Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin

Retinal lipofuscin which accumulates with age in the retinal pigment epithelium (RPE) is subjected to daily exposures high fluxes of visible light and exhibits potent photosensitising properties; however, molecules responsible for its photoreactivity remain unknown. Here, we demonstrate that autooxidation docosahexaenoate (DHE) leads formation products absorbing, addition UVB UVA light, also light. The DHE oxidation exhibit properties similar lipofuscin, including generation an excited triplet state characteristics as state, photosensitised singlet oxygen superoxide. quantum yields superoxide by oxidised photoexcited are 2.4- 3.6-fold higher, respectively, than consistent fact contains some chromophores do contribute absorption but not so much properties. Importantly, wavelength dependence photooxidation induced normalised equal numbers incident photons lipofuscin—it steeply increases decreasing wavelength. Altogether, our results include photosensitiser(s) likely photoreactivity.