Chlorogenic Acid Bioavailability Largely Depends on Its Metabolism by the Gut Microflora in Rats

Abstract

Chlorogenic acid, the ester of caffeic acid with quinic acid, is one of the most abundant polyphenols in the human diet with coffee, fruits and vegetables as its major sources. Its antioxidant and anticarcinogenic properties have been well established in animal studies. However, little is known about its gut absorption and metabolism. In the present work, four groups of rats (n = 8) were fed a diet supplemented with chlorogenic, caffeic or quinic acids (250 micromol/d) or an unsupplemented diet for 8 d. Parent compounds and their metabolites were estimated in urine (24-h collection) and plasma by HPLC-electrospray ionization-tandem mass spectrometry. Significant differences in their levels were observed among the groups. The recovery of chlorogenic acid in urine was low (0.8%, mol/mol), and the total urinary excretion of caffeic acid liberated by hydrolysis of chlorogenic acid and its tissular methylated metabolites (ferulic and isoferulic acids) did not account for >0.5% (mol/mol) of the dose ingested. On the other hand, the metabolites of microbial origin, namely, m-coumaric acid and derivatives of phenylpropionic, benzoic and hippuric acids, represented the major compounds in both urine and plasma. Hippuric acid largely originated from the transformation of the quinic acid moiety, and all other metabolites from the caffeic acid moiety. These microbial metabolites accounted for 57.4% (mol/mol) of the chlorogenic acid intake. Such a high abundance of microbial metabolites shows that the bioavailability of chlorogenic acid depends largely on its metabolism by the gut microflora. Their potential importance in explaining the biological effects of dietary polyphenols is emphasized.

Urinary excretion of 13 dietary flavonoids and phenolic acids in free-living healthy subjects – variability and possible use as biomarkers of polyphenol intake

“…Strongest correlations are explained by metabolic filiations such as for chlorogenic acid and caffeic acid (hydrolysis) (Gonthier et al, 2003), gallic acid and 4-O-methylgallic acid, quercetin and isorhamnetin (methylation), enterolactone and enterodiol (hydrolysis and reduction) (Borriello et al, 1985). We also reported in a previous study the excretion of phloretin after consumption of citrus juice and suggested that phloretin is a metabolite of naringenin formed by reductive opening of the heterocycle (Ito et al, 2005).…”

“…This explains the high correlation observed here between these two compounds. mCoumaric acid is also weakly correlated to caffeic acid and is formed by microbial dehydroxylation of the latter in the colon (Gonthier et al, 2003).…”

Commercial spices and industrial ingredients: evaluation of antioxidant capacity and flavonoids content for functional foods development

“…Some researchers affirm that chlorogenic acid is the most common phenolic compound in food and its main sources are fruits, coffee, vegetables, cereals and spices (GONTHIER et al, 2003;CLIFFORD, 1999). In this work, spices were screened for the presence of hydroxycinnamic acids, but these polyphenols were detected only in basil, chives, oregano and rosemary.…”

Biochemical Characteristics, Antimicrobial and Mutagenic Activity in Organically and Conventionally Produced Malus domestica, Annurca

“…Furthermore, the good percentage of p-coumaric acid found in the organically and conventionally produced Annurca could be significant since this biomolecule has received a lot of attention in the recent years for its anti inflammatory in vivo properties [23]. Moreover, the high level of chlorogenic acid, observed mainly in organic fruits is of great meaning as in vivo studies have demonstrated the antioxidant and anticarcinogenic properties of this biomolecule, in general inefficiently absorbed in small intestine, but capable of providing higher yields of microbial metabolites, active compounds responsible for the biological properties attributed to dietary polyphenols [24][25]. The characterization of conventional and organic apple aimed at the identification of compounds developed by plant tissues as part of their defence mechanism was carried out by Lucarini et al [26], which indicated higher levels of both polyphenols and specific phenolic acids, as p-coumaric and caffeic acid, in organically than in conventionally produced apples.…”