Plasma kinetics of zeaxanthin and 3′-dehydro-lutein after multiple oral doses of synthetic zeaxanthin

Abstract

Long-term oral intake of 1 and 10 mg zeaxanthin as beadlets increases plasma zeaxanthin concentrations approximately 4- and 20-fold, respectively. Evidence that all-E-3-dehydro-lutein is formed from zeaxanthin was strong.

Metabolism of lutein and zeaxanthin in rhesus monkeys: Identification of (3R,6′R)- and (3R,6′S)-3′-dehydro-lutein as common metabolites and comparison to humans

“…Thurman et al have also shown this to occur in humans (Thurmann et al, 2005). However, our study is unique in that this conversion was measured without the interference of 3′-dehydro-lutein possibly formed from zeaxanthin (Hartmann et al, 2004). …”

“…The residue was re-dissolved in100 μL hexane and sonicated for 30 s. A 50 μL aliquot was injected into the HPLC system equipped with an HPLC pump (Waters, 616), an autosampler (Waters, 717 plus, 13°C) and a Photodiode Array Detector (Waters, 996). Carotenoids were quantified using a normal-phase, isocratic HPLC system, as previously described (Hartmann et al, 2004) using a polar column (Lichrosorb, Si-60, 5 μm, 250 × 4 mm; Phenomenex, Torrance, CA, USA) with minor modifications. For optimal separation of lutein and zeaxanthin, the mobile phase ratio hexane (Sigma-Aldrich Chemicals, St. Louis, MO, UAS) to acetone (Sigma, 99.9 % water free) was modified to 85:15 (v/v) at a flow rate of 1 mL/min.…”

“…The separation of (3R,6′S)-and (3R,6′R)-3′-dehydro-lutein, lutein and zeaxanthin on chiral-phase HPLC in comparison to normal-phase (Si-60) HPLC is shown in Figure 4. We first applied this chiral-phase separation successfully to the analysis of 3′-dehydro-lutein in human plasma (Höller et al, 2005) out of the LUXEA-study Hartmann et al, 2004;Thurmann et al, 2005). In the recent work, we coupled the chiral separation to HR-MS detection, which enabled us to establish the exact molecular masses of the carotenoids in the chromatograms investigated.…”

“…Recent studies have reported the identification of 3′-dehydro-lutein (in some literature also referred to as 3′-oxolutein or 3′-ketolutein) in human serum after supplementation with either lutein or zeaxanthin at doses ranging from 1-20.5 mg/d for 42 days (Hartmann et al, 2004;Thurmann et al, 2005). It seemed likely that, in course of the metabolic oxidation of lutein or zeaxanthin, two diastereomers of 3′-dehydro-lutein with opposite configuration at C-6′, namely (3R,6′R)-3′-dehydro-lutein and (3R,6′S)-3′-dehydro-lutein respectively could be formed.…”

“…It seemed likely that, in course of the metabolic oxidation of lutein or zeaxanthin, two diastereomers of 3′-dehydro-lutein with opposite configuration at C-6′, namely (3R,6′R)-3′-dehydro-lutein and (3R,6′S)-3′-dehydro-lutein respectively could be formed. However, chiral analysis of 3′-dehydro-lutein extracted from human serum after supplementation with either lutein or zeaxanthin (Hartmann et al, 2004;Thurmann et al, 2005) indicated that the two diastereomers (3R,6′R)-3′-dehydro-lutein and (3R,6′S)-3′-dehydro-lutein are formed independently when lutein or zeaxanthin was supplemented (Höller et al, 2005). While more 3′-dehydro-lutein was formed during supplementation of humans with zeaxanthin than with lutein, both stereoisomers always occurred in approximately equimolar concentrations.…”