Tetramethylpyrazine accelerates the function recovery of traumatic spinal cord in rat model by attenuating inflammation

In the present study, we explored the effects of tetramethylpyrazine (TMP), an alkaloid extracted from the Chinese herbal medicine Ligusticum wallichii Franchat (chuanxiong), on a rat model of contusion spinal cord injury (SCI). The contusion SCI model was induced in rats by a modified Allen's weight-drop method with a severity of 5 g × 50 mm impacting on the T10 segment. In the TMP treatment group, rats were injected intraperitoneally (i.p.) with TMP (200 mg/kg), every 24 h for 5 days, starting half an hour after contusion SCI. The control group was treated with saline. Compared with the control group, the TMP group significantly ameliorated the recovery of hindlimb function of rats. TMP treatment significantly reduced the expression of macrophage migration inhibitory factor, nuclear factor κappa B, pro-inflammatory cytokine interleukin-18 and neutrophil infiltration. On the other hand, TMP enhanced the expression of inhibitor κappa B and anti-inflammation cytokine interleukin-10. In conclusion, our results demonstrate that TMP inhibits the development of inflammation and tissue injury associated with spinal cord contusion in rats which may improve the rats' hindlimb function.