Genotoxic potential of cyproterone acetate: a possible role of reactive oxygen species

Antitumor progestins activity: Cytostatic effect and immune response

Progestins are used to treat some hormone-sensitive tumors. This review discusses the mechanisms of progestins' effects on tumor cells, the differences in the effects of progesterone and its analogs on different tumor types, and the influence of progestins on the antitumor immune response. Progestins cause a cytostatic effect, but at the same time they can suppress the antitumor immune response, and this can promote the proliferation and metastasis of tumor cells. Such progestins as dienogest, megestrol acetate and levonorgestrel increase the activity of NK-cells, which play a major role in the body's fight against tumor cells. The use of existing progestins and the development of new drugs with gestagenic activity may hold promise in oncotherapy.

Nonylphenol and cyproterone acetate effects in the liver and gonads of Lithobates catesbeianus (Anura) tadpoles and juveniles

Environmental pollution plays an important role in amphibian population decline. Contamination with endocrine disrupting chemicals (EDCs) is particularly worrying due to their capacity to adversely affect organisms at low doses. We hypothesized that exposure to EDCs such as 4-nonylphenol (NP) and cyproterone acetate (CPA) could trigger responses in the liver and gonads, due to toxic and endocrine disrupting effects. Growth rate may also be impaired by contamination. We investigated sublethal effects of a 28-day exposure to three different concentrations of NP and CPA on liver pigmentation, gonadal morphology, body mass, and length of tadpoles and juveniles Lithobates catesbeianus. Liver pigmentation and the gonadal morphologies of treated tadpoles did not differ from control, but growth rate was impaired by both pollutants. Juveniles treated with 10 μg/L NP and 0.025 and 0.25 ng/L CPA displayed increased liver melanin pigmentation, but gonadal morphologies, sex ratios, and body mass were not affected after treatments. The increase in liver pigmentation may be related to defensive, cytoprotective role of melanomacrophages. The decreased growth rate in tadpoles indicates toxic effects of NP and CPA. Thus, contamination with NP and CPA remains a concern and sublethal effects of different dosages of the compounds on native species should be determined.

Genotoxic effects of 4-nonylphenol and Cyproterone Acetate on Rana catesbeiana (anura) tadpoles and juveniles

Genotoxic analyses are commonly used in ecotoxicological studies as early biomarkers to investigate the potential effects of environmental contaminants on biological models. Several pollutants can induce DNA damage and, therefore, counting micronuclei and other nuclear abnormalities are efficient tools to evaluate genotoxicity. Some pollutants such as 4-nonylphenol (NP), a detergent used mainly in industries, and Cyproterone Acetate (CPA), an antiandrogenic medicine, have already shown genotoxic effects on some vertebrates. However, although amphibians are considered bioindicators of environmental quality and their populations are declining worldwide, the effects of these compounds on anurans are not yet known and, therefore, we believe that it is important to investigate such effects on anurans. Since water contamination is one of the ultimate causes of amphibian decline, ecotoxicological studies are important to discuss the appropriate solutions to avoid species extinction. Thus, this study investigates the genotoxic effects on Rana catesbeiana tadpoles and juveniles after being exposed to 1, 10 and 100 μg/L NP and 0.025, 0.25 and 2.5 ng/L CPA, by counting the nuclear abnormalities after exposure. The laboratory experiments lasted 28 days. The experimental conditions were the same except for the water volume since tadpoles and juveniles exhibit different habits at different developmental stages. Compared to juveniles, tadpoles were more susceptible to both compounds as indicated by the increased nuclear abnormalities observed in the highest NP concentration and all tested CPA concentrations. The juveniles, on the other hand, responded only to the two highest CPA concentrations. We concluded that CPA, even at very low concentrations, is extremely harmful to both anuran developmental stages and, particularly, to tadpoles. The significant effects observed on tadpoles is an important outcome of this study since 100 μg/L or higher NP concentrations are frequently detected in the environment.

Male contraceptive efficacy of poly herbal formulation, contracept-TM, composed of aqueous extracts of Terminalia chebula fruit and Musa balbisiana seed in rat

CONTEXT

Terminalia chebula Retz (Combretaceae) and Musa balbisiana Colla (Musaceae) have a traditional reputation as a male contraceptive.

OBJECTIVE

To determine the hypo-testicular activity of aqueous extracts of Terminalia chebula (fruit) and Musa balbisiana (seed) separately, and in composite manner at the ratio of 1:1 named as 'Contracept-TM' compared to cyproterone acetate (CPA), for developing a polyherbal contraceptive.

MATERIALS AND METHODS

The separate extract of above said plants or 'Contracept-TM' at the dose of 40 mg/100 g body weight of rat/day or CPA at 2 mg/100 g body weight of rat/day was administered for 28 days. Spermiological, androgenic and oxidative stress sensors, LD50 and ED50/100 g body weight values were measured.

RESULTS

Treatment of individual, 'Contracept-TM' or CPA resulted significant decrease in the count of spermatogonia A (36.36-49.09%), pre-leptotene spermatocyte (19.11-55.30%), mid-pachytene spermatocyte (28.65-47.28%) and step 7 spermatid (29.65-51.59%). Activities of testicular Δ5, 3β (21.25-48.02%),17β-hydroxysteroid dehydrogenases (29.75-55.08%), catalase (19.06-43.29%) and peroxidase (30.76-62.82%), levels of testosterone (28.15-63.44%), testicular cholesterol (19.61-49.33%), conjugated diene (29.69-84.99%) and thiobarbituric acid reactive substances (41.25-86.73%) were elevated compare to the control. The ED50 and LD50 values were 40 mg and 5.8 g (T. chebula), 48 mg and 6.3 g (M. bulbisiana), 40 mg and 6.0 g ('Contracept-TM'), respectively.

DISCUSSION AND CONCLUSION

The said spermiological and androgenic sensors' levels were decreased significantly by 'Contracept-TM' than its constitutional individual plant extract and it may be comparable to standard anti-testicular drug like CPA. So, it may be concluded that above polyherbal formulation is potent for inducing hypo-testicular activity.

Antigenotoxic effects of ascorbic acid against megestrol acetate-induced genotoxicity in mice

The genotoxicity of megestrol acetate was studied in mouse bone marrow cells using sister chromatid exchanges (SCEs) and chromosomal aberrations (CAs) as parameters. Megestrol acetate (8.12, 16.25 and 32.50 mg/ kg of body weight) was injected intraperitoneally separately in different groups of animals. Both CAs and SCEs were statistically increased at 16.25 and 32.50 mg/kg of body weight. Our earlier in vitro studies show the generation of free oxygen radicals, by synthetic progestins responsible for the genotoxic damage. As the genotoxic effects of steroids can be reduced by natural products having antioxidant properties, and ascorbic acid possesses antioxidant activity, ascorbic acid (20, 40 or 60 mg/kg of body weight) administered together with megestrol acetate (32.50 mg/kg of body weight) significantly decreased CAs and SCEs, suggesting an antigenotoxic role of ascorbic acid against megestrol acetate induced genotoxic damage in mice bone marrow cells. The antigenotoxic effect was clearly dose dependent. The highest protective effect was observed at 60 mg/kg body weight of ascorbic acid treated with 32.50 mg/kg body weight of megestrol acetate.

Effect of the steroid K-canrenoate on hsp70 expression and tissue damage in transgenic Drosophila melanogaster (hsp70-lacZ) Bg9

In the present study the effect of 0.1, 0.2, 0.4, 0.8, and 1.0 µL/mL of the steroid K-canrenoate was evaluated in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg(9) for 6, 24, and 48 hours of duration. The treatment of 0.1, 0.2, and 0.4 µL/mL of K-canrenoate did not induce the activity of hsp70 significantly compared to the control. The treatments of 0.8 and 1.0 µL/mL of K-canrenoate not only caused tissue damage but also induced a significant increase in the expression of hsp70 for the different durations of exposure. The results of the present study suggest that the K-canrenoate at 0.8 and 1.0 µL/mL is cytotoxic and caused tissue damage in the third instar larvae of transgenic D. melanogaster (hsp70-lacZ) Bg(9).

Antigenotoxic role of Centella asiatica L. extract against cyproterone acetate induced genotoxic damage in cultured human lymphocytes

The majority of the Indian population use traditional natural preparations derived from plant material for the treatment of various diseases, and for that reason it becomes necessary to assess the mutagenic potential or modulating action of plants extract when associated with other substances. The genotoxicity testing provides human a risk assessment. Earlier in vitro and in vivo studies reveal that the plant extracts from various parts of the plant play a modulating role in xenobiotic effects. Identification and characterization of some active principles may lead to the development of the strategies to reduce the risk for developing cancer in humans. Cyproterone acetate (CPA), a synthetic progestin is not only a genotoxic agent but also a tumor initiating agent. It is used in oral contraceptives formulations and also in the treatment of various sexual and metabolic disorders. In this context, the antigenotoxic effect of Centella asiatica L. extract was studied against the genotoxic effect induced by CPA on human lymphocytes using chromosomal aberrations and sister chromatid exchanges as parameters. The treatment of the two doses of CPA, i.e. 20 and 30 microM was given along with the C. asiatica extract at the dosages of 1.075 x 10(-4), 2.125 x 10(-4), 3.15 x 10(-4) and 4.17 x 0(-4)g/ml of culture medium. A clear dose dependent decrease in the genotoxic damage of CPA was observed, suggesting a protective role of C. asiatica extract during CPA therapy. The results of the present study suggest that the plant extract per se do not have genotoxic potential, but can modulate the genotoxicity of CPA on human lymphocytes in vitro.

Anti-genotoxic effect of Ocimum sanctum L. extract against cyproterone acetate induced genotoxic damage in cultured mammalian cells

The anti-genotoxic effect of Ocimum sanctum L. extract was studied against the genotoxic effect induced by a synthetic progestin cyproterone acetate, on human lymphocytes using chromosomal aberrations, mitotic index, sister chromatid exchanges and replication index as a parameters. About 30 microM of cyproterone acetate was treated with O. sanctum L. infusion, at dosages of 1.075 x 10(-4), 2.125 x 10(-4) and 3.15 x 10(-4) g/ml of culture medium. A clear dose-dependent decrease in the genotoxic damage of cyproterone acetate was observed, suggesting a possible modulating role of the plant infusion. The results of the present study suggest that the plant infusion per se does not have genotoxic potential, but can modulate the genotoxicity of cyproterone acetate on human lymphocytes in vitro.

Genotoxic potential of medroxyprogesterone acetate in cultured human peripheral blood lymphocytes

Medroxyprogesterone acetate was studied at three different concentrations (1, 5 and 10 microM), for its genotoxic effects in human peripheral blood lymphocyte culture using chromosomal aberrations and sister chromatid exchanges as parameters. Duplicate peripheral blood cultures were treated with three different concentrations (1, 5 and 10 microM) of medroxyprogesterone acetate. The study was carried out both in the absence as well as in the presence of metabolic activation (S9 mix) with and without NADP. Medroxyprogesterone acetate was found genotoxic at 5 and 10 microM in the presence of S9 mix with NADP. To study the possible mechanism of the genotoxicity of medroxyprogesterone acetate, superoxide dismutase and catalase at different doses were used separately and in combination with 10 microM of medroxyprogesterone at different doses in the presence of S9 mix with NADP. Superoxide dismutase treatment results in an increase of the genotoxic damage but catalase treatment reduce the genotoxic damage of medroxyprogesterone acetate. Catalase treatment in combination with superoxide dismutase also results in the further reduction of the genotoxic damage. The results of the present study reveal that medroxyprogesterone acetate is genotoxic only in the presence of metabolic activation (S9 mix) with NADP. Treatments with superoxide dismutase and catalase suggests the possible generation of reactive oxygen species by redox cycling of various forms of quinones, similar to estrogens, that are the results of aromatic hydroxylation by cytochrome P450s.

Protective effect of nordihydroguaiaretic acid (NDGA) against norgestrel induced genotoxic damage

Nordihydroguaiaretic acid (NDGA) is a phenolic lignan and possesses antioxidant and number of properties potentially useful to man. The effect of NDGA was studied against norgestrel induced genotoxic damage, using sister chromatid exchanges (SCEs), chromosomal aberrations (CAs), mitotic index (MI) and replication index (RI) as parameters. Amounts of 5, 10 and 20 microM of norgestrel was tested for its genotoxic effect in the absence as well as presence of S9 mix, and was found to be genotoxic at 10 and 20 microM in the presence of S9 mix. Again, 10 microM of norgestrel was treated with 0.5 and 1 microM of NDGA, separately, in the presence of S9 mix. Similar treatment was given with 20 microM of norgestrel. Treatments given with NDGA result in the reduction of SCE, CA and increase of MI as well as RI, suggesting its protective action on human lymphocytes in vitro against the norgestrel induced genotoxic damage.