###### Abstract  
Presently, plasma-treated solutions (PTS) are widely introduced into medicine. Plasma-activated solutions contain various reactive forms of oxygen and nitrogen which provide the desired biological effects. Yet it remains unclear exactly which components of the treated solution are the most important and what the difference is between the plasma-treated solution and a chemically prepared solution composed of the same components. In this work, we show that the chemically prepared mixture of nitrites, nitrates, and hydrogen peroxide with concentrations similar to the plasma-treated solution exerts a fundamentally different effect on a cell culture. The chemically prepared solution has higher cyto- and genotoxicity and causes necrosis, while under the action of the plasma-treated solution, apoptotic processes develop in the cells slowly. plasma-treated solutions (PTS); leukemia; chemistry reactives; reactive oxygen species +
Footnote †: journal: Applied  
create stable compounds that exist in the solution during a therapeutically significant time. Mainly, these are nitrites, nitrates, and oxygen peroxide. The nitrites and the nitrates are in kinetic equilibrium with nitrogen oxides of corresponding valence. The long-lived biologically active compounds can decompose into short-lived species during catalysis of the components of the nutritional mediums or biological liquids [12]. In [13; 19; 20], [PERSON] showed that the hydrogen peroxide and nitrite ions exhibit biological action in cold-plasma-treated solutions. Cancerous cells are protected from the action of hydrogen peroxide by the catalase ferment that is found on their cellular membrane and neutralizes the peroxide. During the chemical interaction of hydrogen peroxide with nitrites, peroxinitrite (ONOO\({}^{-}\)) is created, which becomes a source of singlet oxygen (\({}^{1}\)O\({}_{2}\)). The singlet oxygen inhibits the catalase and allows hydrogen peroxide, peroxinitrite, and other short-lived species to penetrate the cell. Normally, the cancerous cells themselves also generate hydrogen peroxide and peroxinitrite, but they are inactivated. Due to the inhibition of catalase, the cell begins to release the oxygen and nitrogen reactive species into the surrounding medium and initiates similar processes in other tumor cells. The creation of HOCI from chlorine and peroxide leads to the peroxidation of lipids and triggers apoptosis. In this process, it is the reactive oxygen and nitrogen species released by the cells themselves that play a major role in the destruction of cancerous cells. The cold-plasma-treated solution only starts the self-destruction of the cells by activating the catalase. Healthy cells are less affected than the tumor ones because they contain other fermentents on their membranes and do not generate the reactive oxygen and nitrogen species. Based on the works of [PERSON], we make an assumption in this work that a chemically prepared solution of hydrogen peroxide, nitrites, and nitrates will act on the cells similarly to the cold-plasma-treated solution under the condition that it has similar concentrations of hydrogen peroxide, nitrites, and nitrates. A similar work was performed in 2016 by [PERSON] et al. [21], the cold plasma being used to treat the nutritious medium for the cell cultures of the lactose gland and glioblastoma. [PERSON] showed that adding nitrites to the nutritious medium increases the survivability of the cells; adding hydrogen peroxide decreases their survivability; adding both nitrites and hydrogen peroxide decreases the survivability more than pure hydrogen peroxide; and adding the cold-plasma-treated nutritious medium decreases their survivability even further. [PERSON]'s studies showed that T-lymphoblastoid leukemia cells begin to die by apoptosis one day after exposure to cold plasma or the addition of hydrogen peroxide to the nutrient medium. At the same time, the level of toxicity for different modes of cold plasma and hydrogen peroxide did not differ [22].