| dc.description.abstract | Abstract. Age‑related hearing loss (ARHL) is a major public
health concern, which is characterized by gradual, progres‑
sive sensorineural hearing loss and deterioration of sound
localization, with no effective treatment available to date. The
aim of the present study was to evaluate the efficacy of resve‑
ratrol to prevent and treat ARHL. For this purpose, 32 male
C57BL/6 mice were assigned to four groups: Early treatment,
late treatment, control and sham control. The experiment
lasted for 15 months. Treatment was started at three months
of age in the early treatment group and at sixth months in
the late treatment group. The auditory brainstem response
test was performed once every three months. At the end of
the study period, inducible nitric oxide synthase (iNOS),
cyclooxygenase (COX)‑2, NF‑κB, Bcl‑2, Bcl‑xL, Bax, Bcl‑2
homologous antagonist/killer (Bak), caspase‑3 and caspase‑9
levels in the cochlear tissues of the animals were analyzed by
reverse transcription‑quantitative PCR. Hearing thresholds of
the mice in the early treatment group were better than those in
the other groups (P<0.001) at the end of the study. However,
hearing levels in the late treatment group were not significantly
different from those in the control groups (P>0.05), although
mean thresholds were lower. The threshold shift in the early
treatment group was significantly lower at all frequencies when
compared with those in the control groups (P<0.001). The
mRNA expression levels of pro‑apoptotic genes Bax and Bak were lower (P<0.05), anti‑apoptotic genes Bcl‑2 and Bcl‑xL
were higher (P<0.05), NF‑κB, COX‑2 and iNOS as genes that
have a role in inflammation and caspase‑3 and caspase‑9 as
genes with a vital role in apoptosis were lower (P<0.05) in the
early treatment group when compared with the late treatment
and control groups. These results suggested that resveratrol is
effective in the prevention of ARHL, particularly when started
prior to the beginning of hearing loss. | en_US |
