Dietary genistein supplementation improves intestinal mucosal barrier function in Escherichia coli O78-challenged broilers

Abstract Genistein has multiple biological activities in both humans and animals. However, a protective effect of genistein on Escherichia coli (E. coli)-induced intestinal mucosal barrier dysfunction remains unknown. In the present study, a total of 288 1-day-old male Arbor Acre broilers fed a corn-soybean basal diet unsupplemented or supplemented with 20 mg genistein/kg diet were subjected to E. coli serotype O78 (108 cfu per bird) infection or equal volume of sodium chloride at 19 days of age. Sera and tissue samples were collected 2 day after E. coli infection. Growth performance, index of immune-related organs, mortality rate at 7 day post E. coli challenge, intestinal barrier permeability, protein level of inflammatory cytokines, sIgA, tight junction protein, and mRNA of apoptotic genes in jejunum were determined. The results showed that E. coli challenge led to a reduced average daily gain, a decreased thymus index, and bursal index in broilers, an increase of fluorescein isothiocyanate (FITC)-dextran in serum, and a decreased sIgA in jejunum. These effects were reversed by genistein administration. Western blot results showed that E. coli infection led to increased protein level of claudin-1 and zonula occludens (ZO)-1, which was markedly abolished by genistein. Moreover, E. coli infection-resulted increase of TNF-α and IL-6, and enhanced apoptosis were abrogated by genistein in jujunum of broilers. In conclusion, the results indicate that genistein supplementation improves intestinal mucosal barrier function which is associated with a regulatory effect on tight junction proteins, sIgA, apoptosis, and secretion of inflammatory cytokines in jejunum of E. coli-challenged broilers.