Simvastatin protects ischemic spinal cord injury from cell death and cytotoxicity through decreasing oxidative stress: in vitro primary cultured rat spinal cord model under oxygen and glucose deprivation-reoxygenation conditions

BACKGROUND Ischemia and the following reperfusion damage are critical mechanisms of spinal cord injury. Statins have been reported to decrease ischemia-reperfusion injury in many organs including the spinal cord. Anti-oxidative effect is one of the main protective mechanisms of statin against neuronal death and cytotoxicity. We hypothesized that statins' anti-oxidative property would yield neuroprotective effects on spinal cord ischemia-reperfusion injury METHODS: Primary cultured spinal cord motor neurons were isolated from Sprague-Dawley rat fetuses. Ischemia-reperfusion injury model was induced by 60 min of oxygen and glucose deprivation (OGD) and 24 h of reoxygenation. Healthy and OGD cells were treated with simvastatin at concentrations of 0.1, 1, and 10 μM for 24 h. Cell viability was assessed using water-soluble tetrazolium salt (WST)-8, cytotoxicity with LDH, and production of free radicals with DCFDA (2',7'-dichlorofluorescein diacetate). RESULTS OGD reduced neuronal viability compared to normoxic control by 35.3%; however, 0.1-10 μM of simvastatin treatment following OGD improved cell survival. OGD increased LDH release up to 214%; however, simvastatin treatment attenuated its cytotoxicity at concentrations of 0.1-10 μM (p < 0.001 and p = 0.001). Simvastatin also reduced deteriorated morphological changes of motor neurons following OGD. Oxidative stress was reduced by simvastatin (0.1-10 μM) compared to untreated cells exposed to OGD (p < 0.001). CONCLUSIONS Simvastatin effectively reduced spinal cord neuronal death and cytotoxicity against ischemia-reperfusion injury, probably via modification of oxidative stress.