Soybean β-Conglycinin Prevents Age-Related Hearing Impairment.
Obesity-related complications are associated with the development of age-related hearing impairment. β-Conglycinin (β-CG), one of the main storage proteins in soy, offers multiple health benefits, including anti-obesity and anti-atherosclerotic effects. Here, to elucidate the potential therapeutic application of β-CG, we investigated the effect of β-CG on age-related hearing impairment. Male wild-type mice (age 6 months) were randomly divided into β-CG-fed and control groups. Six months later, the body weight was significantly lower in β-CG-fed mice than in the controls. Consumption of β-CG rescued the hearing impairment observed in control mice. Cochlear blood flow also increased in β-CG-fed mice, as did the expression of eNOS in the stria vascularis (SV), which protects vasculature. β-CG consumption also ameliorated oxidative status as assessed by 4-HNE staining. In the SV, lipofuscin granules of marginal cells and vacuolar degeneration of microvascular pericytes were decreased in β-CG-fed mice, as shown by transmission electron microscopy. β-CG consumption prevented loss of spiral ganglion cells and reduced the frequencies of lipofuscin granules, nuclear invaginations, and myelin vacuolation. Our observations indicate that β-CG ameliorates age-related hearing impairment by preserving cochlear blood flow and suppressing oxidative stress.
Department of Otolaryngology, Aichi Medical University, Aichi, Japan.
Tohru
T
Tanigawa
Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Rei
R
Shibata
Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Kazuhisa
K
Kondo
Department of Otolaryngology, Aichi Medical University, Aichi, Japan.
Nobuyuki
N
Katahira
Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Takahiro
T
Kambara
Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Yoko
Y
Inoue
Department of Otolaryngology, Aichi Medical University, Aichi, Japan.
Hiroshi
H
Nonoyama
Department of Otolaryngology, Aichi Medical University, Aichi, Japan.
Yuichiro
Y
Horibe
Department of Otolaryngology, Aichi Medical University, Aichi, Japan.
Hiromi
H
Ueda
Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Toyoaki
T
Murohara
D000818:Animals; D052179:Antigens, Plant / Q000008:administration & dosage* / Q000737:chemistry; D001835:Body Weight; D003051:Cochlea / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D004195:Disease Models, Animal; D005916:Globulins / Q000008:administration & dosage* / Q000737:chemistry; D006801:Humans; D051379:Mice; D009765:Obesity / Q000150:complications* / Q000188:drug therapy / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects; D011304:Presbycusis / Q000188:drug therapy* / Q000473:pathology; D055314:Seed Storage Proteins / Q000008:administration & dosage* / Q000737:chemistry; D030262:Soybean Proteins / Q000008:administration & dosage* / Q000737:chemistry; D013025:Glycine max / Q000737:chemistry*
D052179:Antigens, Plant; D005916:Globulins; D055314:Seed Storage Proteins; D030262:Soybean Proteins; C013894:beta-conglycinin protein, Glycine max