Salvianolic acid B combined with mesenchymal stem cells contributes to nucleus pulposus regeneration

To investigate whether salvianolic acid B is able to enhance repair of degenerated intervertebral discs by mesenchymal stem cells (MSCs) through the promotion of MSC differentiation into nucleus pulposus cells in a nucleus-pulposus-like environment and by enhancing the trophic effect of MSCs on residual nucleus pulposus cells (mediated by transforming growth factor-β1).

Successful intervertebral disc degeneration models, established by aspiration of the nucleus pulposus in New Zealand white rabbits, were randomly divided into eight groups: Group A was treated with MSC transplantation. Group B was treated with MSC transplantation and salvianolic acid B, with the subgroups B1, B2, B3, and B4 receiving 0.01 mg/L, 0.1 mg/L, 1 mg/L, and 10 mg/L salvianolic acid B, respectively. Groups C and D were treated with phosphate buffer saline and sham graft, respectively. Group E was the normal control group. At the end of week 8, the type II collagen, proteoglycan, transforming growth factor-β1, and water contents in each group were examined by semi-quantitative immunohistochemistry, spectrophotometry, enzyme-linked immunosorbent assay, and magnetic resonance, respectively.

The content of type II collagen, proteoglycan, transforming growth factor-β1, and water in groups B3 and B4 were significantly higher than those in group A (p < 0.01).

Salvianolic acid B (1 mg/L to 10 mg/L) plus MSC transplantation was more effective in repairing degenerated intervertebral discs than was stem cell transplantation alone.