Bioavailability Is Improved by Enzymatic Modification of the Citrus Flavonoid Hesperidin in Humans: A Randomized, Double-Blind, Crossover Trial

Abstract

Hesperidin is the predominant polyphenol consumed from citrus fruits and juices. However, hesperidin is proposed to have limited bioavailability due to the rutinoside moiety attached to the flavonoid. The aim of this study was to demonstrate in human subjects that the removal of the rhamnose group to yield the corresponding flavonoid glucoside (i.e., hesperetin-7-glucoside) will improve the bioavailability of the aglycone hesperetin. Healthy volunteers (n=16) completed the double-blind, randomized, crossover study. Subjects randomly consumed hesperetin equivalents supplied as orange juice with natural hesperidin ("low dose"), orange juice treated with hesperidinase enzyme to yield hesperetin-7-glucoside, and orange juice fortified to obtain 3 times more hesperidin than naturally present ("high dose"). The area under the curve (AUC) for total plasma hesperetin of subjects consuming hesperetin-7-glucoside juice was 2-fold higher than that of subjects consuming the "low" dose hesperidin juice [3.45+/-1.27 vs. 1.16+/-0.52 mmol/(L.h), respectively, P>0.0001]. The AUC for hesperetin after consuming the hesperetin-7-glucoside juice was improved to the level of the "high" dose hesperidin juice [4.16+/-1.50 mmol/(L.h)]. The peak plasma concentrations (C(max)) of hesperetin were 4-fold higher (2.60+/-1.07 mmol/L, P<0.0001) after subjects consumed hesperetin-7-glucoside juice compared with those consuming "low" dose hesperidin juice (0.48 +/- 0.27 mmol/L), and 1.5-fold higher than those consuming "high" dose hesperidin juice (1.05+/-0.25 mmol/L). The corresponding T(max) was much faster (0.6+/-0.1 h, P<0.0001) after subjects consumed hesperetin-7-glucoside juice compared with "low" dose (7.0+/-3.0 h) and "high" dose (7.4+/-2.0 h) hesperidin juices. The results of this study demonstrated that the bioavailability of hesperidin was modulated by enzymatic conversion to hesperetin-7-glucoside, thus changing the absorption site from the colon to the small intestine. This may affect future interventions concerning the health benefits of citrus flavonoids.

Relative bioavailability of the flavonoids quercetin, hesperetin and naringenin given simultaneously through diet

“…Flavonoids in plasma were completely hydrolysed as described in Nielsen et al (2006). Plasma samples were added 25 ml aqueous ascorbic acid (20 mg/ml) and 0.5% formic acid to pH ¼ 4 and applied to Evolute ABN columns (25 mg, Mikrolab, Aarhus, Denmark).…”

“…The 'juice mix' was provided to fasting individuals in the morning, along with a standardized flavonoid-free diet (0-24 h), after which the individuals maintained a flavonoid-free diet (24-48 h). Blood and urine samples were collected as described previously (Nielsen et al, 2006). Flavonoid aglycones were quantified in the 'juice mix' (30 mg/l quercetin, 28 mg/l naringenin and 32 mg/l hesperetin) and flavonoid glycosides in the 'juice mix' were identified according to Breinholt et al (2003).…”

“…Blood and urine samples were collected as described previously (Nielsen et al, 2006). Flavonoid aglycones were quantified in the 'juice mix' (30 mg/l quercetin, 28 mg/l naringenin and 32 mg/l hesperetin) and flavonoid glycosides in the 'juice mix' were identified according to Breinholt et al (2003).Flavonoids in plasma were completely hydrolysed as described in Nielsen et al (2006). Plasma samples were added 25 ml aqueous ascorbic acid (20 mg/ml) and 0.5% formic acid to pH ¼ 4 and applied to Evolute ABN columns (25 mg, Mikrolab, Aarhus, Denmark).…”

“…Plasma samples were added 25 ml aqueous ascorbic acid (20 mg/ml) and 0.5% formic acid to pH ¼ 4 and applied to Evolute ABN columns (25 mg, Mikrolab, Aarhus, Denmark). The eluted flavonoid aglycones were evaporated to dryness and re-dissolved in 200 ml 0.5% formic acid and 10% methanol, and 250 ng 13 C-daidzein was added as external standard.Determination of flavonoids in urine is essentially described elsewhere (Nielsen et al, 2006), except for the inclusion of solid-phase extraction (Isolute SPE 100, Mikrolab) before injection into the liquid chromatographymass spectrometry system. Statistical analyses were performed using Wilcoxon matched pair tests (SPSS version 14.0).…”

The pleiotropic effects of fisetin and hesperetin on human acute promyelocytic leukemia cells are mediated through apoptosis, cell cycle arrest, and alterations in signaling networks

“…Hesperidin and hesperetin are the most important examples of these flavonones found in citrus fruits such as lemon and orange with a wide range of pharmacological properties including antioxidant, anti-inflammatory, and anticancer effects [13]. Hesperidin could be considered as a pro-drug, since it is metabolized to hesperetin before absorption [14]. Promising results derived from a noticeable body of evidence displayed that hesperetin could mediate its anticancer effects in several cancer types by affecting several cellular targets.…”