Center for Research on Dietary Botanical Supplements at Iowa State University, Iowa State University, Ames, Iowa 50011, USA.
J Agric Food Chem. 2009 Oct 14;57(19):8820-30. doi: 10.1021/jf901202y.
Because of the popularity of Echinacea as a dietary supplement, researchers have been actively investigating which Echinacea constituent or groups of constituents are necessary for immune-modulating bioactivities. Our prior studies indicate that alkylamides may play an important role in the inhibition of prostaglandin E2 (PGE(2)) production. High-performance liquid chromatography fractionation, employed to elucidate interacting anti-inflammatory constituents from ethanol extracts of Echinacea purpurea, Echinacea angustifolia, Echinacea pallida, and Echinacea tennesseensis, identified fractions containing alkylamides and ketones as key anti-inflammatory contributors using lipopolysaccharide-induced PGE(2) production in RAW264.7 mouse macrophage cells. Nitric oxide (NO) production and parallel cytotoxicity screens were also employed to substantiate an anti-inflammatory response. E. pallida showed significant inhibition of PGE(2) with a first round fraction, containing gas chromatography-mass spectrometry (GC-MS) peaks for Bauer ketones 20, 21, 22, 23, and 24, with 23 and 24 identified as significant contributors to this PGE(2) inhibition. Chemically synthesized Bauer ketones 21 and 23 at 1 microM each significantly inhibited both PGE(2) and NO production. Three rounds of fractionation were produced from an E. angustifolia extract. GC-MS analysis identified the presence of Bauer ketone 23 in third round fraction 3D32 and Bauer alkylamide 11 making up 96% of third round fraction 3E40. Synthetic Bauer ketone 23 inhibited PGE(2) production to 83% of control, and synthetic Bauer alkylamide 11 significantly inhibited PGE(2) and NO production at the endogenous concentrations determined to be present in their respective fraction; thus, each constituent partially explained the in vitro anti-inflammatory activity of their respective fraction. From this study, two key contributors to the anti-inflammatory properties of E. angustifolia were identified as Bauer alkylamide 11 and Bauer ketone 23.
由于紫锥菊作为膳食补充剂的普及，研究人员一直在积极研究紫锥菊的哪种成分或成分组对于免疫调节的生物活性是必要的。我们之前的研究表明，烷酰胺可能在抑制前列腺素 E2（PGE2）的产生中发挥重要作用。高效液相色谱（HPLC）分级分离，用于从紫锥菊、狭叶紫锥菊、白花紫锥菊和紫锥菊的乙醇提取物中阐明相互作用的抗炎成分，鉴定出含有烷酰胺和酮的部分，这些部分使用脂多糖诱导的 RAW264.7 小鼠巨噬细胞中的 PGE2 产生来作为关键的抗炎贡献者。还进行了一氧化氮（NO）产生和并行细胞毒性筛选，以证实抗炎反应。紫锥菊提取物的第一轮分离物对 PGE2 表现出显著的抑制作用，该分离物含有气相色谱-质谱（GC-MS）峰为 Bauer 酮 20、21、22、23 和 24，其中 23 和 24 被鉴定为对这种 PGE2 抑制有显著贡献的物质。1μM 的化学合成 Bauer 酮 21 和 23 分别显著抑制 PGE2 和 NO 的产生。从狭叶紫锥菊提取物中产生了三批分离物。GC-MS 分析鉴定出第三轮分离物 3D32 中存在 Bauer 酮 23，第三轮分离物 3E40 中 96%由 Bauer 烷酰胺 11 组成。合成 Bauer 酮 23 抑制 PGE2 的产生，达到对照的 83%，合成 Bauer 烷酰胺 11 以其各自在相应分离物中存在的内源性浓度显著抑制 PGE2 和 NO 的产生；因此，每个成分部分解释了其各自分离物的体外抗炎活性。从这项研究中，鉴定出两种对狭叶紫锥菊抗炎特性有重要贡献的物质，分别为 Bauer 烷酰胺 11 和 Bauer 酮 23。
