Impact of dose on the bioavailability of coffee chlorogenic acids in humans

Abstract

Single servings of coffee beverage containing low (412 µmol), medium (635 µmol) and high (795 µmol) amounts of chlorogenic acids were administered to eleven healthy volunteers in a double-blind randomised controlled trial. Analysis of plasma and urine collected for 24-h revealed the presence of 12 metabolites in plasma and 16 metabolites in urine, principally in the form of sulphates, and to a lesser extent glucuronides of caffeic, ferulic, dihydrocaffeic and dihydroferulic acids, as well as intact feruloylquinic and caffeoylquinic acids, and sulphated caffeoylquinic acid lactones. Median values of peak plasma concentrations after increasing doses of chlorogenic acids were 1088, 1526 and 1352 nM. In urine the median amounts of metabolites excreted after 24-h following consumption of the three coffees were 101, 160 and 125 µmol, accounting for 24%, 25% and 16% of the doses ingested. Peak plasma concentration and urinary excretion values showed trends towards a reduced bioavailability of chlorogenic acids associated with the highest dose ingested, when expressed as percentages of intake.Potential biomarkers of coffee intake were identified as feruloylquinic acids and sulphated caffeoylquinic acid lactones in plasma and urine with positive moderate to strong coefficients of determination for peak plasma concentrations (0.60-0.81) and amounts excreted in urine (0.36-0.73) (P < 0.05).

Phytochemical uptake following human consumption of Montmorency tart cherry (L. Prunus cerasus) and influence of phenolic acids on vascular smooth muscle cells in vitro

“…participants a single serving of a coffee beverage fortified with CHL, the serving consisted of low (412 μmol), CHL that was found the MC concentrate that represents a sensible portion to consume, rather than an artificially 309 derived concentration used previously [34,35]. In support of this, a previous study using comparable…”

The colonic metabolites dihydrocaffeic acid and dihydroferulic acid are more effective inhibitors of in vitro platelet activation than their phenolic precursors

“…62 In comparison, a single serving of espresso coffee provides between 24 -422 mg of CGA and 51 -322 of caffeine, corresponding to approximately 6 -12 mM CGA and 8 -16 mM caffeine depending on the type of roast and the volume consumed. 63 In the studies about the bioavailability of coffee phytochemicals, plasma levels up 1.5 µM CGA and 13 µM methylxanthines have been reported after the intake of coffee beverages providing 2 -4 mM CGA and 1 mM methylxanthines, 19,21,23 with higher plasma concentrations of CGA (up to 10 µM) reported after the intake of roasted coffee. Based on previous results, 40,39 the highest dose tested of phenolic extracts was 100 µg/mL in the present study, corresponded to approximately 200 µM CGA and 50 µM methylxanthines; however, the doses tested for phenolic extracts ≤ 1 µg/mL would be within the physiological range for CGA (equivalent to approximately ≤ 2 µM CGA), while all tested concentrations would be physiological for methylxanthines.…”

“…57 On the contrary, concentrations of at least 100 µM were necessary to inhibit the expression of TRAP-and ADPinduced P-selectin by the early metabolites CA and FA, and 5-CQA, respectively, 42,58 while the 12 results of this study showed a significant decrease of ADP-induced P-selectin expression at noticeably lower concentrations (20, 10 and 1 µM for CA, FA and 5-CQA, respectively), indicating that the colonic metabolites may have an even stronger effect on platelet function than their phenolic precursors. Early metabolites from CGA appear at 1 -2 h after coffee intake, and have a short life time of approximately 30 min, 21,59 whereas DHCA and DHFA appear in the circulation 5 -10 h after consumption and their life time is between 0.7 and 2.1 h. 19 A longer circulation time of colonic metabolites, together their higher effect on platelet function, suggest that these colonic metabolites may be the main contributors to the beneficial effect of CGA-rich foods on human platelet function. The differences in efficacy could relate to their molecular structure.…”

“…20 In addition, plasma levels of 3,5-dicaffeoylquinic acid (3,5-DCQA) have been reported to be as high as 2.5 µM after the intake of a green coffee extract, 20 although most studies suggested the hydrolysis of 3,5-DCQA to monoacylquinic acid as the main biotransformation pathway. 18,19 Caffeic (CA) and ferulic (FA) acids are the main early metabolites,…”

“…These metabolites are found in plasma at levels up to 0.7 and 1 µM, respectively, 5 -10 h after intake of 400 mL of coffee containing approximately 600 mg CGA. 19 On the contrary, caffeine is quickly and completely absorbed in the small intestine and transported to the liver where it is metabolized into the dimethylxanthines paraxanthine, theobromine and theophylline, which are further metabolized to monomethylxanthines. 22 Previous studies have shown that plasma levels of caffeine can increase to 2 -12 µM, and theobromine can increase to 0.5 -16 µM, after intake of 9.9 -70 mg of caffeine and 0.2 -84 mg of theobromine, respectively, which are present in 3.5 g of coffee and 15 g of cocoa.…”