In vitro studies on the intestinal absorption of curcumin in rats.

When everted sacs of rat intestines were incubated with 50-750- micrograms of curcumin in 10 ml incubation medium, 30-80% of the added curcumin disappeared from the mucosal side. No curcumin was however detectable in the serosal fluid. Less than 3% of the added curcumin was found in the tissue at the highest concentration. In experiments with [3H[ curcumin, 5-6% of added radioactivity was found in the serosal side. TLC examination of the mucosal extract showed the presence of 2 compounds, 1 corresponding to curcumin and the other to a less polar, colourless compound. The serosal fluid had no curcumin but a compound whose RF was identical with the colourless compound present in the mucosal side. These experiments indicated that curcumin undergoes transformation during absorption from the intestine.