title: p-Cresol inhibits IL-12 production by murine macrophages stimulated with bacterial immunostimulant.
abstract: p-Cresol, an end product of aromatic amino acids, is produced from food proteins by intestinal bacteria, and is detectable in blood and feces. Especially, blood and fecal levels of p-cresol are high in chronic renal failure (CRF) patients. Although it has been suggested that p-cresol is toxic in the body, the effect of p-cresol on immune responses has not yet been clarified. In this study, we investigated the effect of p-cresol on IL-12 production of macrophages stimulated with Lactobacillus casei strain Shirota (LcS) in vitro. Pre-incubation with p-cresol inhibited IL-12 p40 production of LcS-stimulated J774.1 cells, a murine macrophage-like cell line, in a dose-dependent manner. IL-12 p40 and p70 production of LcS-stimulated murine peritoneal macrophages was also inhibited by p-cresol. The inhibitory effect was not dependent on the cytotoxicity of p-cresol. These results indicate that blood and fecal p-cresol may have adverse effects on the host defense system in CRF patients.
authors.affiliation: Yakult Central Institute for Microbiological Research, Kunitachi, Tokyo, Japan. koji-kawakami@yakult.co.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Kawakami
authors.forename: Ikuyo
authors.initials: I
authors.lastname: Makino
authors.forename: Ikuo
authors.initials: I
authors.lastname: Kato
authors.forename: Kazumi
authors.initials: K
authors.lastname: Uchida
authors.forename: Masaharu
authors.initials: M
authors.lastname: Onoue
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003408:Cresols / Q000378:metabolism / Q000633:toxicity*; D007114:Immunization; D018664:Interleukin-12 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D007676:Kidney Failure, Chronic / Q000276:immunology; D007780:Lacticaseibacillus casei / Q000276:immunology; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D003408:Cresols; D018664:Interleukin-12; C032538:4-cresol