Ethnopharmacology relevance

Enteromorpha has long been recorded in traditional Chinese medicine, with cholesterol-lowering, anti-cancer, anti-inflammatory and antibacterial effects. Recently, we extracted the polyphenol-enriched fraction from Enteromorpha clathrata (E. clathrata) by ethyl acetate (ECPs), and isolated six individual polyphenols from ECPs via high-speed counter-current chromatography (HSCCC) with high-performance liquid chromatography (HPLC).

Aim of the study

In this study, we explored the anti-inflammatory activity and underlying mechanism of ECPs in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages.

Materials and methods

ECPs and the six polyphenols were used for nitric oxide (NO) assay to identify the components with potent inflammation inhibitory effect. Enzyme-linked immunosorbent assay (ELISA), quantitative real-time PCR (qPCR), flow cytometry, and Western blot analysis were applied to further investigate their anti-inflammatory effects and underlying mechanism in LPS-stimulated RAW264.7 cells.

Results

ECPs and the three individual polyphenols, including (−)-epicatechin, epigallocatechin-3-O-gallate and (−)-epicatechin-3-O-gallate, showed in vitro immunosuppressive activity by altering the cell biology at the gene, protein and functional levels in a dose- and species-dependent manner. Their anti-inflammatory effects were achieved by inhibiting LPS-induced production of nitric oxide and its upstream enzyme inducible nitric oxide synthase (iNOS), the pro-inflammatory cytokines including interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), as well as the phagocytotic capacity, without cytotoxicity. The mechanism study further revealed that these anti-inflammatory properties were, at least partly, attributed to the suppressed activation of nuclear factor-κB (NF-κB) and p38 mitogen-activated protein kinase (MAPK) signaling pathways.

Conclusions

These findings indicated for the first time the correlation between the anti-inflammatory activity of ECPs and NF-κB and MAPK signaling pathways, suggesting that polyphenol-enriched organic fraction of E. clathrata could be potential candidate as therapeutic agent for treating inflammatory diseases.

中文翻译：

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从浒苔中提取的多酚通过抑制 MAPKs/NF-κB 信号通路减轻脂多糖诱导的 RAW 264.7 细胞的炎症

民族药理学相关性

浒苔在中药中早有记载，具有降低胆固醇、抗癌、抗炎、抗菌等作用。最近，我们用乙酸乙酯（ECPs）从浒苔（E. clathrata ）中提取富含多酚的部分，并通过高速逆流色谱（HSCCC）和高效液相色谱（HPLC）从ECPs中分离出六种单独的多酚。 ）。

研究目的

在这项研究中，我们探讨了 ECP 在脂多糖 (LPS) 诱导的 RAW 264.7 巨噬细胞中的抗炎活性和潜在机制。

材料和方法

ECPs 和六种多酚用于一氧化氮(NO) 测定，以确定具有有效炎症抑制作用的成分。应用酶联免疫吸附测定 (ELISA)、定量实时 PCR (qPCR)、流式细胞术和蛋白质印迹分析进一步研究它们在 LPS 刺激的 RAW264.7 细胞中的抗炎作用和潜在机制。

结果

ECPs和三种单独的多酚，包括 (-)-表儿茶素、表没食子儿茶素-3 - O-没食子酸酯和 (-)-表儿茶素-3- O-没食子酸酯，通过改变基因、蛋白质和以剂量和物种依赖性方式的功能水平。它们的抗炎作用是通过抑制 LPS 诱导的一氧化氮及其上游酶的产生来实现的诱导型一氧化氮合酶 (iNOS)、促炎细胞因子包括白细胞介素 1 β (IL-1β)、白细胞介素 6 (IL-6) 和肿瘤坏死因子-α (TNF-α)，以及吞噬能力，无细胞毒性。机制研究进一步表明，这些抗炎特性至少部分归因于核因子-κB (NF-κB) 和 p38 丝裂原活化蛋白激酶 (MAPK) 信号通路的抑制激活。

结论

这些发现首次表明 ECPs 的抗炎活性与 NF-κB 和 MAPK 信号通路之间的相关性，表明E. clathrata的富含多酚的有机部分可能是治疗炎症性疾病的潜在候选药物。