## 3 Results and Their Discussion
Figure 7: Dependence of the level of vitality of the healthy (blue diamonds) and tumor (red squares) cells on the time of processing by the direct piezodischarge of the physiological solution added to the nutritional medium. The cells were kept in the RPMI nutritional medium with the addition of 10% fetal bovine serum, amphotericin, and gentamycinin, in a thermostat with increased CO2 concentration (5%) at temperature of 37 \({}^{\circ}\)C. In detail, the experimental conditions are described in the Section 2. Figure 9 shows that the chemically prepared solution of nitrites, nitrates, and hydrogen peroxide has a similar effect on the mononuclear leucocytes and a stronger cytotoxic effect on the mieloblastosis cells than the physiological solution treated by the direct piezodischarge. In this case, there was a correlation between the MTT test and the trypan blue dye. Although nitrites (NO2) themselves do not have a damaging effect on the cells, and they even increase the vitality of mieloblastosis cells compared to the control, together with hydrogen peroxide (H2O2), they have a stronger cytotoxic effect than hydrogen peroxide alone. The addition of nitrates (NO3) increases the cytotoxic effect further (by 30-50%). Figure 9: Dependence of the level of vitality of (**A**) conventionally healthy and (**B**) tumor (mieloblastosis) cells on the concentration of nitrites, nitrates, and hydrogen peroxide added to the nutritional medium. Concentrations 1–3 correspond to those in the physiological solution treated by the direct piezodischarge during 30, 60, and 90 s, respectively (1: H2O2—2.08 uM, NO2—0.058 mM, NO3——0.286 mM; 2: H2O2—6.91 uM, NO2———0.091 mM, NO3——0.378 mM; 3: H2O2—10.08 uM; NO2——0.103 mM, NO3——0.725 mM). An asterisk * indicates a statistically significant difference (\(p<0.05\)) from the control, an asterisk above the frame indicates a statistically significant difference (\(p<0.05\)) between different experimental samples. The experimental conditions are described in the Section 2. This result confirms [PERSON]'s studies [19; 20], which talk about the combined action of the reactive forms of nitrogen and oxygen. The damage to the DNA of both types of cells under the action of the chemically prepared solution of nitrites, nitrates, and hydrogen peroxide shown in Figure 10 is also more pronounced than under the action of the physiological solution treated by direct piezodischarge; it reaches 100%. Same as the vitality, the level of DNA damage after nitrites are added is the same as in the control and is even lower for some concentrations. When both nitrites and hydrogen peroxide are added, the DNA damage is more severe than one only hydrogen peroxide is added. The addition of the combination of nitrites, nitrates and hydrogen peroxide produces approximately the same result as the addition of nitrites and hydrogen peroxide. Figure 10: Dependence of the level of DNA damage of (**A**) conventionally healthy and (**B**) tumor (mieloblastosis) cells on the concentration of nitrites, nitrates, and hydrogen peroxide added to the nutritional medium. Concentrations 1–3 correspond to those in the physiological solution treated by the direct piezodischarge during 30, 60, and 90 s, respectively (1: H\({}_{2}\)O\({}_{2}\)—2.08 \(\upmu\)M, NO\({}_{2}\)——0.058 mM, NO\({}_{3}\)——0.286 mM; 2: H\({}_{2}\)O\({}_{2}\)—6.91 \(\upmu\)M, NO\({}_{2}\)——0.091 mM, NO\({}_{3}\)——0.378 mM; 3: H\({}_{2}\)O\({}_{2}\)–10.08 \(\upmu\)M\({}_{3}\)\(\mathrm{NO_{2}}\)——0.103 mM, NO\({}_{3}\)——0.725 mM). An asterisk * indicates a statistically significant difference (\(p<0.05\)) from the control, an asterisk above the frame indicates a statistically significant difference (\(p<0.05\)) between different experimental samples. The experimental conditions are described in the Section 2. Figure 11 shows that necrosis is prevalent among the types of cell death during the action on the cells of the chemically prepared solution of nitrites, nitrates, and hydrogen peroxide.