Pharmacokinetics of curcumin conjugate metabolites in healthy human subjects.
BACKGROUND
Curcumin is a polyphenol, found in the spice turmeric, that has promising anticancer properties, but previous studies suggest that absorption of curcumin may be limited.


METHODS
This study examined the pharmacokinetics of a curcumin preparation in healthy human volunteers 0.25 to 72 h after a single oral dose. Curcumin was administered at doses of 10 g (n = 6) and 12 g (n = 6). Subjects were randomly allocated to dose level for a total of six subjects at each dose level. Serum samples were assayed for free curcumin, for its glucuronide, and for its sulfate conjugate. The data were fit to a one-compartment absorption and elimination model.


RESULTS
Using a high-performance liquid chromatography assay with a limit of detection of 50 ng/mL, only one subject had detectable free curcumin at any of the 14 time points assayed, but curcumin glucuronides and sulfates were detected in all subjects. Based on the pharmacokinetic model, the area under the curve for the 10 and 12 g doses was estimated (mean +/- SE) to be 35.33 +/- 3.78 and 26.57 +/- 2.97 mug/mL x h, respectively, whereas C(max) was 2.30 +/- 0.26 and 1.73 +/- 0.19 mug/mL. The T(max) and t(1/2) were estimated to be 3.29 +/- 0.43 and 6.77 +/- 0.83 h. The ratio of glucuronide to sulfate was 1.92:1. The curcumin conjugates were present as either glucuronide or sulfate, not mixed conjugates.


CONCLUSIONS
Curcumin is absorbed after oral dosing in humans and can be detected as glucuronide and sulfate conjugates in plasma.
Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, USA.
Shaiju K
SK
Vareed
Madhuri
M
Kakarala
Mack T
MT
Ruffin
James A
JA
Crowell
Daniel P
DP
Normolle
Zora
Z
Djuric
Dean E
DE
Brenner
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid; D003474:Curcumin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D005260:Female; D020719:Glucuronides / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D013431:Sulfates / Q000097:blood; D013997:Time Factors
D020719:Glucuronides; D013431:Sulfates; D003474:Curcumin