The potential of phenothiazinium dyes as cytotoxicity markers in cisplatin-treated cells

Author(s)

Pereira, Luiz Miguel ; Portapilla, Gisele Bulhoes ; Brancini, Guilherme Thomaz Pereira ; Possato, Bruna ; da Costa, Cassia Mariana Bronzon ; Abreu-Filho, Pericles Gama ; Wainwright, Mark ; Yatsuda, Ana Patricia ; Braga, Gilberto ubida Leite

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 13, n. 1, p. 17-pg., 2023-06-23.

Abstract

Assessing the in vitro toxicity of compounds on cell cultures is an important step during the screening of candidate molecules for diverse applications. Among the strategies employed to determine cytotoxicity, MTT, neutral red, and resazurin are commonly used. Methylene blue (MB), a phenothiazinium salt, has several uses, such as dye, redox indicator, and even as treatment for human disease and health conditions, such as malaria and methemoglobinemia. However, MB has only been sparsely used as a cellular toxicity indicator. As a viability indicator, MB is mostly applied to fixed cultures at high concentrations, especially when compared to MTT or neutral red. Here we show that MB and its related compounds new methylene blue (NMB), toluidine blue O (TBO), and dimethylmethylene blue (DMMB) can be used as cytotoxicity indicators in live (non-fixed) cells treated for 72 h with DMSO and cisplatin. We compared dye uptake between phenothiazinium dyes and neutral red by analyzing supernatant and cell content via visible spectra scanning and microscopy. All dyes showed a similar ability to assess cell toxicity compared to either MTT or neutral red. Our method represents a cost-effective alternative to in vitro cytotoxicity assays using cisplatin or DMSO, indicating the potential of phenothiazinium dyes for the screening of candidate drugs and other applications. (AU)

• FAPESP's process: 18/21020-3 - Actin-depolymerization factor (NcADF): oxidation as regulator of NcADF activity on programmed cell death of Neospora caninum
• Grantee: Ana Patricia Yatsuda Natsui
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• FAPESP's process: 18/10711-5 - Evaluation of the potential of phenothiazinium dyes for Toxoplasma gondii control
• Grantee: Luiz Miguel Pereira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 16/11386-5 - Mechanistic study of perception and response to visible light in the entomopathogenic fungus Metarhizium acridum
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