Cytotoxicity of Endocytosis and Efflux Inhibitors in the BeWo Cell Line

Aims: The purpose of this study was to determine the cell viability and cytotoxicity of various endocytosis and efflux inhibitors which can be used to determine transport and uptake mechanisms in the BeWo (b30 clone) human placental trophoblast cell line. Ethanol and dimethylsulfoxide (DMSO) were also studied since they are often used as cosolvents for administration of these inhibitors.

Methodology: The water-soluble tetrazolium-1 (WST-1) assay was used to quantify cell viability and the lactate dehydrogenase (LDH) assay was used to determine cytotoxicity.

Results: By the WST-1 assay, reduced cell viability was observed following 4 hours of exposure to chlorpromazine (10 µg/mL), colchicine (1 mM), filipin (3 µg/mL), gentamicin (2 mM), GF120918 (1 µM), methyl-β-cyclodextrin (5 mM), and verapamil (100 µM). By the LDH assay, however, no cytotoxicity was observed after 4 hours of exposure to the aforementioned compounds. Amiloride (500 µM), ethanol (up to 0.1% v/v), and DMSO (up to 0.1% v/v) did not reduce cell viability nor induce cytotoxicity.

Conclusion: This information is valuable when selecting potential inhibitors of endocytosis and efflux and the selection of time points for mechanistic studies.