| Summary: | 碩士 === 靜宜大學 === 食品營養學系 === 99 === Presbycusis is associated with the accumulation of free radicals and apoptosis. Moreover, the degeneration of nerve with aging may decrease the transmission of auditory nervous system then lead the prevalence of presbycusis. Tempeh contains abundant isoflavones and GABA which might promote the capacities of the antioxidative and neuron protection. Thus, the purposes of this study were to examine the effects of tempeh on the presbycusis. 9-month-old SAMP8 mice were divided into control and 900 mg/Kg BW tempeh groups, while SAMR1 mice was used to be the normal control. The auditory brainstem response (ABR) threshold shifts on the baseline (9 months) and 12 months were analyzed. The biochemical values was analyzed after sacrificed, and the catalase (CAT), glutathione peroxidase (GPx), B-cell lymphoma 2(Bcl-2)、Bcl-2 homologous antagonist/killer(Bak), neurotrophin-3 (NT-3), tyrosine kinase receptor (Trk C) and γ-amino butyric acid (GABA) Aβ3 receptor mRNA expressions of brain stem, temporal lobe and inner ear were also examined. The results showed that the ABR threshold shifts were significantly increased in the SAMP8 control group when compare with SAMR1 control group. The supplements of tempeh could reduce the ABR threshold shifts, and were similar with the SAMR1 control group. Antioxidant enzymes, antiapoptotic factors and neuroprotection factors of mRNA expression decreased accompany with the aging progression. The supplements of tempeh significantly increase not only the anti-oxidant enzymes expression, (CAT and GPx mRNA), but also the anti-apoptotic factor expression, (Bcl-2 mRNA) in brain stem, temporal lobe and inner ear. However, there were not significant differences on the pro-apoptotic factor expression, (Bak mRNA) among three groups. In addition, tempeh also significantly increased the neuroprotection factor, NT-3, Trk C and GABA Aβ3 mRNA receptor expression in brain stem, temporal lobe and inner ear. In summary, we conclude that tempeh could improve the antioxidant and anti-apoptotic factors in the brain and inner ear, enhanced the capacity of neuron transmission by up-regulation of neurotrophic factor and related receptor, and might recover the releases of the GABA Aβ3 receptor related neurotransmitters, which might retarded the process of presbycusis.
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