Lipids Extracted from Eggs Possess Immunoregulatory Effects on RAW264.7 Cells by Activating the MAPK and NF-κB Signaling Pathways.

This study was conducted to evaluate the potential anti-inflammatory and immune-enhancement properties of lipids derived from eggs on RAW264.7 cells. Firstly, we determined the fatty acid compositions of lipids by performing gas chromatography analysis. The results showed that lipids contained saturated fatty acids (24.37%), monounsaturated fatty acids (20.90%), and polyunsaturated fatty acids (54.73%). They also contained notably high levels of DHA (25.91%) and EPA (22.05%) among the total fatty acids. Our results for the immune-associated biomarkers showed that lipids had immune-enhancing effects on RAW264.7 cells. At the maximum dose of 300 µg/mL, lipids generated NO (119.53%) and showed greater phagocytosis (63.69%) ability as compared with untreated cells. lipids also upregulated the expression of , , , and genes and effectively upregulated the phosphorylation of MAPK (JNK, p38, and ERK) and NF-κB p65, indicating that these lipids could activate the MAPK and NF-κB pathways to stimulate macrophages in the immune system. Besides their immune-enhancing abilities, lipids significantly inhibited LPS-induced RAW264.7 inflammatory responses via the NF-κB and MAPK pathways. The results indicated that these lipids significantly reduced LPS-induced NO production, showing a decrease from 86.95% to 38.89%. Additionally, these lipids downregulated the expression of genes associated with the immune response and strongly suppressed the CD86 molecule on the cell surface, which reduced from 39.25% to 33.80%. Collectively, these findings imply that lipids extracted from eggs might have biological immunoregulatory effects. Thus, they might be considered promising immunomodulatory drugs and functional foods.