Acetic acid solution

The sulforhodamine B (SRB) assay was used to determine cell viability. 44 After being cultured with and without the compound of interest for 18 hours, adherent cells (1 × 10 5 cells per well) were fixed using 50 µL of a trichloroacetic acid solution (50% w/v) (Sigma-Aldrich, St Louis, MO, USA) and incubated at 4 °C for 1 hour. Subsequently, the plates were washed five times with distilled water and allow to air dry. Afterwards, 100 µL of SRB solution (0.4% w/v) (Sigma-Aldrich, St Louis, MO, USA) were added to each well and incubated for 30 minutes at room temperature in the dark. After that time, the supernatant was eliminated, and the plate was washed five times with an acetic acid solution (1% v/v) (Panreac, Barcelona, Spain) and left to air dry. At the end, 100 µL of a Tris base solution ( pH 10.5, 10 mmol L -1 ) (Sigma-Aldrich, St Louis, MO, USA) was added to each well. The optical density (OD) was quantified at 510 nm using a multi-well plate reader spectrophotometer (BioTek, Bad Friedrichshall, Germany) to evaluate the cell survival.