Curcumin is the major yellow pigment in turmeric and curry and has antioxidant, anti-inflammatory, and antitumor activities. It inhibits nitric oxide (NO) production (IC50 = 6 μM) and reduces inducible nitric oxide synthase (iNOS) activity in LPS-stimulated RAW 264.7 cells. Curcumin inhibits release of histamine and the inflammatory cytokines TNF-α, IL-1β, IL-6, and IL-8 from HMC-1 mast cells. In vivo, curcumin decreases serum levels of histamine and TNF-α, inhibits histopathological changes of nasal mucosa, and decreases the number of sneezes and nasal rubbing in a mouse model of ovalbumin-induced rhinitis.