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

BACKGROUND： Studies have shown that both salviae miltiorrhizae and ligustrazine can promote protein expression of nerve growth factor （NGF） and regeneration of peripheral nerve. OBJECTIVE： To verify the effect of salviae miltiorrhizae and ligustrazine hydrochloride injection on axonal 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 the Laboratory of Traditional Chinese Medicine and the Institute of Bioengineering of Jinan University from July to December 2008. MATERIALS： Salviae miltiorrhizae and ligustrazine hydrochloride injection （containing 20 mg salviae miJtiorrhizae and 100 mg ligustrazine per 100 mL injection） was provided by Guizhou Baite Pharmaceutical, China; salviae miltiorrhizae and ligustrazine decoctions （containing 1 g raw drug per 1 mL decoction） were provided by Guangzhou Baiyunshan Factory for Traditional Chinese Medicine, China; rabbit-anti-rat NGF monoclonal antibody was provided by Beijing Biosynthesis Biotechnology, China. METHODS： A total of 80 healthy, male, Sprague Dawley rats were used to establish a sciatic nerve injury model via neurotomy, and were then randomly assigned to 4 groups： salviae miltiorrhizae and ligustrazine hydrochloride injection group （intraperitoneal injection of 35 mL/kg per day salviae miltiorrhizae and ligustrazine hydrochloride injection）, saIviae miltiorrhizae group （intragastric peffusion of 2 mL salviae miltiorrhizae）, ligustrazine group （intragastric peffusion of 2 mL ligustrazine）, and model group （intraperitoneal injection of 35 mL/kg per day saline）, with 20 rats in each group. Thereafter, rats in each group were then divided into 4 subgroups according to varying time 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 and silver staining combined with image analysis to calculate the axonal regeneration rate; NGF expression was detected using immunohistochemistry and Western blot analysis; toe interspace was measured by behavior at 4 and 8 weeks. RESULTS： With increasing time after sciatic nerve expression, and toe interspace gradually increased njury, the axonal regeneration rate, NGF protein At 4 and 8 weeks post-surgery, axonal regeneration rate and NGF protein expression were significantly increased in the injured tissue of the salviae miltiorrhizae and ligustrazine hydrochloride injection, salviae miltiorrhizae, and ligustrazine groups, compared with the model group （P 〈 0.05 or P 〈 0.01）, and toe interspace was remarkably enlarged （P 〈 0.05 or P 〈 0.01）, especially in the salviae miltiorrhizae and ligustrazine hydrochloride injection group. CONCLUSION： Salviae miltiorrhizae and ligustrazine hydrochloride injection promoted axonal regeneration and NGF protein expression in the injured sciatic nerve, and also enhanced neurofunctional recovery. Its effect was superior to salviae miltiorrhizae or ligustrazine alone.

Anti-fibrotic Effects of Salvia miltiorrhiza and Ligustrazine Injection on LX-2 Cells Involved with Increased N-myc Downstream-Regulated Gene 2 Expression

Objective: To investigate the effects of Salvia miltiorrhiza and Ligustrazine Injection（SML） on proliferation and apoptosis of human hepatic stellate cell LX-2 and the expression of N-myc downstreamregulated gene 2（NDRG2, a tumor suppressor gene）. Methods: HSCs from the LX-2 cell line were cultured in vitro. The proliferative state of different initial LX-2 cell numbers was measured using a 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide（MTT） colorimetric assay. LX-2 cells were plated in 96-well plates at an approximate density of 2.50×10;cells/mL and cultured for 24 h followed by the application of different concentrations of SML（1, 2, 4 and 8 μL/mL）. Cell proliferation was measured using the MTT assay at 24 and 48 h. Apoptosis was detected by flow cytometry at 24 h. LX-2 cells were treated with different concentrations of SML and extracted with protein lysis buffer. The levels of NDRG2 and β-catenin were measured by Western blot. Results: With the exception of the 1 and 2 μL/mL concentrations, 4 and 8 μL/mL SML inhibited cell proliferation in a concentration-dependent manner at 24 and 48 h（P<0.05）. With the exception of the 1 and 2 μL/mL concentrations, the NDRG2 expression level was greatly increased in a concentration-dependent manner. However, the level of β-catenin was unaffected. Conclusion: SML inhibit LX-2 cell proliferation in a concentration-dependent manner, and the mechanism may be associated with NDRG2 over-expression.