Dietary Lutein Reduces Ultraviolet Radiation-Induced Inflammation and Immunosuppression
Ultraviolet radiation (UVR) promotes skin cancer development by mutagenic, immunosuppressive, and oxidative-stress-inducing mechanisms; however, certain antioxidants may counteract and prevent UVR-induced photodamage. Lutein is a xanthophyll carotenoid with potent antioxidant activity. Because reactive oxygen species (ROS) are believed to have a role in UVR-induced skin damage, we investigated whether lutein can modify UVR effects including the tissue swelling response to midrange UVR (280-320 nm, ultraviolet B (UVB) radiation) and UVB suppression of contact hypersensitivity (CHS) in both the local and the systemic models of UV-induced immunosuppression. We found that compared to mice fed the standard laboratory diet, mice fed dietary lutein demonstrated significant inhibition of ear swelling owing to UVB radiation. Mice exposed to 1700 J per m2 UVB radiation four times at daily intervals and then sensitized to dinitrofluorobenzene at the site of irradiation showed a decreased CHS response upon challenge. This suppression by UVB radiation was significantly inhibited by lutein feeding. When UVB radiation was given at a single dose of 10,000 J per m2 to inhibit the induction of CHS at a distant, nonirradiated site, no effect of lutein was seen. Finally, lutein accumulated in the skin of mice following diet supplementation and was shown to decrease ROS generation following UVR exposure. Thus, lutein modulates the skin's response to UVR and may contribute to the defense against some of the deleterious effects of solar radiation.