INVESTIGADORES
GONZALEZ MAGLIO Daniel Horacio
congresos y reuniones científicas
Título:
Effect of cyclooxygenase inhibition on acute ultraviolet B irradiated mice skin
Autor/es:
GONZALEZ MAGLIO DANIEL H.; PAZ MARIELA LAURA; FERRARI ALEJANDRO; NIETO JORGE D.; LEONI JULIANA
Lugar:
St. Louis, Missouri, USA
Reunión:
Congreso; 66th SID Annual Meeting; 2005
Institución organizadora:
Society for Investigative Dermatology
Resumen:
In the present study we examined the effect of the
topical application of a non steroid anti-inflammatory drug (naproxen) on the
epidermal damage after an acute dose of ultraviolet B (UVB) radiation. We
evaluated the expression of cyclooxygenases (COX) 1 and 2 and the inducible
nitric oxide synthase (iNOS), as well as prostaglandin E2 (PGE2)
synthesis and histological alterations.
Female SKH-1 hairless mice were divided into 4 groups according to the
treatment: 1, non irradiated control; 2, irradiated; 3, irradiated plus
naproxen (0 hours post UVB); 4, irradiated plus naproxen (6 hours post UVB).
Mice were irradiated with a dose of 200 mJ/cm2 and sacrificed 24
hours later to remove dorsal skin. One fraction was processed for histological
analysis and the rest was treated to scrape the epidermis in order to make
homogenates. The expression of the enzymes was studied by western blot and the
PGE2 levels were assessed by ELISA. To perform the histological
analysis 15 m skin sections were fixed in p-formaldehyde and stained with
hematoxilin-eosin. The epidermal integrity features as well as the number of
sun burn cells were evaluated performing an histological blind assay.
The results show that the epidermal expression of COX-1 and COX-2 are not
affected in any of the studied conditions whereas the level of their product,
PGE2, is significantly decreased in groups 3 and 4 compared with
groups 1 and 2 (19.5 and 10.9 vs 328.6 and 1032.9 g/mg of protein). iNOS
expression is clearly suppressed by naproxen as shown by the results, expressed
as ratios relative to the control group; the values are from group 1 to 4
respectively: 1, 2.49,1.63 and 0.77. The naproxen treatment produces a slight
improvement in the epidermal integrity features, but it does not affect the
number of epidermal sun burn cells.
Topical application of naproxen reduces epidermal damage after UVB irradiation,
since it decreases the levels of inflammatory-related molecules like PGE2
and iNOS.