Background Non-operative treatments for mild to moderate knee osteoarthritic (OA) is recommended. Plai (Zingibercassumunar Roxb.) belongs to the ginger family. It is a Thai herb used in Thai traditional medicine for relieving muscle and joint pain (1–2). Plai has anti-inflammatory activities due to compounds found in its extracts (1–4). These findings suggest that topical plai cream is a potentially useful drug for the treatment of painful OA of the joints. Since there have not been any studies on the efficacy of plai cream alone for relieving symptoms of OA knee joint, we aimed to test its value.
Objectives To assess the efficacy of topical plai cream for the treatment of primary osteoarthritis (OA) knee.
Methods This was a 9-week (4 weeks treatment + 1 week wash-out + 4 weeks placebo) phase III randomized, double-blind, controlled, cross-over, community trial of Plai vs. placebo, in adults with OA of the knee. This study aimed to determine whether Plai cream was more effective at reducing pain than a placebo cream, as measured using a visual analog scale (VAS) plus the Western Ontario McMaster (WOMAC) score.
Results A total of 120 pairs of subjects were enrolled. The mean different VAS favoring Plai varied between 0.46 and 1.4 (p<0.05). The respective percentage of patients in the Plai group who reached MCII of VAS, WOMAC pain, stiffness and function was 37.9%, 40.10%, 26.45% and 54.58%. The respective percentage of patients in the Plai group who experienced 50% improvement of VAS, WOMAC pain, stiffness and function was 33.33%, 31.77%, 41.66% and 24.68%. The respective number of cases needed to treat to reduce pain of Plai based on MCII and 50% improvement of VAS was 2.63 (95% CI; 2.44, 2.84) and 3 (95% CI; 2.75, 3.29). Four cases in the Plai group had a mild skin reaction.
Conclusions This cross-over, randomized, controlled, communit, trial demonstrated that Plai cream is an effective topical agent for relieving the symptoms of mild to moderate OA knee.
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Disclosure of Interest None declared