Randomized double-blind placebo-controlled study of the efficacy of Litsea japonica fruit extract in subjects with mild to moderate knee osteoarthritis

In this randomized, double-blind, placebo-controlled study, we evaluated the efficacy of Litsea japonica fruit extract (LJF) in subjects with knee osteoarthritis (OA). Eighty-seven 50- to 70-year-old subjects with knee OA were assigned to a placebo group, a low-dose LJF group (LJF-L, 100 mg/d) or a high-dose LJF group (LJF-H, 200 mg/d) for 12 weeks. The outcome measures were pain score assessed using a visual analog scale (VAS); Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores; and blood and urine biomarkers. In response to LJF consumption, VAS scores; WOMAC total scores; WOMAC scores on the pain, stiffness and function subscales; and blood MMP-9 levels significantly improved over the course of the examined 12-week period (P = 0.0001, 0.0102, 0.0293, 0.002, 0.0152 and 0.026, respectively). This study suggests that LJF may reduce joint pain and stiffness and improve joint function in subjects with painful knee OA.Study identifier: KCT0001029 (www.who.int/ictrp/en/).