Biotransformations, Antioxidant System Responses, and Histopathological Indexes in the Liver of Fish Exposed to Cyanobacterial Extract

Author(s)

Paulino, Marcelo Gustavo ^[1] ; Tavares, Driele ^[1] ; Terezan, Ana Paula ^[2] ; Sakuragui, Marise Margareth ^[1] ; Pesenti, Emanuele ^[3] ; Giani, Alessandra ^[4] ; Cestari, Marta Margareth ^[3] ; Fernandes, Joao Batista ^[2] ; Fernandes, Marisa Narciso ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Physiol Sci, Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Chem, Sao Paulo, SP - Brazil

^[3] Univ Fed Parana, Dept Genet, Curitiba, Parana - Brazil

^[4] Univ Fed Minas Gerais, Dept Bot, Belo Horizonte, MG - Brazil

• Document type: Journal article
• Source: Environmental Toxicology and Chemistry; v. 39, n. 5 MAR 2020.
• Web of Science Citations: 0

Abstract

Radiocystis fernandoi, a microcystin (MC) producer, has been common in cyanobacterial blooms in tropical regions. Microcystin is a hepatotoxin that causes tissue damage and even death in animals, including humans; its detoxification process may involve biotransformation and activation of the antioxidant defense system. We evaluated the detoxification pathway, examined the antioxidant defense system responses, and determined the alterations and the organ histopathological indexes in the liver of the tropical fish Hoplias malabaricus after acute and subchronic intraperitoneal exposure to microcystin. The crude microcystin extract of R. fernandoi had predominantly MC-RR and MC-YR. The detoxification process was activated by increasing ethoxyresorufin-O-deethylase activity, whereas glutathione S-transferase was inhibited. The activity of the antioxidant defense enzymes superoxide dismutase (SOD) and glutathione peroxidase decreased after acute exposure; the SOD-catalase system and the glutathione level increased after subchronic exposure. The carbonyl protein level, lipid peroxidation (LPO), and DNA damage were unchanged after acute exposure, whereas protein carbonyl was unchanged, LPO decreased, and DNA damage increased after subchronic exposure. Histopathological alteration indexes differed between acute and subchronic exposure, but the histopathological organ indexes indicate liver dysfunction in both exposure periods. We conclude that MC-RR and MC-YR induce different liver responses depending on the time of exposure, and the antioxidant defense responses after subchronic exposure may help to partially restore the liver function. Environ Toxicol Chem 2020;00:1-11. (c) 2020 SETAC (AU)

• FAPESP's process: 12/00728-1 - Effects of microcystins present in the crude extract of cyanobacterium, Microcystis aeruginosa, in the liver and muscle of traírão, Hoplias lacerdae.
• Grantee: Marcelo Gustavo Paulino
• Support Opportunities: Scholarships in Brazil - Doctorate