ALH-L1005 attenuates endotoxin induced inner ear damage.

ABSTRACT

OBJECTIVE: To assess whether this compound (ALH-L1005) is conceivably an effective agent in protecting against cochlear damage induced by LPS. MATERIALS AND METHODS: Tube formation using human umbilical vein endothelial cell (HUVEC) and matrix metalloproteinase (MMP)-9 inhibition assay was performed. 24 guinea pigs were randomly divided into three groups. Intratympanic instillation of LPS (n=8) as negative control, instillation of oxytetracycline 1h after LPS as positive control (n=8), and intratympanic instillation of ALH-L1005 (n=8) 1h after LPS were considered experimental group. Evaluation by auditory brainstem response (ABR) measurement, cochlear blood flow, and blood-labyrinth barrier (BLB) permeability were performed. Cochlear hair cells were observed by field emission-scanning electron microscopy (FE-SEM). MMP-9 activation was measured by gelatin zymography. RESULTS: For HUVEC, the tube formation was suppressed in a dose dependant manner. ALH-L1005 inhibited the MMP-9 activity prominently. It also attenuated the elevation of LPS-induced hearing threshold shift and recovery of CBF. By FE-SEM, cochlear hair cells could be preserved in experimental group. ALH-L1005 significantly reduced the BLB opening compared to LPS group. Active MMP-9 expression could be detected in the LPS group. In contrast to ALH-L1005 group, active MMP-9 expression was not detected. CONCLUSION: Our results conclude that ALH-L1005 showed a protective effect in the cochlear lateral wall damage induced by LPS.