Preventive effect of bis-eugenol, a eugenol ortho dimer, on lipopolysaccharide-stimulated nuclear factor kappa B activation and inflammatory cytokine expression in macrophages.
Eugenol exhibits antioxidant and anti-inflammatory activities, but at higher concentrations acts as an oxidant and potent allergen. It was earlier shown that bis-eugenol synthesized by the oxidation of eugenol was less cytotoxic and more highly antioxidative than eugenol. But its anti-inflammatory mechanism remains yet unclear. Since nuclear factor-kappa B (NF-kappa B) is a key transcriptional factor in the expression of inflammatory cytokines, we examined whether eugenol and bis-eugenol are inhibitors of NF-kappa B activation. We observed that bis-eugenol, but not eugenol, clearly inhibited the degradation of inhibitory kappa B-alpha in RAW264.7 murine macrophages stimulated with lipopolysaccharide and, consequently, the transcriptional activity of the stimulated NF-kappa B in the cells. In addition, bis-eugenol actually inhibited LPS-stimulated expression of inflammatory cytokines at both gene and protein levels. These findings suggest that bis-eugenol acts as a potent inhibitor of NF-kappa B.
Murakami
Yukio
Y
Department of Oral Diagnosis, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado City, Saitama 350-0283, Japan.
Shoji
Masao
M
Hanazawa
Shigemasa
S
Tanaka
Shoji
S
Fujisawa
Seiichiro
S
D000818:Animals; D016207:Cytokines / Q000378:metabolism*; D019281:Dimerization; D005054:Eugenol / Q000494:pharmacology*; D007249:Inflammation; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008262:Macrophage Activation; D008264:Macrophages / Q000187:drug effects*; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*
D016207:Cytokines; D008070:Lipopolysaccharides; D016328:NF-kappa B; D005054:Eugenol