Comparative effect of electroacupuncture and moxibustion on the expression of substance P and vasoactive intestinal peptide in patients with irritable bowel syndrome

To compare the impacts of electroacupuncture (EA) and moxibustion (Mox) on the primary gastrointestinal symptoms and the expressions of colonic mucosa-associated neuropeptide substance P (SP) and vasoactive intestinal peptide (VIP) in patients with either diarrhea-predominant or constipation-predominant irritable bowel syndrome (IBS-D and IBS-C, respectively). Eighty-five IBS patients were randomly allocated to the EA and Mox groups. Zusanli (ST 36) and Shangjuxu (ST 37) were selected as acupoints for electroacupuncture or warm moxibustion treatment once a day for 14 consecutive days. Before and after the treatment sessions, a Visual Analog Pain Scale and the Bristol Stool Form Scale were used to evaluate gastrointestinal symptoms. There were four dropout cases, leaving 81 participants (41 with IBS-D and 40 with IBS-C) who volunteered to undergo colonoscopy before and after the treatment sessions. During colonoscopy, sigmoid mucosa were collected to detect SP and VIP expression using immunohistochemistry assay. Both EA and Mox treatments were effective at relieving abdominal pain in IBS-D and IBS-C patients. However, Mox was more effective at reducing diarrhea in IBS-D patients, whereas EA was more effective at improving constipation in IBS-C patients. EA and Mox treatments both down-regulated the abnormally increased SP and VIP expression in the colonic mucosa, with no significant difference shown between the two treatments. Both EA and Mox treatments are effective at ameliorating gastrointestinal symptoms by reducing SP and VIP expression in the colonic mucosa of IBS patients.