Background: Leukotrienes and prostaglandines are important mediators of inflammation. While prostaglandine synthesis can be influenced by NSAIDs therapeutical approaches to the 5-lipoxygenase pathway are rare. Resinous extracts of Boswellia serrata (H15, indish incense), known from traditional ayurvedic medicine, decrease leukotriene synthesis in vitro. Case reports suggest a clinical role for that drug.
Methods: Outpatients with active RA have been enrolled into a multicenter controlled trial. Patients received 9 tablets of active drug (3600 mg) or placebo daily in addition to their previous therapy. Doses of NSAIDs could be adjusted on demand. Efficacy parameters, Ritchies Index for swelling and pain, ESR, CRP, pain on VAS and NSAID dose were documented at baseline and 6 and 12 weeks after initiation. Mean values and medians were calculated to compare the groups for significant or clinically relevant change from baseline or difference between both groups at any time point of observation.
Results: A total of 78 patients were recruited in 4 centers, the data have been published in abstract form. Only 37 patients (verum 18, placebo 19), enrolled in Ratingen were available for detailed efficacy and safety analysis. All evaluations in these patients were performed by one investigator (G.H.). There was no subjective, clinical or laboratory parameter showing a significant or clinically relevant change from baseline or difference between both groups at any time point of observation. The mean NSAID dose reduction reached levels of 5.8% (H15) and 3.1% (placebo). One patient in each group showed a good response in all parameters but 4 patients in each group worsened. The others showed no alteration of their disease.
Conclusion: Treatment with H15 showed no measurable efficacy. Controlled studies including a greater patient population are necessary to confirm or reject our results.