Oxidation of lactate to pyruvate mediates the cytotoxic potential of physical plasma‐treated saline solutions in ovarian cancer

Epithelial ovarian cancer (EOC) is the most common type of gynecological tumor, presenting poor prognosis at diagnosis and with recurrences being frequently observed. Reactive species generated by physical plasma and transferred into liquids have shown promising results in cancer therapy. Recently, Ringer's lactate solution was exposed to plasma showing selective anticancer activity on EOC cells. In this work, we compared the effect of plasma treatment, using the kINPen plasma jet, on Ringer's saline and Ringer's lactate solution. These two plasma‐treated liquids were analyzed chemically by quantifying reactive species and the extent of lactate oxidation. The biological efficiency of the plasma‐treated liquids was explored in EOC cells. The results show that lactate is affected by plasma treatment, displaying a reduction of cytotoxic potential. Comparison of plasma‐treated Ringer's and plasma‐treated Ringer's lactate revealed the oxidation of lactate to pyruvate that tends to diminish the cytotoxic potency of the plasma‐treated liquid despite presenting similar concentrations of long‐lived reactive oxygen and nitrogen species.