二十二碳六烯酸免疫调节活性

Immunomodulatory Activity of Docosahexaenoic Acid

以小鼠巨噬细胞RAW264.7细胞为研究对象,采用噻唑蓝法、细胞染色法、相关酶活力的测定以及蛋白免疫印迹等方法,研究二十二碳六烯酸(docosahexaenoic acid,DHA)的免疫调节活性。噻唑蓝实验结果表明,当DHA质量浓度为800 ng/m L,作用48 h时,RAW264.7细胞增殖率达到最大值,为73.03%。中性红实验结果表明DHA可以显著增强RAW264.7细胞的吞噬活性。扫描电子显微镜结果显示DHA具有促进RAW264.7细胞活化的作用;吖啶橙染色结果表明在DHA作用下,细胞核酸代谢旺盛,RAW264.7细胞被激活;糖原染色结果表明DHA能通过促进RAW264.7细胞内糖原代谢加快细胞的分化。通过对RAW264.7细胞中相关酶活力的测定,结果表明DHA能够显著提高酸性磷酸酶、溶菌酶和超氧化物歧化酶的活力。丝裂原活化蛋白激酶(mitogen-activated protein kinases,MAPKs)蛋白通路结果表明:DHA能够引起细胞外信号调节激酶1/2、p38和应激活化蛋白激酶出现一定程度的磷酸化,说明DHA诱导巨噬细胞激活部分依赖了MAPKs信号转导通路。以上研究结果证明:DHA具有一定的免疫调节活性,可为DHA的应用提供理论依据。

In this study, the immunomodulatory activity of docosahexaenoic acid（DHA） in mouse macrophage RAW264.7 cells was detected by MTT, cell staining, related enzyme activities and Western blot. The MTT assay showed that cell proliferation index reached the maximum level of 73.03% after 48 h of incubation at DHA concentration of 800 ng/m L. The neutral red phagocytosis of RAW264.7 cells was significantly enhanced by DHA. The activation of RAW264.7 cells could be promoted by DHA as observed under scanning electron microscopy. Acrine orange（AO） staining showed that the nucleic acid metabolism of RAW264.7 cell was enhanced by DHA. Periodic acid-Schiff（PAS） staining indicated that DHA promoted the glycogen metabolism and accelerated the differentiation of RAW264.7 cells. Besides, the activities of acid phosphatase, lysozyme and superoxide dismutase were increased by DHA. DHA could increase the phosphorylation of ERK1/2, p38 mitogen-activated protein kinases（MAPKs） and JNK in the MAPKs pathway, indicating that DHA-induced macrophage activation in part depends on the MAPKs pathway. Our results confirmed that DHA had immunomodulatory activity, which will provide a scientific basis for the application of DHA.