EFFECTS OF CURCUMIN ON CLINICAL OUTCOMES AND INFLAMMATORY BIOMARKERS IN KNEE OSTEOARTHRITIS: A RANDOMIZED TRIAL.

BACKGROUND: Osteoarthritis (OA) is a chronic degenerative disease of the joints in which pain, functional impairment, and low-grade inflammation appear. Curcumin, the active ingredient extracted from Curcuma longa, has biological effects of both anti-inflammatory and antioxidant activity. However, its influence on inflammatory biomarkers in OA is less consistent. OBJECTIVE: To evaluate the impact of curcumin supplementation on clinical outcomes and inflammatory biomarkers in patients with knee OA. METHODS: In this prospective randomised single-blind placebo-controlled trial, patients with knee OA were assigned to curcumin supplementation or a placebo for three months. A total of 125 participants were randomized, and 80 completed the study. Clinical outcomes were measured with the Visual Analogue Scale (VAS) for pain and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). To assess the effects of curcumin on inflammatory biomarkers, tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and high-sensitivity C-reactive protein (hs-CRP) were measured before and after drug therapy. RESULTS: Compared to placebo, curcumin supplementation significantly reduced VAS and WOMAC scores that were mainly related to clinical outcomes. A significant reduction in TNF-α was seen, showing a potent anti-inflammatory effect. Conversely, levels of IL-6 decreased slightly, and no significant change was noted for hs-CRP. CONCLUSION: Curcumin supplementation significantly improves pain and functional outcomes in knee OA, exerting selective anti-inflammatory effects, with a pronounced impact on TNF-α compared to IL-6 and hs-CRP. This pattern may be explained by curcumin's modulation of upstream inflammatory pathways via nuclear factor kappa B (NF-κB) inhibition and AMP-activated protein kinase (AMPK) activation, which lead to pathway-dependent effects within the inflammatory cascade. Curcumin may represent a promising adjunct therapy for osteoarthritis, although further studies are needed to clarify its long-term effects and mechanisms.