Effects Of Soy Isoflavones On Intestinal Mucosal Epithelial Cells In Chickens

Soybean isoflavones (ISO) is a kind of phytoestrogens which mainly exist in the leguminous plants, and the maximum content was found in soybean. ISO mainly include three ingredients, namely soybean daidzein, genistein and giycitein. Studies have shown that the ISO has many physiological functions, such as reducing blood fat, anti-tumor, and antioxidant, etc. In animal production, ISO has some effects on immune function, production performance and reproductive performance of animals. In recent years, some scholars pointed out that soy isoflavones have effects on small intestinal morphology and function. Digestion and absorption of nutriention are the main functions of small intestine, so the quantitative changes of intestinal epithelial cells can affect these functions directly. Small intestinal epithelial cells continuously immigrate from stem cells in the basal part of small intestinal crypt, and Notch signaling pathway play an important role in regulating the differentiation of stem cells.Histologic and immunohistochemical methods were used to examine the effects of soy isoflavones on intestinal mucosal epithelial cells of chickens, the expression of Notch2, Jagged 1, Jagged2 and Hesl gene in the Notch signal pathway were detect to explore the effect mechanism using molecular biological methods. Thirty 1 day old Hailan white chicken were randomly divided into 3 groups, consisting of two experimental groups (group A and group B) and one control group (group C). The group A and group B were fed with the basal diet adding 10 mg/kg and 20 mg/kg soybean isoflavones, respectively, and the group C was fed with basal diet. Samples of duodenum, jejunum and ileum were collected at 7 days old, small intestinal mucosal columnar epithelial cells and goblet cells were counted and analyzed in the paraffin-embedded sections stained with HE and AB-PAS, respectively. The other samples were stored in liquid nitrogen for extracting RNA and detecting the expression of related ligand and receptor genes in the Notch signal pathway.The results showed that:Comparing with the control group, the number of goblet cells in small intestinal mucosa increased in group A (10 mg/kg), there was no significant difference between them (P>0.05). The expression of Notch2 receptor and Jagged2 ligand were inhibited in the Notch signal pathway. The number of goblet cells in small intestinal mucosa increased significantly(P<0.05) in group B (20 mg/kg). The expression of Notch2 receptor, Jagged1, Jagged2 ligand and Hesl genes were all inhibited in the Notch signal pathway. Soybean isoflavones had no effect on the number of columnar epithelial cells in small intestinal mucosa.The results indicate that the number of goblet cells in small intestinal mucosa increased after adding soybean isoflavones in the diet, soybean isoflavones may regulate the proliferation and differentiation of small intestinal mucosal epithelial cells by inhibiting the expression of receptor and ligand genes in the Notch signal pathway. This research provides theoretical basis for adding soybean isoflavones in diet.