Edaravone protects hearing from acute acoustic trauma in guinea pigs / 中华耳鼻咽喉头颈外科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To assess whether the free radical scavenger, edaravone, could provide protection from oxidative stress and hearing loss induced by noise exposure.</p><p><b>METHODS</b>Forty-eight guinea pigs were divided into six groups and exposure to a stationary noise at 125 dB SPL for 2 h only once. Group A measured hearing and reactive oxygen species (ROS) level without noise exposure. Group B intratympanic saline injection. Group C intratympanic edaravone injection. Group D exposed to noise for 2 h. Group E intravenous edaravone injection after noise exposure. Group F intratympanic edaravone injection after noise exposure. All animals of group D, E and F were measured hearing with ABR before noise exposure, immediately after noise exposure and at 2, 6, 12, 24, 48, 72 h after noise exposure, and then were decapitated for ROS measurement with electron spin resonance technology.</p><p><b>RESULTS</b>After noise exposure, the ABR threshold of group D increased immediately after acute acoustic trauma and did not get right finally, while group F came back about 10 dB SPL. The normal level of ROS in the cochlea of guinea pigs was about 21.68 (cm/g) and significantly increased after acute acoustic trauma, reaching its peak in 2h, and didn't return to normal after 72 h. Group E did not inhibit free radicals, while group F showed significant effect on inhibiting production of free radicals.</p><p><b>CONCLUSIONS</b>The level of ROS in cochlea were decreased significantly after intratympanic edaravone injection. The mechanism may due to its effective clearance of the ROS in cochlea.</p>