Aims: Following the peripheral nervous system trauma, prescribing anti-inflammatory agents is one of the strategies to control the damage and promoting the recovery process. The aim of this study was to investigate the effects of methylprednisolone on improvement of motor function and tissue changes following sciatic nerve transection and repairing by decellularized scaffolds transplantation in rats.

Materials & Methods: In this experimental study, 50 adult male Wistar rats were randomly divided into 5 groups of 10; negative control group (receiving no medication with transection of the sciatic nerve), sham group (nerve-mediated surgery with solvent drug), experimental groups 1 and 2 (transection of the sciatic nerve and scaffold transplantation with 1- and 30mg/kg of methylprednisolone intraperitoneally) and experimental group 3 (transection of the sciatic nerve and scaffold transplantation with solvent drug). Behavioral, electrophysiological and tissue tests were performed during the experiment. Data were analyzed by SPSS 16 software and using one-way ANOVA and Tukey's post hoc tests.

Findings:  the rate of repair and improvement of motor function was increased significantly in the treated groups with methylprednisolone compared to the control group (p<0.05). Musculoskeletal atrophy of gastrocnemius was decreased in methylprednisolone treated groups. In addition, the number of neural fibers, axon diameter and thickness of myelin sheath were significantly higher in the treated groups (p<0.05).

Conclusion: The prescription of methylprednisolone increases the amount of motor improvement and tissue repair after the sciatic nerve transection and the decellularized scaffold transplantation. Recovery of the motor and tissue functions at high dose of methylprednisolone is better than low dose.