Protective effect of 17beta-estradiol on oxidative stress and liver dysfunction in aged male rats.
In aging liver oxidative stress increases due to the decrease in antioxidant bio-molecules such as estrogens which can be modified by hormonal replacement therapy (HRT). With this in mind, we hypothesized that age-related decline in steroidogenesis may be associated with the impairment of the antioxidant defense cells in liver, the increase in lipid peroxidation, hepatic dysfunction and histological changes; estrogens prevent all these changes induced by aging. 17beta-estradiol treatment was initiated in 12 month-old Wistar rats, and continued until 18 months of age. Our results showed that 17beta-estradiol (E2) level in the serum of the aged untreated rats was reduced by -32% in 18 month-old rats compared to the young animals (4-month-old). The superoxide dismutase (SOD), catalase (CAT), and gluthatione peroxidase (GPX) activities were reduced by -47, -46, and -29% respectively in old rat liver. In addition, the TBARs in liver and hepatic dysfunction parameters in plasma such as gamma-glutamyl transferase (GGT), phosphatase alkalin (PAL) as well as bilirubin level increased significantly in old rats, and histological changes were investigated. In E2-treated rats, protective effects were observed. Indeed, 17beta-estradiol attenuates all changes induced by aging. The 17beta-estradiol level was higher in old E2-treated rats compared to the control rats. Moreover, the SOD, CAT and GPX activities were higher by +28, +15, and +11% respectively. This anti-aging effect of estrogens was clarified by a lower level of lipid peroxidation and liver dysfunction parameters as well as by histological observation.
Hamden
K
K
Animal Ecophysiology laboratory, Faculty of Sciences, Sfax, Tunisia. hamdenkhalid@yahoo.fr
Carreau
S
S
Ellouz
F
F
Masmoudi
H
H
El
Feki A
FA
D000375:Aging / Q000502:physiology*; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001663:Bilirubin / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D004958:Estradiol / Q000097:blood / Q000494:pharmacology*; D005979:Glutathione Peroxidase / Q000378:metabolism; D008099:Liver / Q000033:anatomy & histology / Q000187:drug effects*; D008297:Male; D009929:Organ Size; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D005723:gamma-Glutamyltransferase / Q000378:metabolism
D017392:Thiobarbituric Acid Reactive Substances; D004958:Estradiol; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase; D001663:Bilirubin