Different suppressive effects of canthaxanthin and fucoxanthin on cellular responses of human dermal fibroblasts to ultraviolet A irradiation

Ultraviolet A (UVA) exposure is a major cause of skin damage and changes in the skin's appearance. UVA promotes the production of reactive oxygen species (ROS), which damages dermal fibroblasts. ROS also induce the expression of matrix metalloproteinase-1 (MMP-1), an enzyme that degrades collagen, leading to wrinkle formation. We focused on carotenoids, widely distributed natural antioxidants, to find candidate cytoprotective and anti-wrinkle agents. Canthaxanthin and fucoxanthin suppressed the UVA-induced decrease in cell viability. Fucoxanthin also suppressed ROS production; hence, this may be a molecular mechanism. In contrast, canthaxanthin significantly suppressed MMP-1 mRNA expression in UVA-irradiated fibroblasts without inhibiting ROS production. Subsequent analyses suggested that canthaxanthin could bind and inhibit p38 kinase activity by which it shows a cytoprotective effect and an inhibitory effect on MMP-1 mRNA expression. These 2 carotenoids may be potential agents for attenuating UVA-induced skin damage, and canthaxanthin may be a potential anti-wrinkle agent.