Lee Tzong Huei, Huang Nai Kuei, Lai Tzi Chung, Yang Aleck T Y, Wang Guei Jane
Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan, Republic of China.
J Ethnopharmacol. 2008 Mar 28;116(3):518-27. doi: 10.1016/j.jep.2007.12.019. Epub 2008 Jan 15.
The aim of this study was to examine the anti-inflammatory effects of aerial part of Clematis crassifolia Benth. (Ranunculaceae) based on an iNOS inhibition in lipopolysaccharide (LPS) activated macrophages. Bioassay-guided fractionation and purification led to the isolation of ibotanolide B (1), calceolarioside B (2), trans-caffeic acid (3), anemonin (4) and 3',4',5,7-tetrahydroxy-6-C-glucopyranosylflavone (5). Their structures were elucidated on the basis of spectroscopic analysis. All these compounds inhibited NO production, detected as nitrite, in activated macrophages except 5. Among them, anemonin (4) was the most potent. Analyses of reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting revealed that it decreased the expression of iNOS mRNA and protein in activated RAW 264.7 cells. In isolated rat thoracic aortic rings, anemonin prevented the vascular hyporeactivity to phenylephrine induced by LPS whereas it did not affect acetylcholine-induced endothelial NO-dependent relaxation, an index of endothelial NOS (eNOS) activity. These results indicated that the potential anti-inflammatory effect of anemonin, the naturally occurring selective iNOS inhibitor, may provide a rationale for the medical use of Clematis crassifolia.
本研究旨在基于脂多糖（LPS）激活的巨噬细胞中诱导型一氧化氮合酶（iNOS）的抑制作用，考察粗齿铁线莲地上部分（毛茛科）的抗炎作用。生物测定导向的分馏和纯化导致分离出鹅掌楸毒素B（1）、毛蕊花糖苷B（2）、反式咖啡酸（3）、白头翁素（4）和3'，4'，5，7-四羟基-6-C-吡喃葡萄糖基黄酮（5）。基于光谱分析阐明了它们的结构。除化合物5外，所有这些化合物均抑制活化巨噬细胞中以亚硝酸盐形式检测到的一氧化氮（NO）生成。其中，白头翁素（4）活性最强。逆转录-聚合酶链反应（RT-PCR）和蛋白质印迹分析表明，它降低了活化的RAW 264.7细胞中iNOS mRNA和蛋白的表达。在分离的大鼠胸主动脉环中，白头翁素可预防LPS诱导的对去氧肾上腺素的血管反应性降低，而不影响乙酰胆碱诱导的内皮型一氧化氮合酶（eNOS）活性指标——内皮NO依赖性舒张。这些结果表明，天然存在的选择性iNOS抑制剂白头翁素的潜在抗炎作用，可能为粗齿铁线莲的药用提供理论依据。
