Cytotoxicity to Melanoma and Proliferation to Fibroblasts of Cold Plasma Treated Solutions With Removal of Hydrogen Peroxide and Superoxide Anion

Abstract

Cold atmospheric pressure plasma (CAP) is widely used in research for biomedical applications and is a promising therapy to selectively eradicate cancer cells. However, there is no unity for the species that cause this different effect. The aim of this article was to further determine the key reactive species causing differences in viability between melanoma cells (B16) and fibroblasts (L929). In this article, the cell viability of two cell lines exposed directly to the CAP was tested. The result shows CAP exhibit different cytotoxicity against the viability of two cell lines. The proliferation of B16 cells is significantly inhibited. By using superoxide anions scavengers and catalase, long-lived reactive oxygen species (ROS) generated by CAP, such as hydrogen peroxide (H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ), were found to have stronger cytotoxicity to B16. Besides, the B16 cells were significantly inhibited after simultaneously scavenging free radicals and hydrogen peroxide, while it has the opposite effect on L929 cells. In order to explore whether there may be other long-lived species, such as protein oxides, which have important effects on cells, CAP-treated bovine serum albumin (BSA) was applied in cultured cells. We observed the inhibition effect of CAP-treated BSA on the growth of B16 but proliferation versus L929 cells. The content of peroxide in CAP-treated BSA was measured by xylenol orange method. The rate of peroxide reduction in B16 cells is faster than that of L929 cells. In addition, after adding certain enzymes to cells, the effects of CAP on intracellular ROS generation were examined by liquid chromatography/mass spectrometry (LC/MS). There is a significant difference in the content of O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">·-</sup> and H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> in the two cells.