Preventive effects of isoflavones, genistein and daidzein, on estradiol-17beta-related endometrial carcinogenesis in mice

The roles and clinical applications of interleukins in endometrial carcinoma

As a common malignant tumor of the female reproductive system, endometrial carcinoma (EC) seriously endangers women's health with an increasing incidence. The oncogenesis and progression of cancer are closely linked with immune microenvironment, of which interleukins are the important components. In order to illustrate the roles and clinical applications of interleukins in EC, literature of interleukins and EC were reviewed. Based on the present studies, interleukins play crucial roles in the oncogenesis and development of EC via regulating the proliferation, migration, invasion, angiogenesis, apoptosis, pyroptosis and autophagy of EC as well as the immune function against EC. And some of the interleukins seems to have prospective clinical applications in EC, such as evaluating the risk of tumorigenesis, discriminating the malignancy from benign disorders or normal condition, indicating cancer aggressiveness, predicting the prognosis of patients and serving as the novel therapy. However, there is still a long way to go before the clinical applications of interleukins in EC come into reality. Nevertheless, it is certain that the exploration of interleukins will definitely be of great benefit to the screening, diagnosis and treatment of EC in the future.

Chrysin attenuates estradiol-induced endometrial hyperplasia in rats via enhancing PPARα activity

Endometrial hyperplasia (EH) is a complex condition that commonly affects women after menopause. Since the current available treatments for EH are mainly invasive, there is a need for developing new treatment modalities. Chrysin (Ch) is a dihydroxyflavone with numerous promising therapeutic potentials. In this study, Ch's protective effects on estradiol (E2)-induced EH were studied in rats. Animals were allocated randomly to five groups and were treated for 4 weeks as follows: Group 1, control: received the vehicle; group 2, Ch: received Ch 25 mg/kg; group 3, estradiol (E2): received E2 (3 mg/kg) 3 × weekly subcutaneously and the vehicle. Group 4, E2 + Ch 10 mg/kg and group 5, E2 + Ch 25 mg/kg: Ch was given once daily at 10 mg/kg or 25 mg/kg, respectively. In addition, E2 was administered 3 × weekly (3 mg/kg) in groups 4 and 5. Ch inhibited the E2-induced increase in uterine weights and histopathological changes. Ch lowered the cyclin D1 expression. Ch raised the caspase-3 content and Bax mRNA expression. Furthermore, it corrected the raised Bcl2 mRNA expression due to E2. Ch inhibited MDA accumulation and GSH depletion. It also prevents E2-induced SOD and GPx exhaustion. It also ameliorated the rise in NFκB, TNF-α, and IL-6 expression. These effects were correlated with an enhanced PPARα activity ratio relative to the E2 group. This suggests that Ch attenuates EH in this model by exerting anti-proliferative, anti-oxidant, and anti-inflammatory effects partially through increasing PPARα activity.

Excess Heme Promotes the Migration and Infiltration of Macrophages in Endometrial Hyperplasia Complicated with Abnormal Uterine Bleeding

In patients, endometrial hyperplasia (EH) is often accompanied by abnormal uterine bleeding (AUB), which is prone to release large amounts of heme. However, the role of excess heme in the migration and infiltration of immune cells in EH complicated by AUB remains unknown. In this study, 45 patients with AUB were divided into three groups: a proliferative phase group (n = 15), a secretory phase group (n = 15) and EH (n = 15). We observed that immune cell subpopulations were significantly different among the three groups, as demonstrated by flow cytometry analysis. Of note, there was a higher infiltration of total immune cells and macrophages in the endometrium of patients with EH. Heme up-regulated the expression of heme oxygenase-1 (HO-1) and nuclear factor erythroid-2-related factor 2 (Nrf2) in endometrial epithelial cells (EECs) in vitro, as well as chemokine (e.g., CCL2, CCL3, CCL5, CXCL8) levels. Additionally, stimulation with heme led to the increased recruitment of THP-1 cells in an indirect EEC-THP-1 co-culture unit. These data suggest that sustained and excessive heme in patients with AUB may recruit macrophages by increasing the levels of several chemokines, contributing to the accumulation and infiltration of macrophages in the endometrium of EH patients, and the key molecules of heme metabolism, HO-1 and Nrf2, are also involved in this regulatory process.

Piceatannol SNEDDS Attenuates Estradiol-Induced Endometrial Hyperplasia in Rats by Modulation of NF-κB and Nrf2/HO-1 Axes

Endometrial hyperplasia (EH) is the most common risk factor for endometrial malignancy in females. The pathogenesis of EH has been directly linked to uterine inflammation, which can result in abnormal cell division and decreased apoptosis. Piceatannol (PIC), a natural polyphenolic stilbene, is known to exert anti-inflammatory, antioxidant and anti-proliferative activities. The aim of the present study was to examine the potential preventive role of PIC in estradiol benzoate (EB)-induced EH in rats. A self-nanoemulsifying drug delivery system (SNEDDS) was prepared to improve the solubility of the PIC. Therefore, thirty female Wistar rats were divided into five groups: (1) control, (2) PIC SNEDDS (10 mg/kg), (3) EB (0.6 mg/kg), (4) EB + PIC SNEDDS (5 mg/kg) and (5) EB + PIC SNEDDS (10 mg/kg). The administration of PIC SNEDDS prevented EB-induced increases in uterine weights and histopathological changes. Additionally, it displayed pro-apoptotic and antioxidant activity in the endometrium. Immunohistochemical staining of uterine sections co-treated with PIC SNEDDS showed significantly decreased expression of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and nuclear transcription factor-kappa B (NF-κB). This anti-inflammatory effect was further confirmed by a significant increase in Nrf2 and heme oxygenase-1 (HO-1) expression. These results indicate that SNEDDS nanoformulation of PIC possesses protective effects against experimentally induced EH.

The role of isoflavones in augmenting the effects of radiotherapy

Cancer is one of the major health problems and the second cause of death worldwide behind heart disease. The traditional soy diet containing isoflavones, consumed by the Asian population in China and Japan has been identified as a protective factor from hormone-related cancers. Over the years the research focus has shifted from emphasizing the preventive effect of isoflavones from cancer initiation and promotion to their efficacy against established tumors along with chemo- and radiopotentiating effects. Studies performed in mouse models and results of clinical trials emphasize that genistein or a mixture of isoflavones, containing in traditional soy diet, could be utilized to both potentiate the response of cancer cells to radiotherapy and reduce radiation-induced toxicity in normal tissues. Currently ongoing clinical research explores a potential of another significant isoflavone, idronoxil, also known as phenoxodiol, as radiation enhancing agent. In the light of the recent clinical findings, this article reviews the accumulated evidence which support the clinically desirable interactions of soy isoflavones with radiation therapy resulting in improved tumor treatment. This review discusses important aspects of the development of isoflavones as anticancer agents, and mechanisms potentially relevant to their activity in combination with radiation therapy of cancer. It gives a critical overview of studies characterizing isoflavone targets such as topoisomerases, ENOX2/PMET, tyrosine kinases and ER receptor signaling, and cellular effects on the cell cycle, DNA damage, cell death, and immune responses.

Effects of Isoflavone Supplementation on the Response to Medroxyprogesterone in Premenopausal Women with Nonatypical Endometrial Hyperplasia: A Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVE

The purpose of this study was to evaluate the impact of isoflavone supplementation compared with placebo on endometrial histology and serum estradiol levels in premenopausal women with nonatypical endometrial hyperplasia.

MATERIALS AND METHODS

The present double-blindplacebo-controlled clinical trial was conducted on 100 women with nonatypical endometrial hyperplasia in the age range of 30 to 45 years. Participants were randomly assigned to receive 50 mg of isoflavone (n = 50) or placebos (n = 50) daily for three months. Both groups received the standard treatment of nonatypical endometrial hyperplasia. Endometrial biopsy and blood samples were taken at the baseline and three months after the intervention. The incidence of drug side effects was assessed as well.

RESULTS

After three months, 88.4% of isoflavone-administered subjects had a significant histological improvement compared to 68.9% subjects in the placebo group (P=0.02). There were no significant differences between the two groups in the changes of serum estradiol levels and the incidence of drug side effects.

CONCLUSION

The findings of the present study demonstrated that the coadministration of 50 mg of isoflavones and medroxyprogesterone acetate increases the treatment efficacy in women with nonatypical endometrial hyperplasia. Clinical Trial Registration. This trial was registered on the Iranian website for clinical trial registration (https://www.irct.ir/trial/53553).

Female infertility and herbal medicine: An overview of the new findings

Infertility is defined as the failure to achieve a successful pregnancy after 12 months' sexual activity that affects 15%-17% of couples in the world and about 50% of them are related to female infertility factors. In this study, using the PRISMA checklist and MeSH keywords, 128 articles were extracted from various databases (PubMed, Cochrane library, WHO, Iranmedex, Science Direct, SID, and Google Scholar search engine) without language and time restrictions, and 128 articles were selected after eliminating duplicate studies. In this review, we present some solid evidence for role of herbal medicine in the treatment of female infertility. The results of this study showed that different parts of some plants are rich in polyphenolic compounds (isoflavones and flavonoids) and other compounds which are beneficial to in reproductive health in women. The compounds in these plants, along with regulating the female endocrine pathways, and improving symptoms of menopause, treat female reproductive disorders such as polycystic ovary syndrome (PCOS), premature ovarian failure (POF), endometriosis, hyperprolactinemia, and hypothalamic dysfunction; moreover, because of their anticancer, antioxidant, and antidepressant properties, they can be used in traditional medicine or in the pharmaceutical industry as safe compounds in women's health.

Investigation of inhibition effect of daidzein on osteosarcoma cells based on experimental validation and systematic pharmacology analysis

Objective

This study aims to explore the effect of daidzein, which is a natural isoflavone compound mainly extracted from soybeans, on osteosarcoma and the potential molecular mechanism.

Material and Methods

143B and U2OS osteosarcoma cells were treated with gradient concentrations of daidzein, and MTT assay was used to determine the cell proliferation capacity and IC₅₀. Hoechst 33342 staining and Annexin V-FITC/PI detection were used to determine apoptosis. Cell cycle was analyzed by flow cytometry, and migration ability were detected by transwell assays and scratch wound assay. An osteosarcoma xenograft mice model was applied to investigate the effect of daidzein on osteosarcoma in vivo. Systematic pharmacology and molecular modeling analysis were applied to predict the target of daidzein to osteosarcoma, and the target Src was verified by western blotting. We also observed the effect of daidzein on cell proliferation and apoptosis of Src-overexpressing osteosarcoma cells.

Results

In vitro, daidzein significantly inhibited 143B and U2OS osteosarcoma cell proliferation and migration, and induced cell cycle arrest. In vivo, daidzein exerts antitumor effects in osteosarcoma xenograft mice. After systematic screening and analysis, Src-MAPK signaling pathway was predicted as the highest-ranked pathway. Western blot demonstrated that daidzein inhibited phosphorylation of the Src-ERK pathway in osteosarcoma cells. Also, overexpression of Src could partially reverse the inhibitory effects of daidzein on osteosarcoma cell proliferation.

Conclusion

Daidzein exerts an antitumor effect on osteosarcoma, and the mechanism may be through the Src-ERK pathway.

Kamishoyosan (a Japanese traditional herbal formula), which effectively reduces the aggressive biting behavior of male and female mice, and potential regulation through increase of Tph1, Tph2, and Esr2 mRNA levels

Kamishoyosan (KSS), a Japanese traditional herbal formula, is used to treat symptoms related to the autonomic nervous system in men and women; it is especially known for improving the symptoms of irritability (e.g., bad temper and persistent anger). Although clinical and ethological studies of KSS have been conducted, its efficacy in reducing irritability remains to be validated. In the present study, male and female ddY-strain mice were isolation-reared for 8 weeks (from the third postnatal week) to induce pathologically aggressive biting behavior (ABB), which was used as an indicator of irritability. The ABB of mice toward metal rods was measured using the Aggressive Response Meter. An intraperitoneal administration of KSS (100 mg/kg) effectively reduced ABB in male and female mice at 2 h after the administration; however, this effect was canceled by prior administration of WAY-100635 [a 5-hydroxytryptoamine (5-HT)-1A receptor antagonist; 0.5 mg/kg] and bicuculline (a type-A gamma-aminobutyric acid receptor antagonist; 1.0 mg/kg). Additionally, tamoxifen, ICI-182780, and G-15 (all estrogen receptor antagonists) inhibited the action of KSS in a dose-dependent manner. Furthermore, gene expression of tryptophan hydroxylase (Tph) 1 and Tph2 were increased and 5-HT immunofluorescence was slightly increased in the dorsal raphe nucleus (DRN) of isolation-reared mice administered with KSS. Collectively, these results indicate that KSS effectively reduces ABB in isolation-reared male and female mice through stimulation of 5-HT production in the DRN. Our findings also suggest that gene expression of estrogen receptor (Esr) 2 increased in the DRN might be associated with the reduction of ABB.

In silico drug repositioning based on drug-miRNA associations

Drug repositioning has become a prevailing tactic as this strategy is efficient, economical and low risk for drug discovery. Meanwhile, recent studies have confirmed that small-molecule drugs can modulate the expression of disease-related miRNAs, which indicates that miRNAs are promising therapeutic targets for complex diseases. In this study, we put forward and verified the hypothesis that drugs with similar miRNA profiles may share similar therapeutic properties. Furthermore, a comprehensive drug–drug interaction network was constructed based on curated drug-miRNA associations. Through random network comparison, topological structure analysis and network module extraction, we found that the closely linked drugs in the network tend to treat the same diseases. Additionally, the curated drug–disease relationships (from the CTD) and random walk with restarts algorithm were utilized on the drug–drug interaction network to identify the potential drugs for a given disease. Both internal validation (leave-one-out cross-validation) and external validation (independent drug–disease data set from the ChEMBL) demonstrated the effectiveness of the proposed approach. Finally, by integrating drug-miRNA and miRNA-disease information, we also explain the modes of action of drugs in the view of miRNA regulation. In summary, our work could determine novel and credible drug indications and offer novel insights and valuable perspectives for drug repositioning.

Novasoy and genistein inhibit endometrial cancer cell proliferation through disruption of the AKT/mTOR and MAPK signaling pathways

OBJECTIVES

Excess estrogen states, such as those generated by obesity, have long been associated with the development of type I endometrial cancers. Epidemiological studies have linked consumption of isoflavones with a decreased incidence of endometrial malignancy. Thus, our goal was to assess the effect of the isoflavones, novasoy and genistein, on cell proliferation, cell cycle, apoptosis, progesterone receptor (PR) and estrogen receptor-alpha (ERα) expression and the AKT/mTOR and MAPK pathways in endometrial cancer cells.

METHODS

The endometrial cancer cell lines ECC-1 and RL-95-2 were used. Cell proliferation was assessed with MTT assay after exposure to novasoy and genistein at varying concentrations. Cell cycle progression was analyzed by flow cytometry. Apoptosis was assessed by flow cytometery for annexin V expression and ELISA for caspase-3 activity. Expression of ERα, PR and hTERT mRNA were evaluated using real time RT-PCR. Western immunoblotting was performed to evaluate the effects of novasoy and genistein on the AKT/mTOR and MAPK signaling pathways.

RESULTS

Novasoy and genistein inhibited cell growth in a dose-dependent manner in both cell lines through induction of cell cycle G2 arrest and apoptosis. Treatment with novasoy and genistein decreased hTERT expression in a dose-dependent manner. Genistein decreased ERα mRNA expression while increasing PR expression. Genistein induced phosphorylation of p42/44 in a dose dependent manner in both cell lines but reduced phosphorylation of S6 in only the RL-95-2 cells.

CONCLUSIONS

Novasoy and genistein inhibited cell proliferation through varying pathways in different cell lines but included decreased ERα expression and subsequent alteration in the expression of proteins upstream and downstream of the AKT/mTOR and MAPK pathways. Thus, isoflavones may be a promising therapeutic agent in the treatment and prevention of endometrial cancer.

Chemopreventive Effects of Hydroxymatairesinol on Uterine Carcinogenesis in Donryu Rats

Hydroxymatairesinol (HMR), obtained from the heartwood of spruce (Picea abies), has been demonstrated to exert chemopreventive effects on the development of mammary tumors in rats. To examine the influence of HMR on uterine carcinogenesis, adult Donryu rats were initiated with a single intrauterine treatment of N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) at 11 weeks of age and fed thereafter 0, 200, or 600 ppm HMR mixed in the soy-containing diet until 15 months of age. Incidences of uterine adenocarcinoma in both 200 and 600 ppm HMR-dosed groups were significantly reduced to 11% and 15%, respectively, less than 50% of 0 ppm, at the end of the experiment (P < 0.05). A delay in the start of persistent estrus by HMR was observed at 8 months of age compared with controls given carcinogen alone. From urinalysis, HMR was metabolized mainly to enterolactone and hydroxyenterolactone. These findings suggest that HMR or its metabolites exert chemopreventive effects in the rat ENNG-uterine carcinogenesis model.

Therapeutic options for management of endometrial hyperplasia

Endometrial hyperplasia (EH) comprises a spectrum of changes in the endometrium ranging from a slightly disordered pattern that exaggerates the alterations seen in the late proliferative phase of the menstrual cycle to irregular, hyperchromatic lesions that are similar to endometrioid adenocarcinoma. Generally, EH is caused by continuous exposure of estrogen unopposed by progesterone, polycystic ovary syndrome, tamoxifen, or hormone replacement therapy. Since it can progress, or often occur coincidentally with endometrial carcinoma, EH is of clinical importance, and the reversion of hyperplasia to normal endometrium represents the key conservative treatment for prevention of the development of adenocarcinoma. Presently, cyclic progestin or hysterectomy constitutes the major treatment option for EH without or with atypia, respectively. However, clinical trials of hormonal therapies and definitive standard treatments remain to be established for the management of EH. Moreover, therapeutic options for EH patients who wish to preserve fertility are challenging and require nonsurgical management. Therefore, future studies should focus on evaluation of new treatment strategies and novel compounds that could simultaneously target pathways involved in the pathogenesis of estradiol-induced EH. Novel therapeutic agents precisely targeting the inhibition of estrogen receptor, growth factor receptors, and signal transduction pathways are likely to constitute an optimal approach for treatment of EH.

Impact of Nutrition on Non-Coding RNA Epigenetics in Breast and Gynecological Cancer

Cancer is the second leading cause of death in females. According to the American Cancer Society, there are 327,660 new cases in breast and gynecological cancers estimated in 2014, placing emphasis on the need for cancer prevention and new cancer treatment strategies. One important approach to cancer prevention involves phytochemicals, biologically active compounds derived from plants. A variety of studies on the impact of dietary compounds found in cruciferous vegetables, green tea, and spices like curry and black pepper have revealed epigenetic changes in female cancers. Thus, an important emerging topic comprises epigenetic changes due to the modulation of non-coding RNA levels. Since it has been shown that non-coding RNAs such as microRNAs and long non-coding RNAs are aberrantly expressed in cancer, and furthermore are linked to distinct cancer phenotypes, understanding the effects of dietary compounds and supplements on the epigenetic modulator non-coding RNA is of great interest. This article reviews the current findings on nutrition-induced changes in breast and gynecological cancers at the non-coding RNA level.

Phytoestrogen genistein inhibits EGFR/PI3K/NF-kB activation and induces apoptosis in human endometrial hyperplasial cells

Endometrial hyperplasia is an estrogen-dependent disease and is the most frequent precursor of endometrial cancer, diagnosed in pre- and peri-menopausal women.

Chemopreventive and chemotherapeutic effects of genistein, a soy isoflavone, upon cancer development and progression in preclinical animal models

Genistein is one of isoflavones mostly derived in a leguminous plant. It is well known as one of phytoestrogens that have structures similar to the principal mammalian estrogen. It has diverse biological functions including chemopreventive properties against cancers. Anticancer efficacies of genistein have been related with the epidemiological observations indicating that the incidence of some cancers is much lower in Asia, where diets are rich in soyfoods, than Western countries. This review deals with in vivo anticancer activities of genistein identified in animal studies being divided into its effects on carcinogenesis and cancer progression. Because animal studies have advantages in designing the experiments to suit the goals, they imply diverse information on the anticancer activity of genistein. The in vivo animal studies have adopted the specific animal models according to a developmental stage of cancer to prove the anticancer efficacies of genistein against diverse types of cancer. The numerous previous studies insist that genistein effectively inhibits carcinogenesis in the DMBA-induced animal cancer models by reducing the incidence of adenocarcinoma and cancer progression in the transgenic and xenograft animal models by suppressing the tumor growth and metastatic transition. Although the protective effect of genistein against cancer has been controversial, genistein may be a candidate for chemoprevention of carcinogenesis and cancer progression and may deserve to be the central compound supporting the epidemiological evidence.

Genistein as a Potential Anticancer Agent against Ovarian Cancer

Genistein is known as the major component of isoflavone, which is present in high-soy diets. Genistein has received much attention because of its chemopreventive and therapeutic effects on various types of cancers. Numerous studies have shown that genistein has antineoplastic effects against ovarian cancer. Several epidemiological studies have shown that women who have high consumption of isoflavones have a relatively low incidence of ovarian cancer. Genistein inhibits ovarian carcinogenesis by pleiotropic mechanisms. A higher affinity to estrogen receptor β is one probable explanation for its ability to reduce the risk of ovarian cancer. Genistein also targets multiple cellular signal transduction pathways associated with cell cycle regulation and apoptosis. In addition, genistein has been suggested to have antiangiogenic and antioxidant activities. Herein, we summarize recent results from epidemiological and experimental studies to identify the role of genistein in ovarian cancer. Further studies are needed to achieve conclusive results and determine the clinical applications of genistein.

Endometrial, breast and liver safety of soy isoflavones plus Lactobacillus sporogenes in post-menopausal women

OBJECTIVE

To assess the safety of a nutraceutical compound containing soy isoflavones and Lactobacillus sporogenes on endometrium, breast and liver function.

SETTING

Outpatient Menopausal Clinic.

STUDY DESIGN

130 healthy postmenopausal women suffering from menopausal symptoms were randomized to receive soy isoflavones 60 mg and Lactobacillus sporogenes 1 billion spores (group E: 65 women) or calcium and vitamin D₃ (group C: 65 women). Safety of the treatment was assessed at baseline and after 1 year taking into account endometrial thickness, mammographic density, serum levels of transaminases, γ-GT and bilirubin. Efficacy of the treatment was evaluated rating the score of menopausal symptoms at baseline and every 3 months. The statistical analysis was carried out with χ², Fisher exact's test and ANOVA.

RESULTS

After 12 months of treatment mammographic density, endometrial thickness and hepatic function did not show significant differences between groups, while menopausal symptoms were progressively and significantly reduced in severity and frequency during treatment with soy isoflavones plus Lactobacillus sporogenes versus calcium plus vitamin D₃.

CONCLUSION

A 12 months treatment with a nutraceutical compound based on isoflavones and Lactobacillus sporogenes at the recommended doses is safe for endometrium, mammary glands and liver function in postmenopausal women.

(-)-Epigallocatechin-3-gallate induces apoptosis in human endometrial adenocarcinoma cells via ROS generation and p38 MAP kinase activation

(-)-Epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, has been shown to inhibit carcinogenesis of various tumor types. The aim of this study was to elucidate the antiproliferative potential of EGCG and its mechanism in human endometrial cancer cells (Ishikawa cells) and primary endometrial adenocarcinoma cells. The antiproliferative effect of EGCG was evaluated by cell viability assay. Apoptosis was measured by annexin/propidium iodide staining. Reactive oxygen species (ROS) generation was measured by using 2',7'-dichlorofluorescin diacetate dye. Expression of mitogen-activated protein kinases, proliferation and apoptotic markers were measured by immunoblot analysis. EGCG was found to inhibit proliferation in Ishikawa as well as in primary endometrial adenocarcinoma cells and effectively down-regulated the expression of proliferation markers, i.e., estrogen receptor α, progesterone receptor, proliferating cell nuclear antigen and cyclin D1. EGCG also decreased the activation of ERK and downstream transcription factors fos and jun. EGCG caused apoptotic cell death accompanied by up-regulation of proapoptotic Bax and down-regulation of antiapoptotic protein Bcl2. EGCG induced the cleavage of caspase-3 and poly(ADP-ribose) polymerase, the hallmark of apoptosis. EGCG significantly induced the ROS generation as well as p38 activation in Ishikawa cells, which appeared to be a critical mediator in EGCG-induced apoptosis. The apoptotic effect of EGCG and the p38 activation were blocked by pretreatment of cells with the ROS scavenger N-acetylcysteine. EGCG reduced the glutathione levels, which might be responsible for enhanced ROS generation causing oxidative stress in endometrial cancer cells. Taken together, these results suggest that EGCG inhibits cellular proliferation via inhibiting ERK activation and inducing apoptosis via ROS generation and p38 activation in endometrial carcinoma cells.

Influence of ferutinin on bone metabolism in ovariectomized rats. II: role in recovering osteoporosis

The aim of the present investigation, which represents an extension of a previous study, was to investigate the effect of ferutinin in recovering severe osteoporosis due to estrogen deficiency after rat ovariectomy and to compare phytoestrogen effects with those of estrogens commonly used in hormone replacement therapy (HRT) by women with postmenopausal osteoporosis. The animal model used was the Sprague-Dawley ovariectomized rat. Ferutinin was orally administered (2 mg kg(-1) per day) for 30 or 60 days starting from 2 months after ovariectomy (i.e. when osteoporosis was clearly evident) and its effects were compared with those of estradiol benzoate (1.5 microg per rat twice a week, subcutaneously injected) vs. vehicle-treated ovariectomized (OVX) and sham-operated (SHAM) rats. Histomorphometric analyses were performed on trabecular bone of lumbar vertebrae (4th and 5th) and distal femoral epiphysis, as well as on cortical bone of femoral diaphysis. Bone histomorphometric analyses showed that ferutinin seems to display the same effects on bone mass recorded with estradiol benzoate, thus suggesting that it could enhance the recovery of bone loss due to severe estrogen deficiency in OVX rats. On this basis, the authors propose listing ferutinin among the substances representing a potential alternative for the treatment of postmenopausal osteoporosis, which occurs as a result of estrogen deficiency.

Phytoestrogens: endocrine disrupters or replacement for hormone replacement therapy?

OBJECTIVES

This review presents findings with clear statements from the literature as well as own results of effects of soy, red clover and their isoflavones as well as of the Cimicifuga racemosa extract BNO 1055. Experimental and clinical effects on climacteric complaints, osteoprotective effects, activity in the urogenital tract, and risks concerning cardiovascular diseases and mammary and endometrial tissue will be compared, also in comparison to classical hormone preparations. The question whether soy and red clover products and/or Cimicifuga racemosa (CR) preparations are endocrine disrupters or may fulfill the criteria of the so-called phyto-SERMs will be discussed.

METHODS

Review of selected publications since 1980 and summary of unpublished own results of the authors.

RESULTS

Experimental and clinical evidences suggest that soy/red clover and their isoflavones do not fulfill the criteria of an ideal SERM. They appear to have mild osteoprotective effects but do not improve climacteric complaints. Furthermore, they seem to stimulate uterine growth and mammary epithelial proliferation. In ovariectomized rats, the CR extract BNO 1055 showed many of the beneficial effects of 17beta-estradiol, including effects in the brain/hypothalamus to reduce serum LH levels, effects in the bone to prevent osteoporosis and estrogenic effects in the urinary bladder. The CR extract BNO 1055 had no uterotrophic effect.

CONCLUSION

If clinical studies confirm these results, the Cimicifuga racemosa preparation BNO 1055 would appear as an ideal SERM and may therefore be an alternative to hormone replacement therapy.

Prevention of chemically induced mammary tumorigenesis by daidzein in pre-pubertal rats: the role of peroxidative damage and antioxidative enzymes

Isoflavones are biologically active plant derived compounds that have several health promoting effects. In the present study hitherto unknown effects of one of the well known isoflavonoids, daidzein, has been evaluated on its chemo-preventive action against breast cancers in pre-pubertal rats. Either daidzein (500 mug/g bwt) or vehicle, dimethyl sulphoxide (DMSO), was administered at 16th, 18th, and 20th day post-partum and the chemopreventive efficacy was evaluated in dimethylbenz[a]nthracene (DMBA) induced Sprague-Dawley rats, at 50th day. To elucidate the mechanism of action, the antioxidative status was also examined in the liver and mammary gland of prebubertal rats using two different doses of daidzein (0.5 mg/kg bwt and 50 mg/kg bwt, p.o.) for 10 days. The specific activity of antioxidant enzymes as well as reduced glutathione (GSH) level and peroxidative damage were evaluated spectrophotometrically, both in liver as well as in mammary gland. Animals treated with daidzein pre-pubertally, showed a significant reduction in the tumorigenesis of mammary gland up to 37.4% as compared to animals induced for tumors with DMBA. In animals treated with 50 mg/kg of daidzein, a significant increase in the specific activities of the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione transferase (GST), DT-diaphorase (DTD), and in GSH content were observed in both liver and mammary gland. Expectedly, the specific activity of lactate dehydrogenase (LDH) and level of peroxidative damage was decreased, as compared to that of control group of animals. Our results suggest that, daidzein can be considered as a potent chemopreventive agent against mammary carcinogenesis in pre-pubertal animals, with modulation of antioxidant enzymes being one of its mechanisms of actions.

Comparative effects of estradiol, raloxifene, and genistein on the uterus of ovariectomized mice

To explore the uterine effects of administration of compounds that exert their bone-sparing functions through estrogen receptors, we administered 17beta-E2, raloxifene, or genistein to ovariectomized mice and analyzed the uterus weight and histology 4 weeks after beginning the treatments. Results indicated that raloxifene and genistein have partial agonistic properties on the uterus in estrogen-depleted mice, and that genistein induced apoptosis and several atypias in the glandular epithelium of endometrium, as demonstrated in hematoxylin-eosin-stained histological sections.

Do soy isoflavones cause endometrial hyperplasia?

For many years, hormone replacement therapy (HRT) was considered the gold standard for the symptomatic treatment of menopause. Clinical trials have found that HRT reduces the symptoms of hot flashes and sweating, while also decreasing vaginal dryness and urinary tract infections. HRT has also been shown to be protective against colon cancer (37%) and hip fractures (34%). However, recent findings from the Women's Health Initiative (WHI) have revealed that long-term HRT may actually lead to an increase in heart disease (29%), breast cancer (26%) and other adverse events, such as stroke (41%). Consequently, many women in the United States and abroad are actively looking for alternative treatments for menopause, including botanical dietary supplements.

Uterine phenotype of young adult rats exposed to dietary soy or genistein during development

Dietary soy intake is associated with protection from breast cancer, but questions persist on the potential risks of the major soy isoflavone genistein (GEN) on female reproductive health. Here, we evaluated intermediate markers of cancer risk in uteri of cycling, young adult Sprague-Dawley rats lifetime exposed to one of three AIN-93G semipurified diets: casein (CAS), soy protein isolate (SPI+ with 276 mg GEN aglycone equivalents/kg) and CAS+GEN (GEN at 250 mg/kg). Postnatal day 50 (PND50) rats lifetime exposed to GEN or SPI+ had similar uterine luminal epithelium height, myometrial thickness, endometrial gland numbers, endometrial immunoreactive proliferating cell nuclear antigen (PCNA), and serum estrogen and progesterone, as CAS-fed rats. GEN-fed rats showed modestly increased apoptosis in uterine glandular epithelium, compared to those of CAS- or SPI+-fed groups. Diet had no effect on the uterine expression of genes for the tumor suppressors PTEN, p53 and p21, and the apoptotic-associated proteins Bcl2, Bax and progesterone receptor. Uterine tissue and serum concentrations of total GEN were higher in rats fed GEN than in those fed SPI+. Human Ishikawa endocarcinoma cells treated with GEN-fed rat serum tended to exhibit increased apoptotic status than those treated with CAS-fed rat serum. Exogenously added GEN (0.2 and 2 microM) increased, while estradiol-17beta (0.1 microM) decreased Ishikawa cell apoptosis, relative to untreated cells. Results suggest that lifetime dietary exposure to soy foods does not alter uterine cell phenotype in young adult rats, while GEN, by enhancing uterine endometrial glandular apoptosis in vivo and in vitro, may confer protection against uterine carcinoma. Given its limited influence on uterine phenotype of young adult females, GEN, when taken as part of soy foods or as supplement, should be favorably considered for other potential health benefits.

Phytoestrogens derived from red clover: an alternative to estrogen replacement therapy?

The benefits of plant extracts from soy and red clover as alternatives to conventional hormone replacement therapy (HRT) have been debated in the past. Here, an attempt has been made to summarize the biochemical and pharmacological data in the light of clinical aspects. Red clover and soy extracts contain isoflavones, which have a high affinity to estrogen receptor alpha (ERalpha), estrogen receptor beta (ERbeta), progesterone receptor (PR) and androgen receptor (AR). The higher affinity to ERbeta compared to ERalpha has been used as an explanation why red clover extracts function as food additives to treat menopausal disorders and may reduce risk of breast cancer. Biochemical analysis shows that these representatives of phytoestrogens have multiple actions beside selective estrogen receptor modulator (SERM)-activity. They act as selective estrogen enzyme modulators (SEEMs), have antioxidant activity and interact with transcription factors such as NF-kappaB. Furthermore, it is indicated that they have protective effects on osteoporosis and the cardiovascular system. Currently 40-50mg of isoflavones (biochanin A, daidzein, formononetin and genistein) are recommended as daily dose. This recommendation is based on the daily intake of phytoestrogens in a traditional Japanese diet.

High dose of phytoestrogens can reverse the antiestrogenic effects of clomiphene citrate on the endometrium in patients undergoing intrauterine insemination: a randomized trial

OBJECTIVE

To compare the effectiveness of clomiphene citrate (CC) alone or combined with phytoestrogens (PE) in ovulation induction in patients who had intrauterine insemination in a randomized, double-blind study.

METHODS

A total of 134 women aged 25-35 years, who were infertile for at least 2 years and who had oligomenorrhea or amenorrhea associated with a positive menstrual response to the intramuscular progesterone-challenge test were enrolled. They were randomly treated with CC (100 mg daily for 5 days) and CC (100 mg daily for 5 days) in combination with PE (1500 mg daily for 10 days). We estimated the difference in uterine artery pulsatily index, number of preovulatory follicles, endometrial thickness, and pregnancy rate.

RESULTS

Both treatments increased follicle-stimulating hormone, luteinizing hormone, and 17beta-estradiol plasma concentrations, but the differences were not statistically significant. However, the differences in endometrial thickness of the two groups were statistically significant. No significant differences in the pulsatility index values and in the number of preovulatory follicles were noted.

CONCLUSION

A high dose of phytoestrogens can reverse the deleterious effects of clomiphene citrate on endometrial thickness and could contribute to higher pregnancy rates.

Cancer prevention by natural compounds

Increasing attention is being paid to the possibility of applying cancer chemopreventive agents for individuals at high risk of neoplastic development. For this purpose by natural compounds have practical advantages with regard to availability, suitability for oral application, regulatory approval and mechanisms of action. Candidate substances such as phytochemicals present in foods and their derivatives have been identified by a combination of epidemiological and experimental studies. Plant constituents include vitamin derivatives, phenolic and flavonoid agents, organic sulfur compounds, isothiocyanates, curcumins, fatty acids and d-limonene. Examples of compounds from animals are unsaturated fatty acids and lactoferrin. Recent studies have indicated that mechanisms underlying chemopreventive potential may be combinations of anti-oxidant, anti-inflammatory, immune-enhancing, and anti-hormone effects, with modification of drug-metabolizing enzymes, influence on the cell cycle and cell differentiation, induction of apoptosis and suppression of proliferation and angiogenesis playing roles in the initiation and secondary modification stages of neoplastic development. Accordingly, natural agents are advantageous for application to humans because of their combined mild mechanism. Here we review naturally occurring compounds useful for cancer chemprevention based on in vivo studies with reference to their structures, sources and mechanisms of action.

Effects of Purified Puerarin on Voluntary Alcohol Intake and Alcohol Withdrawal Symptoms in P Rats Receiving Free Access to Water and Alcohol

Alcohol preferring (P) rats, given "free choice" of water, exhibited daily intake of 60-75 g of water/kg of body weight. When given "free choice" of water and 15% ethanol, P rats consumed 7-13 g of alcohol/kg. Their water intake decreased proportionally to the alcohol intake, but total fluid intake did not differ significantly. Alcohol withdrawal after 50 days of alcohol drinking caused withdrawal symptoms such as hypersensitivity, poor coordination, and tremors. A daily 50 mg/kg dose of puerarin (PU) caused approximately 50% suppression in alcohol intake, but did not affect body weight and food and total fluid intake in P rats receiving "free choice" of water and 15% ethanol. Alcohol ingestion gradually returned to the control level despite consistent PU intake. However, alcohol intake following alcohol withdrawal was suppressed in PU-fed P rats. PU suppressed the severity of alcohol withdrawal symptoms. Thus, withdrawal symptoms do not occur in PU-fed rats even though their alcohol ingestion is comparable to that in control P rats. Brain, plasma, and liver samples were analyzed for the presence of kudzu root isoflavones, which are mostly PU (>90% of total isoflavones) and a trace amount of daidzin. Liver samples obtained from PU-fed P rats contained 20-30 microg/g of PU. An important observation was that plasma or brain samples obtained from PU-fed or alcohol + PU-fed rats did not contain PU. This study indicated that PU feeding transiently suppressed alcohol intake and abolished withdrawal symptoms at a time when alcohol intake had returned to the control level. The absence of PU in plasma and brain indicates the possibility that some nonspecific mechanism may be involved in the anti-alcoholism effects of PU in P rats.

Soy protein isolate with isoflavones does not prevent estradiol-induced endometrial hyperplasia in postmenopausal women: a pilot trial

OBJECTIVE

To test the hypothesis that soy protein isolate (SPI) with isoflavones opposes the proliferative effects of exogenous estradiol (E2) on the endometrium after menopause.

DESIGN

Thirty-nine postmenopausal women were randomized to receive daily for 6 months either 0.5 mg E2 + placebo, 1.0 mg E2 + placebo, 0.5 mg E2 + 25 g SPI with 120 mg isoflavones, or 1.0 mg E2 + 25 g SPI with 120 mg isoflavones. Primary outcome measures were endometrial histology, ultrasound endometrial thickness, and Ki67 staining quantification, a marker of cellular proliferation. Secondary outcome measures were serum lipids and markers of bone resorption.

RESULTS

Endometrial hyperplasia, endometrial stromal and epithelial cellular proliferation, and sonographically measured endometrial thickness were similarly affected in all groups. SPI did not lessen the beneficial effects of E2 on lipids and markers of bone resorption.

CONCLUSION

In this pilot study, SPI with isoflavones did not protect the endometrium from E2-induced hyperplasia in postmenopausal women. If higher, long-term doses of isoflavone supplementation are found to be safe for postmenopausal women, then future studies combining E2 with isoflavones may be feasible as an alternative to traditional hormone replacement therapy.

Phytoestrogens: endocrine disrupters or replacement for hormone replacement therapy?

OBJECTIVES

This review presents findings with clear statements from the literature as well as own results of effects of soy, red clover and their isoflavones as well as of the Cimicifuga racemosa extract BNO 1055. Experimental and clinical effects on climacteric complaints, osteoprotective effects, activity in the urogenital tract, and risks concerning cardiovascular diseases and mammary and endometrial tissue will be compared, also in comparison to classical hormone preparations. The question whether soy and red clover products and/or Cimicifuga racemosa (CR) preparations are endocrine disrupters or may fulfill the criteria of the so-called phyto-SERMs will be discussed.

METHODS

Review of selected publications since 1980 and summary of unpublished own results of the authors.

RESULTS

Experimental and clinical evidences suggest that soy/red clover and their isoflavones do not fulfill the criteria of an ideal SERM. They appear to have mild osteoprotective effects but do not improve climacteric complaints. Furthermore, they seem to stimulate uterine growth and mammary epithelial proliferation. In ovariectomized rats, the CR extract BNO 1055 showed many of the beneficial effects of 17beta-estradiol, including effects in the brain/hypothalamus to reduce serum LH levels, effects in the bone to prevent osteoporosis and estrogenic effects in the urinary bladder. The CR extract BNO 1055 had no uterotrophic effect.

CONCLUSION

If clinical studies confirm these results, the Cimicifuga racemosa preparation BNO 1055 would appear as an ideal SERM and may therefore be an alternative to hormone replacement therapy.

Genistein treatment protects mice from ionizing radiation injury

The radioprotective and behavioral effects of an acute administration of the isoflavone genistein (4',5,7-trihydroxyflavone) were investigated in adult CD2F1 male mice. Mice were administered a single subcutaneous (s.c.) dose of genistein either 24 h or 1 h before a lethal dose of gamma radiation (9.5-Gy of cobalt-60 at 0.6 Gy min(-1)). Mice received saline, PEG-400 vehicle or genistein at 3.125, 6.25, 12.5, 25, 50, 100, 200, or 400 mg kg(-1) body weight. For mice treated 24 h before irradiation there was a significant increase in 30-day survival for animals receiving genistein doses of 25 to 400 mg kg(-1) (p<0.001). In contrast, the 30-day survival rates of mice treated with genistein 1 h before irradiation were not significantly different from those of the vehicle control group. Additionally, the acute toxicity of genistein was evaluated in non-irradiated male mice administered a single s.c. injection of saline, vehicle, or genistein at 100, 200 or 400 mg kg(-1). At these genistein doses there were no adverse effects, compared with controls, on locomotor activity, grip strength, motor coordination, body weight, testes weight, or histopathology. These results demonstrate that a single s.c. administration of the flavonoid genistein at non-toxic doses provides protection against acute radiation injury.

Inhibitory effects of toremifene on N-methyl-N-nitrosourea and estradiol-17beta-induced endometrial carcinogenesis in mice

Short- and long-term experiments were designed to determine the effects of toremifene (TOR) on estrogen-related endometrial carcinogenesis in mice. In the short-term experiment, a single low dose of TOR (0.2 mg / 30 g body weight) decreased expression of c-fos, interleukin (IL)-1alpha, estrogen receptor (ER)-alpha mRNAs and corresponding proteins induced by estradiol-17beta (E(2)), in the uteri of the ovariectomized mice. Expression of ER-beta mRNA was increased by the TOR treatment, compared with the control. In the long-term experiment, 106 female ICR mice were given N-methyl-N-nitrosourea (MNU) into their uterine corpora. The animals were divided into four groups as follows: group 1, E(2) diet (5 ppm) plus TOR (0.2 mg / 30 g body weight, subcutaneously, every four weeks); group 2, E(2) diet alone; group 3, basal diet plus TOR. Group 4 served as the control. TOR treatment decreased the incidence of MNU and E(2)-induced endometrial adenocarcinoma and atypical hyperplasia at the termination of the experiment (30 weeks after the start). These results suggest that TOR exerts preventive effects against estrogen-related endometrial carcinogenesis in mice, through the suppression of c-fos as well as IL-1alpha expression induced by E(2). Such suppressive effects of TOR may be related to the decreased ER-alpha and increased ER-beta expressions.