The protective effects of Ginkgo biloba extract (EGb-761) on radiation-induced dermatitis: an experimental study.
BACKGROUND
Irradiation of the skin induces production of free radicals, resulting in oxidative stress. EGb-761, an extract from the leaves of the Ginkgo biloba tree, has been reported to be an effective exogenous antioxidant based on its free-radical scavenger properties.


OBJECTIVE
To investigate the protective effect of G. biloba extract (EGb-761) on radiation-induced dermatitis in rats.


METHODS
Forty male Wistar rats were divided equally into four groups: group 1 received sham radiotherapy (RT) without EGb-761, group 2 received sham RT with EGb-761, group 3 received RT without EGb-761, and group 4 received RT with EGb-761. Levels of malondialdehyde (MDA), nitric oxide (NOx) and glutathione (GSH) were measured. Dermatitis was assessed with a semiquantitative dermatitis item score. The intensity of staining and diffusion of expression for proliferating cellular nuclear antigen (PCNA) and transforming growth factor (TGF)-β3 were also evaluated.


RESULTS
The enhanced oxidative stress seen after RT was markedly diminished when EGb-761 was administered with RT; significantly lower mean MDA (P < 0.005) and higher mean GSH (P < 0.001) levels were seen in group 4 compared with group 3. Although there was a decrease in NOx levels, this was not significant. All (100%) of the animals in group 3 developed dermatitis, whereas only 13% of the animals in group 4 did so (P < 0.0001). There was a significant difference between group 1 and group 3 in PCNA and TGF-β3 staining (P < 0.05), whereas no difference was seen between groups 3 and 4; however, the intensity of staining and diffusion of expression were lower in group 4 than in group 3.


CONCLUSIONS
Prophylactic administration of EGb-761 seems to have a protective effect against radiation-induced dermatitis.
Department of Radiation Oncology, Gazi University Faculty of Medicine, Ankara, Turkey. eda.yirmibesoglu@kocaeli.edu.tr
E
E
Yirmibesoglu
E
E
Karahacioglu
D
D
Kilic
N
N
Lortlar
G
G
Akbulut
S
S
Omeroglu
D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D004195:Disease Models, Animal; D020441:Ginkgo biloba; D005978:Glutathione / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D011855:Radiodermatitis / Q000378:metabolism / Q000517:prevention & control*; D051381:Rats; D017208:Rats, Wistar; D000096983:Ginkgo Extract
D000975:Antioxidants; D005978:Glutathione; D008315:Malondialdehyde; D009569:Nitric Oxide; D010936:Plant Extracts; C063170:Ginkgo biloba extract; D000096983:Ginkgo Extract