STW 5 is effective in treating experimental ulcerative colitis using the DSS model

STW 5 (Iberogast®) is an herbal preparation that is effective clinically in functional dyspepsia (1) and irritable bowel syndrome (2). Since STW 5 also has marked anti-inflammatory activity (3), it was of interest to explore its potential effectiveness against inflammatory bowel disease (IBD). An experimental model reflecting ulcerative colitis in man was adopted, whereby colitis is induced in rats by feeding them 5% Dextran Sulfate Sodium (DSS) in drinking water for one week. STW 5 (0.5ml/kg to 5ml/kg) and sulfasalazine (300mg/kg) as a reference standard were administered orally daily for one week before initiation of colitis induction and continued during DSS feeding. The animals were then sacrificed, the colons examined, and tissue samples taken for measurement of relevant parameters. DSS induced a sharp decrease in body weight which was more effectively normalized by STW 5 than by sulfasalazine. It also led to shortening of colon length and an increase in colon mass index, effects that were reversed by treatment with either drug. Changes in myeloperoxidase, reduced glutathione, glutathione peroxidase, superoxide dismutase, TNFα and MIP-2 induced by DSS were also reversed by STW 5 and by sulfasalazine almost to the same extent. The biochemical findings could be substantiated histopathologically. Furthermore, the sensitivity of colon segments towards motor agonists such as carbachol and potassium chloride was assessed ex-vivo. STW 5 normalized the depressed responsiveness of the colon induced by DSS. The findings point to a potential usefulness of STW 5 in the clinical setting of ulcerative colitis.

References: 1. Schmulson MJ (2008) Nature clinical practice gastroenterology & hepatology 5: 136–137

2. Liu JP et al (2006). Cochrane Review, Issue 1.

3. Khayyal MT et al. (2009) Planta Med 75: 1034