Phyto-oestrogen content of berries, and plasma concentrations and urinary excretion of enterolactone after a single strawberry-meal in human subjects

Br J Nutr. 2000 Apr;83(4):381-7.

Abstract

Quantitative data on phyto-oestrogen, particularly lignan, content in edible plants are insufficient. We, therefore, measured isoflavonoids and lignans in nine edible berries using an isotope dilution gas chromatography-mass spectrometry method for foods and found substantial concentrations of the lignan secoisolariciresinol (1.39-37.18 mg/kg DM), low amounts of matairesinol (0-0.78 mg/kg DM) and no isoflavones. To determine pharmacokinetics and urinary excretion pattern of the mammalian lignan enterolactone derived from plant lignans, a study with human subjects was conducted. Five healthy women and two men consumed, after a 72 h period of a phyto-oestrogen-free regimen, a single strawberry-meal containing known amounts of plant lignans. Basal and post-meal blood and urine samples were collected at short intervals. The samples were analysed using time-resolved fluoroimmunoassay of enterolactone. The meal increased plasma concentration of enterolactone after 8-24 h and in urine in the 13-24 h and 25-36 h urine collections. High individual variability of the metabolic response was observed. Enterolactone excreted in the urine collected throughout the 48 h post-meal yielded on average 114% of the plant lignans consumed. It is concluded that berries containing relatively high concentrations of plant lignans contribute to plasma and urinary levels of mammalian enterolactone in human subjects.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Female
  • Fluoroimmunoassay
  • Fruit / chemistry*
  • Gas Chromatography-Mass Spectrometry
  • Humans
  • Isoflavones / analysis*
  • Lactones / blood
  • Lactones / pharmacokinetics*
  • Lactones / urine
  • Lignans / analysis*
  • Lignans / pharmacokinetics
  • Male
  • Middle Aged

Substances

  • Isoflavones
  • Lactones
  • Lignans