Procyanidin dimer B2 [epicatechin-(4beta-8)-epicatechin] suppresses the expression of cyclooxygenase-2 in endotoxin-treated monocytic cells.
Date Published: Friday, June 23, 2006
Biochem Biophys Res Commun 2006, 345 (1), 508-15.
Authors: hang, W. Y.; Liu, H. Q.; Xie, K. Q.; Yin, L. L.; Li, Y.; Kwik-Uribe, C. L.; Zhu, X. Z.
The anti-inflammatory activity of the predominant procyanidin dimer in cocoa, dimer B2, was investigated in this study. Pretreatment of the reduced COX-2 expression induced by the endotoxin lipopolysaccharide (LPS) in differentiated human monocytic cells (THP-1) in culture. To further elucidate the underlying mechanism of COX-2 inhibition by procyanidin, we examined their effects on the activation of extracellular signal-regulated protein kinase (ERK), Jun-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK), which are upstream enzymes known to regulate COX-2 in many cell types. Pretreatment with decreased the activation of ERK, JNK, and p38 MAPK. In addition, procyanidin dimer B2 suppressed the NF-kappaB activation through stabilization of IkappaB proteins, suggesting that these signal-transducing enzymes could be potential targets for procyanidin dimer B2. By affecting the expression rather than the activity of COX-2, these in vitro data reported herein give further evidence on the anti-inflammatory protection by procyanidins.