OBJECTIVETo study the regulatory effect of Huoxiang Zhengqi Extract (HZE) on the intestinal mobility in rat model of diarrhea-predominant irritable bowel syndrome (D-IBS).

METHODSEighty experimental rats were randomly divided into two parts, forty in each. Rats in one part were used in the carbon powder experiment, while the rest rats were used in the gastrointestinal transit test. Rats in each part were divided into five groups, i.e., the blank control group, the model group, and the high, moderate, and low HZE treated groups, eight in each. Normal rats consisted of the blank control group. Except for the blank control group, D-IBS model was established by gastrogavage of senna at the dose of 0.2 g/mL at 25 degrees C with 2-h restraint stress of extremities for six successive days. After modeling, high (804 mg/kg), moderate (536 mg/kg), and low (268 mg/kg) dose HZE was respectively administered to rats of the three corresponding groups. Effect of HZE on the small intestine propulsion rate and serum levels of nitric oxide (NO), 5-hydroxytryptamine (5-HT) as well as chromaffin cells in colonic epithelium (EC) were detected by carbon powder experiment, gastrointestinal transit test, nitrate reductase method, ELISA, and immunohistochemistry, respectively.

RESULTSCompared with the model group, HZE could lower the small intestine propulsion rate of D-IBS model rats, attenuate the colon transition, improve serum NO level, lower 5-HT level, and lessen the amount of EC.

CONCLUSIONHZE showed regulatory effect on the intestinal function of D-IBS rats.