The impact of piracetam and hyperbaric oxygen administration on recovery of nerve damage in rats with mock sciatic nerve injury

Background: The incidence of peripheral nerve damage is about 13-23/100,000 persons/year in developed countries. Peripheral nerve damage develops as a result of many mechanisms and has a complex treatment. The hyperbaric oxygen (HBO) treatment has local and systemic effects such as antiedema, antimicrobial, hyperoxygenation, neovascularization, pressure effect, and reducing reperfusion damage. Piracetam is a derivative of GABA and has many effects at the peripheral vascular level. It is used as a nootropic in clinical practice. The aim of this study is to examine the effect of piracetam and the HBO treatment on nerve repair due to peripheral nerve damage. Methods: In this study, 40 adult male Wistar Albino rats were used. All rats were divided into 4 groups of 10. Standard care conditions were provided to Group K after the experimentally formed sciatic nerve injury. The Group HBO was formed sciatic nerve injuries and treated with HBO for 14 days. The treatment was applied at 2.5 ATA pressure for 1 hour. Piracetam was intraperitoneally administered to Group P twice a day at a dose of 250mg/kg/day for 14 days after the formation of the nerve injury. Group C was treated with hyperbaric oxygen therapy 1 hour a day at 2.5 ATA pressure for 14 days and intraperitoneal piracetam in two equal doses of 250mg/kg/day for 14 days after the formation of sciatic nerve injury. The process was completed after 14 days and the rats were sacrificed. Sciatic nerve samples obtained were evaluated histopathologically and blood samples that were collected from the rats' hearts were stored for biochemical parameters. Results: There was no statistically significant difference between the axonal continuity, capillary formation, and myelin sheath generation values of Group K, Group HBO, Group P, and Group C (p=0.281; p=0.418; p=0.931). A statistically significant difference was observed between the groups in terms of the numbers of fibroblast and inflammatory cells (p=0.036, p=0.011). The fibroblast numbers of Group P were significantly higher than Group K (p=0.025) while there was no statistically significant difference between other groups. There a statistically significant difference was found between the inflammatory cell numbers of Group K, Group C, and Group P (p=0.011). The inflammatory cell numbers of Group P were significantly higher than Group K (p=0.037) while the inflammatory cell numbers of Group C were significantly higher than Group K (p=0.014). There were no statistically significant differences between the S100B values of Group K, Group HBO, Group P, and Group C (p=0.070). A statistically significant difference was observed between the HIF-1 alpha levels of Group K, Group HBO, Group P, and group C (p=0.001). The HIF-1 alpha levels of Group K were significantly higher than those of Group HBO (p=0.028), Group P (p=0.001), and Group C (p=0.012). Regarding the neuron-specific enolase values of Group K, Group HBO, Group P, and Group C, there were significant differences between the groups except for Group K and Group P (p=0.011) The neuron-specific enolase values of Group P were found to be significantly higher than group K (p=0.006) Conclusion: This study found that the treatment outcomes of HBO administration were similar to the control group. However, piracetam did not fully affect the treatment in the treated group and there are findings indicating that it limits and delays the treatment. The changes it causes on oxidative stress parameters such as HIF-1 alpha and neuron-specific enolase values also support these results.