[ODP8A] a. Applications of Microorganisms and Microbial Products

[ODP-227] Hericium erinaceus ethanol extracts have endotoxin-neutralizing activity

○Hiraku Osawa^1,2, Sakura Onoue³, Kazuyoshi Kawahara³, Kenji Matsushita⁴, Hiroyuki Tada² (¹Sch. Dent., Tohoku Univ., ²Dept. Oral Immunol., Sch. Dent., Tohoku Univ., ³Dept. Biosci., College Sci. Engineer., Kanto Gakuin Univ., ⁴Dept. Oral Dis. Res., NCGG)

Objective: Macrophages play an important role in the induction of inflammatory diseases. We examined the effects of mushroom extracts on the inhibition of proinflammatory cytokine production by human macrophages. Methods: Human monocytic THP-1 cells were induced to differentiate into macrophages by OCT, a vitamin D₃ analog. Ethanol extracts and hot water extracts from edible mushrooms were prepared by Hokuto Corporation. IL-1β, IL-6, and IL-8 levels in the culture supernatants were measured by ELISA. Results: Lipopolysaccharide (LPS) from Escherichia coli-induced IL-1β, IL-6, and IL-8 production by OCT-treated THP-1 cells was inhibited by pretreatment of the LPS with ethanol- or hot water-extracts from mushrooms. Hericium erinaceus-derived ethanol extracts (HEE) inhibited LPS-induced IL-8 production. Similar to LPS, pretreatment of synthetic E. coli-type lipid A with HEE suppressed IL-8 production. Furthermore, ergosterol, a component of edible mushrooms, also suppressed LPS-induced IL-8 production. This indicates that ergosterol may conjugate with lipid A. Conclusion: H. erinaceus exerts endotoxin-neutralizing effects on macrophages through the inhibition of CD14-dependent activation.