Abstract
Abstract: :
Purpose: Lutein (L) and zeaxanthin (Z) physiologically occur in the retina and are concentrated in the yellow spot (macula lutea) of primate retina, where they are thought to have a protective effect against damage by energy-rich blue light. Thus both carotenoids may potentially contribute to risk reduction of age-related macula degeneration and regular intake by diet or long-term supplementation is recommended. The goal of this study was to assess chronic toxicity of lutein and zeaxanthin in primates with special emphasis on the eye. Methods: A 52 week oral toxicity study was conducted in Cynomolgus monkeys with L or Z as a 10% beadlet formulation at dose levels of 0 (placebo), 0.2 and 20 mg/kg/day. A comprehensive examination of the eyes was performed that included ophthalmoscopy and biomicroscopy examinations, fundus photography, and electroretinography (ERG). Post mortem examinations of the retina of the right eye included macroscopic inspection, microscopic pathology under polarized and bright light, for peripheral retina and macula, confocal microscopy of macula, and histopathological examination of the peripheral retina. A determination of lutein and zeaxanthin in retina and lens of the left eye was performed by HPLC. Results: Long-term administration resulted in dose-dependent increase of L and Z in plasma, liver, macula and peripheral retina. There was no clinical or morphological evidence for treatment-related adverse changes, specifically no crystal formation in the eyes of the monkeys during or after 52 weeks treatment with Z or L. Conclusion: Oral (gavage) administration of L and Z in Cynomolgus monkeys at dose levels of 0.2 and 20 mg/kg/day for 52 weeks did not induce toxic effects evident by clinical investigations parameters, necropsy and histopathology.
Keywords: 462 macular pigment • 308 age-related macular degeneration • 316 animal model