Abstract B22: The human skin bacteria Staphylococcus epidermidis ameliorates UVB-induced free radicals through reduction of labile iron

Abstract

Abstract UVB-induced skin damage results in various inflammatory disorders through the induced generation of reactive oxygen species (ROS) that quickly inundate tissue antioxidants and chronic disorders; in severe cases it can lead to skin cancer. We investigated efficacies of human skin commensal bacteria S. epidermidis (ATCC12228) with glycerol, which on fermentation produces electrons. In vivo affirmation on ICR mice has confirmed the antioxidative role of topically applied S. epidermidis with glycerol against UVB irradiation and maintained sufficient expression of 4-hydroxynonenal (4-HNE) and cyclobutane pyrimidine dimer (CPD), a major biomarker for lipid peroxidation and DNA damage. Upon UVB irradiation in keratinocyte cell lines treated with glycerol mediated S. epidermidis fermentation product show the reduced intracellular oxidative stress. S. epidermidis or glycerol alone in In vivo topical application in mice skin and in vitro fermentation product treatment in keratinocytes does not influence the level of oxidative stress. Further electrochemical behavior of glycerol mediated S. epidermidis fermented medium found to produce electron transfer; this result suggests the electrogenic and antioxidant property of S. epidermidis. The electrons produced by S. epidermidis fermentation product initiate reduction of free radicals by converting toxic Fe3+ (ferric ion) back to nontoxic Fe2+ (ferrous ion); thereby it terminates Fenton’s reaction and maintains iron hemostasis. The novel pathway linking electrons produced by probiotic skin bacteria and iron metabolism has been further analyzed. Note: This abstract was not presented at the conference. Citation Format: Arun Balasubramaniam, Sunita Keshari, Prakaso Adi, Chun-Ming Huang. The human skin bacteria Staphylococcus epidermidis ameliorates UVB-induced free radicals through reduction of labile iron [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr B22.