Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT 59812, USA.
Food Chem Toxicol. 2010 May;48(5):1170-7. doi: 10.1016/j.fct.2010.02.007. Epub 2010 Feb 10.
Echinacea is a top-selling herbal remedy that purportedly acts as an immunostimulant. However, the specific immunomodulatory effects of Echinacea remain to be elucidated. We focused on defining the effects of Echinacea purpurea extracts in dendritic cells (DCs), which generate innate and adaptive immune responses. We hypothesized that E. purpurea extracts would enhance murine bone marrow-derived DC (BMDC) activation leading to increased immune responses. The fate and function of DCs from C57Bl/6 mice was evaluated following 48h exposure to E. purpurea root and leaf extracts. Flow cytometry revealed that the polysaccharide-rich root extract increased the expression of MHC class II, CD86, and CD54 surface biomarkers whereas the alkylamide-rich leaf extract inhibited expression of these molecules. Production of IL-6 and TNF-alpha increased in a concentration-dependent manner with exposure to the root, but not leaf, extract. In contrast, the leaf but not root extract inhibited the enzymatic activity of cyclooxygenase-2. While both extracts decreased the uptake of ovalbumin by BMDCs, the leaf but not root extract inhibited the antigen-specific activation of naïve CD4(+) T cells from OT II/Thy1.1 mice. Collectively, these results suggest that E. purpurea can be immunostimulatory, immunosuppressive, and/or anti-inflammatory depending on the portion of the plant and extraction method.
紫锥菊是一种畅销的草药疗法，据称具有免疫刺激作用。然而，紫锥菊的具体免疫调节作用仍有待阐明。我们专注于定义紫锥菊提取物对树突状细胞（DC）的作用，树突状细胞产生先天和适应性免疫反应。我们假设紫锥菊提取物会增强小鼠骨髓来源的树突状细胞（BMDC）的激活，从而增强免疫反应。在 48 小时内暴露于紫锥菊根和叶提取物后，评估 C57Bl/6 小鼠的 DC 命运和功能。流式细胞术显示，富含多糖的根提取物增加了 MHC 类 II、CD86 和 CD54 表面生物标志物的表达，而富含烷基酰胺的叶提取物抑制了这些分子的表达。IL-6 和 TNF-α的产生呈浓度依赖性增加，与根提取物而不是叶提取物接触有关。相反，叶提取物而不是根提取物抑制环加氧酶-2 的酶活性。虽然两种提取物都减少了 BMDC 对卵清蛋白的摄取，但只有叶提取物而不是根提取物抑制了来自 OT II/Thy1.1 小鼠的幼稚 CD4(+)T 细胞的抗原特异性激活。总的来说，这些结果表明，紫锥菊可以根据植物的部分和提取方法具有免疫刺激、免疫抑制和/或抗炎作用。
