Curcumin as a clinically-promising anti-cancer agent: pharmacokinetics and drug interactions

ABSTRACT

Introduction: Curcumin has been extensively studied for its anti-cancer properties. While a diverse array of in vitro and preclinical research support the prospect of curcumin use as an anti-cancer therapeutic, most human studies have failed to meet the intended clinical expectation. Poor systemic availability of orally-administered curcumin may account for this disparity.

Areas covered: This descriptive review aims to concisely summarise available clinical studies investigating curcumin pharmacokinetics when administered in different formulations. A critical analysis of pharmacokinetic- and pharmacodynamic-based interactions of curcumin with concomitantly administered drugs is also provided.

Expert opinion: The encouraging clinical results of curcumin administration are currently limited to people with colorectal cancer, given that sufficient curcumin concentrations persist in colonic mucosa. Higher parent curcumin systemic exposure, which can be achieved by several newer formulations, has important implications for optimal treatment of cancers other than those in gastrointestinal tract. Curcumin-drug pharmacokinetic interactions are also almost exclusively in the enterocytes, owing to extensive first pass metabolism and poor curcumin bioavailability. Greater scope of these interactions, i.e. modulation of the systemic elimination of co-administered drugs, may be expected from more-bioavailable curcumin formulations. Further studies are still warranted, especially with newer formulations to support the inclusion of curcumin in cancer therapy regimens.

KEYWORDS:

• Anti-cancer
• bioavailability
• clinical pharmacokinetics
• curcumin
• interaction
• metabolism
• pharmacodynamics

Article highlights

Key points contained in the article are:

• A summary of the recent findings of curcumin potential activity as an anti-cancer agent.

• Overview of the major pathways of curcumin metabolism.

• Comprehensive summary of reported curcumin pharmacokinetic data from clinical studies.

• Description of improvements in bioavailability achieved by newer, commercially-available curcumin formulations.

• Evidence of curcumin drug-interactions in both preclinical and clinical studies.

• Critical analysis of implications brought about by the development of newer curcumin formulations and knowledge gaps that should be explored in future studies.

This box summarizes key points contained in the article.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

J Adiwidjaja is supported by a scholarship from Indonesia Endowment Fund for Education (Lembaga Pengelola Dana Pendidikan/LPDP).