Photo-excitation of carotenoids causes cytotoxicity via singlet oxygen production.
Biochem Biophys Res Commun
; 417(1): 640-5, 2012 Jan 06.
Article
en En
| MEDLINE
| ID: mdl-22185691
ABSTRACT
Carotenoids, natural pigments widely distributed in algae and plants, have a conjugated double bond system. Their excitation energies are correlated with conjugation length. We hypothesized that carotenoids whose energy states are above the singlet excited state of oxygen (singlet oxygen) would possess photosensitizing properties. Here, we demonstrated that human skin melanoma (A375) cells are damaged through the photo-excitation of several carotenoids (neoxanthin, fucoxanthin and siphonaxanthin). In contrast, photo-excitation of carotenoids that possess energy states below that of singlet oxygen, such as ß-carotene, lutein, loroxanthin and violaxanthin, did not enhance cell death. Production of reactive oxygen species (ROS) by photo-excited fucoxanthin or neoxanthin was confirmed using a reporter assay for ROS production with HeLa Hyper cells, which express a fluorescent indicator protein for intracellular ROS. Fucoxanthin and neoxanthin also showed high cellular penetration and retention. Electron spin resonance spectra using 2,2,6,6-tetramethil-4-piperidone as a singlet oxygen trapping agent demonstrated that singlet oxygen was produced via energy transfer from photo-excited fucoxanthin to oxygen molecules. These results suggest that carotenoids such as fucoxanthin, which are capable of singlet oxygen production through photo-excitation and show good penetration and retention in target cells, are useful as photosensitizers in photodynamic therapy for skin disease.
Texto completo:
1
Colección:
01-internacional
Asunto principal:
Carotenoides
/
Fármacos Fotosensibilizantes
/
Oxígeno Singlete
/
Xantófilas
/
Fármacos Dermatológicos
Tipo de estudio:
Etiology_studies
Límite:
Humans
Idioma:
En
Revista:
Biochem Biophys Res Commun
Año:
2012
Tipo del documento:
Article
País de afiliación:
Japón