The dose dependent neuroprotective effect of alpha-lipoic acid on experimental spinal cord injury

ObjectThe purpose of this study was to investigate the dose dependent neuroprotective effect of ?-lipoic acid on induced spinal cord injury (SCI). The authors also compared the activity of ?-lipoic acid to that of the well known antioxidant, methylprednisolone (MPS).Methods.56 Spraque-Dawley rats, weighing between 210-300 mg were randomly divided into seven groups, (Groups 1?7). Those in Groups 1 were control animals that underwent laminectomy only, after which nontraumatized spinal cord samples were obtained 24 hours postsurgery. Spinal cord injury was induced in all other groups, and cord samples were obtained at 24 hours postsurgery. The rats in Group 2 underwent SCI alone; those in Group 3 received 30mg/kg of MPS intraperitoneally immediately after trauma was induced; and those in Groups 4, 5, 6 and 7 received 50-100-150-200 mg/kg of ?-lipoic acid, respectively, by intraperitoneal injection immediately after trauma was induced. 24 hours postsurgery rats in group 7 were totally dead and were excluded from statistics. Compared with the levels in control animals, lipid peroxidation (MDA levels) were significantly elevated in rats in Groups 2 and 6, but there were no statistical differences among those in Groups 3,4 and 5 in this regard. Compared with the findings in rats in Group 3, histopathological damage post-SCI was the same in rats in Groups 3,4 and 5. The neurological examination comparisons revealed no gross difference in Groups 3,4 and 5.ConclusionAnalysis of these findings showed that administration of 50-100 mg/kg of ?-lipoic acid decreased the level of lipid peroxidation and protected the spinal cord histopathology. With these findings it can be suggested that the neuroprotection of ?-lipoic acid is as effective as methylprednisolon.