Enhancement of the UVA induction of haem oxygenase‐1 expression by β‐carotene in human skin fibroblasts

Abstract
Beta-Carotene has often been discussed as a means to reduce the risk of skin photodamage. We studied the antioxidative potential of beta-carotene in human skin fibroblasts exposed to ultraviolet A light. Surprisingly, we found a pro-oxidative effect of beta-carotene. Using the induction of haem oxygenase-1 as a marker for oxidative stress, we found a strong enhancement of gene expression by beta-carotene in ultraviolet A-irradiated cells. This effect was clearly suppressed by concomitant addition of vitamin E but only moderately by vitamin C. The results show that beta-carotene has pro-oxidative properties in human skin fibroblasts exposed to ultraviolet-A light.