Eupafolin inhibits PGE2 production and COX2 expression in LPS-stimulated human dermal fibroblasts by blocking JNK/AP-1 and Nox2/p47(phox) pathway.

Abstract

Eupafolin, a major active component found in the methanol extracts of Phyla nodiflora, has been used to treat inflammation of skin. We examined its effects on cyclooxygenase-2 (COX-2) expression in LPS-treated human dermal fibroblasts. Lipopolysaccharide (LPS) significantly increased prostaglandin-E2 (PGE2) production associated with increased COX-2 expression in Hs68 cells. This effect was blocked by eupafolin, TLR-4 antibody, antioxidants (APO and NAC), as well as inhibitors, including U0126 (ERK1/2), SB202190 (p38), SP600125 (JNK1/2), and Tanshinone IIA (AP-1). In gene regulation level, qPCR and promoter assays revealed that COX-2 expression was attenuated by eupafolin. In addition, eupafolin also ameliorated LPS-induced p47 phox activation and decreased reactive oxygen species (ROS) generation and NADPH oxidase (Nox) activity. Moreover, pretreatment with eupafolin and APO led to reduced LPS-induced phosphorylation of ERK1/2, JNK, and p38. Further, eupafolin attenuated LPS-induced increase in AP-1 transcription factor binding activity as well as the increase in the phosphorylation of c-Jun and c-Fos. In vivo studies have shown that in dermal fibroblasts of LPS treated mice, eupafolin exerted anti-inflammation effects by decreasing COX-2 protein levels. Our results reveal a novel mechanism for anti-inflammatory and anti-oxidative effects of eupafolin that involved inhibition of LPS-induced ROS generation, suppression of MAPK phosphorylation, diminished DNA binding activity of AP-1 and attenuated COX-2 expression leading to reduced production of prostaglandin E2 (PGE2). Our results demonstrate that eupafolin may be used to treat inflammatory responses associated with dermatologic diseases.

• Authors: Ming-Horng Tsai, Zih-Chan Lin, Chan-Jung Liang, Feng-Lin Yen, Yao-Chang Chiang, Chiang-Wen Lee
• Journal: Toxicology and applied pharmacology (Toxicol Appl Pharmacol) Vol. 279 Issue 2 Pg. 240-51 (Sep 01 2014) ISSN: 1096-0333 [Electronic] United States
• PMID: 24967690 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Antioxidants
• Cyclooxygenase 2 Inhibitors
• Flavones
• Lipopolysaccharides
• Membrane Glycoproteins
• Protein Kinase Inhibitors
• RNA, Messenger
• Reactive Oxygen Species
• Transcription Factor AP-1
• Cyclooxygenase 2
• PTGS2 protein, human
• CYBB protein, human
• NADPH Oxidase 2
• NADPH Oxidases
• neutrophil cytosolic factor 1
• JNK Mitogen-Activated Protein Kinases
• eupafolin
• Dinoprostone

Topics

• Antioxidants (pharmacology)
• Cell Line
• Cyclooxygenase 2 (genetics, metabolism)
• Cyclooxygenase 2 Inhibitors (pharmacology)
• Dinoprostone (metabolism)
• Dose-Response Relationship, Drug
• Down-Regulation
• Fibroblasts (drug effects, metabolism)
• Flavones (pharmacology)
• Genes, Reporter
• Humans
• JNK Mitogen-Activated Protein Kinases (antagonists & inhibitors, metabolism)
• Lipopolysaccharides (pharmacology)
• Membrane Glycoproteins (genetics, metabolism)
• NADPH Oxidase 2
• NADPH Oxidases (genetics, metabolism)
• Oxidative Stress (drug effects)
• Phosphorylation
• Promoter Regions, Genetic
• Protein Kinase Inhibitors (pharmacology)
• RNA Interference
• RNA, Messenger (metabolism)
• Reactive Oxygen Species (metabolism)
• Signal Transduction (drug effects)
• Skin (drug effects, enzymology)
• Time Factors
• Transcription Factor AP-1 (metabolism)
• Transfection