June 7, 2011
Effect of the reduced form of coenzyme Q10 on the progression of age-associated hearing loss
-Collaborative research with Shinshu University-
Kaneka Corporation (headquarters : Osaka, Japan; President: Mr. Kimikazu Sugawara) confirmed the effects of the reduced form of coenzyme Q10 (hereafter, Ubiquinol) in suppressing the progression of age-associated hearing loss in an animal model. The research was conducted in collaboration with Prof. Keiichi Higuchi, Department of Aging Biology, Institute on Aging and Adaptation, Shinshu University Graduate School of Medicine. These results were presented at "The 8th Scientific Meeting of the Japanese Coenzyme Q Association" held in Tokyo University of Technology on January 28, 2011. The result are also scheduled to be presented at “The 11th Scientific Meeting of the Japanese Society of Anti-Aging Medicine” held in Kyoto International Conference Center on May 27-29, 2011.
Kaneka Corporation reported that the repeated administration of Ubiquinol from juvenile stage decelerated the aging in senescence-accelerated (SAMP1) mice in collaboration with Prof. Higuchi in 2006 (Yan J et al. Exp Gerontol 2006). In this study, the mice were fed with a diet containing Ubiquinol at 0 (control) and 0.3% started at age of 1, 7 and 13 months (juvenile, mature and senile stage, respectively). Body weight, food intake and degree of senescence (aging) were compared between Ubiquinol groups and control group. And the effect of Ubiquinol on the progression of age-associated hearing loss was analyzed by the hearing ability of the mice aged 1, 7, 13 and 19 months by using auditory brainstem response (ABR) method*.
As a result, no effect on the deceleration of progression of the degree of senescence was observed in the Ubiquinol groups started from mature and senile stages compared with control group, whereas significant decrease in the progression of the degree of senescence was observed in the Ubiquinol group fed from juvenile stage to 19 months of age compared with control group. In control group, all of the four mice developed hearing abnormalities in high tone at age of 7 months and in middle and low tones at age of 13 months, and all of the two mice developed loss of hearing completely at age of 19 months. In Ubiquinol group, hearing abnormality in high tone, middle tone and low tones were mild and remarkable effects of reducing hearing abnormality were observed, as stated as below.
○ Suppression effect of progression of the hearing abnormality was determined by “The threshold value of the ABR” that is the sound stimulus strength where the specific brain wave no longer appeared.
(1) Mice treated with Ubiquinol from juvenile stage
- Three of the four mice aged 7 months preserved excellent hearing abilities in high tone. The fourth mouse aged 7 months developed mild hearing abnormality in high tone.
- One of four mice aged 13 months preserved excellent hearing ability in high tone. Two of four mice aged 13 months preserved good hearing abilities in high tone with some mild hearing abnormalities. In middle tone and low tone, all mice aged 13 months preserved good hearing abilities with some hearing abnormalities.
- All mice aged 19 months maintained hearing abilities with some abnormalities in all tones.
(2) Mice treated with Ubiquinol from mature stage
- All mice aged 13 months preserved excellent hearing ability in middle tone and low tone.
(3) Mice treated with Ubiquinol from senile stage
- All mice aged 19 months preserved hearing abilities in middle tone and low tone.
* The auditory brainstem response method: A clinical test method that determines the hearing ability by analyzing brain waves of the brainstem induced by acoustic stimulation from ears with computer software. This method is highly valuable in diagnosis and has been used to diagnose hearing loss and brain stem disorder.
