Abstract: Curcumin, a phytonutrient extracted from the rhizome of Curcuma longa has been found to possess potent pharmacological effects from antioxidant properties to anti-inflammatory, antimicrobial/antiviral and even cancer chemopreventive effects. Since there have been no reports about the toxicity, genotoxicity or teratogenicity of curcumin, this natural phenolic compound has been extensively used as a safe agent in numerous preclinical and clinical studies. Several studies have evaluated the effects of curcumin as a natural anti-inflammatory agent, on the proliferation of blood mononuclear cells and vascular smooth muscle cells based on tritiated thymidine uptake. Curcumin has been proved to suppress mitogen-induced proliferation of blood mononuclear cells and inhibit neutrophil activation, smooth muscle cell proliferation and mixed lymphocyte reaction. Recent research on animal models of cancer has also confirmed the cancer chemopreventive properties of curcumin. A previous study on azoxymethane-induced colon, small intestine and stomach cancers in mice reported the reduced incidence and size of tumors following the dietary administration of 0.5-2% curcumin. The beneficial effects of curcumin can be attributed to its effects on cellular enzymes and ability to regulate gene transcription and induce apoptosis. Moreover, daily administration of curcumin (300-800 mg/day) for 21 days was associated with symptom relief in 67 patients with biliary disease. Curcumin can regulate the activity of various enzymes through either direct interaction (e.g. ,cyclooxygenase-2, 5-lipoxygenase and inducible nitric oxide synthase) or regulation of gene transcription via the inhibition of transcription factors (e.g., adaptor protein complex 1, early growth response factor-1 and STAT-3) and their related signaling pathways. The beneficial effects of curcumin have been documented by numerous animal studies and human clinical trials. This phytonutrient can downregulate blood cholesterol levels, prevent platelet aggregation and myocardial infarction, alleviate the symptoms of type II diabetes and decrease the complications of several diseases including rheumatoid arthritis, multiple sclerosis and Alzheimer’s disease. It can also be useful in the treatment of both acute and chronic inflammations. Studies on chemically induced rodent models of colitis have confirmed the benefits of curcumin in the treatment of inflammatory bowel disease. In fact, this phenolic compound was found to significantly reduce mortality, enhance local cytokine and chemokine production, promote neutrophil infiltration and improve colonic morphology.