The cardioprotective effect of red wine has been attributed to resveratrol. The resveratrol-induced protection against ischemia-reperfusion (I/R) injury has been documented in heart, kidney, and brain. Resveratrol scavenges free O2 radicals and upregulates nitric oxide (NO). However, the presence of resveratrol-induced spinal cord protection against I/R injury has not been reported in the literature. The objective of this study was to evaluate the effects of resveratrol on neurologic functions, histopathologic changes, and NO metabolism following temporary spinal cord ischemia (SCI) in rabbits.
Material and methods
SCI was induced with occlusion of the infrarenal aorta in rabbits. In addition to the sham group (group S, n = 7), group C (n = 7) received vehicle 30 minutes before ischemia. Group R1 (n = 7) and R10 (n = 7) received 1 mg/kg and 10 mg/kg resveratrol instead of vehicle, respectively. Blood samples were taken to obtain nitrite/nitrate levels during the surgical procedure. After neurologic evaluation at the 48th hour of reperfusion, lumbar spinal cords were removed for histopathologic examination and malondialdehyde measurement as a marker of oxidative stress.
Results
Five animals in group C had paraplegia while 5 in group R10 had normal neurologic functions. The average Tarlov score of group R10 was significantly higher than that the score of group C (4.1 ± 1.2, vs 1.2 ± 2.2; P = .014). Histopathologic examination revealed higher neuronal viability index in group R10 compared with that of group C (0.82 ± 0.24 vs. 0.46 ± 0.34; P = .018). Nitrite/nitrate levels decreased in group C (from 357 ± 20.15 μmol/L to 281 ± 47.9 μmol/L; P < .01) whereas they increased both in group R1 and group R10 (from 287±28 μmol/L to 310 ± 33.9 μmol/L and from 296 ± 106 μmol/L to 339 ± 87 μmol/L, respectively) during SCI. Malondialdehyde levels of group R10 was lower than those of group C (55 ± 12.9 nmol/mg protein vs 83.9 ± 15.1 nmol/mg protein; P = .001, respectively).
Conclusions
In this model of SCI, resveratrol decreased oxidative stress, increased NO release, and protected spinal cord from I/R injury. Resveratrol-induced neuroprotection is probably mediated by its antioxidant and NO promoting properties. Before considering the clinical use of this natural antioxidant, further research is warranted about its mechanism of effects, timing, and optimum dose.
Abstract
Clinical relevance
Paraplegia that results from spinal cord ischemia is a catastrophic complication of thoracic and thoracoabdominal aorta surgical procedures. Despite several surgical modifications and pharmacologic approaches, paraplegia has not been totally eliminated. On clinical grounds, the efficiency of currently used pharmacologic agents to prevent spinal cord injury during thoracic and thoracoabdominal aorta surgery is very limited and their benefit is controversial. Preischemic infusion of resveratrol protects the spinal cord from ischemia reperfusion injury in rabbits. Following clarification of the underlying protective mechanism, optimal dose, and timing, resveratrol may used in humans as an adjunct to eliminate this catastrophic complication.
