Abstract:

Objective To investigate the repairing effect of ursolic acid extracted from Hippophae rhamnoides L. on sciatic nerve injury in rats. Methods After preparing a sciatic nerve damage model， thirty 2-month old Wistar rats were randomly divided into ursolic acid and control groups， with 15 rats in each group. Ursolic acid group was given Ursolic acid 150 mg/（kg·d） by gavage， while the control group was given the same dose of normal saline for 6 weeks. After 6 weeks， H&E staining was used to observe the pathological changes of rat sciatic nerves， and SFI and MNCV were calculated； The expression of NGF in sciatic nerve was detected by immunohistochemistry， and the expression of GAP-43 in L4-L6 spinal cord was detected by Western blotting. Results After 6 weeks， compared to the control group， the number of regenerated nerve fibers in the ursolic acid group increased， the arrangement was slightly regular， the capillary structure was abundant， and the proliferation of fibroblasts decreased； SFI and MNCV% were significantly increased （P < 0.05）， NGF protein positive expression was significantly increased （P < 0.05）， and the difference was statistically significant （P < 0.05）. GAP-43 protein expression in sciatic nerve tissue was significantly increased （P < 0.05）. Conclusions The intervention of ursolic acid extracted from Hippophae rhamnoides L. can improve the function of rats after sciatic nerve injury， promote the increase of regenerated nerve fibers and the repair of myelin sheath in rats with sciatic nerve injury， which may be related to increased NGF and GAP-43 protein expression in rats.

Key words: ursolic acid extracted from Hippophae rhamnoides L., rats, sciatic nerve, injury, repair effect