Evaluation of the genotoxicity of clomiphene citrate

Clomiphene Citrate Medication for Infertility and Risk of Stillbirth or Neonatal Death: A Population-based Cohort Study

OBJECTIVE

To assess associations between clomiphene citrate (CC) use and perinatal death.

DESIGN

Whole of population data linkage cohort.

SETTING

South Australia.

PARTICIPANTS

All women giving birth between July 2003 and December 2015 (n = 242,077).

METHODS

All births of at least 20 weeks were linked to government records of dispensed medications. A pregnancy was considered exposed to CC if a prescription was dispensed from 90 days before through to the end of a conception window. Descriptive statistics for stillbirths and neonatal deaths were stratified by multiplicity. For singletons, multivariable logistic regression models were used to examine the association of CC exposure with the combined outcome of perinatal death.

MAIN OUTCOME MEASURES

Stillbirths and neonatal deaths (with 28 days of birth) combined as perinatal deaths.

RESULTS

Among singletons, the prevalence of stillbirth was 6.6 per 1000 births, with neonatal deaths of 2.1 per 1000 live births. Among singletons conceived with CC, stillbirth and neonatal death had a prevalence of 10.2 and 3.1 per 1000, respectively. For the combined outcome of perinatal death, the odds ratio was 1.54 (95% confidence interval 1.15, 2.07), stable upon adjustment for factors conveying biological (eg, obesity, pregestational diabetes) and social (eg, disadvantage) risks for perinatal death.

CONCLUSION

Risk of perinatal death may be increased in pregnancies that follow use of CC. While established confounding factors related to infertility were taken into account, there may be some residual contribution of underlying infertility.

Mutagenicity Assessment of Homologous Series of Methyl Ester Sulphonates (MES) Using the Bacterial Reverse Mutation (Ames) Test

Methyl ester sulphonate (MES) is an anionic surfactant that is suitable to be used as an active ingredient in household products. Four palm-based MES compounds with various carbon chains, namely C12, C14, C16 and C16/18 MES, were assayed by the in vitro bacterial reverse mutation (Ames) test in the Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 and the Escherichia coli strain WP2 uvrA, with the aim of establishing the safety data of the compounds, specifically their mutagenicity. The test was also carried out on linear alkylbenzene sulphonate (LAS) for comparison. The plate incorporation method was conducted according to the Organization for Economic Cooperation and Development (OECD) Test Guideline 471. All compounds were tested at five analysable non-cytotoxic concentrations, varying from .001 mg/plate to 5 mg/plate, with and without S-9 metabolic activation. All tested concentrations showed no significant increase in the number of revertant colonies compared to revertant colonies of the negative control. The Ames test indicated that each concentration of C12, C14, C16, C16/18 MES, and LAS used in this study induced neither base-pair substitutions nor frame-shift mutations in the S. typhimurium strains TA98, TA100, TA1535, and TA1537 and the E. coli strain WP2 uvrA. The results showed that C12, C14, C16 and C16/18 MES have no potential mutagenic properties in the presence and absence of S-9 metabolic activation, similarly to LAS. Therefore, the MES is safe to be used as an alternative to petroleum-based surfactants for household cleaning products.

Evaluation of the cytotoxic and genotoxic effects of mycotoxin fusaric acid

Fusaric acid (FA) is produced by several Fusarium species and is commonly found in grains. This investigation was performed to evaluate the cytotoxic and genotoxic effects of FA either in human cervix carcinoma (HeLa) cell line using 3-(4,5-dimethylthiazolyl-2)-2,5 diphenyltetrazolium bromide (MTT) assay and in human lymphocytes using chromosome aberrations (CAs), sister chromatid exchanges (SCEs), micronuclei (MN) as well as comet assay in vitro. The cells were treated with 0.78, 1.56, 3.125, 6.25, 12.50, 25, 50, 100, 200, and 400 µg/mL concentrations of FA. It has potent cytotoxic effect on HeLa cell line measured by MTT assay especially at higher concentrations (200, 400 µg/mL). The half of inhibitory concentration (IC₅₀) evidenced by FA in the HeLa cells was 200 μg/mL at 24 h and between 200 and 400 μg/mL at 48 h. It was also observed that FA produced a significant decrease in mitotic index (MI) at 12.50 µg/mL compared to solvent control. Furthermore, it indicated a cytotoxic effect at the concentrations ranging from 25 to 400 μg/mL in human lymphocytes. The results of this research point out that being exposed to FA at high concentrations show cytotoxicity. Besides FA induced comet tail intensity at 3.125, 6.25, and 12.50 µg/mL concentrations in isolated human lymphocytes. On the other hand, no genotoxic effects were seen in human lymphocytes in vitro using CA, SCE and MN assays.

Safety of clomiphene citrate: a literature review

Clomiphene citrate (CC) is a nonsteroidal compound and induces ovulation indirectly. The wide usage of the CC raises a question; is it safe or not? In the light of this question, this review aimed to highlight all researches and insights into the association between the use of CC and risk of genotoxicity, cytotoxicity, embryotoxicity, teratogenicity and risk of different cancer types. We conducted a MEDLINE/PubMed, Scopus, Web of Science, Google Scholar search. After a careful screening process of all authors, 32 of these articles were considered as appropriate, and reviewed. Our evaluations showed that CC has genotoxic, cytotoxic, embryotoxic and teratogenic properties. There is no association between the use of CC and risk of ovarian, breast, uterine, cervix, endometrium, lung, colorectal cancer, and lymphoma. However, risk increased especially after 6 cycles of use and especially in nulligravid women. The use of CC should be restricted to 6 cycles. Moreover, malignant melanoma and thyroid cancer risk was found to be higher among CC treated women in almost all studies. Further works should be conducted especially in animal models to assess its risk features.

The determination of possible genetic damage to women undergoing in vitro fertilization due to infertility caused by the male factor

In this study, we aimed at determining possible genetic damage to women who were exposed to in vitro fertilization (IVF) due to infertility with male factor. Four different genotoxicity tests were used in human lymphocytes in this study with regard to chromosomal aberration (CA), sister chromatid exchange (SCE), micronucleus (MN), and comet tests. There was a statistically significant increase in sister chromatid exchange (SCE) test in the study group compared with the control group. In addition, a higher rate of MN frequency was determined only in the 21–30 age range study group compared with the control group in the same age range. On the other hand, MN frequency did not differ significantly between the control and total study groups. In addition, there was no significant difference between the control group and the study group in terms of mitotic (MI), replication (RI), and nuclear division (NDI) indices. Furthermore, there was no statistically significant increase for chromosomal aberration and DNA damage to the study groups. Our results showed that in vitro fertilization treatments have a weak risk at the genetic level in cultured human lymphocytes.

Assessment of cytotoxic and genotoxic potential of pyracarbolid by Allium test and micronucleus assay

The present study evaluates the cytotoxic and genotoxic potential of pyracarbolid using both micronuleus (MN) assay, in human lymphocytes, and Allium cepa assay, in the root meristem cells. In Allium test, EC50 value was determined in order to selecting the test concentrations for the assay and the root tips were treated with 25 ppm (EC50/2), 50 ppm (EC50) and 100 ppm (EC50 × 2) concentrations of pyracarbolid. One percent of dimethyl sulphoxide (DMSO) and methyl methane sulfonate (MMS) were used as negative and positive controls, respectively. In the micronucleus assay, the cultures were treated with four concentrations (250, 500, 750 and 1000 µg/ml) of pyracarbolid for 24 and 48 h, negative and positive controls were also used in the experiment parallely. The results showed that mitotic index (MI) significantly reduced with increasing the pyracarbolid concentration at each exposure time. It was also obtained that prophase and metaphase index decreased significantly in all concentration at each exposure time. Anaphase index decreased as well and results were found to be statistically significant, except 24 h. A significant increase was observed in MN frequency in all concentrations and both treatment periods when compared with the controls. Pyracarbolid also caused a significant reduction in the cytokinesis block proliferation index (CBPI) in all concentration and both exposure time.

Induction of sister chromatid exchanges and cell division delays by clomiphene citrate in human lymphocytes

Objective:

Clomiphene citrate (CC) is a selective estrogen receptor modulator and is used for the treatment of in vitro fertilization, intracytoplasmic sperm injection, intrauterine insemination, and so on. In this study, sister chromatid exchanges (SCEs) and cell cycle delays were analyzed to investigate genotoxicity and cytotoxicity of CC in peripheral blood lymphocytes of healthy women.

Methods:

Human peripheral blood lymphocytes obtained from two donors were used to detect genotoxicity and cytotoxicity of CC. Lymphocytes were treated with various concentrations (0.40, 0.80, 1.60, and 3.20 µg/ml) of CC. A negative (distilled water) and a positive control (mitomycin-C = 0.20 µg/ml) were also used simultaneously with test substance-treated cultures. SCEs and cell division delays were measured from 25 cells and 100 cells perdonor, respectively.

Results:

CC significantly increased the mean SCE value at all concentrations compared with the negative control. This increase was found to be dose dependent ( r = 0.83) and at the highest concentration, nearly two times higher increase was observed than the negative control. However, replication index was not affected by the CC treatment.

Conclusion:

The present study shows that CC is genotoxic for human lymphocytes in vitro. Further investigations, especially in vivo are now needed in different test organisms to clarify the genotoxic activity of CC, which should also help to better understand genotoxic mechanism of this ovulation-stimulating drug.

Genotoxicity of the some selective estrogen receptor modulators: a review

The objective of this article is to review genotoxicological profile of the major selective estrogen receptor modulators, including clomiphene, tamoxifen, toremifene, raloxifene. These drugs have been used for infertility treatment and breast cancer prevention in high risk-women. However, some studies reported that especially tamoxifen is a genotoxic agent and is related with endometrial cancer. Our review indicate that clomiphene and tamoxifen were found as genotoxic agent in majority of the tests. However published reports showed that toremifene is a weakly genotoxic agent. The genotoxic effects of raloxifene are still poorly known. Further genotoxicity studies should be conducted especially for raloxifene.