Effect of Astragalus membranaceus in Rats on Peripheral Nerve Regeneration: In Vitro and In Vivo Studies

BACKGROUND: This study provides in vitro and in vivo evaluation of Astragalus membranaceus (AM) on peripheral nerve regeneration. METHODS: In the in vitro study, we analyzed the effects of AM on cell differentiation and neurite outgrowth by using a PC12 cell model. In the in vivo study, silicone rubber chambers filled with the AM water extract were used to bridge a 10-mm sciatic nerve defect in rats. RESULTS: We found that the AM water extract caused a marked enhancement of the nerve growth factor-mediated neurite outgrowth and the expression of growth-associated protein 43 from PC12 cells. Animals from the groups treated with the AM for 8 weeks had a relatively more mature structure with larger mean values of myelinated axon number, endoneurial area, and total nerve area when compared with those in the controls receiving the saline only. CONCLUSION: These results suggest that the silicone rubber tubes present a good framework for the nerve fibers to regenerate across the gap, and the AM extract can be a potential nerve growth-promoting factor, being salutary in aiding the growth of axons in the peripheral nerve.