3.4. Evaluating

Toxicity of AIMS Extract Library. Human alveolar epithelial cells (A549) [51], Madin-Darby canine kidney epithelial cells (MDCK) [52], human leukaemia cells (THP-1) [53], human hepatocellular carcinoma cells (Hep-G2) [54] and human embryonic kidney cells 293 (HEK293) [55] were grown and differentiated in complete RPMI (Roswell Park Memorial Institute Medium) and DMEM (Dulbecco’s Modified Eagle’s medium) tissue culture media (RPMIc and DMEMc, from the Thermo Fisher Scientific, Waltham, MA, USA) by adding 10% FBS, 200 µM L-glutamine and 1 mM HEPES buffer solution. To determine toxicity of the AIMS extract library, 2 × 10⁵ of each cell type were added to a 96-well plate and left for 48 h in a humidified 5% CO₂ incubator at 37 °C to adhere. Extract samples at a final concentration of 0.5 mg mL⁻¹ were added to the wells, then the plates incubated for 4 more days in a humidified 5% CO₂ incubator at 37 °C. Then, resazurin (10 μL of 0.05% w/v) was added and after 4 h, fluorescence measured as described previously. The cell viability was calculated as percentage fluorescence relative to untreated cells.