BioaVailability of Curcumin: Problems and Promises
Figure 1. Structure of curcumin and its metabolites.
found in heart blood, whereas a trace amount (less than 5 µg/mL) was found in the portal blood from 15 min to 24 h after administration of curcumin.32 In another study using tritium-labeled curcumin, the same group showed detectable amounts of curcumin in blood with doses ranging from 10 to 400 mg of curcumin per animal.33 When curcumin was given orally at a dose of 2 g/kg to rats, a maximum serum concentration of 1.35 ( 0.23 µg/mL was observed at time
h, whereas in humans the same dose of curcumin
Wahlstrom, B; Blennow, G. A study on the fate of curcumin in
the rat. Acta Pharmacol. Toxicol. (Copenhagen) 1978, 43 (2), 86– 92. (32) Ravindranath, V.; Chandrasekhara, N. Absorption and tissue distribution of curcumin in rats. Toxicology 1980, 16 (3), 259– 65.
Ravindranath, V.; Chandrasekhara, N. Metabolism of curcumin–
studies with [3H]curcumin. Toxicology 1981, 22 (4), 337–44.
resulted in either undetectable or extremely low (0.006 ( 0.005 µg/mL at 1 h) serum levels.28
Pan et al., for example, investigated the pharmacokinetic properties of curcumin administered either orally or intrap- eritoneal (i.p.) in mice. With oral administration of 1.0 g/kg of curcumin, low plasma levels of 0.13 µg/mL appeared in plasma after 15 min, while a maximum plasma level of 0.22 µg/mL was obtained at 1 h; plasma concentrations then declined below the detection limit by 6 h. Entirely different plasma curcumin levels were found after i.p. administration of 0.1 g/kg. Plasma curcumin levels peaked (2.25 µg/mL) within 15 min of administration and declined rapidly within 1 h.34 Perkins and co-workers examined the pharmacokinetics of curcumin in a Min/+ mouse model of FAP using either
(34) Pan, M. H.; Huang, T. M.; Lin, J. K. Biotransformation of curcumin through reduction and glucuronidation in mice. Drug Metab. Dispos. 1999, 27 (4), 486–94.
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