In vitro and in vivo conjugation of dietary hydroxycinnamic acids by UDP-glucuronosyltransferases and sulfotransferases in humans

Identification of novel circulating coffee metabolites in human plasma by liquid chromatography–mass spectrometry

“…The first identification of 9 lactone derivatives in our study supports this hypothesis. Generally speaking, sulfation is the major conjugation reaction occurring in the human body as at least half of the metabolites of coffee phenolics present in human plasma are sulfated, which is also supported by in vitro studies [30].…”

Effect of edible oils on quercetin, kaempferol and galangin transport and conjugation in the intestinal Caco-2/HT29-MTX co-culture model

“…Although the response factors for each substitution position will not be exactly the same, they will be relatively close. The validity of this assumption is supported by our previous data 16 About 6 x10 -4 cells per cm 2 were seeded on the insert with 76% of Caco-2 and 24% of HT29-MTX cells according to previous practice [15]. Co-cultured cells were allowed to grow and differentiate in DMEM supplemented with 10% FBS, 100 U/ml penicillin/ streptomycin and 0.25 µg/ml amphotericin B.…”

“…Prior to the experiments, the culture medium was replaced by fresh medium for at least [12][13][14][15][16][17][18][19][20][21][22][23][24] hours. Transport experiments were carried out with transport buffer solution consisting of HBSS supplemented with 1.8 mM CaCl 2 (to maintain integrity of the tight junction) and 100 µM ascorbic acid (to minimise degradation of flavonols).…”

Inhibition of hydroxycinnamic acid sulfation by flavonoids and their conjugated metabolites

“…In the human small intestine, SULT1A1 and SULT1A3 are highly expressed and they are both highly active in the conjugation of hydroxycinnamic acids [4]. Of the two isozymes, SULT1A3 activity is known to be relatively resistant to inhibition by flavonoids [17].…”

“…Human studies and in vitro mechanistic studies showed that hydroxycinnamic acids are predominantly sulfated in the intestine and liver [1][2][3][4][5][6].…”