Curcumin, part of the spice turmeric, prevents cancers in rodent intestines. It is being studied in clinical trials of humans to prevent colon cancer. Very little of dietary curcumin goes into the blood stream. These researchers further evaluated the notion that curcumin is metabolized in the intestine. They compared its metabolism in parts intestinal cells with the same parts of liver cells from humans and rats. They also studied the metabolism of curcumin in rat intestinal sacs grown in test tubes. Curcumin conjugates and reduction products were identified using high-performance liquid chromatography. Curcumin glucuronide was found in microsomes of liver and intestine cells. Curcumin sulfate, tetrahydrocurcumin, and hexahydrocurcumin found as curcumin metabolites in the cytosol of these cells. Cytosol is fluid part of the cell. In cells from the intestine, curcumin was conjugated more in human cells than in rat cells. The opposite occurred in cells from the liver. The cytosol of human intestinal and liver cells reduced curcumin 18 and 5 fold more, respectively, than did the same type of cell from rats. The intact rat gut sacs produced curcumin sulfate from curcumin. They concluded that curcumin is metabolized greatly, both conjugated and reduced, in the in the gastrointestinal tract and metabolized more by human than by rat intestines. The metabolism of curcumin should be taken into consideration in planning trials of curcumin given by mouth.
Metabolism of the cancer chemopreventive agent cur…[Cancer Epidemiol Biomarkers Prev. 2002]