Regulation of inflammatory mediators in lipopolysaccharide-stimulated RAW 264.7 cells by 2''-hydroxy-3''-en-anhydroicaritin involves down-regulation of NF-kappaB and MAPK expression.
2''-hydroxy-3''-en-anhydroicaritin, a flavone, was isolated from the Chinese medicinal herb Epimedium brevicornum for the first time. In our previous study, we have carried out a screening program to identify the anti-inflammatory potentials of 2''-hydroxy-3''-en-anhydroicaritin. In the present study, we further found that this compound regulated lipopolysaccharide (LPS)-induced levels of nitric oxide (NO), and prostaglandin E(2) (PGE(2)) (**p<0.01 or *p<0.05), and reduced levels of iNOS and COX-2 in RAW 264.7 macrophages in a concentration-dependent manner. We further investigated signal transduction mechanisms to determine how 2''-hydroxy-3''-en-anhydroicaritin affects RAW264.7 macrophages pretreated with 0.5, 2.5, or 12.5mg/L of 2''-hydroxy-3''-en-anhydroicaritin 1h prior to treatment with 1mg/L of LPS. Thirty minutes later, cells were harvested and mitogen-activated protein kinases (MAPK) activation and I kappaB alpha were measured by western blotting. Alternatively, the macrophages were fixed and nuclear factor-kappaB (NF-kappaB) activation was measured by immunocytochemical analysis. Signal transduction studies showed that the flavone significantly inhibited extracellular signal-regulated kinase (ERK), p38, and c-jun NH2-terminal kinase (JNK) phosphorylation protein expression. The flavone also inhibited p65-NF-kappaB translocation into the nucleus by I kappaB alpha degradation. Therefore, 2''-hydroxy-3''-en-anhydroicaritin may inhibit LPS-induced production of inflammatory cytokines by blocking NF-kappaB and MAPK signaling in RAW264.7 cells.
Ci
Xinxin
X
Institute of Zoonoses, College of Animal Science and Veterinary Medicine, Jilin University, Changchun, Jilin 130062, China.
Liang
Xiaoying
X
Luo
Guojun
G
Yu
Qinlei
Q
Li
Hongyu
H
Wang
Dacheng
D
Li
Rongtao
R
Deng
Xuming
X
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000032:analysis; D015232:Dinoprostone / Q000032:analysis; D015536:Down-Regulation; D044948:Flavonols / Q000494:pharmacology*; D020672:I-kappa B Proteins / Q000032:analysis; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology; D008264:Macrophages / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D009569:Nitric Oxide / Q000032:analysis; D052247:Nitric Oxide Synthase Type II / Q000032:analysis; D010766:Phosphorylation
C543986:2'-hydroxy-3'-en-anhydroicaritin; D000893:Anti-Inflammatory Agents; D044948:Flavonols; D020672:I-kappa B Proteins; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D016328:NF-kappa B; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D020928:Mitogen-Activated Protein Kinases; D015232:Dinoprostone