Early embryonic losses in mice induced by diethylstilbestrol

In vivo studies on evaluation of endophytic fungi extract from Trichoderma viride against cervical cancer

Background

The crude ethyl acetate Trichoderma viride extract obtained from Ziziphus mauritiana was initially analyzed by HPLC for identification of major bioactive compounds, and then, it was subjected for in vivo acute and sub-acute toxicity, cervical cancer studies using Wistar albino rats.

Result

During acute toxicity studies, animal groups treated with distinct dosage of 2000 mg/kg restrained toxicity signs in tested groups compared to controls for 14 days which established to be secure and non-toxic even at high dose. However, in terms of sub-acute toxicity studies, animals were given with repeated amount of (10 mg/kg, 20 mg/kg and 40 mg/kg) for a period of 28 days along with control group. Upon investigations of hematological, biochemical and histopathological studies repeated dose of 20 mg/kg and 40 mg/kg of T. viride extract found to be normal and no other major changes observed among treated groups. During in vivo studies, after treatment of T. viride extract (40 mg/kg) effectively inhibited the cervical cancer cell growth in DES-treated groups. Through HPLC analysis the major compound ursolic acid and 2,5-piperazinedione were mainly identified.

Conclusion

The secondary metabolites of endophytes have been used substantially for the sustainable production of therapeutically important compounds. The limited availability of bioactive principles in plant sources could be surpassed by exploiting the chemical entities in the endophytes. In the present investigation, it has been accomplished that ethyl acetate extract of T. viride was safe at higher and lower dosage could be considered for pharmacological studies from plant may provide an excellent avenue for the discovery of drug candidates against deadly cancer diseases.

Assessment of the in vitro developmental toxicity of diethylstilbestrol and estradiol in the zebrafish embryotoxicity test

The present study investigated the developmental toxicity of diethylstilbestrol (DES) in the zebrafish embryotoxicity test (ZET). This was done to investigate whether the ZET would better capture the developmental toxicity of DES than the embryonic stem cells test (EST) that was previously shown to underpredict the DES-induced developmental toxicity as compared to in vivo data, potentially because the EST does not capture late events in the developmental process. The ZET results showed DES-induced growth retardation, cumulative mortality and dysmorphisms (i.e. induction of pericardial edema) in zebrafish embryos while the endogenous ERα agonist 17β-estradiol (E2) showed only growth retardation and cumulative mortality with lower potency compared to DES. Furthermore, the DES-induced pericardial edema formation in zebrafish embryos could be counteracted by co-exposure with ERα antagonist fulvestrant, indicating that the ZET captures the role of ERα in the mode of action underlying the developmental toxicity of DES. Altogether, it is concluded that the ZET differentiates DES from E2 with respect to their developmental toxicity effects, while confirming the role of ERα in mediating the developmental toxicity of DES. Furthermore, comparison to in vivo data revealed that, like the EST, in a quantitative way also the ZET did not capture the relatively high in vivo potency of DES as a developmental toxicant.

Estrogen receptor alpha (ERα)-mediated coregulator binding and gene expression discriminates the toxic ERα agonist diethylstilbestrol (DES) from the endogenous ERα agonist 17β-estradiol (E2)

Diethylstilbestrol (DES) is a synthetic estrogen and proven human teratogen and carcinogen reported to act via the estrogen receptor α (ERα). Since the endogenous ERα ligand 17β-estradiol (E2) does not show these adverse effects to a similar extent, we hypothesized that DES' interaction with the ERα differs from that of E2. The current study aimed to investigate possible differences between DES and E2 using in vitro assays that detect ERα-mediated effects, including ERα-mediated reporter gene expression, ERα-mediated breast cancer cell (T47D) proliferation and ERα-coregulator interactions and gene expression in T47D cells. Results obtained indicate that DES and E2 activate ERα-mediated reporter gene transcription and T47D cell proliferation in a similar way. However, significant differences between DES- and E2-induced binding of the ERα to 15 coregulator motifs and in transcriptomic signatures obtained in the T47D cells were observed. It is concluded that differences observed in binding of the ERα with several co-repressor motifs, in downregulation of genes involved in histone deacetylation and DNA methylation and in upregulation of CYP26A1 and CYP26B1 contribute to the differential effects reported for DES and E2.

The in vivo developmental toxicity of diethylstilbestrol (DES) in rat evaluated by an alternative testing strategy

In the present study, we evaluated an alternative testing strategy to quantitatively predict the in vivo developmental toxicity of the synthetic hormone diethylstilbestrol (DES). To this end, a physiologically based kinetic (PBK) model was defined that was subsequently used to translate concentration-response data for the in vitro developmental toxicity of DES, obtained in the ES-D3 cell differentiation assay, into predicted in vivo dose-response data for developmental toxicity. The previous studies showed that the PBK model-facilitated reverse dosimetry approach is a useful approach to quantitatively predict the developmental toxicity of several developmental toxins. The results obtained in the present study show that the PBK model adequately predicted DES blood concentrations in rats. Further studies revealed that DES tested positive in the ES-D3 differentiation assay and that DES-induced inhibition of the ES-D3 cell differentiation could be counteracted by the estrogen receptor alpha (ERα) antagonist fulvestrant, indicating that the in vitro ES-D3 cell differentiation assay was able to mimic the role of ERα reported in the mode of action underlying the developmental toxicity of DES in vivo. In spite of this, combining these in vitro data with the PBK model did not adequately predict the in vivo developmental toxicity of DES in a quantitative way. It is concluded that although the EST qualifies DES as a developmental toxin and detects the role of ERα in this process, the ES-D3 cell differentiation assay of the EST apparently does not adequately capture the processes underlying DES-induced developmental toxicity in vivo.

Effects of oestradiol for luteal phase support in fresh embryo transfer cycles: A retrospective cohort study

OBJECTIVE

Any benefit of oestradiol supplementation with progesterone for luteal support after fresh embryo transfer in in vitro fertilisation/intracytoplasmic sperm injection (IVF/ICSI) cycles remains controversial. In this study, we further addressed this question in cycles using gonadotropin-releasing hormone (GnRH) agonist for ovarian stimulation.

DESIGN

A retrospective cohort study in a tertiary teaching and research hospital.

PATIENT(S)

A total of 1602 patients were given oestradiol valerate (E) in addition to progesterone (P) as luteal support. One thousand six hundred and two patients receiving progesterone alone were selected as the control group.

MAIN OUTCOME MEASURE(S)

Live birth rate. Secondary measures included clinical pregnancy rate, miscarriage rate and premature birth rate.

RESULT(S)

Clinical pregnancy and live birth rates were similar for the P alone vs the P+E group. In cycles with oestradiol (E2) levels less than 5000 pmol/L on the day of hCG trigger, E supplementation resulted in a significantly higher live birth rate (23.44% vs 32.92%, OR = 1.60 [95% CI 1.05 to 2.46]). In cycles with oestradiol levels 5000 to 10 000 pmol/L on the day of hCG trigger, E supplementation did not increase the live birth rate (34.43% vs 35.42%, OR = 0.90 [95% CI 0.80 to 1.01]). In cycles with oestradiol levels over 10 000 pmol/L on the day of hCG trigger, the live birth rate was significantly lower (36.83% vs 31.37%, OR = 0.78 [95% CI 0.62 to 0.99]) and the premature birth rate was significantly higher (19.66% vs 28.73%,OR = 1.65 [95% CI 1.05 to 2.59]) in the E supplementation group.

CONCLUSION(S)

Any benefit of oestradiol supplementation for luteal phase support appears to correlate with the serum oestradiol level on the day of hCG trigger. Oestradiol supplementation is beneficial for improving live birth rate in cycles with oestradiol levels less than 5000 pmol/L, but is not recommended in cycles with oestradiol levels over 10 000 pmol/L.

Early to middle gestational exposure to diethylstilbestrol impairs the development of labyrinth zone in mouse placenta

This study was performed to clarify the involvement of impaired labyrinth zone (LZ) of the placenta in the developmental toxicity of diethylstilbestrol (DES). DES at 10 μg/kg per day was administered orally to mice on days 4 through 8 of gestation. Histological observation of the LZ and determination of blood glucose levels in dam and fetus were performed on day 13. A high frequency of embryonic death was observed in the DES group. DES induced the underdevelopment of the plexus vasculosus, extensive maternal blood space and the decreased expression of glucose transporters in the LZ, and a reduction of the glucose level in embryos. These findings suggest that impaired LZ development may be related to the embryolethality of DES.

Effect of estrogen on rat placental development depending on gestation stage

We examined the sequential histopathological changes in the placenta from rats exposed to estrogen. 17 β-estrogiol-3-benzoate was intraperitoneally administered at 100 μg/animal/day during GD 6 to GD 8 (GD6-8 treated group), GD 9 to GD 11 (GD9-11 treated group) and GD 12 to GD 14 (GD12-14 treated group), and the placentas were sampled on GDs 11, 13, 15, 17, and 21. Fetal mortality rates were increased up to approximately 50% in the GD6-8 and 9-11 treated groups, but there was no change of fetal weight on GD 21. An increase in placental weight and a reduction in fetal/placental weight ratio were detected during GD 17 to GD 21 in the GD6-8 treated group. Histopathologically, hypoplasia of metrial gland was detected with defective development of spiral arteries in the GD6-8 and GD9-11 treated groups. A decrease in the thickness of metrial gland was observed from GD 11 onwards in the GD6-8 treated group and from GD 13 onwards in the GD9-11 treated group. The endovascular trophoblasts invaded into the spiral arteries in the deep part of metrial gland in these treated groups. The number of phospho-histone H3 positive cells was decreased on GD 11 or GD 13 in these groups. In the decidua basalis, transitory necrosis was observed with hemorrhage on GD 13 in the GD6-8 and GD9-11 treated groups. In the labyrinth zone, cystic dilatation of the sinusoid was observed with congestion in the GD6-8 treated group, resulting in an increased placental weight. Therefore, we consider that estrogen inhibits the proliferation of decidualized endometrial stromal cells in the metrial gland, and leads to metrial gland hypoplasia with less development of the spiral arteries. The reduced utero-placental blood flow is supposed to be one of the important factors for poor reproductive performance.

Developmental effects of oral exposure to diethylstilbestrol on mouse placenta

Placental growth and function are of biological significance in that placental tissue promotes prenatal life and the maintenance of pregnancy. Exposure to synthetic estrogens causes embryonic mortality and placental growth restriction in mice. The aim of the present study was to examine the effects of diethylstilbestrol (DES) on placenta in mice. DES at 1, 5, 10 or 15 µg kg(-1) day(-1) , or 17β-estradiol (E2 ) at 50 µg kg(-1) day(-1) , was administered orally to ICR mice on days 4 through to 8 of gestation. Expression of ERα, ERβ, ERRβ or ERRγ mRNA in the junctional or labyrinth zone of the placentas on day 13 was assessed using RT-PCR, as well as the embrynic mortality, embryonic and placental weight, histological changes of labyrinth and ultrastructural changes of the trophoblast giant cells (TGCs). Embryo mortalities in the DES 10 and 15 µg kg(-1) day(-1) groups were markedly increased. No significant changes in embryonic and placental weight were observed in any DES- or E2 -exposed groups. Expression of ERα mRNA in the junctional zone with male embryos in the 5 µg kg(-1) day(-1) group was significantly higher than that in the control, whereas expression was not determined in the 15 µg kg(-1) day(-1) group. Histological observation revealed that the placentas exposed to DES at 10 µg kg(-1) day(-1) lacked the developing labyrinth. Ultrastructural observation of the TGCs showed poor rough-surfaced endoplasmic reticulum in the DES 10 µg kg(-1) day(-1) group. The present data suggest that developmental changes induced by DES may be related to interference with the nutrition and oxygen exchange between mother and embryo or decreased protein synthesis, resulting in a high frequency of embryo mortality.