Effect of curcumin on nasal symptoms and airflow in patients with perennial allergic rhinitis

Background: Allergic rhinitis (AR) is a common disorder that can significantly affect patient quality of life. Previous studies have found that curcumin had anti-inflammatory and antioxidant effects and clinical benefits in cancer and asthma. Objective: To determine the efficacy of curcumin in the treatment of AR and to explore the molecular mechanisms involved. Methods: In a randomized, double-blind study, 241 patients with AR received either placebo or oral curcumin for 2 months. The therapeutic effects of curcumin were evaluated by nasal symptoms and nasal airflow resistance. In addition, the production of interferon gamma, interleukin (IL) 4, IL-10, and tumor necrosis factor a from mononuclear cells and IL-8, soluble intercellular adhesion molecule, polyethylene glycol 2, and leukotriene C-4 from polymorphonuclear neutrophils were compared before and after curcumin treatment. Results: Curcumin alleviated nasal symptoms (sneezing and rhinorrhea) and nasal congestion through reduction of nasal airflow resistance. Curcumin was found to exert diverse immunomodulatory effects, including suppression of IL-4, IL-8, and tumor necrosis factor a and increased production of IL-10 and soluble intercellular adhesion molecule. However, curcumin did not affect the release of prostaglandin E-2 and leukotriene C-4 from polymorphonuclear neutrophils. Conclusion: This pilot study provides the first evidence of the capability of curcumin of improving nasal airflow and modulating immune response in patients with AR. (C) 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.