Ginkgo biloba extract (EGb761) protects against aging-related caspase-mediated apoptosis in rat cochlea.
CONCLUSIONS
EGb761 treatment has a significant benefit with an early and preventive effect, reversing the deleterious effect of aging in the integrity of the rat cochlea, even in the late stage of the rat lifespan.


OBJECTIVE
We previously reported a significant relationship between aging and apoptosis in the rat cochlea. This study was designed to investigate the effects of Ginkgo biloba leaf extract (EGb761) on age-associated cochlear caspase activation.


METHODS
Sprague-Dawley rats (n = 80) divided into two groups according to their age (4 months old, younger, YR, and 12 months old, aged-mature, AM) were treated with 100 mg/kg/day body weight of EGb761 extract dissolved in tap water for two periods: 4 and 12 months. Then cochleae were harvested to measure caspase activities, ATP levels, total superoxide dismutase (SOD) activity, and caspase-3 gene expression. Auditory steady-state responses (ASSR) threshold shifts were also measured before sacrifice of the rats.


RESULTS
EGb761 treatment prevents significantly aging-related caspase-induced activities within the cochleae in YR and AM rats. In the short EGb761 treatment, YR rats showed lower levels of caspase-3/7 than AM rats. In contrast, longer treatment did not show significant differences between YR and AM rats. Reduced caspase-3/7 activity in presence of EGb761 correlates with significant improvements of ASSR threshold shifts.
Nevado
Julián
J
Instituto de Genética Médica y Molecular, Hospital Universitario La Paz, Madrid, Spain.
Sanz
Ricardo
R
Sánchez-Rodríguez
Carolina
C
García-Berrocal
José Ramón
JR
Martín-Sanz
Eduardo
E
González-García
José Angel
JA
Esteban-Sánchez
Jonathan
J
Ramírez-Camacho
Rafael
R
D000375:Aging / Q000473:pathology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism*; D003051:Cochlea / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D015834:Cochlear Diseases / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D005260:Female; D020441:Ginkgo biloba; D034381:Hearing Loss / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D010936:Plant Extracts / Q000494:pharmacology*; D012313:RNA / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000096983:Ginkgo Extract
D053148:Caspase 3; D010936:Plant Extracts; D012313:RNA; C063170:Ginkgo biloba extract; D000096983:Ginkgo Extract