Curcumin is the active ingredient of turmeric. It is widely used as a kitchen spice and food colorant throughout India, Asia and the Western world. Curcumin is a major constituent of curry powder, to which it imparts its characteristic yellow colour. For over 4000 years, curcumin has been used in traditional Asian and African medicine to treat a wide variety of ailments. There is a strong current public interest in naturally occurring plant-based remedies and dietary factors related to health and disease. Curcumin is non-toxic to human subjects at high doses. It is a complex molecule with multiple biological targets and different cellular effects. Recently, its molecular mechanisms of action have been extensively investigated. It has anti-inflammatory, antioxidant and anti-cancer properties. Under some circumstances its effects can be contradictory, with uncertain implications for human treatment. While more studies are warranted to further understand these contradictions, curcumin holds promise as a disease-modifying and chemopreventive agent. We review the evidence for the therapeutic potential of curcumin from in vitro studies, animal models and human clinical trials.
(Received June 01 2009)
(Revised December 02 2009)
(Accepted December 04 2009)
(Online publication January 26 2010)
Abbreviations: CD, Crohn's disease; COX, cyclo-oxygenase; IBD, inflammatory bowel disease; IKK, IκB kinase; MAPK, mitogen-activated protein kinase; MMP, matrix metalloproteinase; STAT, signal transducer and activator of transcription; Th, T helper cell; UC, ulcerative colitis