Generation of the
reactive oxygen species (ROS) in skin by exposure to ultraviolet (UV) radiation induces a number of cutaneous pathologies such as
skin cancer,
photosensitization, and photoaging among others. Skin
iron catalyzes UV generation of ROS. Topical application of
iron chelators reduces
erythema, epidermal and dermal
hypertrophy, wrinkle formation, tumour appearance. It has been proposed that
iron chelators can be useful agents against damaging effects of both short- and long-term UV exposure. A better understanding of the action mechanisms of
iron chelators, might be useful to developing effective anticancer and antiphotoaging cosmetic products.
Iron chelators may lead to accumulation of
protoporphyrin IX (
PpIX), a strong
photosensitizer. The action of
iron chelators in skin, related to
PpIX increase has not yet been thoroughly studied. Therefore, we have investigated the formation of
PpIX in normal mouse skin after topical application of creams containing
metal chelators. The amount and distribution of
porphyrins formed was determined by means of non-invasive fluorescence spectroscopy.
Deferoxamine (DF),
ethylenediaminetetraacetic acid (
EDTA),
1,2-diethyl-3-hydroxypyridin-4-one (
CP94), but not meso-2,3-dimercaptosuccinic
acid (
DMSA), caused increased accumulation of endogenous
porphyrins in the skin. Fluorescence excitation and emission spectroscopy confirmed that
PpIX was the main fluorescent species. The amount of
PpIX accumulated in skin under the present conditions was not large enough to produce any significant
erythema after light exposure. Further studies are needed to evaluate the role of
PpIX induced by
iron chelators used, against photoaging and
cancer prevention.