Effects of topical Persian medicine Amygdalus communis L. var. Amara kernel oil on the symptoms of knee osteoarthritis: a randomized, triple-blind, active, and placebo-controlled clinical trial

Background: the amygdalus communis l. var. amara (bitter almond) kernel oil (acko) is used topically for palliation of musculoskeletal and joint pains in the traditional persian medicine. also, it had anti-inflammatory effects in experimental studies. objective: evaluation of the efficacy and safety of acko in the symptomatic treatment of knee osteoarthritis. methods: one hundred and fifty six patients were equally randomized to apply acko, diclofenac, or placebo to their knees every 8 hours for 1 month. fifty two, 50, and 51 patients in the acko, diclofenac, and placebo groups, respectively, finished the trial. at the trial’s start and end, the symptoms were assessed using the womac (western ontario and mcmaster universities osteoarthritis index) questionnaire. also, hematological, and liver and kidney function tests were performed. results: both acko and diclofenac reduced the symptoms significantly more than the placebo (p ˂ 0.001). the percent changes of the womac pain and stiffness scores in the acko group were similar to the diclofenac group while the percent changes of the womac function and total scores in the acko group were less than the diclofenac group (p ˂ 0.001). acko and diclofenac had no significant effect on the blood tests. moreover, no adverse effect was identified. conclusions: topical acko and diclofenac are safe, and superior to placebo in reducing the symptoms of oa. while acko is similar to diclofenac in alleviating pain and stiffness, acko is less effective than diclofenac in improving the womac total and function scores.