Effects of trihydroxyethyl rutin on the recovery of nerve function after cervical spinal cord injury in rats

English Keywords:Trihydroxyethyl rutin  Spinal cord injury  Behavior  Histology  Microvascular

English Abstract:

  【Abstract】 Objectives: To investigate the neuroprotective effect of trihydroxyethrutin on cervical spinal cord injury in rats. Methods: 44 adult male SD rats were randomly divided into 4 groups, including the shame group(n=8), injury group(n=12), T50 group with 50mg/kg trihydroxyethyl rutin treatment(1 time/day, intraperitoneal injection, n=12), and T100 group with 100mg/kg trihydroxyethyl rutin treatment(1 time/day, intraperitoneal injection, n=12). The last three groups were all treated with C5 spinal cord hemilateral contusion rat model(contusion depth was 1.2mm). The behavioral changes such as forelimb locomotor scores(FLS) and combing experiment were evaluated at pre-operation and 3d, 1 week, 2 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks and 12 weeks after operation. At 12 weeks, 1 rat in each group was randomly selected to inject with barium-sulfate gelatin for cervical spinal cord microvascular perfusion. After 4℃ overnight, cervical spinal cord tissue was collected under the microscope. Changes in cervical spinal cord microvascular were observed by immunohistochemical staining. Results: At 3 days after the surgery, the FLS of the injury group, the T50 group and the T100 group were 11.33±0.71, 11.55±0.81 and 12.36±1.15 points, respectively. At 8 weeks after the surgery, compared with the shame group(17.0 points), the FLS of the injury group, the T50 group and the T100 group returned to normal. And at 10 weeks after the surgery, the injury group returned to normal. The results of the grooming experiment were similar to those of FLS, with the T100 group returning to normal(5.0 points) at 12 weeks, the T50 group returning to normal at 4.92±0.08 points, and no significant differences between the shame group and the injury group(4.17±0.11 points)(P<0.05). At 12 weeks after surgery, the number of microvessels in the injury group was significantly reduced, and so was that in the T50 group, while it was better than that in the injury group. The number of microvessels in the T100 group was not significantly reduced. Immunohistochemical staining showed that at 12 weeks, the microvascular density of the injury group, the T50 group and the T100 group were 23.50±1.75, 31.33±1.36 and 33.00±1.27, respectively, which were significantly lower than those of the shame group, and there were significant differences between the T50 group and the T100 group and the injury group(P<0.05). The EC staining results showed that the T50 group and T100 group had significantly higher total area of injury side(including cavity area) than the injury group. The injury group had the largest hole area, while the T50 and T100 groups had significantly smaller holes than the injury group. The residual gray matter area of T50 group and T100 group was significantly higher than that of the injury group. Conclusions: Trihydroxyethyl rutin provides neuroprotection in rats with cervical spinal cord injury, by protecting the microvascular structure of cervical spinal cord and alleviating the damage of spinal cord structure.