The effects of caffeic acid phenethyl ester (CAPE) on spinal cord ischemia/reperfusion injury in rabbits

Objective: Oxygen-derived free radicals have been implicated in the pathogenesis of spinal cord neuronal injury after both trauma and ischemia-reperfusion. Caffeic acid phenethyl ester (CAPE), an active component of propolis extract, exhibits antioxidant properties. This experimental study was designed to determine the effect of CAFE on ischemia-reperfusion of spinal cord in rabbits. Methods: Forty-one New Zealand white rabbits were used in the study. The animals undergone aortic occlusion were divided into three groups each consisting of 11 rabbits: methylprednisolone (MP), CAFE, and control. CAFE 10 mu mol/kg, methyl prednisolone (MP) 30 mg/kg or similar dose saline were injected intraperitoneally before surgical intervention. Animals were subjected to 21 min of cross-clamp time. At the end of occlusion time, the clamps were removed and restoration of the blood flow was verified visually. Animals in sham group (n = 8) underwent a surgical procedure similar to the other groups but the aorta was not occluded. Neurological status was scored by assessment of hindlimb motor function deficit. Results: The scores in CAFE group was different from control groups at 48 h (3.91 +/- 0.5 vs. 2.91 +/- 0.7; P = 0.0013). Spinal cord specimens were obtained to determine the tissue levels of malondialdehyde, superoxide dismutase, catalase, and histological changes. Malondialdehyde levels in control group were increased significantly when compared to sham group (124.22 +/- 24.36 and 41.92 +/- 10.08 nmol/g wet tissue, P = 0.0003). MDA levels in the CAFE group were lower than MP group and differences between the two groups were statistically significant (56.77 +/- 15.265 and 107.74 +/- 19.31 nmol/g wet tissue, P = 0.0001), We did not observe additional tissue injury in CAFE group when compared to control group. SOD and CAT activities were not concordant in all the groups. Conclusions: These results suggest that CAFE may be an available agent to protect the spinal cord from ischemia-reperfusion injury. (C) 1999 Elsevier Science B.V, All rights reserved.