effect on ileal mucosa and reduced bacterial translocation in the experimental obstructive jaundice model. Further studies should be carried out to explain the mechanisms of these effects.
INTRODUCTIONThe cytotoxicity of bile salts and the toxicity of high levels of intracellular bilirubin are suspected as mediators of some of the systemic consequences of obstructive jaundice. Recent data sug g est that more complex mechanisms involving changes in gut flora, mucosal integrity, and macrophage-immune system interactions may be responsible for the complications of obstructive jaundice [1] . The gastrointestinal tract is not only a passive organ of nutrient absorption, but it additionally displays important endocrine, immunologic, metabolic, and barrier functions [2] . Bacterial translocation is the migration of bacteria or bacterial products from the intestinal lumen to mesenteric lymph nodes or other extraintestinal organs and sites [3] . Obstructive jaundice impairs intestinal barrier function leading to bacterial and endotoxin translocation in experimental and clinical studies. It affects the three levels of gut barrier globally; the immune barrier, the biological barrier, and and the mechanical barrier [2] . Moreover, biliary obstruction in the rats results in a significant depression of the reticuloendothelial system (RES) phagocytic function, which may cause impaired systemic bacterial clearance and is associated with decreased survival following E. coli endotoxemia [4] . Propolis is a natural product collected by honey bees from various plant sources. It has antibacterial, Abstract AIM: To investigate the effects of propolis on bacterial translocation and ultrastructure of intestinal morphology in experimental obstructive jaundice.
METHODS:Thirty Wistar-Albino male rats were randomly divided into three groups, each including 10 animals: groupⅠ, sham-operated; group Ⅱ, ligation and division of the common bile duct (BDL); group Ⅲ, BDL followed by oral supplementation of propolis 100 mg/kg per day. Liver, blood, spleen, mesenteric lymph nodes, and ileal samples were taken for microbiological, light and transmission electron microscopic examination on postoperative 7 th d after sacrification.
RESULTS:The mean number of villi per centimeter and mean mucosal height of the propolis group were significantly different in the BDL group (P = 0.001 and 0.012, respectively). The electron microscopic changes were also different between these groups. Sham and BDL + propolis groups had similar incidence of bacterial translocation (BT). The BDL group had significantly higher rates of BT as compared with sham and BDL + propolis groups. BT was predominantly detected in MLNs and the most commonly isolated bacteria was Escherichia coli .
CONCLUSION:Propolis showed a significant protective