Effects of oral Ginkgo biloba supplementation on cataract formation and oxidative stress occurring in lenses of rats exposed to total cranium radiotherapy.
OBJECTIVE
To determine the antioxidant role of Ginkgo biloba (GB) in preventing radiation-induced cataracts in the lens after total-cranium irradiation of rats with a single radiation dose of 5 Gy.


METHODS
Sprague-Dawley rats were randomly divided into three groups. Group 1 received neither GB nor irradiation (control group). Group 2 was exposed to total-cranium irradiation of 5 Gy in a single dose [radiation therapy (RT) Group], and group 3 received total cranium irradiation from a cobalt-60 teletherapy unit, plus 40 mg/kg per day GB (RT+GB group). At the end of the tenth day, the rats were killed and their eyes were enucleated to measure the antioxidant enzymes, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the lipid peroxidation level [malondialdehyde (MDA)].


RESULTS
Irradiation significantly increased both the MDA level and the activity of GSH-Px, and significantly decreased the activity of SOD in the rat lenses. GB supplementation significantly increased the activities of SOD and GSH-Px enzymes and significantly decreased the MDA level. Total cranium irradiation of 5 Gy in a single dose promoted cataract formation, and GB supplementation protected the lenses from radiation-induced cataracts.


CONCLUSIONS
We suggest that Ginkgo biloba is an antioxidant that protects the rat lens from radiation-induced cataracts.
Department of Radiation Oncology, Atatürk University, Faculty of Medicine, 25240 Erzurum, Turkey. mvertekin@hotmail.com.
Mustafa Vecdi
MV
Ertekin
Ibrahim
I
Koçer
Ihsan
I
Karslioğlu
Seyithan
S
Taysi
Akçahan
A
Gepdiremen
Orhan
O
Sezen
Ercan
E
Balci
Nuri
N
Bakan
D000284:Administration, Oral; D000818:Animals; D001921:Brain / Q000528:radiation effects*; D002386:Cataract / Q000201:enzymology / Q000209:etiology / Q000517:prevention & control*; D003037:Cobalt Radioisotopes; D005260:Female; D020441:Ginkgo biloba / Q000737:chemistry*; D005979:Glutathione Peroxidase / Q000378:metabolism; D007908:Lens, Crystalline / Q000201:enzymology / Q000528:radiation effects*; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use; D011833:Radiation Injuries, Experimental / Q000201:enzymology / Q000209:etiology / Q000517:prevention & control*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000378:metabolism
D003037:Cobalt Radioisotopes; D010936:Plant Extracts; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase