title: Methylene blue toxicity in zebrafish cell line is dependent on light exposure.
abstract: Methylene blue (MB) has been widely applied in the clinical area and is currently being used in aquaculture as biocide. Some recent studies have emphasized the importance of understanding the action mechanism and the MB cellular targets. In this sense, zebrafish is considered a relevant model to study the intrinsic pathway of apoptosis as well as the cellular responses involving DNA damage and repair. So, the aim of the present study was to compare MB action mechanisms in a zebrafish cell line, both in the absence (MB alone; dark toxicity) and in the presence of photosynthetically active radiation (MB+PAR; phototoxicity). There was a significant increase of the levels of reactive oxygen and nitrogen species 3 h after MB treatment, whereas this increase was only observed 12 h after treatment with MB+PAR. All treatments with MB resulted in an increase in DNA damage after 3 and 6 h. However, cell death by apoptosis was observed from 6 h after treatment with MB+PAR and 12 h after treatment with MB alone. The expression of genes related to apoptosis was altered after MB and MB+PAR treatment. Therefore, this zebrafish cell line is sensitive to the photodynamic action of MB; MB is able to generate DNA damage and induce apoptosis in this cell line both alone and in the presence of PAR. However, the pathways leading to apoptosis in this model appear to be dependent on the type of MB exposure (in the presence or absence of PAR).
authors.affiliation: Programa de Pós-Graduação em Ciências Fisiológicas-Fisiologia Animal Comparada, Universidade Federal do Rio Grande-FURG, Av. Itália km 8, 96203-900, Rio Grande, Rio Grande do Sul, Brazil.
authors.forename: Simone Rutz da
authors.initials: SR
authors.lastname: Costa
authors.affiliation: Programa de Pós-Graduação em Ciências Fisiológicas-Fisiologia Animal Comparada, Universidade Federal do Rio Grande-FURG, Av. Itália km 8, 96203-900, Rio Grande, Rio Grande do Sul, Brazil.
authors.forename: Mauricio da Costa
authors.initials: Mda C
authors.lastname: Monteiro
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Rio Grande-FURG, Av. Itália km 8, 96203-900, Rio Grande, Rio Grande do Sul, Brazil.
authors.forename: Flavio Manoel Rodrigues
authors.initials: FM
authors.lastname: da Silva Júnior
authors.affiliation: Programa de Pós-Graduação em Ciências Fisiológicas-Fisiologia Animal Comparada, Universidade Federal do Rio Grande-FURG, Av. Itália km 8, 96203-900, Rio Grande, Rio Grande do Sul, Brazil.|Instituto de Ciências Biológicas, Universidade Federal do Rio Grande-FURG, Av. Itália km 8, 96203-900, Rio Grande, Rio Grande do Sul, Brazil.
authors.forename: Juliana Zomer
authors.initials: JZ
authors.lastname: Sandrini
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D016923:Cell Death / Q000187:drug effects / Q000528:radiation effects; D002460:Cell Line; D004249:DNA Damage; D015870:Gene Expression / Q000187:drug effects; D022781:Hepatocytes / Q000187:drug effects* / Q000528:radiation effects*; D008027:Light; D008751:Methylene Blue / Q000633:toxicity*; D015027:Zebrafish
chemical_list: D008751:Methylene Blue
keywords: apoptosis; gene expression; genotoxicity; hepatocyte; methylene blue; photodynamic action