Jia Yu-Xi, Li Jin-Ran, Mao Cui-Ying, Yin Wei-Tian, Jiang Ri-Hua
Department of Orthopaedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China.
Jilin University Bethune School of Medical Sciences, Changchun, Jilin 130021, P.R. China.
Exp Ther Med. 2014 May;7(5):1141-1146. doi: 10.3892/etm.2014.1546. Epub 2014 Feb 14.
Glycyrrhizin has a role in immune regulation in the central nervous system, but its impact on sciatic nerve injury had not previously been reported. In this study, a BALB/c mouse model of sciatic nerve injury was used to explore the role of glycyrrhizin in sciatic nerve repair and its underlying mechanism. Glycyrrhizin with intragastric gavage of 10 and 20 mg/kg weight per day (mid- and high-dose, respectively) inhibited p75 neurotrophin receptor (p75NTR) expression at the protein and mRNA levels versus the 5 mg/kg (low-dose) group and control (0.9% NaCl solution) at one, two, four and eight weeks following sciatic nerve injury, and simultaneously improved the action potential amplitude and motor nerve conductive velocity. Combined Marsland, Glees and Erikson's silver stain and Luxol fast blue staining results indicated that high- and mid-dose glycyrrhizin promoted improved sciatic nerve myelination compared with the low-dose or control groups eight weeks after injury. Immunofluorescence staining demonstrated that glycyrrhizin had an inhibitory effect to a certain degree on local hypertrophic scar and inflammatory responses in the mouse model. In conclusion, glycyrrhizin can promote sciatic nerve regeneration and functional repair, in which doses of 10 and 20 mg/kg per day are more effective than lower doses, and such regeneration is associated with the downregulation of p75NTR.
甘草酸在中枢神经系统的免疫调节中发挥作用，但其对坐骨神经损伤的影响此前尚未见报道。在本研究中，采用BALB/c小鼠坐骨神经损伤模型，探讨甘草酸在坐骨神经修复中的作用及其潜在机制。与坐骨神经损伤后1、2、4和8周时5 mg/kg（低剂量）组及对照组（0.9%氯化钠溶液）相比，每天按10和20 mg/kg体重进行灌胃的甘草酸（分别为中剂量和高剂量）在蛋白质和mRNA水平抑制了p75神经营养因子受体（p75NTR）的表达，同时提高了动作电位幅度和运动神经传导速度。联合Marsland、Glees和Erikson银染及Luxol固蓝染色结果表明，损伤8周后，与低剂量组或对照组相比，高剂量和中剂量甘草酸促进了坐骨神经髓鞘形成改善。免疫荧光染色表明，甘草酸对小鼠模型中的局部肥厚性瘢痕和炎症反应有一定程度的抑制作用。总之，甘草酸可促进坐骨神经再生和功能修复，其中每天10和20 mg/kg的剂量比低剂量更有效，且这种再生与p75NTR的下调有关。
