Mechanisms underlying the potential usefulness of STW 5 in reflux esophagitis

Abstract

STW 5, a multi-component herbal preparation, was shown to relieve heartburn and concomitant reflux symptoms in patients with functional dyspepsia and to prevent inflammation in an acute model of reflux esophagitis (RE), without affecting the pH of the refluxate. The present study assesses the efficacy of STW 5 in a sub-chronic model of RE, and the underlying mechanisms both in vivo and in vitro. Rats were pretreated for 7d with STW 5 or omeprazole (as reference drug) before surgical induction of esophagitis. RE was achieved by ligation of the fore-stomach and covering the pylorus with a piece of Nelaton catheter. Rats were treated for a further 10d with the drugs and then sacrificed, their esophagi excised, weighed and evaluated macroscopically. Tissue homogenates were used for determination of cytokines using a cytokine array. Both STW 5 and omeprazole, improved body weight, tissue damage score and esophageal weight index to similar extents. However, STW 5 had a much more pronounced anti-inflammatory effect. As shown in the cytokine array, STW 5 inhibited the majority of the measured pro-inflammatory cytokines induced by surgical reflux, suggesting a direct anti-inflammatory and/or mucosa protecting action.