NOS2 and cancer: Curcumin, a natural phenolic compound extracted from the rhizome of turmeric (Curcuma longa L.), belong to the family Zingiberaceae has generated research interest because it possesses pleiotropic biological and pharmacological properties, such as anti-cancer, anti-inflammatory, antibacterial, antioxidant and anti-rheumatic etc. The underlying mechanism includes its inhibitory effects on pro-inflammatory cytokines such as IL-6, TNF-α, IL-1β, cyclooxygenase (COX-2), inducible nitric oxide synthase (iNOS), and transcription factors such as nuclear factor (NF-kB), activator protein-1 (AP-1).