Curcumin Inhibits Colon Cancer Progression in Rat Model

NEW ORLEANS--Curcumin and sulindac sulfone both can inhibit colon carcinogenesis in a rat model during the initiation and post-initiation stages. But a study from the American Association for Cancer Research meeting suggests that during the promotion and progression stages, only curcumin inhibits tumor development.

In the new study, Bandaru S. Reddy, DVM, PhD, chief of the Division of Nutritional Carcinogenesis at the American Health Foundation, Valhalla, NY, and his colleagues tested the tumor-inhibiting abilities of curcumin (the component of the spice turmeric that makes it orange yellow in color) and sulindac sulfone (an investigational NSAID).

All of the 6-week-old male F344 rats ate a control diet to start. One week into the experiment and again the following week, all rats received subcutaneous injections of azoxymethane, a chemical that can induce colon tumors. Fourteen weeks later, some rats were switched to diets containing curcumin or sulindac sulfone. The rats remained on the special diets for 36 weeks.

The results strongly suggest that curcumin can inhibit cancer during the promotion stage, Dr. Reddy said at a press conference. Most (85%) of the control rats developed colon cancers, an average of 1.91 tumors each. Of rats that took in 0.6% of their diet as curcumin, just 57% developed cancers, with an average of 0.77 tumors per rat. A second group of rats ate a 0.2% curcumin diet; 61% developed tumors, with an average of 1.28 tumors each. Those on a 0.12% sulindac sulfone diet differed little from the controls; 78% developed tumors, with an average 1.44 tumors each.

This study suggests that curcumin could be a promising treatment for polyps, Dr. Reddy said. Some cancer centers in the United States are now running clinical trials of curcumin in the prevention of colon cancer.