The protective effect of dexmedetomidine on bupivacaine-induced sciatic nerve inflammation is mediated by mast cells

Abstract

Purpose: This study was designed to assess the correlation between the neuroprotective effect of dexmedetomidine and oxidative stress, neural inflammation and mast cell stability in rats with bupivacaine-induced sciatic nerve toxicity. Methods: Forty adult Wistar Albino rats, eight rats per group, were used. Saline (0.3 ml of 0.9%), dexmedetomidine (20 µg/kg), 0.5% bupivacaine or 0.5% bupivacaine+dexmedetomidine (20 µg/kg) was injected into the sciatic nerve. A control group of rats received no injection. Fourteen days after injection, the sciatic nerves were harvested and total oxidant status, total anti-oxidant status, paraoxonase-1, galectin-3 and matrix metalloproteinase 2 and 9 levels were measured in the sciatic nerves. In addition, the presence and status of inflammation, edema, and mast cells were evaluated histopathologically. Results: The combination of dexmedetomidine and bupivacaine alleviated oxidative stress. In addition, it decreased matrix metalloproteinase 9 and galectin-3 levels and increased matrix metalloproteinase 2 levels. Moreover, it stabilized recruited mast cells at the injury site; however, it did not significantly decrease inflammation or edema. Conclusion: Dexmedetomidine may ameliorate bupivacaine-induced neurotoxicity by modulating mast cell degranulation. The neuroprotective effect of dexmedetomidine may make it a suitable adjuvant agent to local anesthetics in peripheral nerve blocks.