A study on the fate of curcumin in the rat.

The uptake, distribution and excretion of curcumin in Sprague-Dawley rats has been studied. When administered orally in a dose of 1 g/kg, curcumin was excreted in the faeces to about 75%, while negligible amounts of curcumin appeared in the urine. Measurements of blood plasma levels and biliary excretion showed that curcumin was poorly absorbed from the gut. No apparent toxic effects were seen after doses of up to 5 g/kg. When intravenously injected or when added to the perfusate of the isolated liver, curcumin was actively transported into bile, against concentration gradients of several hundred times. The major part of the drug was however metabolized. In suspensions of isolated hepatocytes or liver microsomes 90% of the added curcumin was metabolized within 30 min. In view of the poor absorption, rapid metabolism and excretion of curcumin, it is unlikely that substantial concentrations of curcumin occur in the body after ingestion.