Quercetin attenuates inflammatory processes after spinal cord injury in an animal model

Objectives: We have shown earlier that administration of the flavonoid quercetin significantly contributed to recovery of motor function after spinal cord compression injury in the adult rat. Using the same animal model, we have now designed a set of experiments to test the hypothesis that quercetin attenuates oxidative stress-related inflammatory processes early after spinal cord trauma. Methods: Mid-thoracic spinal cord compression injury in adult male Wistar rats was caused by extradural application and closure of a 50 g calibrated aneurysm clip for 5 s. Myeloperoxidase (MPO) levels were determined in spinal cord tissue and serum of quercetin-treated animals and controls at 6, 12, 24 and 72 h after injury. The white blood count was followed until 72 h after injury. Results: In quercetin-treated animals, MPO activity was significantly decreased in tissue at 12 and 24 h and in serum at 6, 12 and 24 h after injury, compared with saline controls. In quercetin-treated animals, the prevalence of ED-1 and MPO positive cells was significantly lower than in saline controls. White blood count in venous blood was significantly decreased in quercetin-treated animals at 12 and 24 h after injury. Conclusion: Quercetin attenuated the recruitment of neutrophils to the site of injury. The resulting lower MPO release in the injured tissue is likely to decrease the extent of secondary injury and might at least partially explain the neuroprotective effect of the flavonoid quercetin. Spinal Cord (2010) 48, 857-861; doi:10.1038/sc.2010.45; published online 4 May 2010