title: Procyanidin dimer B2 [epicatechin-(4beta-8)-epicatechin] suppresses the expression of cyclooxygenase-2 in endotoxin-treated monocytic cells.
abstract: The anti-inflammatory activity of the predominant procyanidin dimer in cocoa, dimer B2, was investigated in this study. Pretreatment of the procyanidin dimer B2 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 expression in many cell types. Pretreatment with procyanidin dimer B2 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.
authors: Department of Pharmacology II, Shanghai Institute of Materia Medica, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, China.
authors: Wei-Yu
authors: WY
authors: Zhang
authors: Hua-Qing
authors: HQ
authors: Liu
authors: Ke-Qiang
authors: KQ
authors: Xie
authors: Lin-Lin
authors: LL
authors: Yin
authors: Yu
authors: Y
authors: Li
authors: Catherine L
authors: CL
authors: Kwik-Uribe
authors: Xing-Zu
authors: XZ
authors: Zhu