[Correlation study of rhubarb and expression changes of antimicrobial peptides in the small intestine of mice].

OBJECTIVE

To study the correlation between rhubarb and expressions of antimicrobial peptides (AP) in the small intestine of mice by observing the effect of rhubarb on it.

METHODS

Thirty healthy ICR mice were randomly divided into the test group and the control group, fifteen in each. Ten percent rhubarb decoction and equal volume of normal saline solution was respectively given to mice of the two groups by gastrogavage. Mice were sacrificed 24 h later. The small intestines from the ligament of Treitz to the ileocecal junction were removed by ventrotomy. The lumen of each resected intestine was rinsed with 10% acetic acid solution and the perfusate was collected. The small intestine homogenate was prepared using 30% acetic acid solution. The equivalent samples were electrophoresed on 12.5% AU-PAGE and Tricine-16.5% SDS-PAGE, and peptide bands were visualized with Coomassie brilliant blue R-250 or ammoniacal silver-stained respectively. And then analysis of gel imaging and gel overlay assay were performed. The bactericidal activity and expressions of AP in the small intestine of samples in the two groups were compared. The molecular weight of AP in the small intestine was measured.

RESULTS

After gastrogavaged with rhubarb decoction, changes of AP contents in the small intestine homogenate of mice were not obvious, but the molecular weights of AP were different. But the AP contents in the small intestine perfusate obviously increased, with the molecular weights being 14.3 to 18.4 kDa. But its bactericidal capacity showed no statistical difference when compared with that of the control group (P>0.05).

CONCLUSIONS

Rhubarb enhanced the expressions of partial APs in the small intestine, which might possibly be one of its mechanisms of protecting and strengthening the intestinal barrier.