Efficacy and short-term safety of topical Dwarf Elder (Sambucus ebulus L.) versus diclofenac for knee osteoarthritis: A randomized, double-blind, active-controlled trial

Ethnopharmacological relevance: Sambucus ebulus L. (S. ebulus) has had long-standing application in Traditional Persian Medicine for joint pain and for a variety of bone and joint disorders. According to traditional use of S. ebulus and its relevant pharmacologic properties, this study was designed to evaluate the efficacy and short-term safety of topical use of S. ebulus in patients with knee osteoarthritis (OA). Methods and materials: Seventy nine patients with knee OA were randomly enrolled in 2 parallel arms of a pilot randomized, double-blind, active-controlled clinical trial. The patients were treated by topical S. ebulus gel or 1% diclofenac gel, three times a day, as much as a fingertip unit for 4 weeks. Patients were assessed prior to enrollment and, then, 2 and 4 weeks subsequent to the intervention, in terms of scores of visual analogue scale (VAS) for self-grading of their knee joint pain, and according to 3 different domains of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. Any observed adverse effects were also scrutinized. Results: The mean values of WOMAC pain score, total WOMAC score and VAS score for pain of the S. ebulus group were significantly lower compared with the diclofenac group (P=0.004, P=0.04, and P<0.001, respectively). In addition, no serious adverse effect was reported. Conclusion: This pilot study showed that topical treatment with S. ebulus gel can be recommended for alleviating symptoms of patients with knee OA. However, longer trials involving larger samples size, are needed for achieving a comprehensive understanding about the efficacy and safety of S. ebulus in knee OA. (C) 2016 Published by Elsevier Ireland Ltd.