¹³C-lutein is differentially distributed in tissues of an adult female rhesus macaque following a single oral administration: a pilot study

Despite the growing awareness regarding lutein's putative roles in eyes and brain, its pharmacokinetics and tissue distribution in primates have been poorly understood. We hypothesized that ¹³C-lutein will be differentially distributed into tissues of an adult rhesus macaque (Macaca mulatta) 3 days following a single oral dose. After a year of prefeeding a diet supplemented with unlabeled lutein (1 μmol/kg/d), a 19-year-old female was dosed with 1.92 mg of highly enriched ¹³C-lutein. Tissues of a nondosed, lutein-fed monkey were used as a reference for natural abundance of ¹³C-lutein. On the third day postdose, plasma and multiple tissues were collected. Lutein was quantified by high-performance liquid chromatography–photodiode array detector, and ¹³C-lutein tissue enrichment was determined by liquid chromatography quadrupole time-of-flight mass spectrometry. In the tissues of a reference monkey, ¹²C-lutein with natural abundance of ¹³C-lutein was detectable. In the dosed monkey, highly enriched ¹³C-lutein was observed in all analyzed tissues except for the macular and peripheral retina, with the highest concentrations in the liver followed by the adrenal gland and plasma. ¹³C-lutein accumulated differentially across 6 brain regions. In adipose depots, ¹³C-lutein was observed, with the highest concentrations in the axillary brown adipose tissues. In summary, we evaluated ¹³C-lutein tissue distribution in a nonhuman primate following a single dose of isotopically labeled lutein. These results show that tissue distribution 3 days following a dose of lutein varied substantially dependent on tissue type.