[Effect of extract of Ginkgo biloba leaves on expression of inducible nitric oxide synthase after sciatic nerve injury: experiment with rats].
OBJECTIVE
To investigate the effect of extract of Ginkgo biloba leaves (EGb50) on the expression of inducible nitric oxide synthase (iNOS) after sciatic nerve injury.


METHODS
156 male SD rats were randomly divided into 3 groups: experiment group (n=72), undergoing section and anastomosis of sciatic nerve and then gastric perfusion of EGb50 200 mg.kg-1.d-1; injury control group (n=72), undergoing section and anastomosis of sciatic nerve and then gastric perfusion of normal saline daily; and sham operation group (n=12), undergoing sham operation and gastric perfusion of normal saline daily. The rats were killed at different time points: 1, 3, 7, 14, 21, and 28 days after the operation. The sciatic nerve distant to the anastomotic sites with a length of 0.5 cm was cut out to undergo immunohistochemistry and RT-PCR to detect the protein and mRNA expression of iNOS.


RESULTS
No obvious iNOS protein and mRNA expression was seen in the sham operation group. 3, 7, 14, and 21 days after operation the mean values of absorbance of iNOS in the sciatic nerve specimens of the experiment group were all significantly lower than those of the injury control group (P<0.05, P<0.01). High mRNA expression of iNOS began to be shown in the sciatic nerve specimens since 1day after the operation and remained at a high level till 7 days after and then began to decrease in the injury control group. The levels of mRNA expression of iNOS in the sciatic nerve specimens 1, 3, and 7 days after the operation of the experiment group were all significantly lower than those of the injury control group (all P<0.01), and there was no significant difference in the levels mRNA expression of iNOS 14, 21, and 28 days after the operation between the experiment group and injury control group (all>0.05).


CONCLUSIONS
The extract of Gingko biloba promotes the regeneration of nervous tissues, probably by inhibiting the expression of iNOS.
Lin
Hao-dong
HD
Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai 200040, China.
Wang
Huan
H
Chen
De-song
DS
Li
Ji-feng
JF
Gu
Yu-dong
YD
D000818:Animals; D046935:Bilobalides / Q000494:pharmacology; D020441:Ginkgo biloba / Q000737:chemistry*; D007150:Immunohistochemistry; D008297:Male; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis* / Q000235:genetics; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012584:Sciatic Nerve / Q000187:drug effects* / Q000293:injuries / Q000378:metabolism
D046935:Bilobalides; D010936:Plant Extracts; D012333:RNA, Messenger; D052247:Nitric Oxide Synthase Type II