+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: not found

      Methylated flavonoids have greatly improved intestinal absorption and metabolic stability.

      Drug metabolism and disposition: the biological fate of chemicals

      Biological Transport, physiology, Caco-2 Cells, Cell Fractionation, Cell Membrane Permeability, Chromatography, High Pressure Liquid, Flavonoids, chemistry, metabolism, pharmacokinetics, Glucuronides, Half-Life, Humans, Intestinal Absorption, Methylation, Microsomes, Liver, enzymology, Molecular Structure, Sulfates

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          To better understand the relationship between the chemical structure and biological fate of dietary polyphenols, the hepatic metabolic stability and intestinal absorption of methylated polyphenols, in comparison with unmethylated polyphenols, were investigated in pooled human liver S9 fraction and human colon adenocarcinoma (Caco-2) cells. Consistent with previous in vivo studies, the two well known unmethylated polyphenols resveratrol (3,5,4'-trihydroxystilbene) and quercetin (3,5,7,3',4'-pentahydroxyflavone) were rapidly eliminated by the S9 fraction in the presence of the appropriate cofactors for conjugation and oxidation. In contrast, the methylated flavones, i.e., 7-methoxyflavone, 7,4'-dimethoxyflavone, 5,7-dimethoxyflavone, and 5,7,4'-trimethoxyflavone, were relatively stable, indicating high resistance to hepatic metabolism. The corresponding unmethylated flavones, i.e., 7-hydroxyflavone, 7,4'-dihydroxyflavone, chrysin (5,7-dihydroxyflavone), and apigenin (5,7,4'-trihydroxyflavone), were rapidly eliminated because of extensive glucuronidation and/or sulfation just as resveratrol and quercetin were. The rate of intestinal absorption was evaluated using Caco-2 cells grown in porous inserts. The methylated flavones showed approximately 5- to 8-fold higher apparent permeability (P(app), 22.6-27.6 x 10(-6) cm s(-1)) of apical to basolateral flux than the unmethylated flavones (P(app), 3.0-7.8 x 10(-6) cm s(-1)). The lower P(app) values for the unmethylated flavones correlated with their extensive metabolism in the Caco-2 cells. Thus, combined use of the hepatic S9 fraction and Caco-2 cells will be useful for predicting the oral bioavailability of dietary polyphenols. The higher hepatic metabolic stability and intestinal absorption of the methylated polyphenols make them more favorable than the unmethylated polyphenols to be developed as potential cancer chemopreventive agents.

          Related collections

          Author and article information



          Comment on this article