Abstract 1286: Pharmacodynamics of oral curcumin in plasma and rectal mucosa in a Phase IIa trial

Abstract

Abstract Background: Curcumin, a dietary polyphenol derivative of turmeric, has potent cancer reductive activity in in vivo colon carcinogenesis models. We administered curcumin at doses of 2 g or 4 g to separate groups of 20 healthy human smokers with > 8 aberrant crypt foci (ACF). The 2 g dose showed no ACF reduction while the 4 g dose showed a 46% reduction (p<0.005) We analyzed native curcumin and its conjutes in matched plasma and rectal mucosa biopsy sample from 21 participants at 2g and 18 participants at 4g. Methods: Curcuminoid products were extracted from homogenized biopsy tissue and ultacentrifuged plasma and evaporated under argon. The separation was performed on a Symmetry® C18 column. The mobile phase used under gradient conditions was 25% acetonitrile with 74.9% containing 0.1% acetic acid (25:74.9:0.1; v/v/v; A) and 100% acetonitrile containing 0.1% acetic acid (99.9:0.1; v/v; B) The flow rate was 0.3 mL/min and injection volume for all samples was 10 µL. The lower limit of detection for curcumin from human plasma was 5 ng/mL and from human colonic mucosa was 50 ng/5mg tissue. Results: See Table below (summarized by pre and post treatment dose for plasma and mucosal concentrations) Conclusions: Native curcumin is not detectable in the majority of biopsy and plasma samples. Conjugated curcumin is detectable in all plasma samples and the majority of mucosal biopsies with a significant increase in plasma concentrations at 4g. We postulate the conjugates detected in the rectal mucosa are delivered systemically from absorption and conjugation higher in the gastrointestinal tract and may have biologic activity. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1286. doi:10.1158/1538-7445.AM2011-1286