Traditional curry spice curcumin may provide an inexpensive, well-tolerated, and effective treatment for inflammatory bowel disease - Crohn's and ulcerative colitis - report researchers.
The National Institutes of Health estimates that some two million Americans suffer from IBD, which is of unknown origin, but thought to be caused by a combination of genetic, environmental, and immunologic factors. The two debilitating illnesses are characterised by chronic recurrent ulceration of the bowel, abdominal pain, digestive problems, diarrhoea or constipation.
Curcumin is a component of the spice turmeric - Curcuma longa - used in curries and mustard, whose anti-inflammatory properties have already been recognised, while its role in the reduction of colonic cancer in animal models has also been established.
Although effective, current available agents are expensive and not without side effects, say the researchers, led by by B. Salh, at the Jack Bell Research Centre at the Vancouver General Hospital, in Vancouver, British Columbia, Canada. Consequently, they suggest there is a need for alternative agents that may be equally or more effective as well as being cheaper.
The researchers used the dinitrobenzene sulfuric acid (DNB) murine model of colitis, which has been previously validated. Seven-week-old mice had inflammation induced with instillation of 100 µl of DNB (60 mg/ml) in 50 per cent ethanol with control animals receiving 100 µl of 50 per cent ethanol alone. After this, they were kept in position for 30 seconds before being returned to their cages.
On day 5, post-induction was conducted for evaluation of the colitis. Test groups of five mice had curcumin added to their diet at a concentration of 0.25 per cent beginning five days before the DNB instillation. Animals were weighed daily after induction of colitis.
The study results revealed a clear reduction in the amount of weight loss in the animals pretreated with curcumin, according to Salh. Curcumin was found to improve intestinal cell function in DNB-induced colitis, while mucosal ulceration, thickening of the wall, and significant infiltration with inflammatory cells in the DNB-treated animals were all reduced in those animals pretreated with curcumin.
The team also noted that when animals were pretreated with curcumin, there was a clear reduction in DNA binding, thus proving that curcumin does indeed inhibit NF-kappa B activation in the colon in vivo. These findings indicate for the first time that curcumin is able to impact on an important transcriptional mechanism in the gastrointestinal tract, they added.
However Salh adds that the team is not entirely certain how curcumin achieves its effects. He therefore concludes that as it has been shown to possess free radical scavenging - antioxidant - properties in addition to its effects on the activation of NF-kappa B, its in vivo effects may well rely on a complementation of these two and other activities.
Finally, although curcumin has been shown to be safe up to levels as high as 10 per cent (100,000 ppm), the researchers said it showed effectiveness at a concentration as low as 0.25 per cent, a dose which was well tolerated with no reduction in dietary intake.
The team's findings 'Curcumin Attenuates DNB-Induced Murine Colitis' appear in the July 2003 edition of the American Journal of Physiology-Gastrointestinal and Liver Physiology.