Significant immunomodulatory properties of curcumin in patients with osteoarthritis; a successful clinical trial in Iran

[Display omitted] •Curcumin ameliorates the severity and activity of OA disease.•Therapeutic effects of curcumin related to its suppressor properties on Th17 cells.•Curcumin directs the ratio of Treg/Th17 cells into Treg cells.•Curcumin prevents B cell activation in OA patients. Osteoarthritis (OA) routinely is known as a multifactorial degenerative joint disease. This trial aimed to assess the curcumin (an active element of turmeric) effects on the immune responses in OA patients. Thirty patients were selected according to the American College of Rheumatology (ACR) criteria and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and equally divided into the two groups; intervention (received Sinacurcumin® 80 mg daily) and placebo, followed for 3 months. In the intervention group, our data showed a noticeably decrease in Visual Analog Score (VAS), C-reactive protein (CRP), CD4+ and CD8+ T cells, Th17 cells and B cells frequency. Additionally, Treg cells indicated a significant increase and Treg/Th17 cells ratio showed a meaningfully shifted toward Treg lymphocytes. In conclusion, our data indicated that clinical manifestation was ameliorated considerably following the administration of curcumin. Moreover, our data demonstrated the immunomodulatory effects of curcumin in OA patients.