Effects of Cilostazol on Oxidative Stress, Systemic Cytokine Release, and Spinal Cord Injury in a Rat Model of Transient Aortic Occlusion

Background: Cilostazol is a phosphodiesterase inhibitor that has anti-inflammatory potential in addition to vasodilator and antiplatelet effects. The aim of this study was to determine the influence of cilostazol on biochemical markers of oxidative damage, proinflammatory cytokine release, and spinal cord injury after transient aortic occlusion in rats. Methods: Animals were randomized into 3 groups. Sham group rats were subjected to laparotomy without aortic occlusion. Control group rats were pretreated with intraperitoneal dimethyl sulfoxide, and cilostazol group rats received intraperitoneal cilostazol (20 mg/kg/day) for 3 days before the induction of ischemia. Ischemia was induced by clamping of the infrarenal aorta, and 48 hours after reperfusion, Tarlov grades were assessed and spinal cord conduction velocities (SCCVs) were measured using epidural electrical stimulation. Erythrocyte superoxide dismutase (SOD) and catalase activities and plasma malondialdehyde, serum tumor necrosis factorea, interleukin-1 beta, and interleukin-6 levels were analyzed. Spinal cord histopathology was examined to determine neuronal damage and tissue inflammation. Results: Aortic occlusion caused significant increases in SOD, catalase activities, and malondialdehyde and cytokine levels accompanied by spinal cord injury. Cilostazol significantly reduced malondialdehyde levels but did not significantly alter the activations of antioxidant enzymes, levels of proinflammatory cytokines, or histologic severity of inflammation. The differences regarding the results of Tarlov grading, SCCVs, and neuronal viability between the ischemic and cilostazol pretreated groups were statistically nonsignificant. Conclusion: The present experimental study indicated that cilostazol pretreatment used in this study before aortic occlusion decreased lipid peroxidation, which may be related to the reduction of reactive oxygen species. Cilostazol did not significantly suppress systemic cytokine release and prevent spinal cord inflammation and injury; however, it did show some benefit. Additional investigations might be needed to determine the critical dose of cilostazol for clarifying the protective role of this drug in spinal cord ischemia/reperfusion injury.