[ODP22] 5. Pathogenicity -b. Toxins, effectors and physically active substances

[ODP-131] Red ginseng extracts relieve atopic dermatitis by reducing alpha-hemolysin production from S. aureus

Yuina Iwasaki¹, Sakura Tsutamoto², Risa Imamiya², Keiichi Samukawa³, Hiroshi Iwao⁴, Dendi Krisna Nugraha⁵, Yasuhiko Horiguchi⁵, Mayuko Osada-Oka¹ (¹Food Hyg. Env. Health., Grad. Sch. Life Env. Sci., Kyoto Pref. Univ., ²Faculty Life Env. Sci., Kyoto Pref. Univ., ³Dept. Pharm., Osaka City Univ. Med. Sch., ⁴Shitennouji Univ., ⁵Dept. Mol. Bacteriol., RIMD, Osaka Univ.)

The skin microbiome is directly associated with atopic dermatitis (AD). α-toxin, also known as α-hemolysin, produced by S. aureus positively correlates with AD severity and is a therapeutic target for the control of AD. We reported that red ginseng extracts (RGEs) suppressed phosphorylation of p70 ribosomal protein S6 kinase in macrophages and basophils in AD mice, suggesting that RGEs have an anti-inflammatory effect on the AD. In this study, we examined whether RGEs suppress the AD development by S. aureus. By using the RNA-seq technique, we analyzed the expression levels of 2,726 genes in S. aureus BAA-1717 strain that had been incubated for 3 or 6 h in the presence or absence of RGEs. RGEs reduced the expressions of 169 genes and increased the expressions of 129 genes. The mRNA levels of α-/γ-/δ-hemolysin and both saeS/R and agrC/A in the two component systems, which regulate the expression of the hemolysin genes, were decreased by RGEs. Next, we examined the effect of culture medium of S. aureus (Sa-CM) with or without RGEs against AD mice. The expression levels of Ifn-gamma and Ccl-2 mRNA were higher in ears of AD mice than in ears of control mice. These mRNA levels in ears of AD mice were further increased by Sa-CM without RGEs, but not by Sa-CM with RGEs. These results suggest that RGEs show inhibitory effects on the AD development by the infection with S. aureus.