Beneficial effect of the traditional chinese drug shu-xue-tong on recovery of spinal cord injury in the rat

Abstract

Shu-Xue-Tong (SXT) is a traditional Chinese drug widely used to ameliorate stagnation of blood flow, such as brain or myocardial infarction. Whether SXT may have therapeutic value for spinal cord injury (SCI), during which ischemia plays an important role in its pathology, remains to be elucidated. We hypothesized that SXT may promote SCI healing by improving spinal cord blood flow (SCBF), and a study was thus designed to explore this possibility. Twenty-five male Sprague-Dawley rats were used. SCI was induced by compression, and SXT was administrated 24 h postinjury for 14 successive days. The effects of SXT were assessed by means of laser-Doppler flowmetry, motor functional analysis (open-field walking and footprint analysis), and histological analysis (hematoxylin-eosin and thionin staining and NeuN immunohistochemistry). SXT significantly promoted SCBF of the contused spinal cord and enhanced the recovery of motor function. Histological analysis indicated that the lesion size was reduced, the pathological changes were ameliorated, and more neurons were preserved. Based on these results we conclude that SXT can effectively improve SCI.

Figure 1

Footprint analysis at 7 and 14 days after injury. Arrows point to the direction of walking. SHAM: sham group; SAL: saline control; SXT: SXT treated group. SHAM: normal walking with normal stride width and length. SAL 7 d: there is only toe dragging. No plantar stepping appears. SXT 7 d: plantar prints appear. SAL 14 d: plantar stepping begins to appear in the saline group. The toe dragging was still serious. SXT 14 d: the animal resumes almost normal walking. Scale  bar = 2 cm.

Figure 2

Statistical analysis of footprints. SHAM: Bilaterally laminectomized. 0 d: Preinjury normal control. SAL: saline control, SXT: Shu-Xue-Tong treated. (a) The SAL group shows no recovery at 7 d, 14 d, while the SHAM group has no toe dragging at all. The SXT group resumes significant plantar stepping at 7 d and is almost normal at 14 d. (b) Both stride width and stride length are significantly improved in the SXT group at 14 d. **P < .01; *P < .05; ^# P < .05.

Figure 3

HE and thionin staining at 14 d. (a) and (b) HE staining. (a) Saline control, (b) SXT treated. The boundary of the lesion site is outlined. The lesion area is significantly smaller in (b). (c) The lesion area is prominently reduced in the SXT group (P < .01). (d)–(g) Thionin staining. (d) and (f) Saline control. (e) and (g) SXT treated. The boxes in (d), (e) are the areas adjacent to the lesion sites, showing that there is larger number of neurons in the SXT treated animal. (f) and (g) are successive blown-ups of the boxes in (d) and (e), displaying the abundance of microglia cells in the saline control. (f in (f) is the high magnification of the box at the upper left part of the figure). Scale bar in (a), (b) and (d)–(e) = 500 μm; in (f) and (g) = 100 μm; in (f) = 25 μm.

Figure 4

NeuN immunohistochemistry at 14 d. (a) Saline control. (b) SXT treated. The photos of two areas of similar size were taken 1000 μm away from the lesion. Note that there is larger number of neurons in the SXT group. Scale bar = 200 μm. (c) As compared to the SAL group, the number of neurons is significantly higher in the SXT group (P < .05).

Figure 5

Diagrammatic summary of the beneficial effect of SXT in ameliorating the secondary injury.