Targeted metabolic profiling of pomegranate polyphenols and urolithins in plasma, urine and colon tissues from colorectal cancer patients

Mol Nutr Food Res. 2014 Jun;58(6):1199-211. doi: 10.1002/mnfr.201300931. Epub 2014 Feb 16.


Scope: Urolithins are bioactive metabolites produced by the gut microbiota from ellagitannins (ETs) and ellagic acid (EA). We investigated whether urolithins could be detected in colon tissues from colorectal cancer (CRC) patients after pomegranate extract (PE) intake.

Methods and results: CRC patients (n = 52) were divided into controls and PEs consumers (900 mg/day for 15 days) before surgical resection. PEs with low (PE-1) and high (PE-2) punicalagin:EA ratio were administered. Twenty-three metabolites, but no ellagitannins, were detected in urine, plasma, normal (NT) or malignant (MT) colon tissues using UPLC-ESI-QTOF-MS/MS (UPLC, ultra performance liquid chromatography; QTOF, quadrupole TOF). Free EA, five EA conjugates, gallic acid and 12 urolithin derivatives were found in colon tissues. Individual and total metabolites levels were higher in NT than in MT, independently of the PE consumed. The maximal mean concentration (1671 ± 367 ng/g) was found in NT after consumption of PE-1 and the lowest concentration (42.4 ± 10.2 ng/g) in MT with PE-2. Urolithin A or isourolithin A were the main urolithins produced (54 and 46% patients with urolithin A or isourolithin A phenotype, respectively). High punicalagin content (PE-2) hampered urolithins formation.

Conclusion: Significant levels of EA derivatives and urolithins are found in human colon tissues from CRC patients after consumption of pomegranate. Further studies are warranted to elucidate their biological activity.

Keywords: Clinical trial; Colon cancer; Ellagic acid; Pomegranate; Urolithins.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Body Mass Index
  • Chromatography, Liquid
  • Colon / drug effects
  • Colon / metabolism
  • Colorectal Neoplasms / metabolism*
  • Coumarins / blood
  • Coumarins / metabolism*
  • Coumarins / urine
  • Ellagic Acid / metabolism
  • Female
  • Humans
  • Hydrolyzable Tannins / blood
  • Hydrolyzable Tannins / urine
  • Limit of Detection
  • Lythraceae / chemistry*
  • Male
  • Metabolomics / methods*
  • Middle Aged
  • Plant Extracts / pharmacology
  • Polyphenols / pharmacology*
  • Reproducibility of Results
  • Tandem Mass Spectrometry


  • Coumarins
  • Hydrolyzable Tannins
  • Plant Extracts
  • Polyphenols
  • 3,8-dihydroxy-6H-dibenzo(b,d)pyran-6-one
  • Ellagic Acid
  • punicalagin