Kye-Yoon Yoon¹, Kui-Jin Kim¹, Hyung-Sun Youn², Sei-Ryang Oh³, Boo-Yong Lee^1,

Brazilin, is a bioactive compound extracted from Caesalpinia sappan Linn, has been reported the protective effect of the immune system. Particular attention is now devoted to better understanding of the molecular basis of bazilin anti-inflammatory activity. In the present study, we studied the effect of brazilin on the Raw264.7 macrophage cell lines by a nutrigenomics approaches. Raw264.7 cells were treated with braziln, then treated with LPS to cause inflammation. The nuclear transcription κB (NF-κB) promoter activity were analyzed with dual luciferase assay kit. The gene expression and production levels of pro-inflammatory cytokine interleukin (IL)-1β, tumor necrosis factor (TNF)α, and IL-6 were evaluated with semi-quantitative RT-PCR and with ELISA, respectively. We also examined inflammatory signaling, including mitogen-activated protein kinase (MAPK) pathway, iNOS, COX2, and IRAK4. Our findings demonstrated that brazilin down-regulated the expression of IRAK4 protein lead to suppress of c-Jun NH₂ terminal kinase (JNK) signaling, and subsequently inactivation of nuclear transcription κB (NF-κB), inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2) thus promoting the expression of the downstream target pro-inflammatory cytokines such as IL-1β, TNFα and IL-6 in LPS stimulated Raw264.7 macrophage cell. Thus, brazilin showed anti-inflammatory activity in Raw264.7 macrophage cell targeting IRAK4 mediated signaling pathway.

Brazilin, inflammation, NF-κB, IRAK4, MAPK