Boswellia serrata extract for the treatment of collagenous colitis. A double-blind, randomized, placebo-controlled, multicenter trial

BACKGROUND AND AIMS: The objective of this study was to investigate the effect of Boswellia serrata extract (BSE) on symptoms, quality of life, and histology in patients with collagenous colitis.

MATERIALS AND METHODS: Patients with chronic diarrhea and histologically proven collagenous colitis were randomized to receive either oral BSE 400 mg three times daily for 6 weeks or placebo. Complete colonoscopy and histology were performed before and after treatment. Clinical symptoms and quality of life were assessed by standardized questionnaires and SF-36. The primary endpoint was the percentage of patients with clinical remission after 6 weeks (stool frequency<or=3 soft /solid stools per day on average during the last week). Patients of the placebo group with persistent diarrhea received open-label BSE therapy for a further 6 weeks.

RESULTS: Thirty-one patients were randomized; 26 patients were available for per-protocol-analysis. After 6 weeks, the proportion of patients in clinical remission was higher in the BSE group than in the placebo group (per protocol 63.6%; 95%CI, 30.8-89.1 vs 26.7%, 95%CI, 7.7-55.1; p=0.04; intention-to-treat 43.8% vs 26.7%, p=0.25). Compared to placebo, BSE treatment had no effect on histology and quality of life. Five patients discontinued BSE treatment prematurely. Discontinuation was due to adverse events (n=1), unwillingness to continue (n=3), or loss to follow-up for unknown reasons (n=1). Seven patients received open-label BSE therapy, five of whom achieved complete remission.

CONCLUSIONS: Our study suggests that BSE might be clinically effective in patients with collagenous colitis. Larger trials are clearly necessary to establish the clinical efficacy of BSE.