Therapeutic effects of cold plasma-activated water on MCF7 breast cancer tumors in a mouse model

Breast cancer is the most common cancer affecting women, and plasma-activated water (PAW) is emerging as a potential therapeutic approach. While early results are encouraging, additional research is necessary to assess its long-term effects and identify the most effective methods of application. Therefore, this study aimed to investigate the effects of PAW on an MCF7 breast cancer mouse model. A total of eighteen BALB/c mice were divided into three groups (n = 6/group): one negative control group and two tumor groups injected with MCF7 cells. After 91 days of MCF7 injection, the tumor groups received either distilled water (DW) or PAW (for 3 min) twice weekly via oral gavage for 28 days. The results revealed that the conductivity, H2O2, and NO2- values were significantly higher for PAW than for DW, while pH was lower (P < 0.001). Hematological analysis showed an increase in neutrophil counts, neutrophil %, eosinophil %, and neutrophil/lymphocyte ratio in MCF7 and PAW groups. Conversely, there were reductions in red blood cells (RBC), platelets (PLT), hemoglobin (HGB), and hematocrit (HCT) percentages, while mean corpuscular hemoglobin concentration (MCHC) increased. Both the control and PAW groups had higher total antioxidants and levels of α-L-fucosidase, while MCF7 had elevated arginase levels. The CD44⁺/CD24⁻ and CD44⁺/CD24⁺ cell populations were highest in the MCF7 group and reduced in the PAW group. The percentage of parent cells in late apoptosis was significantly higher in the PAW group than in the MCF7 and DW groups. Histopathology analysis revealed carcinoma features in the MCF7 group, while PAW reduced these effects. Immunostaining showed increased ER-α and Caspase-3 expression in the MCF7 group, with PAW moderating expression levels. Overall, these findings suggest that PAW may offer promising therapeutic applications in managing oxidative stress and hindering cancer cell progression.