UVA photoprotective properties of an artificial carotenylflavonoid hybrid molecule.

Carotenoids and flavonoids represent two classes of natural antioxidants, a biological activity, which is determined by their chemical structure. To combine their antioxidant properties, a dual functional carotenylflavonoid hybrid molecule was synthesized. The antioxidant activity of this compound was tested in human dermal fibroblasts exposed to UVA irradiation. Test parameters were hemeoxygenase-1 (HO-1) expression, malondialdehyde (MDA), and reactive oxygen species (ROS) formation and cell viability. For comparison, the substructure components of the carotenylflavonoid, 4-hydroxyflavone and 11′-apo-β-carotenylbenzene, were also tested. Incubation of cells with the carotenylflavonoid and 11′-apo-β-carotenylbenzene attenuated UVA-induced HO-1 expression. In the MDA assay, the carotenylflavonoid and 11′-apo-β-carotenylbenzene were moderately effective at low concentrations. At higher concentrations, the compound provoked an increase of MDA, which was confirmed by the H2DCF-DA assay measuring ROS formation...