Experiment Study Of Effects Of Lycium Barbarum Polysaccharides On Formation Of Traumatic Neuroma After Sciatic Nerve Were Mutilated In Rats

Objective To investigate the effect of lycium barbarum polysaccharides (LBP )on expression of nerve growth factor(NGF) in nerve tissue, spinal nerve ganglia and the corresponding spinal cord after sciatic nerve were cut off in rats, and investigate the related mechanism of LBP inhibit NGF, then research whether LBP can inhibit the formation of the traumatic neuroma and pain .Methods The first part: 72 female SD rats were randomly divided into three groups: Control group, Model group and LBP group. Model group and LBP group were cut off 2cm right sciatic nerve, LBP group were intraperitoneal injected LBP 10mg/(kg?d), Model group and control group were given the same dose of physiological saline while Control group were treated without any surgical operation. Six rats were choosed randomly from each group and the near-heart never of sciatic nerve and conjoint dorsal root ganglia and the corresponding spinal cord were obtained at the7th, 14th, 21st and 28th day after surgery; the immunohistochemistry method was used to evaluate the expression of NGF. The second part: 40 male and female SD rats were randomly divided into two groups: Control group and LBP group,( n=20). Model operation and drugs injection were same as the first part. We observed the deficiency of nail of the operated limb everyday in order to estimate pain appearance use autotomy scores were calculated. 28 days after surgery, Light microscope and electron microscopy were used to observe the formation of traumatic neuroma after sciatic nerve were mutilated. Results The first part: The mean density of NGF from the near-heart never of sciatic nerve and conjoint dorsal root ganglia and the corresponding spinal cord in Model group and LBP group is higher than control group. Compared with Model group, The mean density of NGF from the near-heart never of sciatic nerve and conjoint dorsal root ganglia and the corresponding spinal cord in LBP group is significantly lower at the 7 th, 14 th, 21 st and 28 th day after surgery(P<0.05). 28 days after surgery, There are 5 rats in LBP group occurred autophagy with the incidence is 25%, while in control group, 12 rats occurred autophagy with the incidence is 60%, and there is difference in the autophagy between the two groups(P<0.05). Results from the light microscope shown that in LBP group, 8 rats grow neuroma with the incidence is 40%, while in control group, 16 rats grow neuroma with the incidence is 80%, and there is significantly difference in the formation of traumatic neuroma between the two groups(P<0.05). We can find from the light microscope that: cells grows disorderly and infiltrated muscle cells can be find in control group; also, there are hyperplastic axon cells and lemnocyte in some neuroma with the form is small pieces and cords. In LBP group, there is less nerve fibroplasia and nerve fibre distributed in order. We can find from the Transmission Electron Microscope that there are lots of neuraxon, more cambiform fibroblast cells, more collagenous fibre in control group, while in LBP group, there is less myelin sheath near the severed nerve, less schwann cell and fibroblast, also, there is sparsed collagen fiber.Conclusion LBP can inhibit the expression of NGF in the near-heart never of sciatic nerve and segmental ganglionconjoint and the corresponding spinal cord. LBP can inhibit the formation of traumatic neuronal and pain after sciatic nerve was mutilated in rats.