Progesterone Derivatives Research Articles

Steroidal 5α-reductase inhibitors using 4-androstenedione as substrate

The aim of this study was to determine the capacity of some progesterone derivatives, to inhibit the conversion of labeled androstenedione ([3H] 4-dione) to [3H]dihydrotestosterone ([3H]DHT) in prostate nuclear membrane fractions, where the 5α-reductase activity is present. The enzyme 5α-reductase catalyzes the 5α-reduction of 4-dione whereas the 17β-hydroxysteroid dehydrogenase catalyzes the transformation of 4-dione to testosterone or 5α-dione to dihydrotestosterone (DHT). Moreover, we also investigated the role of unlabeled 5α-dione in these pathways. In order to determine the inhibitory effect of different concentrations of the progesterone derivatives in the conversion of [3H] 4-dione to [3H]DHT, homogenates of human prostate were incubated with [3H] 4-dione, NADPH and increasing concentrations of non-labeled 5α-dione. The incubating mixture was extracted and purified using thin layer chromatography. The fraction of the chromatogram corresponding to the standard of DHT was separated and the radioactivity determined. The results showed that the presence of [3H] 4-dione plus unlabelled 5α-dione produced similar levels of DHT as compared to [3H] 4-dione. On the other hand, the results indicated that 17α-hydroxypregn-4-ene-3,20-dione 5 and 4-bromo-17α-hydroxypregn-4-ene-3,20-dione 7b, were the most potent steroids to inhibit the conversion of [3H] 4-dione to [3H]DHT, showing IC50 values of 2 and 1.6 nM, respectively.

Dienogest: an oral progestogen for the treatment of endometriosis

Dienogest is a progestogen that combines the pharmacological properties of 19-norprogestins and progesterone derivatives. Dienogest has a potent effect on endometrial tissue, producing antiproliferative effects on endometriotic cells, as well as anti-inflammatory and antiangiogenic actions. Dienogest has been systematically investigated for the treatment of endometriosis through comprehensive study programs in Europe and Japan. Clinical experience of dienogest at 2 mg daily orally demonstrates that it significantly reduces endometriotic lesions and provides effective pain relief comparable to the current efficacy standard, combined with a favorable safety and tolerability profile that allows long-term use. Study data over 15 months show sustained pain relief and low incidences of treatment-related adverse events. As with other progestogens, spotting or breakthrough bleeds are common, but usually lessen during long-term treatment. Dienogest does not produce antiestrogenic side effects, such as bone mass lo...

Progestins as inhibitors of the human 20-ketosteroid reductases, AKR1C1 and AKR1C3

The human aldo-keto reductases 1C1 and 1C3 (AKR1C1 and AKR1C3) are important 20-ketosteroid reductases in pre-receptor regulation of progesterone action. Both AKR1C1 and AKR1C3 convert progesterone to the less potent metabolite 20α-hydroxyprogesterone, although AKR1C1 has a higher catalytic efficiency than AKR1C3. Recently, we reported significant up-regulation of AKR1C1 and AKR1C3 in ovarian endometriosis, a complex estrogen-dependent disease. The typical characteristics of endometriosis are increased formation of estradiol, which stimulates proliferation of endometriotic tissue, and disturbed action of the protective progesterone. Although progestins have been used for treatment of endometriosis since the 1960s, their detailed mechanisms of action are still not completely understood. In the present study, we evaluated the potential inhibitory effects of progestins on the pre-receptor regulatory enzymes AKR1C1 and AKR1C3. We examined the following progestins as inhibitors of progesterone reduction catalyzed by recombinant AKR1C1 and AKR1C3: progesterone derivatives (dydrogesterone, its metabolite, 20α-hydroxydydrogesterone; and medroxyprogesterone acetate), 19-nortestosterone derivatives (desogestrel, norethinodrone and levonorgestrel), and the androgen danazol. Dydrogesterone, medroxyprogesterone acetate, 20α-hydroxydydrogesterone and norethinodrone inhibited AKR1C1 and AKR1C3 with K i values of 1.9 μM, 7.9 μM, 20.8 μM and 48.0 μM, and of 0.5 μM, 1.4 μM, 18.2 μM and 6.6 μM, respectively. Levonorgestrel and desogestrel preferentially inhibited AKR1C3 with K i values of 5.6 μM and 39.1 μM, respectively. Our data thus show that dydrogesterone, medroxyprogesterone acetate, 20α-hydroxydydrogesterone and norethinodrone inhibit AKR1C1 and AKR1C3 in vitro, although their physiological inhibitory effects still need to be evaluated further. Additionally, we investigated whether progestin dydrogesterone can be metabolized to its active 20α-hydroxymetabolite by AKR1C1 and AKR1C3. AKR1C1 converted dydrogesterone with a high catalytic efficiency while AKR1C3 was less active, which suggests that in vivo dydrogesterone is metabolized mainly by AKR1C1. Docking simulations of dydrogesterone into AKR1C1 and AKR1C3 also support these experimental data.

Fetal origin of allergic asthma: insights on mechanistic cues and therapeutic targets arising from a mouse model of prenatal stress challenge

Background Prenatal stress challenge is a pivotal environmental factor which has been proposed to increase the vulnerability of offspring to develop chronic immune diseases in later life. We analyze the effect of prenatal exposure to stress during late gestation in mice. Materials and methods BALB/c mice were exposed to sound stress during late gestation. Maternal serum and placentas were analyzed. Fetal development was scored. Allergic asthma was induced in the offspring by using an ovalbumin protocol. We analyzed immune cells in lungs, bronchioalveolar fluid (BAL) and lung-draining lymph nodes as well as cytokine concentrations in the BAL. Further, stress-challenged pregnant females were treated with a progesterone derivative, followed by fetal analyses and evaluation of the vulnerability towards asthma in the offspring. Results Stress challenge resulted in decreased serum levels of maternal progesterone and testosterone, and increased serum levels of estradiol associated with placental endocrine dysfunction, such as low expression of proliferin. Fetal development was impaired upon stress challenge, especially in females. Prenatally stressed female adult offspring revealed an increased susceptibility toward asthma, mirrored by an increased airway response, influx of inflammatory cells and increased T helper 2 cytokines in the BAL. Further, we observed decreased frequencies of regulatory T cells (CD3 + CD4 + CD25 + foxP3 +) . Progesterone supplementation abrogated the impaired intrauterine development as well as the susceptibility toward asthma. Conclusions Our study revealed that prenatal stress severely interferes with the intrauterine development, resulting in offspring with an increased vulnerability toward asthma-like symptoms. Supplementation of progesterone during stress-challenged pregnancies abrogates gender-dependently the increased susceptibility toward asthma.

Activated protein C resistance among postmenopausal women using transdermal estrogens

Although the route of estrogen administration is known to be an important determinant of the thrombotic risk among postmenopausal women using hormone therapy, recent data have shown that norpregnane derivatives but not micronized progesterone increase venous thromboembolism risk among transdermal estrogens users. However, the differential effects of progesterone and norpregnanes on hemostasis have not yet been investigated. We set up a cross-sectional study among healthy postmenopausal women aged 45 to 70 years. The impact of activated protein C (APC) on endogenous thrombin potential was investigated in the plasma samples of 108 women who did not use any hormone therapy (n = 40) or who were treated with transdermal estrogens combined with micronized progesterone (n = 30) or norpregnane derivatives (n = 38). After exclusion of women with factor V Leiden and/or G20210A prothrombin gene mutations, there was no significant change in APC sensitivity among women who used transdermal estrogens combined with micronized progesterone compared with nonusers. Women using transdermal estrogens combined with norpregnanes were less sensitive to APC than were nonusers (P = 0.003) or users of transdermal estrogens combined with micronized progesterone (P = 0.004). In addition, prothrombin fragment 1 + 2 concentration was higher in users of transdermal estrogens plus norpregnanes than in nonusers (P = 0.004). Other hemostatic parameters did not vary significantly across the different subgroups. Transdermal estrogens combined with norpregnanes may induce APC resistance and activate blood coagulation. These results provide a biological support to epidemiological data regarding the potential thrombogenic effects of norpregnanes. However, these findings need to be confirmed in a randomized trial.

Menopausal hormone therapy and breast cancer risk: Impact of different treatments. The European Prospective Investigation into Cancer and Nutrition

Menopausal hormone therapy (MHT) is characterized by use of different constituents, regimens and routes of administration. We investigated the association between the use of different types of MHT and breast cancer risk in the EPIC cohort study. The analysis is based on data from 133,744 postmenopausal women. Approximately 133,744 postmenopausal women contributed to this analysis. Information on MHT was derived from country-specific self-administered questionnaires with a single baseline assessment. Incident breast cancers were identified through population cancer registries or by active follow-up (mean: 8.6 yr). Overall relative risks (RR) and 95% confidence interval (CI) were derived from country-specific Cox proportional hazard models estimates. A total of 4312 primary breast cancers were diagnosed during 1,153,747 person-years of follow-up. Compared with MHT never users, breast cancer risk was higher among current users of estrogen only (RR: 1.42, 95% CI 1.23-1.64) and higher still among current users of combined MHT (RR: 1.77, 95% CI 1.40-2.24; p = 0.02 for combined vs. estrogen-only). Continuous combined regimens conferred a 43% (95% CI: 19-72%) greater risk compared with sequential regimens. There was no significant difference between progesterone and testosterone derivatives in sequential regimens. There was no significant variation in risk linked to the estrogenic component of MHT, neither for oral vs. cutaneous administration nor for estradiol compounds vs. conjugated equine estrogens. Estrogen-only and combined MHT uses were associated with increased breast cancer risk. Continuous combined preparations were associated with the highest risk. Further studies are needed to disentangle the effects of the regimen and the progestin component.

Osteoclast differentiation factor RANKL controls development of progestin-driven mammary cancer

Breast cancer is one of the most common cancers in humans and will on average affect up to one in eight women in their lifetime in the United States and Europe. The Women's Health Initiative and the Million Women Study have shown that hormone replacement therapy is associated with an increased risk of incident and fatal breast cancer. In particular, synthetic progesterone derivatives (progestins) such as medroxyprogesterone acetate (MPA), used in millions of women for hormone replacement therapy and contraceptives, markedly increase the risk of developing breast cancer. Here we show that the in vivo administration of MPA triggers massive induction of the key osteoclast differentiation factor RANKL (receptor activator of NF-κB ligand) in mammary-gland epithelial cells. Genetic inactivation of the RANKL receptor RANK in mammary-gland epithelial cells prevents MPA-induced epithelial proliferation, impairs expansion of the CD49f(hi) stem-cell-enriched population, and sensitizes these cells to DNA-damage-induced cell death. Deletion of RANK from the mammary epithelium results in a markedly decreased incidence and delayed onset of MPA-driven mammary cancer. These data show that the RANKL/RANK system controls the incidence and onset of progestin-driven breast cancer.

Efficacy, safety, and patient acceptability of the combined chlormadinone acetate-ethinylestradiol oral contraceptive

Efficacy, safety, and patient acceptability of the combined chlormadinone acetate-ethinylestradiol oral contraceptive Serena Ferrari, Marianna Cannoletta, Matteo Generali, Lucia Cazzato, Angelo CagnacciDepartment of Obstetrics, Gynecology, and Pediatrics, Azienda Ospedaliero, Universitaria di Modena, ItalyAbstract: Since their introduction in 1959, development of hormonal contraceptives has been ongoing, with the ultimate aim of creating not only an effective and safe contraceptive method, but also a drug able to meet the need for treatment of other conditions, such as acne, seborrhea, and hirsutism, with few or no side effects. With this objective, a new progestin, chlormadinone acetate (CMA), has been developed as a derivative of progesterone for ­contraception. This new molecule has been introduced in combination with ethinylestradiol (EE) 30 µg as a safe ­contraceptive with antiandrogenic properties. Many clinical studies have investigated this new oral combination and found it to be safe, with a Pearl Index similar to that of other combined hormonal contraceptives. CMA, because of its antiandrogenic properties, has been also considered effective for resolution of acne, seborrhea, and hirsutism. The data show it to be a safe molecule in terms of glucose and lipid metabolism. No major weight changes have been linked with its use, and it seems to be the only progestin able to reduce fat mass during use. The CMA-EE combination is well tolerated and acceptable to women. Adverse events related to its use are similar to those reported with other third-generation ­contraceptives. We can conclude that CMA-EE is an effective, safe, and well tolerated ­antiandrogenic hormonal contraceptive.Keywords: chlormadinone acetate, acne, weight, metabolism, safety, hormonal contraceptive

ChemInform Abstract: Synthesis and Pharmacological Evaluation of 4-Halo Progesterone Derivatives as Antiandrogen.

The pharmacological activity of eight pregnane derivatives 17-α acetoxyprogesterone 9, 17-α acetoxy-4, 5-epoxypregnan-3, 20-dione 10, 17-α acetoxy-4-chloro-4-pregnene-3, 20-dione 11, 17-α acetoxy-4-bromo-4-pregnene-3, 20-dione 12, 17-α hydroxy-4-bromo-4-pregnene-3, 20-dione 13, 4-chloro-17-α hydroxy-4-pregnene-3, 20-dione 14, 17-α benzoyloxy-4-bromo-4-pregnene-3, 20-dione 15 and 17-α benzoyloxy-4-chloro-4-pregnene-3, 20-dione 16 was aeter, mined. These compounds were evaluated as antiandrogens on gonadectomized hamster seminal vesicles.The pharmacological data in this study indicate that compounds 15 and 16 having a C-17 benzoyloxy moiety showed the highest antiandrogenic activity as measured by the reduction of the weight of the seminal vesicles, followed by the steroids 11 and 12 (17-α acetoxy group). The free alcohols 13 and 14 exhibited a lower antiandrogenic activity. Apparently, the ester moiety at C-17 is a necessary requirement for the presence of high antiandrogenic activity. shows the inhibitory effect on the conversion of testosterone (T) to DHT, of the above described steroids as measured by the amount of produced DHT 2 expressed as pmoles of DHT/g of protein/h.Steroids 11, 12 and 16 showed a much higher inhibitory activity on the conversion of testosterone (T) to dihydrotestosterone (DHT) than presently used finasteride 3.

EMAS position statement: Managing obese postmenopausal women

Introduction Obesity is a public health problem, with overweight individuals representing approximately 20% of the adult world population. Postmenopausal status is associated with higher prevalence of obesity, as 44% of postmenopausal women are overweight, among whom 23% are obese. Obesity often co-exists with other diseases, the most important being diabetes mellitus, dyslipidemia and hypertension. Furthermore, obesity increases the risk of gynecologic cancer, cardiovascular disease, venous thromboembolism, osteoarthritis and chronic back pain. Aim To formulate a position statement on the management of the menopause in obese women. Materials and methods Literature review and consensus of expert opinion. Results and conclusions Obese women seeking hormone therapy should be evaluated for their individual baseline risk of developing breast cancer, cardiovascular disease and venous thromboembolism. These risks should be weighed against expected benefit from symptom relief, improved quality of life and osteoporosis prevention. The lowest effective estrogen dose should be used (CEE 0.300–0.400 mg or estradiol 0.5–1 mg orally daily or 25–50 μg estradiol transdermally). With regard to progestogens, although no RCT data exist, there are observational studies showing that micronized progesterone or dydrogesterone may have a better risk profile with respect to breast cancer risk. There are no RCT data comparing various progestogens with regard to VTE risk. There are observational data, however, suggesting that micronized progesterone or pregnane derivatives may be associated with a lower VTE risk in postmenopausal women taking HT compared to nonpregnane derivatives. There is a rationale in suggesting the use of transdermal HT in obese women, since this route of administration has been associated with a lesser risk of venous thromboembolism than oral therapy.

Depo-Provera does not alter disease progression in SIVmac-infected female Chinese rhesus macaques.

Depo-Provera (medroxyprogesterone acetate), a long-acting derivative of progesterone, is utilized during many nonhuman primate microbicide studies to facilitate simian immunodeficiency virus (SIV) infection by thinning the vaginal epithelium. To date, the systemic effects of this steroid hormone in regard to SIV/HIV pathogenesis are not well understood, but an increase in infection rates and lymphoproliferation following progesterone application has been reported. Therefore, a proactive study using 20 Chinese rhesus macaques was designed to investigate the effect of a single Depo-Provera injection on SIV disease progression. Group 1 (n = 10) was treated with 30 mg Depo-Provera intramuscularly 30 days prior to intravenous challenge with 50 TCID(50) SIVmac251, while Group 2 (n = 10) remained untreated, but received the same amount of SIV. Blood samples were taken at predetermined intervals to measure RNA viral loads, CD4(+), CD8(+), and CD20(+) lymphocyte counts and percentages and absolute numbers of naive and memory T lymphocytes. Upon statistical endpoint data analysis, none of the parameters measured were shown to be significantly different between the groups. One animal in the Depo-Provera-treated group and two macaques in the control group were euthanized prior to study end due to the development of clinical signs (in weeks 43 and 51, respectively). All other animals were euthanized between weeks 68 and 71 post-SIV infection. Histopathological evaluations revealed that 5 of 10 animals in each group had developed simian AIDS (SAIDS). In summary, this prospective study demonstrated that a single injection of 30 mg Depo-Provera did not have a significant influence on SIV disease progression.

Molecular interactions of progesterone derivatives with 5α-reductase types 1 and 2 and androgen receptors

The aim of this study was to ascertain the inhibitory effect of several progesterone derivatives for 5 alpha-reductase types 1 and 2 isozymes and to determine the binding to the androgen receptor. The 3,20-dioxopregna-4-ene-17 alpha-yl acetate 4 containing an acetoxy group in C-17 and steroid 17 alpha-hydroxypregn-4-ene-3,20-dione 5 having a hydroxyl group in the same position inhibited both isozymes. On the other hand, 17 alpha-hydroxy-4,5-epoxypregnan-3,20-dione 6 with an epoxy function at C-4, inhibited only the type 1 enzyme. Steroid 4-chloro-17 alpha-hydroxypregn-4-ene-3,20-dione 7a and 4-bromo-17 alpha-hydroxypregn-4-ene-3,20-dione 7b having the C-4 conjugated system and a chlorine or a bromine atom at C-4 respectively, inhibited both types of 5 alpha-reductase. These results indicate that an increase in the electronegativity of ring A produces a major inhibitory activity for 5 alpha-reductase type 1; however this increase was not observed for type 2 enzyme. When the free hydroxyl group of 7a or 7b was esterified, compounds 3,20-dioxo-4-chloropregn-4-ene-17 alpha yl-4-ethylbenzoate 8a and 3,20-dioxo-4-bromopregn-4-ene-17 alpha yl-4-ethylbenzoate 8b were obtained; these steroids inhibited only the 5 alpha-reductase type 2 enzyme. Finasteride and steroids 4, 5, 7b, 8a showed a comparable in vivo pharmacological activity, however the IC(50) values of these compounds were higher as compared to that of finasteride. These results indicated also that steroids 4, 5, 7a, and 7b bind to the androgen receptor whereas compounds 6, 8a and 8b failed to do so. The overall data from this study showed that steroids 5 and 7b bind to the AR and decreased of the growth of prostate and seminal vesicles. Moreover, 4 decreased also the growth of seminal vesicles.

Synthesis and cytotoxicity studies of steroid-functionalized titanocenes as potential anticancer drugs: sex steroids as potential vectors for titanocenes.

Six titanocenyls functionalized with steroidal esters have been synthesized and characterized by infrared, (1)H, and (13)C NMR spectroscopy and elemental analysis. Among those steroids, dehydroepiandrosterone, trans-androsterone, and androsterone are androgens and pregnenolone is a progesterone precursor. Clionasterol is a natural steroid compound. These steroid-functionalized titanocenyls were tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay for in vitro cytotoxicity for MCF-7 breast cancer and HT-29 colon cancer cells. All complexes exhibited more cytotoxicity than titanocene dichloride. The titanocenyls containing androgen and progesterone derivatives as pendant groups had higher antiproliferative activities than those with cholesterol steroid compounds. Of particular significance is titanocenyl-dehydroepiandrosterone complex, which is 2 orders of magnitude more cytotoxic than titanocene dichloride and also shows much more sensitivity and selectivity for the MCF-7 cell line.

Influence of neurosteroids on the pathogenesis of multiple sclerosis

This paper summarizes neuroendocrine effects on myelination and their possible relevance for the pathogenesis of multiple sclerosis (MS). Steroid hormones known as neurosteroids are synthesized in the human central nervous system (CNS) and exert local effects on glial and neuronal tissue. Progesterone derivatives seem to act as promyelinating factors in the slow but continuous process of myelin maintenance in the adult human brain. Diminished production of these myelin-promoting factors may lead to the formation of structurally altered and less stable myelin, resulting in the observed pathology of the normal-appearing white matter (NAWM) in MS. Dysmyelination, characterized by an altered myelin protein composition, reduced myelin content and increased vulnerability of the myelin sheath, precedes the formation of inflammatory lesions and the clinical onset of disease. Defects in the myelin sheath first occur in mechanically strained areas of the brain, where myelin turnover is physiologically increased. The continuous exposure of myelin proteins, normally sheltered from immunosurveillance, will lead to microglia activation and phagocytosis of myelin. Phagocytic cells from the brain and myelin material may drain to cervical lymph nodes with subsequent priming of T-cells. Finally, heterogenous focal auto-inflammatory reactions contribute to the clinical symptoms of the disease. Neurosteroids influence the biochemical composition of myelin proteins and promote myelin renewal. These promyelinating neurosteroidal functions seem to be impaired in the MS brain. Contrary to the view of auto-inflammatory demyelination being a causative factor in MS pathogenesis, it is argued here that widespread dysmyelination in the adult human brain precedes and induces a focal immune response to various myelin compounds.

Combined Transdermal Testosterone Gel and the Progestin Nestorone Suppresses Serum Gonadotropins in Men

Previous studies have shown that administration of testosterone (T) alone or combined with a progestin has considerable contraceptive efficacy in men. Retrospective data from most hormonal male contraceptive studies have shown that addition of a progestin to testosterone (T) increased the rate and extent of the suppression of spermatogenesis. Nestorone (NES), a progesterone derivative without androgenic or estrogenic activity, has been investigated in women as a potential contraceptive but has not been studied in men. This prospective, randomized, open-label, 2-center trial investigated the effectiveness of transdermal NES gel alone, or in combination with T in suppressing gonadotropin, a surrogate marker for suppression of spermatogenesis. The study subjects were 100 healthy male volunteers who were randomized to 20 days of daily application with 1 of 5 groups (20 per group): either 2 or 4 mg NES (groups 1 and 2); 10 gm of T gel (group 3); or 10 gm of T gel plus either 2 or 4 mg NES (groups 4 and 5). Because there was suboptimal suppression of serum gonadotropins (0.5 IU/L or less) in about half of the study subjects in group 5 (daily 10 gm of T gel plus 4 mg NES), 2 additional groups were randomized to apply a higher dose of NES: daily 10 gm T gel plus either 6 or 8 mg NES gel (groups 6 and 7). The primary study outcome was the percentage of study subjects who had serum luteinizing hormone and follicle-stimulating hormone suppressed to 0.5 IU/L or less after 20 days of treatment. Of the original 140 volunteers, 16 were not efficacy evaluable because of noncompliance with the gel application and 5 withdrew primarily due to adverse reactions. The remaining 119 study subjects were compliant and had few serious adverse events. Both the NES alone and the T gel alone suppressed gonadotropins significantly but the reduction was greater with the T gel alone. The use of the higher doses of the NES gel (6 or 8 mg/d) in combination with the 10 gm T gel suppressed serum gonadotropin levels to less than 0.5 or 1 IU/L in significantly more men than either gel alone (P < 0.05). These findings demonstrate that the use of higher doses of NES (6 mg/d or higher) in combination with T gel has a substantial additive effect on the suppression of gonadotropins and is well tolerated.

Comparison between steroid binding to membrane progesterone receptor α (mPRα) and to nuclear progesterone receptor: Correlation with physicochemical properties assessed by comparative molecular field analysis and identification of mPRα-specific agonists

Recent results showing that the binding characteristics of 33 steroids for human membrane progesterone receptor alpha (hu-mPRα) differ from those for the nuclear progesterone receptor (nPR) suggest that hu-mPRα-specific agonists can be identified for investigating its physiological functions. The binding affinities of an additional 21 steroids for hu-mPRα were determined to explore the structure–activity relationships in more detail and to identify potent, specific mPRα agonists. Four synthetic progesterone derivatives with methyl or methylene groups on positions 18 or 19, 18a-methylprogesterone (18-CH 3P4, Org OE 64-0), 13-ethenyl-18-norprogesterone (18-CH 2P4, Org 33663-0), 19a-methylprogesterone (19-CH 3P4, Org OD 13-0) and 10-ethenyl-19-norprogesterone (19-CH 2P4, Org OD 02-0), showed similar or higher affinities than progesterone for hu-mPRα and displayed mPRα agonist activities in G-protein and MAP kinase activation assays. All four steroids also bound to the nPR in cytosolic fractions of MCF-7 cells. However, two compounds, 19-CH 2P4 and 19-CH 3P4, showed no nPR agonist activity in a nPR reporter assay and therefore are selective mPRα agonists suitable for physiological investigations. The structure–binding relationships of the combined series of 54 steroids for hu-mPRα deviated strikingly from those of a published set of 60 3-keto or 3-desoxy steroids for nPR. Close correlations were observed between the receptor binding affinities of the steroids and their physicochemical properties calculated by comparative molecular field analysis (CoMFA) for both hu-mPRα and nPR. A comparison of the CoMFA field graphs for the two receptors revealed several differences in the structural features required for binding to hu-mPRα and nPR which could be exploited to develop additional mPR-specific ligands.

Different progestins in the treatment of endometriosis - are there relevant differences?

Oral progestins without an estrogen component have been described to be effective in the treatment of endometriosis. Several different substances have been tested, which are on the one hand derivatives of the natural progesterone or of the C-17-OH-progesteron, or on the other hand derivatives of C-19-nortestosteron. Their common characteristic is the secretory transformation of estrogen primed uterine endometrium for which different dosages are necessary because of their different biological activities. They are different with regard to their profile and potency of action on hypothalamicpituitary axis, metabolic processes, breast tissue and genital organs. They are effectively similar with regard to endometriosis related complaints if sufficient doses are administered. No effects are noted on reduced fertility in endometriotic patients and the data are inconsistent concerning direct effects on the endometriotic cells.

Selected Line Difference in the Effects of Ethanol Dependence and Withdrawal on Allopregnanolone Levels and 5α‐Reductase Enzyme Activity and Expression

Allopregnanolone (ALLO) is a progesterone derivative that rapidly potentiates gamma-aminobutyric acid(A) (GABA(A)) receptor-mediated inhibition and modulates symptoms of ethanol withdrawal. Because clinical and preclinical data indicate that ALLO levels are inversely related to symptoms of withdrawal, the present studies determined whether ethanol dependence and withdrawal differentially altered plasma and cortical ALLO levels in mice selectively bred for differences in ethanol withdrawal severity and determined whether the alterations in ALLO levels corresponded to a concomitant change in activity and expression of the biosynthetic enzyme 5alpha-reductase. Male Withdrawal Seizure-Prone (WSP) and -Resistant (WSR) mice were exposed to 72 hours ethanol vapor or air and euthanized at select times following removal from the inhalation chambers. Blood was collected for analysis of ALLO and corticosterone levels by radioimmunoassay. Dissected amygdala, hippocampus, midbrain, and cortex as well as adrenals were examined for 5alpha-reductase enzyme activity and expression levels. Plasma ALLO was decreased significantly only in WSP mice, and this corresponded to a decrease in adrenal 5alpha-reductase expression. Cortical ALLO was decreased up to 54% in WSP mice and up to 46% in WSR mice, with a similar decrease in cortical 5alpha-reductase activity during withdrawal in the lines. While cortical gene expression was significantly decreased during withdrawal in WSP mice, there was a 4-fold increase in expression in the WSR line during withdrawal. Hippocampal 5alpha-reductase activity and gene expression was decreased only in dependent WSP mice. These results suggest that there are line and brain regional differences in the regulation of the neurosteroid biosynthetic enzyme 5alpha-reductase during ethanol dependence and withdrawal. In conjunction with the finding that WSP mice exhibit reduced sensitivity to ALLO during withdrawal, the present results are consistent with the hypothesis that genetic differences in ethanol withdrawal severity are due, in part, to modulatory effects of GABAergic neurosteroids such as ALLO.

Neuroendocrine circuitry and endometriosis: progesterone derivative dampens corticotropin-releasing hormone-induced inflammation by peritoneal cells in vitro

Clinical symptoms of endometriosis, such as pain and infertility, can be described as persistent stressors. Such continuous exposure to stress may severely affect the equilibrium and bidirectional communication of the endocrine and immune system, hereby further aggravating the progression of endometriosis. In the present study, we aimed to tease apart mediators that are involved in the stress response as well as in the progression of endometriosis. Women undergoing diagnostic laparoscopy due to infertility were recruited (n = 69). Within this cohort, early stage of endometriosis were diagnosed in n = 30 and advanced stage of endometriosis in n = 8. Levels of progesterone in serum were determined. Frequency of progesterone receptor (PR) expression on CD56(+) and CD8(+) peritoneal lymphocytes was analysed by flow cytometry. The production of tumour necrosis factor (TNF) and interleukin (IL)-10 by peritoneal leukocytes upon stimulation with the potent stress mediator corticotropin-releasing hormone (CRH) and the progesterone derivative dydrogesterone, or both, were evaluated. Furthermore, the production of progesterone-induced blocking factor (PIBF) by peritoneal leukocytes and the expression of PR in endometriotic tissue were investigated. Levels of progesterone in serum were decreased in women with endometriosis and inversely correlated to pain scores. Furthermore, an increased frequency of CD56(+)PR(+) and CD8(+)PR(+) peritoneal lymphocytes was present in advanced endometriosis. The TNF/IL-10 ratio, reflecting cytokine secretion by peritoneal cells, was higher in cells derived from endometriosis patients and could be further heightened by CRH stimulation, whereas stimulation with dydrogesterone abrogated the CRH-mediated inflammation. Finally, the expression of PIBF by peritoneal leukocytes was increased in endometriosis. Low levels of progesterone in the follicular phase could be responsible for the progression of endometriosis and related pain. Peripheral CRH, increasing upon high psychological stress, might contribute to the peritoneal inflammation present in endometriosis. The therapeutic application of progesterone derivatives, CRH blocking agents as well as improvement of stress coping may disrupt the vicious circle between the chronic peritoneal inflammation and high perception of psychological stress in endometriosis.

4-Pregnen-21-ol-3,20-dione-21-(4-bromobenzenesulfonate) (NSC 88915) and related novel steroid derivatives as tyrosyl-DNA phosphodiesterase (Tdp1) inhibitors.

Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is an enzyme that catalyzes the hydrolysis of 3'-phosphotyrosyl bonds. Such linkages form in vivo when topoisomerase I (Top1) processes DNA. For this reason, Tdp1 has been implicated in the repair of irreversible Top1-DNA covalent complexes. Tdp1 inhibitors have been regarded as potential therapeutics in combination with Top1 inhibitors, such as the camptothecin derivatives, topotecan, and irinotecan, which are used to treat human cancers. Using a novel high-throughput screening assay, we have identified the C21-substituted progesterone derivative, NSC 88915 (1), as a potential Tdp1 inhibitor. Secondary screening and cross-reactivity studies with related DNA processing enzymes confirmed that compound 1 possesses specific Tdp1 inhibitory activity. Deconstruction of compound 1 into discrete functional groups reveals that both components are required for inhibition of Tdp1 activity. Moreover, the synthesis of analogues of compound 1 has provided insight into the structural requirements for the inhibition of Tdp1. Surface plasmon resonance shows that compound 1 binds to Tdp1, whereas an inactive analogue fails to interact with the enzyme. On the basis of molecular docking and mechanistic studies, we propose that these compounds are competitive inhibitors, which mimics the oligonucleotide-peptide Tdp1 substrate. These steroid derivatives represent a novel chemotype and provide a new scaffold for developing small molecule inhibitors of Tdp1.