Polysaccharide extracted from Sargassum fulvellum leads to macrophage activation and Th1 polarization in splenocytes

摘要

Marine organisms are a rich source of structurally diverse bioactive compounds that play a vital role in human health and nutrition. This study examined the immunomodulatory activities of polysaccharide extracted from Sargassum fulvellum in RAW264.7 macrophages and mice splenocytes. S. fulvellum polysaccharide extract (SPE) was obtained by ethanol precipitation after hot water extraction for 2?h. SPE treatment in macrophage cells did not induce cytotoxicity, but increased the levels of nitric oxide (NO) and cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-6, and IL-12p70), except for IL-10, that mediate immune suppression. Treatment also significantly increased the macrophage surface activation markers CD80 and CD86. Additionally, macrophage activation by SPE treatment modulated mitogen-activated protein kinases (MAPKs) and nuclear factor (NF)-κB signaling. In splenocytes, SPE treatment markedly increased cell proliferation and Th1 cytokines (interferon [IFN]-γ), but did not increase Th2 cytokines (IL-4). Taken together, these results suggest that polysaccharide extracted from S. fulvellum could potentially be used as an immunomodulatory agent.