[Neuroprotective effect of icariin on spinal cord injury in rats].

Objective: To study the neuroprotective effect of icariin on spinal cord injury in rats.

Methods: A total 108 SPF male 3-month-old SD rats were divided into experimental group, control group and sham operation group according to the random number table. There were 36 rats in each group. In the control group and the experimental group, the modified Allen's method was used to make the spinal cord injury model. In the sham operation group, only the lamina was cut without damaging the spinal cord. Immediately after operation, the experimental group was given intragastric administration of icariin(100 mg/kg), the control group and sham operation group were given an equal amount of normal saline by gavage, twice a day. BBB score was used to assess the motor function of rats on 1, 2, 3 days after operation. At 72 h after operation, the activity of myeloperoxidase (MPO) was measured by spectrophotometry. Tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β) levels was detected by enzyme-linked immunosorbent assay(ELISA). MPO, TNF-α, IL-1β expression were detected by immunohistochemical staining. Malondialdehyde (MDA) content was detected by thiobarbituric acid method. Superoxide dismutase (SOD) activity was measured by xanthine oxidase method. TUNEL staining was used to detect the apoptosis and apoptosis index(AI) was calculated. The histopathological changes of the spinal cord were observed under a light microscope and the histopathological score was performed using Sirin score method.

Results: BBB score in the control group and the experimental group was significantly lower than that in the sham operation group at each postoperative time point( P <0.05). BBB score in the experimental group was significantly higher than that in the control group at 2 and 3 days after operation ( P <0.05). At 72 h after operation, the MPO activity and the levels of TNF-α, IL-1β in the control group and experimental group were significantly higher than in the sham operation group ( P <0.05), and the experimental group was obviously higher than control group( P <0.05). The expressions of MPO, TNF-α, IL-1β in the control group and experimental group were significantly higher than in the sham operation group ( P <0.05), and the experimental group was significantly lower than of the control group ( P <0.05). MDA content in the control group and the experimental group was significantly higher than that in the sham operation group, and the experimental group was significantly lower than that in the control group ( P <0.05). SOD activity in the control group and the experimental group was significantly lower than that in the sham operation group, and the experimental group was significantly higher than that in the control group ( P <0.05). The AI in the control group and the experimental group was significantly higher than that in the sham operation group, and the experimental group was significantly lower than that in the control group ( P <0.05). The histopathological score in the control group and the experimental group was significantly higher than that in the sham operation group, and the experimental group was significantly lower than that in the control group ( P <0.05).

Conclusions: Icariin can inhibit inflammation, lipid peroxidation and apoptosis after spinal cord injury, reduce histopathological damage of spinal cord, improve the motor function, effectively protect spinal cord tissue, and has an obvious neuroprotective effect.

Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose.

(Copyright© 2018 by the China Journal of Orthopaedics and Traumatology Press.)