Reduced HeLa cell viability in methionine‐containing cell culture medium irradiated with microwave‐excited atmospheric‐pressure plasma

Abstract

The mechanism underlying the death of cancer cells incubated in plasma‐activated medium (PAM) prepared by irradiation of culture medium with atmospheric‐pressure plasma is revealed by analyzing changes in the culture medium composition using liquid chromatography‐tandem mass spectrometry and nuclear magnetic resonance spectroscopy. The concentration of the essential amino acid methionine declined in microwave‐excited plasma‐irradiated medium, whereas, that of methionine sulfoxide increased due to oxidation of methionine. The decrease in methionine concentration in the cell culture medium rather than the increase in methionine sulfoxide leads to the decline in the survival rate of HeLa cells incubated in PAM. These results provide useful insights into the mechanism of selective cancer cell death in PAM.