中文摘要：

目的探讨配体fucoidan活化清道夫受体后能否抑制LPS刺激巨噬细胞分泌IL-12。方法不同剂量的fucoidan（以多价阴离子chondroitin为阴性对照）与RAW264．7作用10min后，加人等量的LPS刺激，检测上清中IL-12p70、IL-6和TNF-α；同时观察不同剂量fucoidan对RAW264．7贴壁的影响。结果不同剂量的fucoidan能不同程度促进LPS诱导RAW264．7分泌炎症因子IL-6和TNF-α，但却能明显地抑制IL-12的分泌；随着所加fucoidan量的增加，RAW264．7细胞的贴壁能力逐渐下降。结论Fucoidan可能通过与清道夫受体SR-A（scavenger receptor A）结合发挥其特异抑制LPS诱导巨噬细胞分泌IL-12的作用。

英文摘要：

Objective To investigate whether hgand of scavenger receptor （SR） could suppress LPS-induced IL-12 production by RAW264.7. Methods RAW264.7 was pre-incubated with different doses of SR ligand fucoidan for 10 min, with 75 μg/mL chondroitin as control, and then 100 ng/mL LPS was added to stimulate the RAW264.7 for 24 h. Concentrations of IL-12p70, IL-6, and TNF-α in culture supematants were determined by ELISA. At the same time, effects of different doses of fucoidan on adherence of RAW264.7 were also observed. Results Pretreatment of fucoidan could increase the levels of IL-6 and TNF-α in culture supematants of RAW264.7, but decreased the level of IL-12. The effect of fucoidan on all three cytokines was specific, because chodroitin, even at 75 μg/mL, has no such affection. As the doses of fucoidan increased, the inhibitory effects of fucoidan on adherence of RAW264.7 enhanced. Conclusion SR ligand fucoidan can selectively suppress LPS-induced IL-12 production by RAW264.7.