Department of Food Science, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung 20224, Taiwan, ROC.
J Ethnopharmacol. 2010 Mar 2;128(1):123-30. doi: 10.1016/j.jep.2009.12.037. Epub 2010 Jan 4.
Porphyra dentata, a red edible seaweed, has long been used worldwide in folk medicine for the treatment of inflammatory diseases such as hypersensitivity, lymphadenitis, bronchitis.
To clarify the anti-inflammatory role of Porphyra dentata crude extract and its identified phenolic compounds by investigating their effect on the nitric oxide (NO)/inducible nitric oxide synthase (iNOS) transcription pathway in macrophage RAW 264.7 cells.
Porphyra dentata crude extract was prepared with methanol. High performance liquid chromatography (HPLC) hyphenated to electrospray ionization mass spectrometry (ESI-MS) and UV detection were utilized to analyze the extract fingerprints. Nitrite measurement, iNOS promoter activity and nuclear factor-kappaB (NF-kappaB) enhancer activity were used to assess the anti-inflammatory effect in lipopolysaccharide (LPS) challenged mouse RAW 264.7 cell line.
Phenolic compounds (catechol, rutin and hesperidin) were identified in the crude extract of Porphyra dentata. The crude extract and the phenolic compounds inhibited the production of NO in LPS-stimulated RAW 264.7 cells. Catechol was a more potent suppressor of the up-regulation of iNOS promoter and NF-kappaB enhancer than rutin and yet, hesperidin alone failed to inhibit either activity.
Our results indicate that catechol and rutin, but not hesperidin, are primary bioactive phenolic compounds in the crude extract to suppress NO production in LPS-stimulated macrophages via NF-kappaB-dependent iNOS gene transcription. The data also explain the anti-inflammatory use and possible mechanism of Porphyra dentata in iNOS implicated diseases.
紫菜，一种红色可食用海藻，在世界各地的民间医学中被长期用于治疗超敏反应、淋巴结炎、支气管炎等炎症性疾病。
通过研究其对巨噬细胞 RAW 264.7 细胞中一氧化氮（NO）/诱导型一氧化氮合酶（iNOS）转录途径的影响，阐明紫菜粗提取物及其鉴定的酚类化合物的抗炎作用。
用甲醇制备紫菜粗提取物。采用高效液相色谱（HPLC）-电喷雾电离质谱（ESI-MS）和紫外检测联用分析提取物指纹图谱。通过亚硝酸盐测定、iNOS 启动子活性和核因子-κB（NF-κB）增强子活性评估脂多糖（LPS）刺激的 RAW 264.7 细胞系中的抗炎作用。
在紫菜粗提取物中鉴定出酚类化合物（儿茶酚、芦丁和橙皮苷）。粗提取物和酚类化合物抑制 LPS 刺激的 RAW 264.7 细胞中 NO 的产生。儿茶酚比芦丁更能抑制 iNOS 启动子和 NF-κB 增强子的上调，但橙皮苷单独不能抑制任何一种活性。
我们的结果表明，儿茶酚和芦丁，但不是橙皮苷，是粗提取物中抑制 LPS 刺激的巨噬细胞中 NO 产生的主要生物活性酚类化合物，通过 NF-κB 依赖性 iNOS 基因转录。这些数据还解释了紫菜在 iNOS 相关疾病中的抗炎作用和可能的机制。
