Resazurin Reduction Assay

The resazurin reduction cell viability and metabolism assay was conducted according to a previously described method (Szychowski et al. 2017a). On the day of analysis, a working solution of 60 μM resazurin was prepared in a medium containing 1% FBS. After 24- and 48-h treatment, cells with increasing concentrations of the VGVAPG peptide medium in the wells were replaced into a working solution of resazurin (100 μL) and the plates were placed in 37 °C. Fluorescence was measured with excitation and emission wavelengths of 530 and 590 nm, respectively, on a FilterMax F5 Multi-Mode microplate reader (Molecular Devices, Corp., Sunnyvale, CA, USA) for 30 min and 1 h after dye addition.