Determination of DNA damage and telomerase activity in stanozolol-treated rats

Abstract

Anabolic androgenic steroids (AAS) are performance-enhancing drugs commonly abused by atheletes. Stanozolol is a synthetic testosterone-derived anabolic steroid. Although it is well known that AAS have several side-effects, there are only few toxicological studies available on the toxic effects and mechanisms of action of stanozolol. The aim of this study was to investigate the genotoxic effects of stanozolol and to determine its effects on telomerase activity in Sprague-Dawley male rats. For this purpose, 34 male rats were divided into 5 groups as follows: i) the control group (n=5); ii) the propylene glycol (PG)-treated group (n=5); iii) the stanozolol-treated group (n=8); iv) the PG-treated group subjected to exercise (n=8); and v) the stanozolol-treated group subjected to exercise (n=8). PG is used as a solvent control in our study. Stanozolol (5 mg/kg) and PG (1 ml/kg) were injected subcutaneously 5 days/week for 28 days. After 28 days, the animals were sacrificed, and DNA damage evaluation (comet assay) and telomerase activity assays were then performed using peripheral blood mononuclear cells (PBMCs). Telomerase activity was measured by using the TeloTAGGG Telomerase PCR ELISA PLUS kit. The results of this study revealed that stanozolol treatment induced DNA damage, while exercise exerted a protective effect. Stanozolol treatment without exercise stimulation was associated with a significant increase in telomerase activity in the PBMCs.

Anabolic androgenic steroids and carcinogenicity focusing on Leydig cell: a literature review

“…Other mechanisms hypothesized involved DNA-damage at different levels include: micronuclei formation [ 34 , 42 ], DNA methylation [ 36 ], ROS-mediated DNA covalent binding [ 39 ], and alterations in telomerases [ 44 – 45 ].…”

“…One of these agents has been proven high-dose nandrolone exposition, which determines a significant DNA damage in blood, liver, bone marrow, brain and testicle cells in experimental animals exposed [ 43 ]. On the other hand, AAS can elicit profound modifications in genetic sequences by means of alterations in telomerase activity [ 44 ]. Nourbakhsh et al [ 45 ], tried to verify the implications of androgens in ovarian carcinogenesis.…”

Stanozolol administration combined with exercise leads to decreased telomerase activity possibly associated with liver aging

“…Even though the mechanisms responsible for stanozolol-induced hepatotoxicity have not yet been clearly identified, proliferative effects on liver cells may play a central role in the observed hepatotoxicity ( 12 , 40 , 41 ). In our previous study, we demonstrated that stanozolol exerted DNA-damaging effects in peripheral blood lymphocytes, probably related to telomerase activity alterations ( 35 ). Although various environmental factors are known to up- and downregulate telomerase activity, the effects of exercise on telomerase activity have not yet been clearly identified ( 42 ).…”

“…Several studies have indicated that physical exercise increases telomerase activity in different cell types ( 52 , 53 ). However, to the best of our knowledge, there is no study available to date investigating the effects of stanozolol on telomerase activity in the presence/absence of exercise, apart from our previous study which focused on circlulating telomerase activity in peripheral blood mononuclear cells (PBMCs) ( 35 ). Our results indicated the elevation of telomerase activity and TERT expression in the liver tissue, which could be associated either with an increased proliferation risk due to stanozolol treatment ( 10 ), rather unlikely for such a short exposure period, or may represent a counteracting mechanism ( 54 ).…”

“…The determination of telomerase activity in rat liver tissue samples was performed quantitatively using the teloTAGGG telomerase PCR ELISA PLUS kit (Roche Diagnostic GmbH, Mannheim, Germany). The kit protocol was followed for telomerase activity assessment as previously described ( 35 , 36 ).…”