Curcumin β-D-Glucuronide Plays an Important Role to Keep High Levels of Free-Form Curcumin in the Blood.
Level 5 - mechanism / opinion, no new human data
Preclinical animal pharmacokinetic and xenograft tumor study
PubMed 28867734 · doi:10.1248/bpb.b17-00339
What was done
Researchers evaluated the pharmacokinetics and metabolism of curcumin and its metabolite, curcumin β-D-glucuronide (CMG), in rats following oral administration (measuring portal vein concentrations) and intravenous CMG injection. Antitumor efficacy was subsequently assessed by administering intravenous CMG to mice bearing HCT116 human colon cancer xenografts and measuring tumor volume and body weight relative to controls.
What was found
Curcumin was conjugated when crossing the intestinal wall. Orally administered CMG was poorly absorbed in rats despite high aqueous solubility. Intravenous CMG injection in rats yielded high circulating levels of free-form curcumin. In mice with HCT116 xenografts, intravenous CMG significantly reduced tumor volume compared to the control group without causing significant body weight loss (no exact numerical concentrations, tumor volumes, or p-values were reported in the abstract).
Why it matters
This study suggests that intravenous administration of curcumin monoglucuronide can serve as a strategy to maintain circulating active free curcumin and suppress tumor growth in preclinical models without evident systemic toxicity.
Limits
All findings are derived from rodent models, and translational relevance to human cancer or human pharmacokinetics remains unproven. The abstract omits sample sizes, numeric pharmacokinetic parameters, quantitative tumor measurements, and precise p-values. Xenograft models do not capture full human tumor complexity or immune interactions.
Cited by
- context Glucuronidated curcumin is completely biologically inactive.