Yangyin Runchang Decoction Improves Intestinal Motility in Mice with Atropine/Diphenoxylate-Induced Slow-Transit Constipation

This study assessed the efficacy and mechanism of action of Yangyin Runchang decoction (YRD) in the treatment of slow-transit constipation (STC). ICR mice were randomly divided into four groups (n = 10/group) and treated with saline (normal control; NC), atropine/diphenoxylate (model control; MC; 20 mg/kg), or atropine/diphenoxylate plus low-dose YRD (L-YRD; 29.6 g/kg) or high-dose YRD (H-YRD; 59.2 g/kg). Intestinal motility was assessed by evaluating feces and the intestinal transit rate (ITR). The serum level of stem cell factor (SCF) and changes in interstitial cells of Cajal (ICCs) were also evaluated. Additionally, the expression of SCF and c-kit and the intracellular Ca(2+) concentration [Ca(2+)](I) were investigated. Fecal volume and ITR were greater in the L-YRD and H-YRD groups than in the MC group. The serum SCF level was lower in the MC group than in the NC group; this effect was ameliorated in the YRD-treated mice. Additionally, YRD-treated mice had more ICCs and elevated expression of c-kit and membrane-bound SCF, and YRD also increased [Ca(2+)](I) in vitro in isolated ICCs. YRD treatment in this STC mouse model was effective, possibly via the restoration of the SCF/c-kit pathway, increase in the ICC count, and enhancement of ICC function by increasing [Ca(2+)](i).