Effects Of Sodium Selenite On Aflatoxin B₁-Induced Ileac Mucosal Immune Damage In Broilers

One hundred and eighty one-day-old healthy Avian broilers were purchased from a commercial rearing farm (Wenjiang, China) and randomly divided into four equal groups of three replicates and fifteen birds per replicate, namely control group, AFB1 group (0.3 mg/kg AFBi),+Se group (0.4 mg/kg Se) and AFB1+Se group (0.3 mg/kg AFB1+0.4 mg/kg Se). By hydride-generation atomic absorption spectroscopy, the content of Se in control group dietary was 0.332 mg/kg. Broilers were provided with drinking water as well as the aforementioned diets ad libitum for 21 days. This stduy was aim to assess the protective effect of sodium selenite on the ileum mucosal immunologic injury induced by AFB1 by the methods of histopathology, immunohistochemistry, flow cytometry (FCM), ELISA and quantitative real-time PCR.No obvious lesions were obseved in liver section of control group; in AFB1 group, bile duct epithelium were hyperplasia arounding the portal area and forming a funicular, or block mass. These results showed that the AFBi poisoning models were successfully set up in chickens. In the control group, the structure of ileal villus were integrated and the epithelial cells were in alignment, no pathological changes were observed. In the AFBi group, shedding of epithelial cells in the apical region of intestinal villus, edema of lamina propria, extension of lymphatic vessel, congestion of intestinal villus were observed. The intestinal villus in AFBi+Se group were similar to those in control group. Compared with those in control group, the percentages of CD3+, CD3+CD4+, CD3+CD8+, the numbers of IgA+cells, the sIgA, IgA, IgG, and IgM contents as well as the mRNA contents of IL-2, IL-6 and TNF-α were decreased in AFB1 group. And the percentages of CD3+, CD3+CD4+, CD3+CD8+, the numbers of IgA+cells, the sIgA, IgA, IgG, and IgM contents as well as the mRNA contents of IL-2, IL-6 and TNF-α in+Se group were decreased than those in control group. However, it’s amazing that when 0.732 mg/kg Se was added in the diet containing 0.3 mg/kg AFB1, the percentages of CD3+, CD3+CD4+, CD3+CD8+, the numbers of IgA+cells, the sIgA, IgA, IgG, and IgM contents as well as the mRNA contents of IL-2, IL-6 and TNF-α were increased in AFB1+Se group when compared with those in AFB1 group. These results showed that AFB1 could reduce the ileac mucosa immune function, and supplied dietary sodium selenite could improve the ileac mucosa immune function impaired by AFB1.In conclusion,0.3 mg/kg AFB1 in the diet could reduce the ileac mucosa immune function, and 0.732 mg/kg supplemented dietary selenium could reduce the ileac mucosa immune function. However,0.732 mg/kg Se was added in the diet containing 0.3 mg/kg AFB1, there were no difference between the AFBi+Se group and the control group. Our study demonstrated that supplied dietary sodium selenite could improve the ileac mucosa immune function of the ileum mucosa impaired by AFB1.