Effects of rhein on intestinal transmission, colonic electromyography and expression of aquaporin-3 by colonic epithelium cells in constipated mice.

Constipation is one of the most common gastrointestinal diseases in the world. This study was to investigate the effects of rhein on intestinal transmission and colonic electromyography and expression of aquaporin-3 (AQP3) in the colonic mucosa of mice with constipation. The mouse model of constipation was established using the compound diphenoxylate. The first defecation time, the number of stools in the initial 6 hours and the promoting rate of eosin were measured as the bowel transit function. The BL-420F system was used to compare changes in the myoelectrical signals in the colons of the mice. Immunohistochemical analysis was used to detect the expression of AQP3 in the colonic mucosa of mice. Rhein had an obvious effect on the first defecation time and the number of red stool in the initial 6 hours. The first defecation time is reduced, and the number of red stools in 6 hours and the promoting rate of the small intestine were significantly increased after the treatment of rhein. In the rhein group, the slow-wave frequency and slow-wave amplitude of colonic myoelectrical activity were increased, and the mean optical density of AQP3 in the colonic mucosa and the area of positive expression were decreased. In conclusion, rhein can improve motor function and colonic electromyography of constipation mice, and reduce expression of AQP3 in the colonic mucosa, thereby relieving the symptoms of constipation effectively.