RESUMEN
OBJECTIVE: To investigate the effects of lycium barbarum polysaccharide (LBP) on the formation of traumatic neuroma and pain after transection of sciatic nerve in rats. METHODS: Forty Sprague-Dawley (SD) rats, weighing 200-220 g, half male and half female, were allocated into 2 groups randomly: LBP group and control group (n = 20 per group). The right sciatic nerves were transected and 2 cm sciatic nerve were removed in all rats of the 2 groups. LBP were intraperitoneally injected in a volume of 10 mg/(kgd) in the LBP group, while the same volume normal saline (NS) in the control group for 28 days. The deficiency of toenail and toe were observed to estimate the autophagy of the operated limb. Light microscope and transmission electron microscope were used to observe the formation of traumatic neuroma after transection of sciatic nerve. RESULTS: Autophagy was observed in 5 rats (25%) of LBP group and in 12 rats (60%) of control group at 4 weeks, showing significant difference (P < 0.05). Neuroma formed in 8 rats (40%) of LBP group and in 16 rats (80%) of control group, showing significant difference (P < 0.05). The observation of light microscope showed that there were unorganized growth cells in the neuroma, infiltrated muscle cells, the regeneration of axons and ensheathing cells to form small patch and funicular structure in the control group, while in the LBP group there were less proliferation of nerve fibers with a regular arrangement. Transmission electron microscope showed that there were lots of axons in nerve tumour, more fusoid fibroblasts, more collagen fiber, and hyperplasia and degenerated myelin sheath in the control group, while in the LBP group there were less myelin sheath in the proximal end of injuring nerves, less Schwann cells and fibroblasts, and sparsed collagen fibers. CONCLUSION: LBP can inhibit autophagy and the formation of traumatic neuroma after transection of sciatic nerve in rats.