Central nervous system migration of astaxanthin and adonixanthin following their oral administration in cynomolgus monkeys

Abstract

Astaxanthin, which has been shown to have significant antioxidant activity, is rapidly spreading as a health functioning ingredient in the health food and cosmetics sec-tors worldwide. It is well known that astaxanthin acts on the brain; however, there is little evidence of brain translocation due to the difficulty in identifying astaxanthin in tissues. Therefore, in this study, we investigated the concentrations of astaxanthin and adonixan-thin, the latter being a biosynthetic intermediate from b-carotene to astaxanthin, in the brain after oral administration in primates. Cynomolgus monkeys were orally administered astaxanthin or adonixanthin at a dose of 50 mg/kg for 10 d, through a disposable catheter inserted into the stomach via the nasal passage. Following euthanization, the monkeys’ brains and various other organs were collected. The carotenoid content in serum and indi-vidual organs was analyzed by high-performance liquid chromatography. Adonixanthin was found to accumulate at a higher concentration than astaxanthin in monkey brain tis-sues. Also, both astaxanthin and adonixanthin were found to be distributed in the heart, spleen, liver, and kidneys. These findings indicate that astaxanthin and adonixanthin can enter the central nervous system of primates following their oral administration. This pro-vides important evidence for the activity of astaxanthin and adonixanthin on the central nervous system.