Egg Yolk Protein Water Extracts Modulate the Immune Response in BALB/c Mice with Immune Dysfunction Caused by Forced Swimming.

The objective of this study was to determine the immunomodulatory effects of egg yolk protein-water extract (EYW) on splenocyte proliferation, cytokine secretion, immunoglobulin production, and NK cell cytotoxic activity in BALB/c mice. The forced swimming test (FST) was used to provide a model for suppressing immune regulation. The proliferation of B cells in the EYW supplementation group was significantly increased from the level to which it was reduced by the FST (from 40.9% to 81.8%, < 0.05). EYW supplementation affected cytokine secretion of splenocytes. Levels of interleukin (IL)-2 and IL-10-as Th1 and Th2 cytokines, respectively-were decreased after the FST. However, EYW supplementation showed that secretion levels of these cytokines were significantly increased to pre-FST levels ( < 0.05). The production of immunoglobulins (IgA and IgG) was increased abnormally after the FST, whereas EYW supplementation significantly decreased it to pre-FST levels ( < 0.05). EYW supplementation also improved NK cell cytotoxic activity against YAC-1 tumor cells compared to the PC group ( < 0.05). These data suggest that EYW has potential as an immunomodulatory agent in the food and/or pharmaceutical industries.