Inhibitory effects of Paeonia suffruticosa on allergic reactions by inhibiting the NF-kappaB/I kappaB-alpha signaling pathway and phosphorylation of ERK in an animal model and human mast cells

The root cortex of Paeonia suffruticosa Andrews (PSA), also known as Moutan Cortex, is known to have anti-allergic and anti-inflammatory properties. This study investigates the effect and mechanism of PSA by in vivo and in vitro methods. Treatings the root cortex from PSA with up to 0.4 mg/ml of an ethanol extract showed no cytotoxicity in human mast cells. The ethanol extract of PSA (200 mg/kg) significantly inhibited the passive cutaneous anaphylaxis reaction in vivo, and suppressed the release of histamine from rat peritoneal mast cells induced by compound 48/80. It was also found that PSA decreased the expressions of TNF-alpha and IL-6 in PMA- and A23187-stimulated HMC-1 cells. The results show the inactivation of I kappaB-alpha and NF-kappaB, as well as suppression of the phosphorylation of extracellular signal-regulated kinase (ERK). Our findings therefore suggest that PSA could be promising for anti-allergic inflammation by inhibiting the NF-kappaB/I kappaB-alpha signaling pathway and the phosphorylation of ERK.