L-Dehydroascorbate efficiently degrades non-thermal plasma-induced hydrogen peroxide

Yasumasa Okazaki; Yuuri Ishidzu; Fumiya Ito; Hiromasa Tanaka; Masaru Hori; Shinya Toyokuni

doi:10.1016/j.abb.2021.108762

L-Dehydroascorbate efficiently degrades non-thermal plasma-induced hydrogen peroxide

Arch Biochem Biophys. 2021 Mar 30:700:108762. doi: 10.1016/j.abb.2021.108762. Epub 2021 Jan 20.

Authors

Yasumasa Okazaki¹, Yuuri Ishidzu², Fumiya Ito², Hiromasa Tanaka³, Masaru Hori⁴, Shinya Toyokuni⁵

Affiliations

¹ Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Showa-Ku, Nagoya, 466-8550, Japan. Electronic address: samasuya@med.nagoya-u.ac.jp.
² Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Showa-Ku, Nagoya, 466-8550, Japan.
³ Center for Low-temperature Plasma Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8603, Japan; Center for Advanced Medicine and Clinical Research, Nagoya University Graduate School of Medicine, Showa-Ku, Nagoya, 466-8550, Japan.
⁴ Center for Low-temperature Plasma Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8603, Japan.
⁵ Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, Showa-Ku, Nagoya, 466-8550, Japan; Center for Low-temperature Plasma Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8603, Japan. Electronic address: toyokuni@med.nagoya-u.ac.jp.

PMID: 33482147
DOI: 10.1016/j.abb.2021.108762

Abstract

Non-thermal plasma (NTP) devices generate reactive oxygen species (ROS) and reactive nitrogen species, such as singlet oxygen (¹O₂), superoxide (O₂^-), hydroxyl radical (^●OH), hydrogen peroxide (H₂O₂), ozone, and nitric oxide at near-physiological temperature. In preclinical studies, NTP promotes blood coagulation, wound healing with disinfection, and selective killing of cancer cells. Although these biological effects of NTP have been widely explored, the stoichiometric quantitation of ROS in the liquid phase has not been performed in the presence of biocompatible reducing agents, which may modify the final biological effects of NTP. Here, we utilized electron paramagnetic resonance spectroscopy to quantitate ^●OH, using a spin-trapping probe 5,5-dimethyl-1-pyrroline-N-oxide; ¹O₂, using a fluorescent probe; and O₂^- and H₂O₂, using luminescent probes, after NTP exposure in the presence of antioxidants. l-ascorbate (Asc) at 50 μM concentration (physiological concentration in serum) significantly scavenged ^●OH, whereas (-)-epigallocatechin gallate (EGCG) and α-tocopherol were also effective at performing scavenging activities at 250 μM concentrations. Asc significantly scavenged O₂^- and H₂O₂ at 100 μM. l-Dehydroascorbate (DHA), an oxidized form of Asc, degraded H₂O₂, whereas it did not quench ^●OH or O₂^-, which are sources of H₂O₂. Furthermore, EGCG efficiently scavenged NTP-induced ¹O₂, O₂^-, and H₂O₂ in Chelex-treated water. These results indicate that the redox cycling of Asc/DHA and metabolites of DHA are important to be considered when applying NTP to cells and tissues. Additionally, ROS-reducing compounds, such as EGCG, affect the outcome. Further studies are warranted to elucidate the interaction between ROS and biomolecules to promote the medical applications of NTP.

Keywords: (-)-Epigallocatechin gallate; Ascorbate; Dehydroascorbate; Electron paramagnetic resonance (EPR); Hydrogen peroxide; Non-thermal plasma (NTP).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Dehydroascorbic Acid / chemistry*
Hydrogen Peroxide / chemistry*
Oxidation-Reduction
Plasma Gases / chemistry*

Substances

Plasma Gases
Hydrogen Peroxide
Dehydroascorbic Acid