, Ali et al, 2020, Viana et al, 2020, Viana et al, 2021.…”