Direct heat incubator

Human cervical adenocarcinoma cells (HeLa cells) were cultured in a Direct Heat incubator (Thermo Scientific, Waltham, MA, USA), under standard culture conditions, i.e., 37 °C and 5% CO₂, on a modified DMEM medium (GIBCO, New York, NY, USA), containing 10% fetal calf serum (Biowest, Nuaillé, France) and a mixture of antibiotics (penicillin G, streptomycin, amphotericin B) (Corning, Manassas, VA, USA). The HeLa cells were purchased from the American Type Tissue Culture Collection (Rockville, MD, USA). Cells were treated for 48 h with azelastine hydrochloride (≥98% HPLC), (4-[(4-chlorophenyl)methyl]-2-(1-methylazepan-4-yl) phthalazin-1-one hydrochloride), which was purchased from Sigma Aldrich (St. Louis, MO, USA). The following concentrations of the test compound were used in the experiment: 15 µM, 25 µM, 45 µM, 60 µM, and 90 µM.
According to the literature data, the tested concentrations are used in research on antihistamine drugs conducted on cancer cell lines. Control cells were cultured in complete maintenance medium without the addition of the test compound.

The HeLa human cervical adenocarcinoma cells were purchased from the American Type Tissue Culture Collection (Rockville, MD, USA). HeLa cells were cultured at 37 °C and 5% CO₂ atmosphere in a DirectHeat incubator (Thermo Fisher Scientific, Waltham, MA, USA) on a modified Dulbecco medium (GIBCO, New York, USA) containing 100 μg/mL penicillin-streptomycin (Corning, Manassas, USA), 10% fetal calf serum (Biowest, Nuaillé, France). Physcion (≥ 98.0%, TLC), 1,8-dihydroxy-3-methoxy-6-methylanthraquinone, was purchased from Sigma-Aldrich (St. Louis, MO, USA).