The Protective Effect of Salvianolic Acid B on Blood-Spinal Cord Barrier After Compression Spinal Cord Injury in Rats

Salvianolic acid B (Sal B), a bioactive compound isolated from the Chinese medicinal herb danshen, is commonly used for the prevention and treatment of cardiovascular disease. The present study was performed to investigate the effect of Sal B on the blood-spinal cord barrier (BSCB) after spinal cord injury (SCI) in a rat model. Sal B (1, 10, and 50 mg/kg i.v.) was administered to rats immediately following SCI. The permeability of the BSCB and spinal cord tissue water content were evaluated. Additionally, the expression levels of tight junction proteins and heme oxygenase-1 (HO-1) were monitored by Western blot analysis. Enzyme-linked immunosorbent assay analysis of spinal cord tissue homogenates was performed 24 h post-SCI to evaluate the expression of inflammation-related cytokines. In addition, the motor recovery of SCI rats was assessed using the Basso, Beattie, and Bresnahan scoring system. Compared to the SCI group, rats treated with Sal B (10, 50 mg/kg) exhibited significantly reduced spinal cord tissue water content and BSCB permeability. Further, the motor function of rats was also greatly improved by Sal B administration. The expression of pro-inflammatory factors TNF-alpha and NF-kappa B was found to be greatly increased 24 h post-SCI, and this upregulation was significantly attenuated by Sal B treatment. The expression of ZO-1 and occludin was upregulated by Sal B (10 mg/kg) treatment after SCI, and this effect was blocked by the HO-1 inhibitor ZnPP. Taken together, our results clearly indicate that Sal B attenuates SCI by promoting the repair of the damaged BSCB, demonstrating that this molecule is a novel and promising therapeutic agent for human SCI.