Curcumin has bright prospects for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic relapsing-remitting condition that afflicts millions of people throughout the world and impairs their daily functions and quality of life. While the aetiology of IBD is not understood well, it appears to be driven by inflammatory cytokines such as tumor necrosis factor (TNF)-alpha. Hence, there is a strong interest in agents that can block the generation or actions of inflammatory cytokines. Curcumin is a bioactive substance present in the rhizomes of the herb "Curcuma longa" which has been used for centuries in Asia, both in traditional medicine and in cooking as turmeric which gives food an exotic natural yellow color. Further, in recent years, a large number of research papers have reported intriguing pharmacologic effects associated with curcumin. These include inhibitory effects on cyclooxygenases 1, 2 (COX-1, COX-2), lipoxygenase (LOX), TNF-alpha, interferon gamma (IFN-gamma), inducible nitric oxide synthase (iNOS), and the transcriptional nuclear factor kappa B (NF-kappaB), in addition to a strong anti-oxidant effect. NF-kappaB is a key factor in the upregulation of inflammatory cytokines that have a high profile in inflammatory diseases, suggesting that curcumin could be a novel therapeutic agent for patients with IBD. Therefore, in recent years, the efficacy of curcumin has been investigated in several experimental models of IBD. The results indicate striking suppression of induced IBD colitis and changes in cytokine profiles, from the pro-inflammatory Th1 to the anti-inflammatory Th2 type. In human IBD, up to now, only one open study has achieved encouraging results. In this study, patients were given curcumin (360 mg/dose) 3 or 4 times/day for three months. Further, curcumin significantly reduced clinical relapse in patients with quiescent IBD. The inhibitory effects of curcumin on major inflammatory mechanisms like COX-2, LOX, TNF-alpha, IFN-gamma, NF-kappaB and its unrivalled safety profile suggest that it has bright prospects in the treatment of IBD. However, randomized controlled clinical investigations in large cohorts of patients are needed to fully evaluate the clinical potential of curcumin.