Protective Effect of Alpha Lipoic Acid on Rat Sciatic Nerve Ischemia Reperfusion Damage

Abstract

Background: Alpha lipoic acid is a potent antioxidant that plays numerous roles in human health. This study examined the effect of ALA on rat sciatic nerve ischemia reperfusion damage. Aims: Protective effect of alpha lipoic acid (ALA) on sciatic nerve following ischemia-reperfusion in rats was investigated by using light microscopy and biochemical methods. Provided that the protective effect of ALA on sciatic nerve is proven, we think the damage to the sciatic nerve that has already occurred or might occur in patients for various reasons maybe prevented or stopped by giving ALA in convenient doses. Study Design: Animal experiment. Methods: Forty-two adult male Sprague-Dawley rats (250-300 grams) were used in this study. Rats were randomly divided into six groups including one control (Group 1), one sham (Group 2), two ischemia-reperfusion (Groups 3 and 4) and two treatment groups (Groups5 and 6). Doses of 60 and 100 mg/kg ALA were given (Group 5 and 6) intra peritoneally twice, 1 and 24 hours before the ischemia to each treatment group. Ischemia was carried out the abdominal aorta starting from the distal part of the renal vein for two hours followed by reperfusion for three hours. In immunohistochemical methods, fibronectin immunoreactivity was analyzed. For biochemical analyses, the tissues were taken in eppendorf microtubes and superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) enzyme activities as well as malondialdehyde (MDA) and nitricoxide (NO) levels were measured. Results: Fibronectin was observed to have increased significantly in the ischemia group; on the other hand, it was observed to have decreased in parallel to the doses in the ALA groups. Biochemical studies showed that SOD and GSHPx declined with ischemia-reperfusion, but the activities of these enzymes were increased in the treatment groups in parallel with the dose. It was found that increased MDA levels with ischemia-reperfusion were decreased in parallel with ALA dose. There were no statistically significant changes in NO. Conclusion: Increased fibronectin observed after ischemia/reperfusion of rat sciatic nerve is reduced after the administration of ALA. This indicates that the function of fibronectin, to reconnect cut nerve segments and regenerate nerves, is more prominent than its function in tissue healing after ischemia. ALA administered before ischemia decreases MDA and increases SOD and GSHPx. We think that ALA may protect against the pathological changes in ischemic nerve and may be used to devise more efficient treatments.