Distribution of grape seed flavanols and theirmetabolites in pregnant rats and their fetuses

Abstract

Scope: Polyphenols have been demonstrated to provide health benefits affecting cellular andphysiological processes. This study aims to evaluate the bioavailability and distribution ofgrape seed flavanol compounds during pregnancy and whether fetuses could be exposed tothese compounds.Methods and results: The distribution of flavanols and their metabolites in rat plasma, liver,white adipose tissue, brain, amniotic fluid, placenta, and fetuses after 1 and 2 h of an acuteintake of a grape seed proanthocyanidin extract was examined by LC-ESI-TOF/MS. Flavanolsand their metabolites were widely distributed in both pregnant and nonpregnant rat plasmaand tissues. In liver, the conjugated forms of flavanols were less available in pregnant thannonpregnant rats. Flavanol metabolites were abundant in maternal placenta but detected at lowlevels in fetuses and amniotic fluid.Conclusion: Flavanol metabolization appears to be less active in the liver during pregnancy.Moreover, data indicated that transport across the placenta is not efficient and for flavanols andtheir metabolites, the placenta seems to act as a barrier. However, these compounds target thefetus and are excreted in the amniotic fluid.

This research was funded by the Spanish Ministry of Economyand Competitiveness (MECC) (AGL2010–19585, IMPROBESproject). We gratefully acknowledge Vanessa Grifoll for her tech-nical assistance.