Sulforaphane attenuates matrix metalloproteinase-9 expression following spinal cord injury in mice

Inflammation plays an important role in the pathogenesis of secondary damage after spinal cord injury (SCI). The present study explored the effect of sulforaphane (SFN), a potent anti-inflammatory extract of cruciferous vegetables, on the expression of two inflammatory mediators, metalloproteinase (MMP)-9 and TNF-α, in a murine model of SCI. Murine spinal cord injury was induced by the application of vascular clips (force of 10 g) to the dura after a three-level T8-T10 laminectomy. The wet/dry weight ratio was used to reflect the percentage of water content of impaired spinal cord tissue at 48 hr after SCI. The mRNA levels of MMP-9 were determined using the reverse-transcriptase polymerase chain reaction (RT-PCR), and protein levels of TNF-α and MMP-9 were detected by enzyme-linked immunosorbent assays (ELISA) at 24 hr after SCI. Gelatin zymography was used to determine MMP-9 activity of spinal cord tissue at 24 hr after SCI. Mice treated with SFN at 1 hr after SCI had lower expression and activity of MMP-9 compared to mice with SCI. The decrease of MMP-9 in mice treated with SFN was associated with decreased levels of spinal cord water content and TNF-α. In summary, suforaphane decreases MMP-9 and TNF-α expression and vascular permeability changes following spinal cord injury in mice.