Anticancer Effects of Plasma-Treated Water Solutions from Clinically Approved Infusion Liquids Supplemented with Organic Molecules

Water solutions treated by Cold Atmospheric Plasmas (CAP) recently stand out in the field of cancer treatment as sources of exogenous blends of Reactive Oxygen and Nitrogen Species (RONS), whose balance is directly involved in physiological as well as pathological pathways. Along with CAP, also phenols and polyphenols could potentially exert promising anti-cancer effects, mostly attributed to their pro-oxidant ability to generate RONS like O2-, H2O2 and a mixture of potentially cytotoxic compounds. Combining the efficacy of both treatments could synergistically attack cancer cells; yet so far this combination is completely unexplored. In this study, L-tyrosine, an amino acid with phenolic side chain, is added to an electrolyte solution exposed to plasma, to evaluate the effects of this combination on RONS generation and cancer cells response to their exposure. The results clearly indicate that the generation of RONS is enhanced when the plasma treatment is performed on the liquid in presence of L-tyrosine. Exposure of four different cancer cell lines to plasma treated solution containing L-tyrosine reveals strong anti-cancer effects. The treatment allows a reduction in cell viability and in oxygen uptake, an increase in intracellular ROS levels and triggers apoptosis pathways in all investigated cancer cells.