Histomorphometric and ultrastructural evaluation of long-term alpha lipoic acid and vitamin B12 use after experimental sciatic nerve injury in rats

Abstract

Aim: To analyze the therapeutic effects of long-term alpha lipoic acid (A-LA) and vitamin B12 use via histomorphometric methods and electron microscopy in the transected sciatic nerves of rats. Material and methods: Forty rats were randomized into five groups (n=8/group). In group I, 1 cm segment of sciatic nerve was resected without any other intervention. In group II (sham), following right sciatic nerve transection, primary epineurial anastomosis was performed by placing the edges of the nerve end-to-end. In group III (saline), after right sciatic nerve transection, the ends of the nerves were brought together and closed after application of intraperitoneal physiologic saline. In group IV, 2 mg/kg of alpha lipoic acid and in group V, 2 mg/kg of vitamin B12 was administered intraperitoneally before surgical intervention. Results: Histomorphometric and electron microscopic analyses revealed that vitamin B12 did not prevent structural changes, abnormal myelination and g-ratio deviations regarding the functional aspects of the sciatic nerve. Alpha lipoic acid was more effective in restructuring the histomorphometric and structural aspects of the nerve with more myelinated fibers with optimal values (0.55-0.68) than vitamin B12 groups, in which the number of myelinated nerve fibers significantly decreased at optimal intervals (0.55-0.68). Conclusion: A-LA administration following peripheral nerve transection injury is more effective in promoting nerve healing regarding the structural aspects of the sciatic nerve compared to vitamin B12 and also myelination of nerve fibers by increasing g-values.