Isolation, synthesis, and cytotoxicity evaluation of two impurities in nomegestrol acetate.

Nomegestrol acetate (NOMAc) is a synthetic progesterone analog and classified as a fourth-generation progestin. It has been approved in many countries for oral contraception, hormonal replacement therapy (HRT), and treatment of various gynecological disorders. There are several synthetic routes reported for the synthesis of NOMAc and they all share the very similar last three to five steps toward the conversion of 6-methylene to 6-methyl-6,7-unsaturated structure. Therefore the final product from different processing routes may have similar impurity profiles. In the analysis of NOMAc, we identified two impurities, impurity A (listed in EP 8.0) and impurity B (not specified in EP 8.0). Both impurities were further confirmed by synthesis. In addition, both impurities and NOMAc were evaluated for their in vitro cytotoxicities against L02 liver cells, mesenchymal stem cells, MCF-7 breast cancer cells, and C33A cervical cancer cells. These three analogs are not cytotoxic to the four cell lines at low concentrations (<20 µM). NOMAc and impurity A showed cytotoxicity to L02, MCF-7, and C33A cells at high concentrations, while impurity B did not show significant cytotoxicity to any of the cell lines tested.

Metformin Enhances Nomegestrol Acetate Suppressing Growth of Endometrial Cancer Cells and May Correlate to Downregulating mTOR Activity In Vitro and In Vivo.

This study investigated the effect of a novel progestin and its combination with metformin on the growth of endometrial cancer (EC) cells. Inhibitory effects of four progestins, including nomegestrol acetate (NOMAC), medroxyprogesterone acetate, levonorgestrel, and cyproterone acetate, were evaluated in RL95-2, HEC-1A, and KLE cells using cell counting kit-8 assay. Flow cytometry was performed to detect cell cycle and apoptosis. The activity of Akt (protein kinase B), mTOR (mammalian target of rapamycin) and its downstream substrates 4EBP1 (4E-binding protein 1) and eIF4G (Eukaryotic translation initiation factor 4G) were assayed by Western blotting. Nude mice were used to assess antitumor effects in vivo. NOMAC inhibited the growth of RL95-2 and HEC-1A cells, accompanied by arresting the cell cycle at G0/G1 phase, inducing apoptosis, and markedly down-regulating the level of phosphorylated mTOR/4EBP1/eIF4G in both cell lines (p < 0.05). Metformin significantly increased the inhibitory effect of and apoptosis induced by NOMAC and strengthened the depressive effect of NOMAC on activity of mTOR and its downstream substrates, compared to their treatment alone (p < 0.05). In xenograft tumor tissues, metformin (100 mg/kg) enhanced the suppressive effect of NOMAC (100 mg/kg) on mTOR signaling and increased the average concentration of NOMAC by nearly 1.6 times compared to NOMAC treatment alone. Taken together, NOMAC suppressing the growth of EC cells likely correlates to down-regulating the activity of the mTOR pathway and metformin could strengthen this effect. Our findings open a new window for the selection of progestins in hormone therapy of EC.

A comparison between the effects of metformin and megestrol on simple endometrial hyperplasia.

INTRODUCTION: Endometrial hyperplasia is one of the most serious causes of severe abnormal bleeding and also can be a precursor of endometrial carcinoma. OBJECTIVE: The purpose of the present study was to compare the effects of metformin and megestrol on the endometrial hyperplasia. METHODS: The study was performed as a randomized clinical trial on 42 cases of histopathologically confirmed simple endometrial hyperplasia without atypia. The eligible women were randomly assigned into two groups. In metformin group, metformin was prescribed, 500 mg twice a day (1000 mg daily), for a duration of 4 weeks, and then, followed by 1500 mg daily, for 8 more weeks. In the megestrol group, megestrol was prescribed 40 mg daily for 12 weeks. At the end of the duration of the treatment, endometrial sampling was performed and the results were compared between the two groups. RESULTS: The women of the two groups did not have significant difference according to age, BMI and gravidity, parity and history of abortion. Overall, 18 women (81.8%) in metformin group and 12 women (60%) in the megestrol group had normal endometrial histology, after 12 weeks of treatment (p = 0.11). CONCLUSION: Metformin is comparable with megestrol for the treatment of simple endometrial hyperplasia.

Body composition and psychological improvement in healthy premenopausal women assuming the oral contraceptive containing micronized estradiol (E2) and nomegestrol acetate (NOMAC).

This observational study was conducted in healthy premenopausal women, who presented themselves for contraceptive advice at the outpatient Family Planning Clinics of the Department of Obstetrics and Gynecology of the University of Cagliari, Hospital-University of Cagliari (Italy). After a screening period of three menstrual cycles, 48 women without contraindications to estroprogestin contraceptives (OCs) were included in the study. The primary purposes of the study were to evaluate whether a 12-month-treatment with the combined OC containing micronized estradiol (1.5 mg, E2) plus nomegestrol acetate (2.5 mg, NOMAC) (E2/NOMAC) interfere on anthropometric indices (AI), body composition (BC) and psychological status (PS). In subjects with dysmenorrhea (#36), its intensity was evaluated using the visuo analogic scale (VAS), both before and during the 12-month-treatment with E2/NOMAC. E2/NOMAC did not modify neither AI nor BC in the 40 subjects who concluded the study. The PS and the VAS of dysmenorrhea were significantly (p < 0.0001) improved from the first cycle of treatment and throughout the E2/NOMAC treatment in comparison with basal values. The study suggests that E2/NOMAC is devoid of negative effects on AI and BC, with additional benefits on PS and dysmenorrhea.

Nomegestrol Acetate Suppresses Human Endometrial Cancer RL95-2 Cells Proliferation In Vitro and In Vivo Possibly Related to Upregulating Expression of SUFU and Wnt7a.

Nomegestrol acetate (NOMAC) has been successfully used for the treatment of some gynecological disorders, and as a combined oral contraceptive with approval in many countries. In this study, we investigated the effects of NOMAC on human endometrial cancer cells in vitro and in vivo. The proliferation of human endometrial cancer cells (RL95-2 and KLE) were assessed using CCK-8 and EdU incorporation assays. Whole-genome cDNA microarray analysis was used to identify the effects of NOMAC on gene expression profiles in RL95-2 cells. RL95-2 xenograft nude mice were treated with NOMAC (50, 100, and 200 mg/kg) or medroxyprogesterone acetate (MPA; 100 and 200 mg/kg) for 28 consecutive days. The results showed that NOMAC significantly inhibited the growth of RL95-2 cells in a concentration-dependent manner, but not in KLE cells. Further investigation demonstrated that NOMAC produced a stronger inhibition of tumor growth (inhibition rates for 50, 100, and 200 mg/kg NOMAC were 24.74%, 47.04%, and 58.06%, respectively) than did MPA (inhibition rates for 100 and 200 mg/kg MPA were 41.06% and 27.01%, respectively) in the nude mice bearing the cell line of RL95-2. NOMAC altered the expression of several genes related to cancer cell proliferation, including SUFU and Wnt7a. The upregulation of SUFU and Wnt7a was confirmed using real-time quantitative polymerase chain reaction and Western blotting in RL95-2 cells and RL95-2 xenograft tumor tissues, but not in KLE cells. These data indicate that NOMAC can inhibit the proliferation of RL95-2 cell in vitro and suppress the growth of xenografts in the nude mice bearing the cell line of RL95-2 in vivo. This effect could be related to the upregulating expression of SUFU and Wnt7a.

Haemostatic and metabolic impact of estradiol pills and drospirenone-containing ethinylestradiol pills vs. levonorgestrel-containing ethinylestradiol pills: A literature review.

OBJECTIVE: Since its introduction 50 years ago, the contraceptive pill has continuously evolved to decrease the risk of venous thromboembolism (VTE) associated with its use. An increased risk of VTE still remains, however. Other concerns, such as effects on lipid and carbohydrate metabolism, have also been reported. In this study we compared two reference combined oral contraceptives (COCs) containing ethinylestradiol (EE)/levonorgestrel (LNG) and EE/drospirenone (DRSP) with COCs containing estradiol (E2) (estradiol valerate [E2V]/dienogest [DNG] and E2/nomegestrol acetate [NOMAC]). They were evaluated according to their influence on recognised haemostatic and metabolic markers. METHODS: A literature search of the MEDLINE/PubMed database was conducted for head-to-head studies. EE/LNG was chosen as the comparator pill. RESULTS: The haemostatic impact of E2 pills and EE/LNG has been extensively compared, in contrast to that of EE/DRSP and EE/LNG. Changes in haemostatic and metabolic marker levels between EE/LNG and E2V/DNG were generally not statistically significant. E2/NOMAC showed statistically significantly favourable results on haemostatic markers and had a neutral effect on carbohydrate and lipid metabolism when compared with EE/LNG. CONCLUSION: E2/NOMAC exhibits less haemostatic and metabolic impact than EE/LNG and other COCs, suggesting that it may be a promising candidate to reduce residual VTE risk associated with COC use. Confirmation from a well-powered prospective clinical trial is, however, needed.

Comparative analysis of the effects of nomegestrol acetate/17 ß-estradiol and drospirenone/ethinylestradiol on premenstrual and menstrual symptoms and dysmenorrhea.

OBJECTIVES: To compare premenstrual and menstrual symptoms in healthy women using nomegestrol acetate/17ß-estradiol (NOMAC/E2) and drospirenone/ethinylestradiol (DRSP/EE) via the Moos Menstrual Distress Questionnaire Form C (MDQ-C). METHODS: Women completed the MDQ-C at baseline and after completion of cycles 1, 3, 6 and 13, for the premenstrual (four days before most recent flow) and menstrual (most recent flow) phases in two randomized controlled trials. Treatment effects of NOMAC/E2 and DRSP/EE on the t-scores of eight MDQ-C symptom domains from 3522 women were examined, and the effects of both treatments on the score for cramps from 1779 women with moderate to severe cramps at baseline. Longitudinal data analysis methods were applied in both analyses. RESULTS: NOMAC/E2 users experienced a significant improvement in Pain, Water Retention, Negative Affect, Impaired Concentration and Behaviour Change domain scores in the menstrual phase compared with DRSP/EE users (p < 0.001 for all comparisons). However, Arousal (emotional and mental) scores worsened with NOMAC/E2 but not with DRSP/EE. Women with moderate to severe cramps experienced an improvement in the cramps score with NOMAC/E2 and DRSP/EE. CONCLUSIONS: NOMAC/E2 was effective in reducing most premenstrual and menstrual symptoms, and was associated with significantly greater improvements in many MDQ-C domain scores compared with DRSP/EE. ( ClinicalTrials.gov: NCT00413062 and NCT00511199).

Effects of estroprogestins containing natural estrogen on vaginal flora.

Estroprogestins with "natural oestrogen" has represented a new option in terms of combined hormonal contraception. So, the aim of this study is to investigate how estroprogestins with natural estrogen may modify the vaginal niche. In literature, very few studies focused on the interaction between hormonal contraception and vaginal milieu. This is a prospective comparative study. We enrolled 60 women from January 2013 to September 2013, 30 of them were administered estradiol valerate dienogest (E2V+DNG - Klaira®) in a quadriphasic regimen, while the other 30 women were administered 17-ß estradiol with nomestrol acetate (EV+NOMAC - Zoely®) in a monophasic regimen. After a baseline study of vaginal milieu at recruitment of patients (Gram stain with Nugent score, vaginal pH, vaginal wet mount for the quantification of leukocytes, Lactobacilli and/or presence of Candida), we performed the same follow-up after six months of estroprogestin therapy. Our results showed that the women treated with E2V+DNG had a trend of an improvement of vaginal health in terms of increase of lactobacillar flora and reduction of vaginal pH in place of women treated with EV+NOMAC that showed a reduction of cervical mucus. Finally, our data about the effects on vaginal flora exerted by two estroprogestin pills (EPs) containing a natural estrogen suggest slight, but interesting differences in terms of vaginal ecology. These differences could be related to the type of estrogen, type of progestin, regimen of administration and, after all, to the net balance between estrogenic and progestin component of the EPs.

Changing convention in combination oral contraceptives: estradiol and nomegestrol acetate in a monophasic 24/4 regimen.

Initial oral contraceptive regimens were characterised by high doses of ethinylestradiol (EE) and a progestogen in a 21-day regimen that either included seven additional hormone-free tablets or simply the 21 days of combination hormonal tablets. These regimens were developed to ensure high contraceptive effectiveness, regular and predictable withdrawal bleeding episodes to mimic a menstrual cycle, and minimal unscheduled vaginal bleeding. However, these regimens were associated with adverse tolerability and safety issues resulting from the dose and characteristics of their hormonal components. Attempts to ameliorate these adverse issues included the development of lower-dose EE regimens, the incorporation of new progestogens, multiphasic regimens, and reduced hormone-free interval regimens. However, the EE component has remained a constant until the recent approval of combination oral contraceptives with an estrogen component other than EE. The development and introduction of an estradiol-based oral contraceptive regimen is presented in this review.

Preclinical pharmacological profile of nomegestrol acetate, a synthetic 19-nor-progesterone derivative.

BACKGROUND: Nomegestrol acetate (NOMAC), a synthetic progestogen derived from 19-nor-progesterone, recently completed clinical trials for use with 17beta-estradiol in a new monophasic combined oral contraceptive. In this review, published as well as previously unpublished preclinical studies that detail the effects of NOMAC on estrogenic, progestogenic, and androgenic systems, as well as mineralocorticoid, glucocorticoid, bone, and metabolic indices are described. METHODS: In vitro assays to determine NOMAC structure-activity relationships used tissue derived from rat uteri. Transactivation profiles were performed using Chinese hamster ovary (CHO) cells transfected with cDNAs encoding human steroid receptors. Estrogenic and anti-estrogenic activities were monitored in vivo in rats as well as in vitro in human breast cancer cells. Standard in vivo techniques were used in rats to determine progestational activity; antigonadotropic, androgenic, mineralocorticoid, and glucocorticoid activities; as well as effects on bone and other metabolic indices. Ovulation inhibition was monitored in rats and primates. NOMAC's effects on cardiovascular systems were determined in dogs and primates. RESULTS: NOMAC was without significant agonistic or antagonistic activity for estrogen receptor alpha or beta in vitro, and inhibited ovulation in rats and monkeys (2.5 mg/kg and 1 mg/kg, respectively). NOMAC lacked androgenic, antimineralocorticoid, glucocorticoid, and metabolic activity and exhibited moderate anti-androgenic activity in rats. NOMAC did not affect bone mineral density (BMD) in rats or hemodynamic and electrophysiologic parameters in dogs and primates. CONCLUSIONS: NOMAC is a selective progestogen structurally similar to progesterone that has modest anti-androgenic activity and does not affect lipid or carbohydrate metabolism, BMD, or many cardiovascular parameters in selected animal models.

Effects of a monophasic combined oral contraceptive containing nomegestrol acetate and 17ß-oestradiol in comparison to one containing levonorgestrel and ethinylestradiol on markers of endocrine function.

OBJECTIVES: To compare the effects of two monophasic combined oral contraceptives, containing either nomegestrol acetate/17ß-oestradiol (NOMAC/E2) or levonorgestrel/ ethinylestradiol (LNG/EE) on endocrine function, androgens, and sex hormone-binding globulin (SHBG). METHODS: Randomised, open-label, multi-centre trial involving 121 healthy women, aged 18-50 years old. Participants received NOMAC/E2 (2.5 mg/1.5 mg) in a 24/4-day regimen (n=60) or LNG/EE (150 µg/30 µg) in a 21/7-day regimen (n=61) for six cycles. The primary outcome was the change from baseline to cycle 6 in markers of adrenal and thyroid function, androgens, and SHBG. RESULTS: Total cortisol, corticosteroid-binding globulin (CBG), and thyroxine-binding globulin (TBG) increased from baseline in both groups, with significantly greater increases in the LNG/EE group. No relevant changes from baseline or differences between the groups were observed for thyroid-stimulating hormone (TSH) and free thyroxine (T4). Androgens and androgen precursors decreased from baseline in both groups, with significantly greater decreases in the LNG/EE group (except for free testosterone). A greater increase in SHBG was observed with NOMAC/E2 than with LNG/EE. CONCLUSIONS: NOMAC/E2 has significantly less influence on markers of adrenal and thyroid function and androgens than LNG/EE. The clinical relevance of these findings requires further study.

Effects of a monophasic combined oral contraceptive containing nomegestrol acetate and 17ß-oestradiol compared with one containing levonorgestrel and ethinylestradiol on haemostasis, lipids and carbohydrate metabolism.

OBJECTIVES: To compare the effects of a combined oral contraceptive (COC) containing nomegestrol acetate and 17ß-oestradiol (NOMAC/E2) on haemostasis, lipids, carbohydrate metabolism, C-reactive protein (CRP) and sex hormone-binding globulin (SHBG) with those of a COC containing levonorgestrel and ethinylestradiol (LNG/EE). METHODS: In a randomised, open-label study, 121 healthy women, 18-50 years of age, were randomly assigned to receive NOMAC/E2 (2.5 mg/1.5 mg) in a 24/4-day regimen (n=60) or LNG/EE (150 µg/30 µg) in a 21/7-day regimen (n=61) for six cycles. The primary outcome was the change from baseline to cycle 6 for all indices. RESULTS: All parameters were similar at baseline between the two groups. Over six cycles, NOMAC/E2 had less effect on most haemostatic indices than LNG/EE. Lipids were essentially unchanged with NOMAC/E2, whereas with LNG/EE high-density lipoprotein cholesterol decreased and low-density lipoprotein cholesterol and triglycerides slightly increased. NOMAC/E2 induced negligible changes in glucose and insulin parameters, in contrast to LNG/EE. A much smaller increase in CRP was observed with NOMAC/E2 than with LNG/EE. NOMAC/E2 was associated with a greater increase in SHBG. CONCLUSIONS: The monophasic COC NOMAC/E2 had less influence on haemostasis, lipids and carbohydrate metabolism than the COC LNG/EE.

Certain progestins prevent the enhancing effect of 17beta-estradiol on NO-mediated inhibition of platelet aggregation by endothelial cells.

OBJECTIVE: Estro-progestin treatments have been associated with an increased risk of thromboembolic events in postmenopausal women. This study examined whether progestins affect the stimulatory effect of estrogens on the endothelial formation of nitric oxide (NO), a potent antithrombotic factor. METHODS AND RESULTS: Experiments were performed with human endothelial cells. Endothelial NO synthase (eNOS) and GTP cyclohydrolase I (GTPCH I) mRNA expression was assessed by RT-PCR, eNOS protein by Western blotting, NO formation by electron spin resonance spectroscopy, and platelet aggregation by an aggregometer. Medroxyprogesterone acetate (MPA), progesterone, levonorgestrel, and nomegestrol acetate prevented the 17beta-estradiol (17beta-E)-induced expression of eNOS mRNA and protein. MPA and progesterone reduced the 17beta-E-induced formation of NO and potentiation of the inhibitory effect of endothelial cells on platelet aggregation whereas levonorgestrel and nomegestrol acetate were without effect. Moreover, MPA and progesterone prevented the 17beta-E-induced expression of GTPCH I mRNA. Mifepristone, a glucocorticoid and progesterone receptor antagonist, and L-sepiapterin prevented the inhibitory effect of MPA and progesterone on platelet aggregation. CONCLUSIONS: Certain progestins, including MPA, attenuate the 17beta-E-induced NO-mediated inhibition of platelet aggregation by endothelial cells through preventing both eNOS and GTPCH I expression most likely via activation of glucocorticoid receptors.

Effects of a monophasic combined oral contraceptive containing nomegestrol acetate and 17 beta-oestradiol on ovarian function in comparison to a monophasic combined oral contraceptive containing drospirenone and ethinylestradiol.

OBJECTIVE: To compare the effects on ovarian activity of two oral contraceptives containing nomegestrol acetate (NOMAC)/17 beta-oestradiol (E2) or drospirenone (DRSP)/ethinylestradiol (EE). METHODS: In this open-label, randomised, six-cycle study, 32 subjects using NOMAC/E2 (2.5-1.5 mg; 24/4-day regimen) were compared to 16 subjects using DRSP/EE (3 mg-30 microg; 21/7-day regimen). Measurements included serum oestradiol, progesterone, follicle stimulating hormone (FSH) and luteinising hormone (LH), and ultrasonography of follicular diameter. RESULTS: No ovulations occurred during treatment. Progesterone was fully suppressed, with mean maximum values <2 nmol/l in both groups over all cycles. For NOMAC/E2, mean maximum follicular diameter decreased from 19.3 mm before treatment to between 6.9 and 8.2 mm during treatment, with no subject having a follicular diameter ≥15 mm. For DRSP/EE, a decrease from 19.6 to between 7.4 and 10.8 mm was observed, with two subjects (12.5%) having a maximum follicle diameter ≥15 mm. These findings were consistent with observed FSH reductions; full suppression of LH surges was observed in both groups. Post-treatment return of ovulation in both groups occurred on average 21 days after the last active tablet intake. CONCLUSIONS: NOMAC/E2 achieves consistent ovulation inhibition, with suppressive effects on the ovaries at least similar to those of DRSP/EE.

The effectiveness of quick starting oral contraception containing nomegestrol acetate and 17-ß estradiol on ovulation inhibition: A randomized controlled trial.

To determine the effectiveness of quick starting combined oral contraception (COC) contain 2.5 mg nomegestrol acetate and 1.5 mg estradiol (NOMAC/E2) comparing with 0.075 mg gestodene and 0.02 mg ethinyl estradiol (GS/EE) on ovarian ovulation inhibition rate, we conducted a non-inferiority randomized controlled trial involving 69 healthy female volunteers aged 18-40 years who had normal menstrual history and were randomized at a 2:1 ratio to take one pack of COC containing either NOMAC/E2 (study group) or GS/EE (control group) starting on menstrual cycle Day7-9. The ovarian activity was assessed by using Hoogland and Skouby grading. Forty-six and 23 participants were randomized to NOMAC/E2 and GS/EE groups, respectively. Baseline characteristics were similar between groups. No significant difference was observed between the study and control groups for ovulation inhibition rate (93.4% vs. 95.6%, risk difference: -2.2%, 95% CI: -13.1, 8.8), ovarian quiescence rate (91.2% vs. 91.2%, P = 1.000), persistent cyst rate (2.2% vs. 4.4%, P = 1.000), and ovulation rate (6.6% vs. 4.4%, P = 1.000). Quick starting COC during day7-9 of menstrual cycle can inhibit ovulation for more than 90%. The quick starting NOMAC/E2 is non-inferior to GS/EE for preventing ovulation and suppressing follicular growth.

Use of an estradiol-based combined oral contraceptives has no influence on attentional bias or depressive symptoms in healthy women.

Combined oral contraceptive (COC) use is associated with small, albeit significant, increases in mental symptom scores, predominantly irritability, depressed mood, and anxiety. Yet, randomized prospective trials are needed to better characterize the women at risk for COC-induced negative mood change. Thus, the primary aim of this sub-study to a placebo-controlled randomized trial was to determine whether COC use influences emotional interference by negative and positive stimuli. Secondly, we wanted to evaluate what factors would predict depressive symptoms at the end of the trial, taking personality factors, history of mental disorders and other demographic factors into account. Sixty-nine women were included, randomized to three cycles of treatment with a COC (1.5 mg estradiol and 2.5 mg nomegestrolacetate) or placebo. An emotional verbal Stroop task was used to measure interference of emotional stimuli, in which participants were asked to only name the color of a presented word, while ignoring the meaning of the word. Four different word categories were used; neutral, positive, depression, and anxiety. For the second aim of the study, rating on the Montgomery-Åsberg Depression Rating Scale during the final days of the trial was used as outcome. We found no interaction between emotional verbal Stroop word category and treatment, indicating that COC treatment did not evoke any differences in emotional interference to the three word categories. Significant predictors for depressive symptoms at the end of the trial were trait anxiety at baseline and prior adverse mood effects by hormonal contraceptive use. Treatment (i.e. whether women had been treated with the COC or placebo) did not play a role in predicting depression scores at the end of the trial. In conclusion, we found no evidence that combined oral contraceptive use is associated with impaired cognitive-emotional processing. Instead, the main predictors of self-rated depression at the end of the trial were baseline trait anxiety and previous mental symptoms during hormonal contraceptive use.

[Nomegestrol acetate: clinical pharmacology]. / Nomegestrolo acetato: farmacologia clinica.

Progestogens are used in clinical practice in some conditions. Their effects depend on their chemical structure, pharmacokinetics, pharmacodynamics, with important differences among various progestogens. Generally, progestins are classified according to their parent molecule, of which often they keep some features. Derivatives of 19-nor-progesterone are characterized by high selectivity of action on progestin receptor. In particular, nomegestrol acetate (NomAc) shows an important progestational potency, neutral gluco-lipid profile, and antigonadotropic activity. It is used for treating menstrual cycle disorders and for hormone replacement therapy in menopause in association with an estrogen. In future, thanks to its antigonadotropic activity, NomAc will be used in estroprogestin combinations in fertile women, thus taking advantage of its tolerability profile and obtaining numerous non-contraceptive benefits as well.

Progestogens and PGRMC1-dependent breast cancer tumor growth: An in-vitro and xenograft study.

OBJECTIVES: A few observational studies have suggested that progesterone and dydrogesterone may have a lower risk of breast cancer than other progestogens. In our earlier xenograft animal experiments, progesterone did not stimulate breast tumors. The aim of this study was to test dydrogesterone for the first time. The study also evaluated the effects of PGRMC1 on proliferation with progestogens. METHODS (1): In-vitro study. The proliferative effects of dydrogesterone and of progesterone were assessed in vitro using T47D cells transfected with PGRMC1 or empty vector in the presence or absence of estradiol. Additionally, to find the strongest proliferator for inclusion as a comparator in the xenograft animal study, norethisterone, levonorgestrel, desogestrel, dienogest, drospirenone, nomegestrol, and cyproterone acetate were tested. METHODS (2): Xenograft main study. PGRMC1-transfected or empty-vector T47D and MCF7 xenotransplants were each treated with four different hormonal preparations: E2+placebo; E2+dydrogesterone; E2+progesterone; E2+norethisterone. A total of 112 castrated mice were randomly allocated to the 16 groups. This was thus a prospective, randomized, blinded, placebo-controlled four-arm study (45-50 days) with the two T47D and two MCF7 xenografts. Tumor volumes were monitored twice weekly. RESULTS (1): In-vitro study. The strongest proliferation was with norethisterone, but only with PGRMC1-transfected cells. There was significant proliferation with dydrogesterone, but not with progesterone in the absence of estradiol. However, no increase in proliferation was achieved by adding dydrogesterone to estradiol compared with the proliferation induced with estradiol alone, in contrast to norethisterone. RESULTS (2): Xenograft main study. There was significantly faster tumor growth with norethisterone + E2 than with E2+placebo in T47D and MCF7 PGRMC1 xenografts, but not with dydrogesterone + E2 or progesterone + E2. There was less tumor growth in empty-vector xenografts, without between-group differences. CONCLUSION: PGRMC1 increases the breast-cell proliferation effects of certain progestogens, including dydrogesterone, in contrast to progesterone, but not during estradiol-induced proliferation, either in vitro or in a xenograft animal model, in contrast to norethisterone. Thus the proliferative potency of dydrogesterone may be similar to that of progesterone. Clinical studies in women overexpressing PGRMC1 are recommended.

Effects of nomegestrol acetate administration on central and peripheral beta-endorphin and allopregnanolone in ovx rats.

The aim of this study was to investigate the effects of nomegestrol acetate (NOMAc) on the central nervous system by analyzing the neurosteroid allopregnanolone and the opioid beta-endorphin (beta-endorphin). 104 Wistar female rats were used in this study; one group of fertile and one group of ovariectomized rats were used as control. The others were ovariectomized and they underwent a 2-week oral treatment of NOMAc (0.05, 0.1, 0.2, 0.5, 1mg/kg/day), alone or with 0.05 mg/kg/day of estradiol valerate (E2V). Allopregnanolone and beta-endorphin were assessed in different brain areas and in circulation. Ovariectomy decreased allopregnanolone anywhere except in the adrenal gland and E2V reversed the effects of ovariectomy. 0.5 and 1mg/kg/day of NOMAc increased allopregnanolone levels in hippocampus. Combined administration of 1mg/kg/day of NOMAc plus E2V induced a further increase of allopregnanolone levels in hippocampus, hypothalamus, and anterior pituitary. NOMAc (1mg/kg/day) decreased the adrenal content of allopregnanolone, both by itself and associated with E2V. NOMAc increased hippocampal and hypothalamic content of beta-endorphin at the highest doses, and it increased positively E2V action, at 1mg/kg/day, also in anterior pituitary and plasma. These findings reinforce the clinical data regarding the capability of NOMAc to modulate the pathways involved in mood and behaviour. In fact, due to the NOMAc action on hippocampus, hypothalamus, and anterior pituitary, our results highlight the selectivity of NOMAc on part of the limbic system and the anterior pituitary, regarding both allopregnanolone and beta-endorphin.

Inhibition of multidrug resistance-associated protein 2 (MRP2) activity by the contraceptive nomegestrol acetate in HepG2 and Caco-2 cells.

Multidrug resistance-associated protein 2 (MRP2) plays a key role in hepatic and intestinal disposition of endo- and xenobiotics. Several therapeutic agents modulate MRP2 activity resulting in pharmacological interactions. Nomegestrol acetate (NMGA) is a progestogen increasingly used in contraceptive formulations. The aim of this work was to evaluate the effect of NMGA on MRP2 activity in HepG2 and Caco-2 cells as models of human hepatocytes and enterocytes, respectively. NMGA (5, 50 and 500 nM; 48 h) decreased MRP2-mediated transport of 2,4-dinitrophenyl-S-glutathione in HepG2 cells, with no effect on MRP2 protein expression. Acute exposure (1 h) to the same concentrations of NMGA failed to affect MRP2 activity, ruling out an inhibitory action directly induced by the drug. In contrast, acute incubation with a lysate of HepG2 cells pre-treated with NMGA, containing potential metabolites, reproduced MRP2 inhibition. Preincubation of lysates with sulfatase but not with ß-glucuronidase abolished the inhibitory action, strongly suggesting participation of NMGA sulfated derivatives. Western blot studies in plasma vs. intracellular membrane fractions ruled out internalization of MRP2 to be responsible for the impairment of transport activity. MRP2-mediated transport of 5(6)-carboxy-2',7'-dichlorofluorescein was not affected in Caco-2 cells incubated for 48 h with either 5, 50 or 500 nM NMGA. Conversely, acute exposure (1 h) of Caco-2 cells to NMGA-treated HepG2 lysates decreased MRP2 activity, being this effect also prevented by pre-treatment of the lysates with sulfatase. Taken together, these findings demonstrate an inhibitory effect of NMGA sulfated metabolites on hepatic and intestinal MRP2 function. Extrapolated to the in vivo situation, they suggest the possibility of pharmacological interactions with coadministered drugs.