Halocynthia aurantium, an edible ascidian species, has not been studied scientifically, even though tunicates and ascidians are well-known to contain several unique and biologically active materials. The current study investigated the fatty acid profiles of the H. aurantium tunic and its immune-regulatory effects on RAW264.7 macrophage cells. Results of the fatty acid profile analysis showed a difference in ratios, depending on the fatty acids being analysed, including those of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA). In particular, omega-3 fatty acids, such as eicosatrienoic acid n-3 (ETA n-3), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), were much higher than omega-6 fatty acids. Moreover, the H. aurantium tunic fatty acids, significantly and dose-dependently, increased the NO and prostaglandin E2 (PGE2) production in RAW264.7 cells, for immune-enhancement without cytotoxicity. In addition, these fatty acids regulated the transcription of immune-associated genes, including iNOS, IL-1β, IL-6, COX-2, and TNF-α. These actions were activated and deactivated via Mitogen-activated protein kinase (MAPK)and NF-κB signaling, to regulate the immune responses. Conversely, the H. aurantium tunic fatty acids effectively suppressed the inflammatory cytokine expressions, including iNOS, IL-1β, IL-6, COX-2, and TNF-α, in LPS-stimulated RAW264.7 cells. Productions of COX-2 and PGE2, which are key biomarkers for inflammation, were also significantly reduced. These results elucidated the immune-enhancement and anti-inflammatory mechanisms of the H. aurantium tunic fatty acids in macrophage cells. Moreover, the H. aurantium tunic might be a potential fatty acid source for immune-modulation.

Asterias amurensis (starfish) is a marine organism that is harmful to the fishing industry, but is also a potential source of functional materials. The present study was conducted to analyze the profiles of fatty acids extracted from A. amurensis tissues and their anti-inflammatory effects on RAW264.7 macrophage cells. In different tissues, the component ratios of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids differed; particularly, polyunsaturated fatty acids such as dihomo-gamma-linolenic acid (20:3n-6) and eicosapentaenoic acid (20:5n-3) were considerably different. In lipopolysaccharide-stimulated RAW264.7 cells, fatty acids from A. amurensis skin, gonads, and digestive glands exhibited anti-inflammatory activities by reducing nitric oxide production and inducing nitric oxide synthase gene expression. Asterias amurensis fatty acids effectively suppressed the expression of inflammatory cytokines such as tumor necrosis factor-α, interleukin-1β, and interleukin-6 in lipopolysaccharide-stimulated cells. Cyclooxygenase-2 and prostaglandin E 2 , which are critical inflammation biomarkers, were also significantly suppressed. Furthermore, A. amurensis fatty acids reduced the phosphorylation of nuclear factor-κB p-65, p38, extracellular signal-related kinase 1/2, and c-Jun N-terminal kinase, indicating that these fatty acids ameliorated inflammation through the nuclear factor-κB and mitogen-activated protein kinase pathways. These results provide insight into the anti-inflammatory mechanism of A. amurensis fatty acids on immune cells and suggest that the species is a potential source of anti-inflammatory molecules.

is a marine organism that causes damage to the fishing industry worldwide; however, it has been considered a promising source of functional components. The present study aimed to investigate the immune-enhancing effects of fatty acids from three organs of on murine macrophages (RAW 264.7 cells). fatty acids boosted production of immune-associated factors such as nitric oxide (NO) and prostaglandin E2 in RAW 264.7 cells. fatty acids also enhanced the expression of critical immune-associated genes, including, and , as well as. Western blotting showed that fatty acids stimulated the NF-κB and MAPK pathways by phosphorylation of NF-κB p-65, p38, ERK1/2, and JNK. fatty acids from different tissues resulted in different levels of NF-κB and MAPK phosphorylation in RAW 264.7 cells. The results increase our understanding of how fatty acids boost immunity in a physiological system, as a potential functional material.

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