Alteration of lymphocyte subpopulations in mice fed lutein from marigold extract

Abstract

Lutein, a member of the xanthophyll carotenoids, has a wide variety of health benefits. These include prevention of age-related macular degeneration or cataracts and protection of ultraviolet -induced skin damage. Lutein also possesses anti-tumor and immune modulatory activities in BALB/c mice. However, in such animal model, the effects of lutein on lymphocyte subpopulations have not yet been assessed and were therefore determined in this study. Female BALB/c mice were fed orally with lutein from marigold extract (10 and 20 mg/kg body weight daily) or vehicle for 4 weeks. Total white blood cell counts and splenic lymphocyte subpopulations were examined on weeks 2 and 4. Lutein from marigold extract did not significantly influence the total numbers of white blood cells during the experimental period. Mice fed marigold lutein had comparable numbers of CD21/35+ (mature B), CD3+ (total T) and CD4+ (T helper) lymphocytes to controls as seen throughout a 4-week period. However, the percentage of CD8+ (T cytotoxic) cells were significantly elevated (p < 0.05) in mice fed marigold lutein 20 mg/kg (week 4) compared to the controls. Together, our results demonstrated that lutein from marigold extract influenced the population of cytotoxic T lymphocytes in BALB/c mice. This finding suggests the enhancement of cell-mediated immunity and may support, partly, anti-tumor activity of such lutein. Key words: Lutein, marigold, lymphocyte subpopulation.