Effect of salviae miltiorrhizae and ligustrazine hydrochloride injection on axonal regeneration and nerve growth factor expression in a rat model of sciatic nerve injury

摘要

BACKGROUND: Studies have shown that both salviae miltiorrhizae and ligustrazine can promoteprotein expression of nerve growth factor (NGF) and regeneration of peripheral nerve.OBJECTIVE: To verify the effect of salviae miltiorrhizae and ligustrazine hydrochloride injection onaxonal regeneration and NGF protein expression in a rat model of sciatic nerve injury.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at theLaboratory of Traditional Chinese Medicine and the Institute of Bioengineering of Jinan Universityfrom July to December 2008.MATERIALS: Salviae miltiorrhizae and ligustrazine hydrochloride injection (containing 20 mgsalviae miltiorrhizae and 100 mg ligustrazine per 100 mL injection) was provided by Guizhou BaitePharmaceutical, China; salviae miltiorrhizae and ligustrazine decoctions (containing 1 g raw drugper 1 mL decoction) were provided by Guangzhou Baiyunshan Factory for Traditional ChineseMedicine, China; rabbit-anti-rat NGF monoclonal antibody was provided by Beijing BiosynthesisBiotechnology, China.METHODS: A total of 80 healthy, male, Sprague Dawley rats were used to establish a sciatic nerveinjury model via neurotomy, and were then randomly assigned to 4 groups: salviae miltiorrhizae andligustrazine hydrochloride injection group (intraperitoneal injection of 35 mL/kg per day salviaemiltiorrhizae and ligustrazine hydrochloride injection), salviae miltiorrhizae group (intragastricperfusion of 2 mL salviae miltiorrhizae), ligustrazine group (intragastric perfusion of 2 mLligustrazine), and model group (intraperitoneal injection of 35 mL/kg per day saline), with 20 rats ineach group. Thereafter, rats in each group were then divided into 4 subgroups according to varyingtime points of 1,2, 4, and 8 weeks post-surgery, with 5 rats in each subgroup.MAIN OUTCOME MEASURES: Axons were quantified using chromotrope 2R-brilliant green andsilver staining combined with image analysis to calculate the axonal regeneration rate; NGFexpression was detected using immunohistochemistry and Western blot analysis; toe interspacewas measured by behavior at 4 and 8 weeks.RESULTS: With increasing time after sciatic nerve injury, the axonal regeneration rate, NGF proteinexpression, and toe interspace gradually increased. At 4 and 8 weeks post-surgery, axonalregeneration rate and NGF protein expression were significantly increased in the injured tissue ofthe salviae miltiorrhizae and ligustrazine hydrochloride injection, salviae miltiorrhizae, andligustrazine groups, compared with the model group (P < 0.05 or P < 0.01), and toe interspace wasremarkably enlarged (P < 0.05 or P < 0.01), especially in the salviae miltiorrhizae and ligustrazinehydrochloride injection group.CONCLUSION: Salviae miltiorrhizae and ligustrazine hydrochloride injection promoted axonalregeneration and NGF protein expression in the injured sciatic nerve, and also enhancedneurofunctional recovery. Its effect was superior to salviae miltiorrhizae or ligustrazine alone.