Purpose
Remifentanil is an ultra-short acting opioid used for general anesthesia. Recently, it is reported that remifentanil is preventive against oxidative stress including ischemia/reperfusion injury and inflammation. However, detailed mechanism is not fully described. We aimed to study free radical scavenging activity of remifentanil against multiple free radicals.
Methods
Free radical scavenging activity of remifentanil was evaluated against nine species of free radicals by electron spin resonance spectroscopy with the spin-trapping method. From dose-response curves, reaction rate constants with free radicals examined were estimated. Antioxidative activity against lipids was assessed by TBARS assay.
Results
Remifentanil significantly scavenged the following five free radical species in dose-dependent manners; hydroxyl radical, tert-butoxyl radical, ascorbyl free radical, singlet oxygen and nitric oxide. Remifentanil did not scavenge superoxide anion, tert-butyl peroxyl radical, DPPH and tyrosyl radical. Remifentanil significantly inhibited oxidation of lipids in mice brain tissue.
Conclusions
Remifentanil dose-dependently scavenged multiple free radicals including hydroxyl radical. It is speculated that the direct free radical scavenging activity of remifentanil might contribute to its antioxidative activity in vitro and in vivo.