PREVENTION OF UV IRRADIATION INDUCED SUPPRESSION OF MONOCYTE FUNCTIONS BY RETINOIDS AND CAROTENOIDS in vitro

Abstract— The effects of stimulation of human peripheral blood monocytes in vitro with retinoids and carotenoids, and subsequent exposure to ultraviolet light of the B wavelength were measured. The compounds were applied to the monocytes in culture for 24 h, and the washed cells were then exposed to UVB light up to 220 J/m². The compounds tested protected the monocyte from UVB induced damage to phagocytic activity. This protection may be due to the antioxidant or UVB energy‐quenching properties of these compounds. Monocyte cytotoxicity against a melanoma cell line was stimulated by exposure to the retinoids or carotenoids, but a protective effect in vitro against UVB damage was not seen for this cell function.