Effect of AST on age-associated changes of vocal folds in a rat model.
OBJECTIVE
Reactive oxygen species (ROS) are associated with aging. Astaxanthin (AST) is a strong antioxidant and has been reported to prevent various ROS-induced diseases. In the current study, we investigated the effect of AST on age-associated histological and mRNA changes of vocal folds.


METHODS
Prospective animal experiment with control.


METHODS
Six-month-old Sprague-Dawley rats were fed on a normal powder diet with 0.01% (w/w) AST (aged AST-treated group) or without AST (aged sham-treated group). After 12 months of feeding, the larynges were harvested for histology, immunohistochemical detection of 4-hydroxy-2-nonenal (4-HNE), and quantitative real-time polymerase chain reaction for basic fibroblast growth factor (bFGF) and hepatocyte growth factor (HGF). Thirteen-week-old rats were used as a young control group (young group).


RESULTS
The expression of 4-HNE, an oxidative stress marker, significantly increased in the two aged groups compared with the young group. Histological examination showed that the deposition of hyaluronic acid in the lamina propria (LP) was significantly reduced in the aged sham-treated group compared with the young group, but no significant difference was observed between the aged AST-treated group and the young group. There were no significant differences in the mRNA expression of bFGF and HGF between the aged AST-treated group and the young group, although the expression of these genes was significantly reduced in the aged sham-treated group as compared with the young group.


CONCLUSIONS
These results suggest that AST has the potential to attenuate age-associated changes of vocal folds.
Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto.
Masanobu
M
Mizuta
Shigeru
S
Hirano
Nao
N
Hiwatashi
Toshiki
T
Kobayashi
Ichiro
I
Tateya
Shin-Ichi
S
Kanemaru
Tatsuo
T
Nakamura
Juichi
J
Ito
D000375:Aging / Q000187:drug effects* / Q000378:metabolism; D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004195:Disease Models, Animal; D005343:Fibrinolytic Agents; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis / Q000235:genetics; D005500:Follow-Up Studies; D005786:Gene Expression Regulation; D017228:Hepatocyte Growth Factor / Q000096:biosynthesis / Q000235:genetics; D007150:Immunohistochemistry; D008297:Male; D018384:Oxidative Stress; D011446:Prospective Studies; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D064706:Vocal Cord Dysfunction / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control*; D014827:Vocal Cords / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D024341:Xanthophylls / Q000494:pharmacology
D000447:Aldehydes; D000975:Antioxidants; D005343:Fibrinolytic Agents; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D024341:Xanthophylls; D016222:Fibroblast Growth Factor 2; D017228:Hepatocyte Growth Factor; C005948:astaxanthine; C027576:4-hydroxy-2-nonenal
AST; age-associated changes; reactive oxygen species; vocal folds