A combination antioxidant therapy prevents age-related hearing loss in C57BL/6 mice.
OBJECTIVE
Age-related hearing loss (ARHL) is characterized by gradual, progressive sensorineural hearing loss, which impairs communication, lending to clinical depression and social withdrawal. There are currently no effective treatments for ARHL. The purpose of this study is to evaluate the potential of a combination antioxidant therapy in preventing ARHL.


METHODS
Randomized controlled trial.


METHODS
Animal study.


METHODS
C57BL/6 mice, a recognized animal model of ARHL, were assigned to one of three groups: early treatment (n = 12), late treatment (n = 9), or control group (n = 9). Treatment groups of mice were fed with a combination agent comprising six antioxidant agents that target four sites within the oxidative pathway: L-cysteine-glutathione mixed disulfide, ribose-cysteine, NW-nitro-L-arginine methyl ester, vitamin B12, folate, and ascorbic acid. Auditory brainstem response (ABR) thresholds were recorded at baseline and every three months following initiation of treatment.


RESULTS
Threshold shifts from baseline were decreased in the treatment groups when compared to the control group at all tested frequencies (P < 0.001). The ABR threshold shift at 12 months of age for the control group was 34.7 dB with a 95% confidence interval (CI) of +/-1.6. The mean threshold shifts for the early and late treatment groups were 7.5 dB (+/-0.87, 95% CI) and 9.2 dB (+/-1.6, 95% CI).


CONCLUSIONS
Combination antioxidant therapy effectively decreased threshold shifts on ABR within an animal model of ARHL. Combination antioxidant therapy, with further research and investigation, may provide a safe and cost-effective method of preventing presbycusis in the growing elderly population.
Heman-Ackah
Selena E
SE
Department of Otolaryngology-Head and Neck Surgery, University of Minnesota, Minneapolis, MN, USA.
Juhn
Steven K
SK
Huang
Tina C
TC
Wiedmann
Timothy S
TS
D000375:Aging; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage; D001309:Auditory Threshold; D003545:Cysteine / Q000008:administration & dosage / Q000031:analogs & derivatives; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D016057:Evoked Potentials, Auditory, Brain Stem; D005978:Glutathione / Q000008:administration & dosage / Q000031:analogs & derivatives; D051379:Mice; D008810:Mice, Inbred C57BL; D019331:NG-Nitroarginine Methyl Ester / Q000008:administration & dosage; D011304:Presbycusis / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D014803:Vitamin B Complex / Q000008:administration & dosage
D000975:Antioxidants; D014803:Vitamin B Complex; C031586:cysteine-glutathione disulfide; D005978:Glutathione; D003545:Cysteine; D001205:Ascorbic Acid; D019331:NG-Nitroarginine Methyl Ester