Volume 10, Issue 6 (November 2008) 10, 837–845; 10.1111/j.1745-7262.2008.00430.x
Protective effects of estrogens and caloric restriction during aging on various rat testis parameters
Khaled Hamden1, Dorothee Silandre2, Christelle Delalande2, Abdelfattah ElFeki1 and Serge Carreau2
1 Department of Animal Ecophysiology, Faculty of Sciences, University of Sfax, PB 802, Sfax 3018, Tunisia
2 USC 2006 INRA-EA 2608, Biochemistry, Caen-14032, France
Correspondence: Dr Serge Carreau, Department of Biochemistry, University of Caen, Esplanade de la Paix, Caen-14032, France. Fax: +33-2-3156-5120. E-mail: firstname.lastname@example.org
Received 24 January 2008; Accepted 16 June 2008.
Aim: To investigate the effects of 17β-estradiol (E2), Peganum harmala extract (PHE) and caloric restriction (CR) on various testis parameters during aging.
Methods: Twelve-month-old male rats were treated for 6 months with either E2 or PHE, or submitted to CR (40%).
Results: Our results show that estrogens and CR are able to protect the male gonad by preventing the decrease of testosterone and E2 levels as well as the decrease of aromatase and estrogen receptor gene expressions. Indeed, E2, PHE and CR treatments induced an increase in the superoxide dismutase activities and decreased the activity of testicular enzymes: gamma-glutamyl transferase, alkaline phosphatase, lactate deshydrogenase as well as the aspartate and lactate transaminases in aged animals. In addition, the testicular catalase and gluthatione peroxidase activities were enhanced in E2, PHE and CR-treated rats compared to untreated animals at 18 months of age. Moreover, the positive effects of estradiol, PHE and CR were further supported by a lower level of lipid peroxidation. Recovery of spermatogenesis was recorded in treated rats.
Conclusion: Besides a low caloric diet which is beneficial for spermatogenesis, a protective antioxydant role of estrogens is suggested. Estrogens delay testicular cell damage, which leads to functional senescence and, therefore, estrogens are helpful in protecting the reproductive functions from the adverse effects exerted by reactive oxygen species (ROS) produced in large quantities in the aged testis.
Keywords: aging, (phyto)estrogens, 17β-estradiol, Peganum harmala, caloric restriction, rat testis, antioxidant enzymes
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