Synergistic effects of Buyang Huanwu decoction and embryonic neural stem cell transplantation on the recovery of neurological function in a rat model of spinal cord injury

The aim of the present study was to investigate the therapeutic effect of a combined treatment of Buyang Huanwu decoction (BYHWD), a well-known formula of traditional Chinese medicine, and neural stem cells (NSCs) on spinal cord injury (SCI) and the associated underlying mechanisms. A SCI model was established by surgery via a complete transection of the T10 vertebra of female Sprague-Dawley rats. Gelatin sponges were used to absorb NSCs labeled with the thymidine analog, 5-bromo-2-deoxyuridine (BrdU), and were transferred into the transected spinal cords. BYHWD was administered once a day by introgastric infusion. Motor functions of the hind limbs were evaluated using the 21-point locomotor rating scale developed by Basso, Beattie and Bresnahan (BBB). The fate of the transplanted NSCs under the various conditions was examined by double immunofluorescence staining, using markers for neurons, astrocytes and oligodendrocytes, with BrdU. Ultrastructural changes of the SCI site following the various treatments were examined under a transmission electron microscope. The number of double positive cells for glial fibrillary acidic protein and BrdU in the BYHWD + NSC group was significantly decreased when compared with that in the NSC group (P<0.05). However, the number of cells that were labeled double positive for myelin basic protein and BrdU, as well as neuron specific enolase and BrdU, was greater in the BYHWD + NSC group when compared with the NSC group. Electron microscopy demonstrated that treatment with BYHWD combined with NSCs significantly alleviated demyelination. Results from the BBB motor function test exhibited a significant improvement in the BYHWD + NSC group when compared with the SCI, BYHWD and NSC only groups. In conclusion, the results demonstrated that the traditional Chinese medicine formula, BYHWD, exerted an effect on the differentiation and migration of NSCs. Combining the administration of BYHWD with NSCs was shown to have a synergistic effect on the recovery of neurological function, mitigating the progress of demyelination or ameliorating the recovery of myelination. Keywords: Buyang Huanwu decoction; neural stem cells; spinal cord injury; traditional Chinese medicine; transplantation.