Objective:To investigate the effect of herbs extracts Qingyi granules on the expression of  claudin-1 of ileum in rats with severe acute pancreatitis (SAP).
Methods:Ninety-six healthy male Wistar rats were randomly divided into sham operation group, SAP model group and SAP+Qingyi granules (treatment)group. SAP model was induced by retrograde injection of  3.5% sodium deoxycholate into the biliopancreatic duct of rats, while the sham operation group were treated only with saline. Treatment group was given orally Qingyi granules at 2 hours before induction of SAP and Q12h after SAP. At 6, 12, 24 and 48 h after SAP, the histopathology of terminal ileum tissue was examined by HE staining, and the expression of  claudin-1 was detected by using immunohistochemistry and real-time PCR respectively.
Results:Compared with SAP  group, the pathological damage of ileum tissue was reduced at 24 and  48 h, the protein and mRNA expression of claudin-1 were all increased at 6, 12, 24 and 48 h after SAP in treatment group (P＜0.05).
Conclusions:Qingyi granules can increase the expression claudin-1 protein and mRNA, and thus can protect the intestinal mucosa and maintain the function of intestinal mucosal barrier.