Immunomodulatory activities of body wall fatty acids extracted from Halocynthia aurantium on RAW264.7 cells.

Tunicates are known to contain biologically active materials however, Halocynthia aurantium has not been thoroughly studied. The current study aimed to analyze the fatty acids profile of H. aurantium body wall and their immunomodulatory effects on RAW264.7 macrophage-like cells. The fatty acids were classified into three categories; saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid (PUFA). Omega-3 fatty acid content, including EPA and DHA, was higher than omega-6 fatty acids. H. aurantium body wall fatty acids exhibited enhanced immune response and anti-inflammatory effects on RAW264.7 macrophage-like cells. Under normal conditions, fatty acids significantly increased nitric oxide (NO) and PGE2 production in a dose-dependent manner, therefore, improving the immune response. On the other hand, in LPS treated RAW264.7 cells fatty acids significantly decreased nitric oxide (NO) and PGE2 production in a dose20 dependent manner, therefore, enhancing anti-inflammatory effects. Fatty acids transcriptionally controlled the expression of the immune-associated genes; iNOS, IL-1β, IL-6, COX-2, and TNF-α, via the MAPK and NF-κB signaling cascades in RAW264.7 cells. However, in LPS-stimulated RAW264.7 cells, H. aurantium body wall fatty acids significantly inhibited expression of inflammatory cytokine similarly, production of COX-2 and PGE2 was inhibited. The results of our present study give an insight into the immune-improvement and anti-inflammatory effects of H. aurantium body wall fatty acids on macrophages. In addition, our study demonstrated that H. aurantium body wall is a potential source of immune-regulatory components.