Prolonged biologically active colonic tissue levels of Curcumin achieved after oral administration- A clinical pilot study including assessment of patient acceptability
Cancer Prev Res. 2013; 6(2):119-128.
The pharmacokinetic and pharmacodynamics parameters of Curcumin have been reported earlier but few data is available describing whether methodologies are suitably robust for Curcuminoids detection in colonic biopsy specimen. Information on the acceptability of prolonged administration of daily Curcumin is not available.
To quantify the levels of Curcuminoids in normal colorectal mucosa of patients undergoing the colorectal endoscopy or surgical resection and to test the hypothesis that most of the Curcuminoids recovered from gut tissue were absorbed in mucosa and thus capable to eliciting direct pharmacological effect.
In a pilot study, 28 patients awaiting gastrointestinal endoscopy or colorectal resection were recruited and administered 2.35 g of Curcuminoids daily for 14 days till surgical procedure was done. Plasma samples were obtained before Curcumin ingestion and on the day of the surgical procedure (between 6.5 and 35.5 h after Curcumin dose) along with 24 hours urine collection between the last 2 doses. Safety and tolerance were monitored. Analysis of Curcuminoids in plasma, urine and colonic mucosa was performed by UPLC-UV with characterization by tandem LC-MS/MS.
Results and Discussion:
- Out of 28 subjects, 24 completed the trial.
- The adverse events recorded were of mild gastrointestinal in nature with no serious adverse event was attributable to Curcumin.
- Curcuminoids concentrations were measured in colorectal tissue biopsies ranging in mass from 0.5 to 6.75 mg. In order to explore how much of the measured Curcuminoids were loosely bound to mucosa and how much have been absorbed in the tissue volume, matched biopsy samples were subjected to a series of KCl washes. Unwashed tissue levels of Curcumin ranged from 0.7 µg/g to 681 µg/g.
- Levels of Curcuminoids were detectable in 9/24 patient’s plasma samples ranged between 8.1- 13.9 ng/ml.
- Curcuminoids were identified in 24 h urine collection of all participants.
Curcumin as daily dose of 2-3 g may be considered as safe and well tolerated during prolonged administration. Curcumin was found to be detectable in GI tract of all patients receiving similar dose of Curcumin for 14 days and the Curcumin glucuronides and sulphates were semi quantitated. In this study sensitive and robust analytical quantitative method for analysis of Curcumin was used. Also pharmacologically active levels of Curcumin were recovered from bowel mucosa even after multiple tissue washes and there was no systemic Curcumin accumulation.
One of the crucial issue for any clinical evaluation is the possible barriers to patient uptake and compliance in the context of chemoprevention. In this trial patient’s attitude towards Curcumin and experience of its use was also evaluated. Hence the regimen used here seems safe, and patients support its use in longterm trials.