Tian Yanzhu, Katsuki Ami, Romanazzi Donato, Miller Matthew R, Adams Serean L, Miyashita Kazuo, Hosokawa Masashi
Faculty of Fisheries Sciences, Hokkaido University.
Cawthron Institute.
J Oleo Sci. 2017 Oct 1;66(10):1149-1156. doi: 10.5650/jos.ess17111. Epub 2017 Sep 15.
Docosapentaenoic acid (22:5n-3, n-3 DPA) is a n-3 polyunsaturated fatty acid (PUFA) found in fish oil, and has been reported to have health benefits. This study investigated conversion of n-3 DPA, and examined the anti-inflammatory effects of n-3 DPA on activated macrophages. Murine macrophage-like RAW264.7 cells were incubated in culture media containing n-3 DPA for 72 h. The level of n-3 DPA in the fatty acid composition of the total lipid fraction increased in a dose-dependent manner. Furthermore, the levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were higher in treated cells than in control cells. In RAW264.7 cells stimulated by lipopolysaccharide (LPS), n-3 DPA significantly down-regulated mRNA expression of pro-inflammatory factors such as IL-6, IL-1β, iNOS and COX-2. Production of IL-6 was also reduced by n-3 DPA in a dose-dependent manner. We found that n-3 DPA treatment resulted in greater IL-6 mRNA down-regulation than that achieved with EPA treatment, and was similar to that of DHA treatment. Furthermore, expression levels of IL-6 and IL-1β mRNAs were measured in the presence of the delta-6 desaturase inhibitor SC26196 in the culture medium to inhibit the conversion of n-3 DPA to DHA. There was no significant difference in the down-regulation in the mRNA expression of pro-inflammatory cytokines in RAW264.7 cells by n-3 DPA with or without presence of SC26196. These results demonstrate that n-3 DPA exhibits anti-inflammatory effects in activated RAW264.7 cells, which are independent of DHA conversion.
二十二碳五烯酸（22:5n-3，n-3 DPA）是一种存在于鱼油中的n-3多不饱和脂肪酸（PUFA），据报道具有健康益处。本研究调查了n-3 DPA的转化情况，并检测了n-3 DPA对活化巨噬细胞的抗炎作用。将小鼠巨噬细胞样RAW264.7细胞在含有n-3 DPA的培养基中培养72小时。总脂质部分脂肪酸组成中的n-3 DPA水平呈剂量依赖性增加。此外，处理细胞中二十二碳六烯酸（DHA）和二十碳五烯酸（EPA）的水平高于对照细胞。在脂多糖（LPS）刺激的RAW264.7细胞中，n-3 DPA显著下调促炎因子如IL-6、IL-1β、诱导型一氧化氮合酶（iNOS）和环氧化酶-2（COX-2）的mRNA表达。n-3 DPA还以剂量依赖性方式降低IL-6的产生。我们发现，n-3 DPA处理导致的IL-6 mRNA下调程度大于EPA处理，且与DHA处理相似。此外，在培养基中存在δ-6去饱和酶抑制剂SC26196的情况下测量IL-6和IL-1β mRNA的表达水平，以抑制n-3 DPA向DHA的转化。无论有无SC26196，n-3 DPA对RAW264.7细胞中促炎细胞因子mRNA表达的下调均无显著差异。这些结果表明，n-3 DPA在活化的RAW264.7细胞中表现出抗炎作用，且与DHA转化无关。
