Chicken embryo extracts enhance spleen lymphocyte and peritoneal macrophages function

Traditionally, chicken embryo eggs are widely considered as an immunomodulatory health product in China and southeast Asia. Besides that, Compendium of Materia Medica, the most famous Chinese pharmacopoeia, has recorded that chicken embryo eggs contributed to the appetite increase and immune function enhancement, especially for the pregnant and aged. Through assessing the immune efficacy of the chicken embryo extracts on immunocompetent cells, the immunomodulatory mechanism and components were explored preliminarily. The raw material was subjected to in vitro gastric and pancreatic digestion successively, and then ligarine was added to separate the digested mixture to water-soluble fraction (WS) and lipid-soluble fraction (LS). Employing in vitro cell models, the immunomodulating activities of the extracts on immunosuppressed mouse were examined, at concentrations ranging from 10 to 500 μg/ml. The cell experiments consisted of the following experiments: spleen lymphocyte proliferation and IL-2 secretion, peritoneal macrophage phagocytosis and NO production. Before cell experiments, Kjeldal method and phenol–sulfuric acid method were employed respectively to determine the total protein and polysaccharide content of WS, and gas chromatography to analyze the fatty acid composition of LS. LS significantly enhanced the spleen lymphocyte proliferation and IL-2 secretion, while peritoneal macrophage phagocytosis and NO production activity were elevated by WS. Both extracts exhibited an immunomodulatory effect with a dose–effect relationship. The findings confirmed the chicken embryo eggs as a potent immunopotentiator on the immunosuppressed mouse, which would be useful for the fruitful application of the chicken embryo eggs to serve as a superior immunostimulatory tonic. Furthermore, the two extracts exhibited a different bioactivity tendency which makes it a significative work to screen the bioactive component for further study.