为研究海参蛋白肽对脂多糖（LPS）诱导小鼠RAW264.7巨噬细胞炎症反应的抑制作用及作用机制，本研究利用LPS刺激RAW264.7巨噬细胞建立炎症模型，采用Griess法测定细胞一氧化氮（NO）含量，实时荧光定量PCR测定细胞内诱导型一氧化氮合酶（iNOS）、肿瘤坏死因子-α（TNF-α）、白介素-1β（IL-1β）、白介素-6（IL-6）以及血红素氧合酶-1（HO-1）mRNA表达。结果表明，海参蛋白肽以浓度依赖效应显著抑制LPS诱导RAW264.7巨噬细胞NO生成以及TNF-α、IL-1β、IL-6和iNOS mRNA表达（p<0.05），显著提高细胞内HO-1 mRNA表达（p<0.05）。HO-1抑制剂锌原卟啉Ⅸ（ZnPP-Ⅸ）部分逆转海参蛋白肽对LPS诱导RAW264.7巨噬细胞炎症反应的抑制作用。具有抗炎活性的海参蛋白肽富含甘氨酸、谷氨酸和天冬氨酸，分子量180~1000 u的组分为72.12%。这些结果说明海参蛋白肽通过上调细胞HO-1 mRNA表达发挥抑制LPS诱导RAW264.7巨噬细胞炎症反应的作用。

The inhibitory effects and mechanisms of peptides from sea cucumber on lipopolysaccharides (LPS)-induced inflammation responses in RAW264.7 murine macrophages were investigated in this study. The inflammation model in RAW264.7 macrophages was established by LPS treatment. The content of nitric oxide generated by inflammatory macrophages was determined using the Griess assay, and the heme oxygenase-1 (HO-1) mRNA expression as well as the mRNA expression of inducible nitric oxide synthase, tumor necrosis factor-α, interleukin-1β (IL-1β), and IL-6 was measured by real-time quantitative polymerase chain reaction. The results showed that the peptides from sea cucumber significantly inhibited LPS-induced NO production by RAW264.7 macrophages in a dose-dependent manner (p < 0.05), inhibited the mRNA expression of tumor necrosis factor-α, IL-1β, IL-6, , and significantly induced HO-1 expression in RAW264.7 macrophages (p < 0.05). These inhibitory effects were partially reversed by co-treatment with zinc (II)-protoporphyrin IX, a specific inhibitor of HO-1. The sea cucumber peptides with anti-inflammatory activity were rich in glycine, glutamic acid, and aspartic acid, and the peptide fraction with a molecular weight ranging from 180 to 1000 u accounted for 72.12%. These results suggest that peptides derived from sea cucumber inhibit inflammation responses in LPS-stimulated RAW264.7 macrophages by up-regulating HO-1 mRNA expression.

国家自然科学基金资助项目（31371753）；公益性行业（农业）科研专项资助项目（201303085）