Bioavailability in humans of the flavanones hesperidin and narirutin after the ingestion of two doses of orange juice.
OBJECTIVE
Flavanones are polyphenols specific of citrus fruits, where they are present in high amounts. Although citrus fruits and juices are widely consumed in the world, little information has been published on flavanone bioavailability in humans. The aim of the present study was to determine the nature of the circulating metabolites, the plasma kinetics and the urinary excretion patterns of the flavanones, hesperidin and narirutin.


METHODS
After an overnight fast, five healthy volunteers ingested 0.5 or 1 l of a commercial orange juice providing 444 mg/l hesperidin and 96.4 mg/l narirutin, together with a polyphenol-free breakfast. Blood was sampled at 10 different timepoints over a 24 h period. Urine was collected for 48 h, in five fractions.


RESULTS
Flavanones metabolites appeared in plasma 3 h after the juice ingestion, reached a peak between 5 and 7 h, then returned to baseline at 24 h. The peak plasma concentration of hesperetin was 0.46+/-0.07 micro mol/l and 1.28+/-0.13 micro mol/l after the 0.5 and 1 l intake, respectively. It was lower for naringenin: 0.20+/-0.04 micro mol/l after the 1 l dose. The circulating forms of hesperetin were glucuronides (87%) and sulphoglucuronides (13%). For both flavanones, the urinary excretion was nearly complete 24 h after the orange juice ingestion. The relative urinary excretion was similar for hesperetin and naringenin and did not depend on the dose: values ranged from 4.1+/-1.2 to 7.9+/-1.7% of the intake.


CONCLUSIONS
In case of a moderate or high consumption of orange juice, flavanones may represent an important part of the pool of total polyphenols present in plasma.
Manach
C
C
Unité des Maladies Métaboliques et Micronutriments, INRA Clermont-Theix, St-Genès Champanelle, France. manach@clermont.inra.fr
Morand
C
C
Gil-Izquierdo
A
A
Bouteloup-Demange
C
C
Rémésy
C
C
D000328:Adult; D001628:Beverages; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D002957:Citrus; D004305:Dose-Response Relationship, Drug; D044950:Flavanones; D005419:Flavonoids / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D006569:Hesperidin / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D006801:Humans; D008297:Male; D012016:Reference Values; D013997:Time Factors
D044950:Flavanones; D005419:Flavonoids; D006569:Hesperidin; C005273:naringenin