An explorative study of non-invasive ultra-weak photon emission and the anti-oxidative influence of oral zinc sulphate in light-sensitive patients with erythropoietic protoporphyria.
_http://www.ncbi.nlm.nih.gov/pubmed/22092997
Skin Res Technol. 2012 Nov;18(4):405-12. doi: 10.1111/j.1600-0846.2011.00586.x. Epub 2011 Nov 16.
An explorative study of non-invasive ultra-weak photon emission and the anti-oxidative influence of oral zinc sulphate in light-sensitive patients with erythropoietic protoporphyria.
Petersen AB, Philipsen PA, Wulf HC.
Source
Department of Dermatology, Copenhagen University Hospital, Bispebjerg Hospital, Copenhagen, Denmark.
Abstract
BACKGROUND:
Erythropoietic protoporphyria (EPP) is a rare, inherited disorder of haem biosynthesis owing to deficient ferrochelatase (FECH) and accumulation of protoporphyrin IX (PPIX). This results in acute cutaneous photosensitivity upon light exposure with production of reactive oxygen species (ROS) and ultra-weak photon emission (UPE) as a by-product. We investigated if UPE evaluated the light sensitivity in EPP patients and influence of zinc treatment.
METHODS:
Fourteen EPP patients took zinc sulphate (3 × 200 mg/day) during spring and summer. Using a photomultiplier (PM), UPE was measured from the buttock skin and dorsal hand before and after solar-simulated light (SUN) exposure. Blood samples were analysed routinely for plasma zinc, iron, ferritin, transferrin, haemoglobin, erythrocyte PPIX and Zn-PPIX.
RESULTS:
UPE in EPP patients resembled that seen in healthy individuals. Without treatment, a seasonal decrease was seen from spring to summer in four control patients. However, oral zinc treatment reduced ROS formation significantly regardless of SUN exposure. After SUN exposure, the initial burst was correlated to plasma iron and erythrocyte PPIX. During treatment, an inverse correlation was found between plasma zinc concentration and the initial burst.
CONCLUSION:
Measurements of UPE can be used for monitoring UVA-induced oxidative processes in vivo in the skin of EPP patients.
Of relevance within the paper:
Besides
its roles in metalloenzymes, zinc functions
as an antioxidant and is a structural component
of membranes (17). Zinc has the capacity
to replace transition metals (Fe,Cu)
from binding sites, which prevents the local
redox-cycling of the metals, the concomitant
production of ROS and the oxidation of macromolecules
in the vicinity (18). Therefore, oral
zinc treatment could potentially reduce the
symptoms of light sensitivity by competing
with iron and acting as an antioxidant; and
thereby contribute to minimise ROS production
and phototoxicity.
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