Critical role of gonadal hormones on the genotoxic activity of the hepatocarcinogen DL-ZAMI 1305

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

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.

Androgenic profile and genotoxicity evaluation of testosterone propionate and novel synthesized heterocyclic steroids

In this study, we tested the androgenic activity of three structurally promising novel synthesized heterocyclic steroids compared with testosterone propionate in male mice. Additionally, the possible genotoxic effects of the novel synthesized heterocyclic steroids in comparison with testosterone propionate on male mice using chromosomal analysis of somatic and germ cells as well as RAPD-PCR were investigated. Male mice were administered with two doses of testosterone propionate, pyridoandrostene derivative 4b, pyrimidinoandrostene derivative 9a and thienoandrostene derivative 12 (200 and 400mg/kg b.w.) daily for 2 weeks. Results indicated that compounds 4b and 12 have androgenic activity as well as testosterone propionate. There were no significant differences in the frequencies of total chromosomal aberrations in both somatic and germ cells as well as no alteration in the DNA bands patterns between control, testosterone propionate and pyridoandrostene 4b treated animals. However, the pyrimidinoandrostene derivative 9a caused significant increase in the mean value of total chromosomal aberrations of both somatic and germ cells (P< or =0.01) as well as enhanced the polymorphic bands patterns as compared to the control and the other tested compounds. On the other hand, thienoandrostene derivative 12 induced significant decrease in the mean values of chromosomal aberrations in both somatic and germ cells, decreased sperm morphological abnormalities, increased the sperm count and motility than control. Our data indicate that testosterone propionate; pyridoandrostene 4b and thienoandrostene derivative 12 have no genotoxic activity. However, pyrimidinoandrostene derivative 9a has genotoxic activity possibly due to a modulation of the different expression of the catalyzing enzyme systems which will be investigated in the nearly future.

Liver genotoxic activity of an epoxide derivative of the hepatocarcinogenic beta-blocker DL-ZAMI 1305

A single administration of the sex-dependent hepatocarcinogenic beta-blocker DL-1-(2-nitro-3-methyl-phenoxy)-3-tert-butylamino-propan-2-ol (DL-ZAMI 1305) induces dose-dependent liver DNA damage, as evaluated by alkaline sucrose gradient analysis, in female but not in male Fisher 344 rats. A single administration of the direct mutagenic epoxide-derivative of DL-ZAMI 1305 3-methyl-2-nitro-1-(2,3-epoxypropoxy)-benzene induces dose-dependent DNA damage in the liver of animals of both sexes. However, also in this case, the genotoxic activity of the compound appears to be significantly higher in female than in male rats. A DNA-damaging capacity similar in the two sexes is instead exerted by DL-ZAMI 1305-unrelated direct mutagens, like N-methyl-N-nitrosourea (MNU) and methyl-methanesulfonate (MMS). The data confirm the sex-dependent susceptibility of rat liver to the genotoxic activity of DL-ZAMI 1305-related molecules, also in the absence of an absolute requirement for a metabolic activation of the compound.