Photoprotection by carotenoids.

Carotenoid pigments have been found to have a protective function against photosensitization in green plants. This protective ability has been exploited in the administration of high doses of beta-carotene to patients with erythropoietic protoporphyria to ameliorate the photosensitivity associated with this disease. The carotenoids seem to exert their light-protective function by quenching excited species such as singlet oxygen and free radicals.