中文摘要：

目的研究祖师麻甲素（daphnetin，DAPH）对于巨噬细胞抗金黄色葡萄球菌（Staphylococcusaureus，S．aureus）的影响。方法选取10、20、40、80和160μM5个浓度的DAPH分别处理小鼠巨噬细胞，采用MTF检测细胞活性确定DAPH的安全浓度范围。分别用二甲基亚砜（dimethyl sulfoxide，DMSO）和DAPH预处理小鼠巨噬细胞株RAW264．7或小鼠腹腔巨噬细胞，并以S．oaureus感染上述细胞。分别通过流式细胞术和平板菌落计数法分析巨噬细胞对细菌的吞噬和清除能力。采用RT—PCR方法检测炎性因子白细胞介素-6（interleukin-6，IL-6）、IL-1β和肿瘤坏死因子-α（tumor necrosis factor—α，TNF-α），以及抗菌效应分子IL-22、再生胰岛来源蛋白3β（regenerating isletderived protein-3β，Reg-3β）、重组小鼠钙结合蛋白S100A8（S100 calcium binding proteinA8，S100A8）和myc互作锌指蛋白-1（myc—interacting zinc finger proteinl，Mizl）的表达水平。结果DAPH可显著增强巨噬细胞对细菌的清除能力，显著上调了IL-22、Reg-3β、S100A8和Mizl等抗菌效应分子的表达，抑制S．aureus感染引起的炎性因子IL-6、IL-1β和TNF—α的表达。结论DAPH对S．aureus引起的感染有保护作用，具有抗菌和抗炎的双重作用。

英文摘要：

Objective To study the effect of daphnetin （DAPH） on the antibacterial activity of macrophages. Methods Firstly, the safety concentration of DAPH（in a range of 10, 20, 40, 80 and 160μM） on macrophages was determined by MTr. Then RAW264. 7 cell lines or murine peritoneal macrophages were pretreated with DMSO aad DAPH, followed by S. aureus infection. The phagocytic activity was analyzed by flow cytometry and the bactericidal capability was tested by CFU counting method in DAPH- treated macrophages. Also, the expression of inflammatory cytokines（IL-6, TNF-α and IL-Iβ） and antimicrobial effector molecules （IL-22, Reg3β, S100A8 and Mizl） were assayed by quantitative PCR. Results Daphnetin treatment significantly enhanced the bacteria-clearance capability of macrophages, although it did not affect cellular phagocytosis. Associated with this, daphnetin remarkably increased the capability of macrophages to express antimicrobial effector molecules while repressing their production of inflammatory cytokines. Conclusion Daphnetin has a protective effect on S. aureus infection with both anti-bacterial and anti- inflammatory properties.