Inhibitory Effect of Flammulina velutipes Proteoglycan on Lipopolysaccharide-induced Inflammation in Caco-2/RAW264.7 Co-culture Model

With the accelerating pace of life and the changing lifestyle, the incidence of inflammatory bowel disease is increasing. Finding inflammation-inhibitory components from the diet is an effective way to prevent and control inflammatory bowel disease. In this study, the inhibitory effect of a proteoglycan extracted from Flammulina velutipes proteoglycans (FPG1-1) on lipopolysaccharide (LPS)-induced inflammation in a co-culture model of Caco-2 intestinal epithelial cells and macrophages RAW264.7 was evaluated by measuring nitric oxide (NO), reactive oxygen species (ROS) and cytokines levels. The results showed that the FPG1-1 at a concentration of 200 μg/mL extremely significantly reduced the production of NO and ROS in macrophages in comparison with the model group (P < 0.01). Besides, FPG1-1 up-regulated the secretion of interleukin (IL)-10 and down-regulated the secretion of tumor necrosis factor (TNF)-α, IL-1β and IL-6. The above results indicate that FPG1-1 can effectively inhibit lipopolysaccharide-induced inflammation in the co-culture model of intestinal epithelial cells and macrophages. This research provides a theoretical basis for the utilization of functional ingredients from Flammulina velutipes and the development of functional foods against inflammatory bowel disease.