Characterization of live yeast cell derivative (LYCD) induced by atmospheric pressure cold plasma and its protective effects on cells

Summary form only given. In previous studies, we have found that during atmospheric pressure cold plasma treatment, oxidative stress pathways are required for yeast cell response. In addition, overexpressions of anti-oxidant superoxide dismutase (SOD) genes can remarkably protective yeast cells from plasma injury. These results are in coincidence with other groups´ findings with mammalian cells, thus encouraging us to explore more on the anti-oxidative responses in eukaryotic cells subjected to plasma treatment, which is valuable for guiding the safety and precautionary measures for potential plasma medicine applications in the near future. In this study, the live yeast cell derivative (LYCD) was obtained by yeast cells exposed to sub-lethal doses of plasma treatment. The characteristics of the LYCD induced by plasma were evaluated by analyzing the collaboration of three important anti-oxidative systems in eukaryotic cells, superoxide dismutase (SOD) system, catalase (CAT) system and glutathione (GSH) system. The SOD and CAT activities, as well as reduced GSH and oxidized GSH amount were tested by kits and compared among the strains. And other important compositions of LYCD were detected by mass spectrum (MS). In addition, LYCD of cells after UV or H₂O₂ are reported to be UV or H₂O₂ protective. We also looked into the effects of LYCD after plasma treatment by applying it to various types of cells subjected to plasma. Then Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) viabilities were measured by colony counting method, while Saccharomyces cerevisiae (S. cerevisiae), human breast cancer (MCF-7) and human embryonic skin fibroblasts (CCC-ESF-1) viabilities were assessed by XTT assay. The results indicated that the activities of SOD, CAT and the reduced GSH amount of LYCD increase linearly with plasma treatment time. More interestingly, those three important antioxidative substances extracted from yeast ce- l can act in accordance with each other. Furthermore, we observed that the LYCD induced by plasma can in turn effectively protect various types of cells from plasma damage. Detailed results will be discussed at the conference.