Identification of pathways of A498 human kidney carcinoma cell death under the action of Gratiola officinalis L. extract and green tea flavonoids using fluorescence imaging techniques

Using fluorescence methods for visualization of human tumor cell apoptosis and necrosis in vitro, the antitumor effects of flavonoid-containing Gratiola officinalis L. and green tea extracts at ultralow concentrations on A498 human kidney carcinoma cells after 24 and 48 h were compared. Fluorescent dyes (propidium iodide and acridine orange) were used in the “living and dead” test, which made it possible to identify the total number of cells that died by necrosis and apoptosis, as well as cells in which apoptosis has started and apoptotic bodies or pycnosis of the nucleus were detected. Gratiola officinalis L. extract had the most pronounced cytostatic activity 48 h after exposure; the number of cells per field of view decreased by a factor of 1.5 compared with the control. Green tea extract at a concentration of 0.0288 mg/mL had the most pronounced cytotoxic activity; its manifestation was growing 48 h after exposure. Gratiola officinalis L. extract exhibited cytotoxic activity at lower concentrations (0.0036 mg/mL).