ABSTRACT
Objective To compare the effect of natural antioxidants TA9001 and EGb761 on c-jun, NOS expression and survival of spinal motoneurons following brachial roots avulsion. Methods One hundred and eighty adult Sprague-Dawley female rats were randomly divided into TA9001, ECb761 and control groups. The right C 5～T 1 nerve roots were avulsed and then the introperitoneal injection of 1ml of 0.5% TA9001, 0.5% EGb761 or normal saline was given immediately and once daily to the rats, respectively. The rats were killed after survival for 4 h, 12 h 1 d,3 d,5 d,and 1 week, 2 weeks, 4 weeks and 6 weeks. The cryostat sections of C 7 segment were prepared and carried with c-jun immunocytochemistry, NADPH-d histochemistry and neutral red counter stain. Results The c-jun and nNOS gene expression was only appeared in injured motoneurons. c-jun was first appeared at 4 h, reached its maximum at 1 d, and grandually decreased till 2 weeks. NOS was first checked at 5 d, mostly at 2 weeks and decreased until 6 weeks. Avulsed motoneuron death started at 2 weeks, reached its peak at 4～6 weeks. Both TA9001 and EGb761 can cause c-jun up-regulation, nNOS down-regulation and more motoneuron survival as compared to control. Furthermore, EGb761 had more power to enhance c-jun expression than TA9901 at each time point. Conclusion It seems that nNOS is more important in motoneuron death mechanism than c-jun. Treatment of either TA9901 or EGb761 can protect the injured motoneurons following root avulsion.