Mun Young Chang1, Seon-Hee Byon2, Hyeon-Cheol Shin3, Song Ee Han2, Ju Yeon Kim2, Jang Yul Byun2, Jong Dae Lee2, Moo Kyun Park4. 1. Department of Otorhinolaryngology-Head and Neck Surgery, Chung-Ang University College of Medicine, Seoul, Republic of Korea. 2. Department of Otolaryngology-Head and Neck Surgery, Soon Chun Hyang University College of Medicine, Seoul, Republic of Korea. 3. CEWIT Center for Systems Biology, State University of New York, Incheon, Republic of Korea. 4. Department of Otolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address: aseptic@snu.ac.kr.
Abstract
OBJECTIVES: Drug-induced ototoxicity from compounds such as aminoglycosides and platinum can damage the inner ear resulting in hearing loss, tinnitus or balance problems and may be caused by the formation of reactive oxygen species (ROS). Dieckol is a phlorotannin polyphenolic compound with strong antioxidant effects found in edible brown algae. This study investigated the protective effects of dieckol on drug-induced ototoxicity in cochlear cultures obtained from neonatal mice. METHODS: Cochlear explants were pretreated with dieckol and exposed to gentamicin for 48h. The explants were then fixed and stained with fluorescein isothiocyanate-phalloidin and the intact hair cells counted. The free radical scavenging activity of dieckol was assessed using a 1,1-diphenyl-2-picrylhydrazyl assay. E. coli (Escherichia coli) cultures were used to evaluate the effect of dieckol on the antibiotic activity of gentamicin. RESULTS: Gentamicin treatment resulted in dose-dependent hair cell loss that was partially protected by dieckol. Moreover, at concentrations >67μM dieckol had significant radical scavenging activity. Dieckol did not compromise the antibiotic effect of gentamicin. CONCLUSIONS: These findings suggest that dieckol can be used as a therapeutic agent that reduces the damage caused by drug-induced ototoxicity.
OBJECTIVES: Drug-induced ototoxicity from compounds such as aminoglycosides and platinum can damage the inner ear resulting in hearing loss, tinnitus or balance problems and may be caused by the formation of reactive oxygen species (ROS). Dieckol is a phlorotannin polyphenolic compound with strong antioxidant effects found in edible brown algae. This study investigated the protective effects of dieckol on drug-induced ototoxicity in cochlear cultures obtained from neonatal mice. METHODS: Cochlear explants were pretreated with dieckol and exposed to gentamicin for 48h. The explants were then fixed and stained with fluorescein isothiocyanate-phalloidin and the intact hair cells counted. The free radical scavenging activity of dieckol was assessed using a 1,1-diphenyl-2-picrylhydrazyl assay. E. coli (Escherichia coli) cultures were used to evaluate the effect of dieckol on the antibiotic activity of gentamicin. RESULTS:Gentamicin treatment resulted in dose-dependent hair cell loss that was partially protected by dieckol. Moreover, at concentrations >67μM dieckol had significant radical scavenging activity. Dieckol did not compromise the antibiotic effect of gentamicin. CONCLUSIONS: These findings suggest that dieckol can be used as a therapeutic agent that reduces the damage caused by drug-induced ototoxicity.
Authors: João Cotas; Adriana Leandro; Pedro Monteiro; Diana Pacheco; Artur Figueirinha; Ana M M Gonçalves; Gabriela Jorge da Silva; Leonel Pereira Journal: Mar Drugs Date: 2020-07-24 Impact factor: 5.118