Evaluation of consumer self-selection of a proposed over-the-counter, progestin-only daily oral contraceptive.

OBJECTIVES: In an effort to switch a norgestrel 0.075 mg progestin-only pill (Opill) from prescription to over-the-counter, we conducted this study to assess whether consumers can use the drug facts label alone to guide appropriate self-selection. STUDY DESIGN: Two studies assessed self-selection: (1) an all-comers, actual-use study evaluating self-selection before purchasing and using norgestrel 0.075 mg and (2) the Targeted Breast Cancer Self-Selection Study evaluating theoretical self-selection among participants with a history of breast cancer. RESULTS: In the actual-use study, based on the label, 1670/1772 participants (94%) were appropriate for use of norgestrel 0.075 mg; 102 (6%) were not appropriate. Of the 102, 66 (65%) correctly did not select and 36 (35%) responded it was okay for them to use norgestrel 0.075 mg. Of the 36 participants who incorrectly self-selected, one had a history of breast cancer and thus might have been adversely affected had they taken norgestrel 0.075 mg. In the Targeted Breast Cancer Self-Selection Study (N = 206), 97% of participants correctly stated norgestrel 0.075 mg was not appropriate for them. CONCLUSIONS: The proposed over-the-counter label enables 98% of potential users to self-select norgestrel 0.075 mg appropriately. Only 2% of potential purchasers may have bought and started to use norgestrel 0.075 mg inappropriately. For two-thirds of these, the potential benefits of their use of the method outweighed any theoretical risks. Adverse clinical consequences of norgestrel 0.075 mg use are unlikely even in those rare cases when the drug facts label was not followed. IMPLICATIONS: The balance of the risk of inappropriate selection to the benefit of taking an over-the-counter progestin-only pill appears to be very much in favor of an overall benefit in terms of unintended pregnancy prevention.

In vitro exposure to environmentally relevant concentrations of norgestrel affects sperm physiology and reproductive success of the Pacific oyster Crassostrea gigas.

Progestins in aquatic environments are of increasing concern, as shown by the results of toxicological studies on adult invertebrates with external fertilization. However, their potential effects on the gametes and reproductive success of such animals remain largely unknown. Thus, the current study assessed the effect of in vitro exposure of environmentally relevant concentrations (10 ng/L and 1000 ng/L) of norgestrel (NGT) on the sperm of Pacific oyster Crassostrea gigas, analyzing sperm motility, ultrastructure, mitochondrial function, ATP status, characteristic enzyme activities, and DNA integrity underlying fertilization and hatching success. The results showed that NGT increased the percentage of motile sperm by elevating intracellular Ca2+ levels, Ca2+-ATPase activity, creatine kinase activity, and ATP content. Although superoxide dismutase activity was enhanced to eliminate reactive oxygen species generated by NGT, oxidative stress occurred, as indicated by the increase in malonaldehyde content and damage to plasma membranes and DNA. As a consequence, fertilization rates decreased. However, hatching rates did not alter significantly, possibly as a result of DNA repair processes. This study demonstrates oyster sperm as a useful, sensitive tool for toxicological research of progestins and provides ecologically relevant information on reproductive disturbance in oysters resulting from exposure to NGT.

The effect of deliberate non-adherence to a norgestrel progestin-only pill: A randomized, crossover study.

OBJECTIVES: To estimate the effects on cervical mucus, ovarian activity and theoretical contraceptive protection of a 6-hour delay and of missing one norgestrel 0.075 mg progestogen-only pill. STUDY DESIGN: In a prospective, two-site, randomized, crossover study, healthy women aged 18 to 35 with BMI <32.0 kg/m² and regular ovulatory cycles completed a baseline 28-day cycle with correct daily pill use followed by two intervention cycles in which, around mid-cycle, one pill was taken 6 hours late or missed completely. We undertook ovarian ultrasonography, estradiol and progesterone measurement, and cervical mucus assessments every 3 to 4 days (daily around the time of the incorrect use) and based the theoretical contraceptive protection score on ovarian activity status, cervical mucus and their temporal relationship. RESULTS: Of 91 potential participants screened, 52 started the study and 46 provided complete data for each intervention cycle. Fourteen participants (30%) ovulated in each of the two intervention cycles, with four during the delayed pill cycle and two during the missed pill cycle having an abnormal luteal phase. Seven participants in the delayed pill cycle, and six with a missed pill had elevated cervical mucus scores temporally associated with the intervention. However only two women, one in the delayed pill cycle and one in the missed pill cycle, had cervical mucus scores in the range considered favorable for fertility. CONCLUSIONS: Delayed or missed intake of a single norgestrel 0.075 mg progestogen-only pill appears to have little effect on theoretical contraceptive efficacy. IMPLICATIONS: This biomedical study suggests that taking a norgestrel 0.075mg progestogen-only pill 6 hours late or missing one pill have little effect on ovarian activity or cervical mucus and may not jeopardize contraceptive efficacy. Correlation with typical use outcomes is necessary to confirm pregnancy risk with delayed or missed norgestrel intake.

Fate of progesterone and norgestrel in anaerobic/anoxic/oxic (A/A/O) process: Insights from biotransformation and mass flow.

Progesterone (P4) and norgestrel (NGT) are two steroid progestogens that can pose adverse effects on aquatic organisms at ng/L levels. Despite increasing concern on their occurrence and removal in wastewater, their fate in the wastewater treatment process has not been well documented. This study identified the transformation products (TPs) of P4 and NGT in anaerobic/anoxic/oxic (A/A/O) process. Potential functional genes involved in biotransformation of P4 and NGT were explored. The elimination or formation behavior of P4, NGT and convinced TPs along various units of A/A/O process was revealed through the mass flow. Results showed that 12 and 13 TPs were identified in the P4 and NGT groups respectively, wherein 10 identical TPs and C-19 structures transformation pathways were observed in both groups. Six genes were found that may be involved in dehydrogenation and isomerization reactions in the pathways. Mass flow indicated that P4 and NGT were mainly eliminated in anaerobic and anoxic units, while convinced TPs mainly formed in anaerobic and anoxic units and were then eliminated in aerobic unit. Further, the ecological risks of the effluent should not be ignored as residual compounds including P4 or NGT and their TPs in the effluent still posed adverse effects on zebrafish transcript levels.

Mechanism of action of a 0.075 mg norgestrel progestogen-only pill 2. Effect on cervical mucus and theoretical risk of conception.

OBJECTIVE: To evaluate the cervical mucus effects of a norgestrel 0.075 mg progestin-only contraceptive pill over a 28-day cycle. STUDY DESIGN: We recruited persons ages 18 to 35 with normal cycles at 2 US academic medical centers. Participants took norgestrel 0.075 mg daily for 28 days at the same time (within a 3 hour window) daily, recorded through a text-message based e-diary. We extracted cervical mucus using a standardized aspiration technique on the day of pill initiation and then at least every 3 to 4 days over the cycle. We monitored subjects for follicular activity with transvaginal ultrasound examination and blood sampling for ovarian hormones and gonadotropins at each visit. We assessed cervical mucus scoring using a 4-category/12-point modified Insler scale (score ≥9 [favoring fertility], 5-8 [intermediate], and ≤4 [unfavorable to fertility]). We stratified cervical mucus scores by serum estradiol levels and ovulatory status based on a modified Hoogland score. RESULTS: Excluding enrollment, we collected and evaluated 413 mucus samples from 51 participants. Participants had a median mucus score of 0 (Interquartile Range 0, 2); most had scores ≤4 (samples = 385, 93%) and none had a score ≥9 favoring fertility. Seventeen (33%) participants ovulated, of which 14 (82%) had unfavorable mucus scores (≤4) at the time of ovulation and 3 (18%) had intermediate scores (5-8). CONCLUSIONS: Norgestrel 0.075 mg daily prevents mucus changes that favor fertility, even during ovulatory cycles. IMPLICATIONS: Daily administration of norgestrel 0.075 mg over an initial 28-day cycle did not result in fertile cervical mucus. Although approximately one-third of users ovulated in this first cycle of pill use, contraceptive efficacy may be maintained by mucus effects.

Mechanism of action of norgestrel 0.075 mg a progestogen-only pill. I. Effect on ovarian activity.

OBJECTIVE: To explore the effect on ovarian activity and ovulation of 28 days of correct daily use of a progestogen-only pill containing norgestrel 0.075 mg. STUDY DESIGN: We performed a prospective, randomized, crossover study at 2 US sites, recruiting healthy women of reproductive age to use norgestrel 0.075 mg daily for three 28-day treatment cycles. We monitored ovarian activity every 3 to 4 days with reproductive hormone measurements and ovarian ultrasonography. Participants recorded pill use in daily diaries. An adjudication committee independent of the research sites assessed ovarian activity using a modified Hoogland score combining hormone concentrations and follicle diameter and appearance (quiescence 1-3, ovarian activity without ovulation 4-5, and ovulatory/postovulatory 6-7). RESULTS: We report here the findings of the initial 28-day treatment cycle in which 51 of 52 recruited participants provided data sufficient for analysis. Two thirds of subjects had no evidence of ovulation (34/51, 66.6%); eight of these (15.7%) had quiescent ovaries (follicle <13 mm diameter) and 26 (51%) had follicular development (follicle >13 mm diameter) without ovulation. Seventeen participants ovulated, of whom 12 (23.5%) had a normal, and 5 (9.8%) an abnormal luteal phase. Persistent ovarian follicles were common among women who had ovarian activity without ovulation, 17 of 26 participants (65.4%) had a large follicle which persisted beyond 28 days. CONCLUSION: During 28 days of exposure to a norgestrel 0.075 mg progestogen-only pill, most women had no evidence of ovulation. IMPLICATIONS: Ovulation inhibition and follicle growth disturbance are important in the mechanism of action of a progestogen-only pill containing norgestrel 0.075 mg.

Oral contraceptive use by formulation and breast cancer risk by subtype in the Nurses' Health Study II: a prospective cohort study.

BACKGROUND: Oral contraceptive use has been associated with a higher breast cancer risk; however, evidence for the associations between different oral contraceptive formulations and breast cancer risk, especially by disease subtype, is limited. OBJECTIVE: This study aimed to evaluate the associations between oral contraceptive use by formulation and breast cancer risk by disease subtype. STUDY DESIGN: This prospective cohort study included 113,187 women from the Nurses' Health Study II with recalled information on oral contraceptive usage from 13 years of age to baseline (1989) and updated data on usage until 2009 collected via biennial questionnaires. A total of 5799 breast cancer cases were identified until the end of 2017. Multivariable Cox proportional hazards models estimated hazard ratios and 95% confidence intervals for the associations between oral contraceptive use and breast cancer risk overall and by estrogen and progesterone receptor and human epidermal growth factor receptor 2 status. Oral contraceptive use was evaluated by status of use (current, former, and never), duration of and time since last use independently and cross-classified, and formulation (ie, estrogen and progestin type). RESULTS: Current oral contraceptive use was associated with a higher risk for invasive breast cancer (hazard ratio, 1.31; 95% confidence interval, 1.09-1.58) when compared with never use, with stronger associations observed for longer durations of current use (>5 years: hazard ratio, 1.56; 95% confidence interval, 1.23-1.99; ≤5 years: hazard ratio, 1.19; 95% confidence interval, 0.95-1.49). Among former users with >5 years since cessation, the risk was similar to that of never users (eg, >5 to 10 years since cessation: hazard ratio, 0.99; 95% confidence interval, 0.88-1.11). Associations did not differ significantly by tumor subtype. In analyses by formulation, current use of formulations containing levonorgestrel in triphasic (hazard ratio, 2.83; 95% confidence interval, 1.98-4.03) and extended cycle regimens (hazard ratio, 3.49; 95% confidence interval, 1.28-9.53) and norgestrel in monophasic regimens (hazard ratio, 1.91; 95% confidence interval, 1.19-3.06), all combined with ethinyl estradiol, was associated with a higher breast cancer risk when compared with never oral contraceptive use. No association was observed for current use of the other progestin types evaluated (norethindrone, norethindrone acetate, ethynodiol diacetate, desogestrel, norgestimate, and drospirenone), however, sample sizes were relatively small for some of the subgroups, limiting these analyses. CONCLUSION: Current oral contraceptive use was associated with a higher risk for invasive breast cancer regardless of disease subtype, however, the risk in former users was comparable with never users 5 years after cessation. In analyses by progestin type, associations were observed for select formulations containing levonorgestrel and norgestrel. Assessment of the associations for newer progestin types (desogestrel, norgestimate, drospirenone) was limited by sample size, and further research on more recently introduced progestins is warranted.

Pharmacokinetic and Pharmacodynamic Profiles of Ethinylestradiol/Norgestimate Combination or Norethindrone upon Coadministration with Elagolix 150 mg Once Daily in Healthy Premenopausal Women.

BACKGROUND: Two pharmacokinetic/pharmacodynamic studies were conducted to evaluate the potential drug-drug interaction between elagolix, an oral gonadotropin-releasing hormone receptor antagonist, and an oral contraceptive (ethinylestradiol [EE] 0.035 mg and norgestimate 0.18/0.215/0.25 mg) or progestin-only contraceptive (norethindrone 0.35 mg) in healthy premenopausal women. METHODS: These phase I studies used a two-period, sequential design, where period 1 included treatment with oral contraceptives, followed by period 2 with contraceptives coadministered with elagolix 150 mg once daily. RESULTS: In study 1, pharmacokinetic exposures for EE in period 2 increased by 30% and the norgestimate metabolites decreased by approximately 15% when coadministered with elagolix. Mean hormone exposure appeared lower for follicle-stimulating hormone (FSH; 31%), luteinizing hormone (LH; 38%), and estradiol (E2; 16%). The percentage of women with consecutive progesterone (P) concentrations above 5 nmol/L was similar in both periods. Norethindrone pharmacokinetic exposures were comparable in both periods. The hormone exposure for LH and FSH was similar, and mean E2 exposure was 32% lower in period 2. The percentage of subjects with consecutive ovulatory P concentrations was also similar in both periods (study 2). Safety and tolerability profiles were unremarkable in both studies. CONCLUSIONS: Coadministration of elagolix 150 mg once daily with oral contraceptives containing EE and norgestimate, or norethindrone, resulted in small pharmacokinetic changes in the oral contraceptive components. Similar or lower FSH, LH, and E2 exposures were observed during coadministration, with ovulatory P concentrations also comparable in both periods. The pharmacodynamic profiles of the oral contraceptives were maintained when coadministered with elagolix.

The paradigm of norgestimate: a third-generation testosterone-derivative progestin with a peripheral anti-androgenic activity and the lowest risk of venous thromboembolism.

INTRODUCTION: Norgestimate (NGM) is a testosterone derivative with peculiar receptor activities. AREAS COVERED: This is a narrative review of the available data on the pharmacotherapy of NGM in combined hormonal contraceptives (CHCs) in terms of contraceptive efficacy, venous thromboembolism (VTE) risk, safety, tolerability and bleeding patterns. A comprehensive literature review was conducted in August 2020 using PubMed with the keyword 'norgestimate'. EXPERT OPINION: NGM shows a mild estrogenic activity associated with anti-mineralocorticoid and anti-androgenic properties, largely responsible for the cardiovascular safety profile. The anti-androgenic property depends on the androgen receptor (AR) nuclear translocation (AR trafficking and its subnuclear distribution), the inhibition of 5α-reductase activity (it possesses higher activity compared to other available progestins), and the increase on sexual hormone binding globulin (SHBG) levels if combined with an estrogenic counterpart. NGM is one of the molecules that best modulates the power of ethinyl-estradiol on the thromboembolic risk, being associated with the lowest VTE risk between different CHCs. NGM has the advantage of retaining peripheral anti-androgenic activity, demonstrated by the impact on lipid and glucose metabolism, and it should be preferred if compared with other similar progestins of the same class of risk which are much more androgenic, such as levonorgestrel.

The Effect of Oral Contraceptive Hormones on Anterior Cruciate Ligament Strength.

BACKGROUND: Women are 2 to 9 times more likely to experience an anterior cruciate ligament (ACL) injury than men. Various hormones including relaxin, progesterone, and estrogen influence ACL strength. Oral contraceptives (OCs) alter these hormone levels; however, studies have yet to comprehensively compare different OCs' effects on the ACL. HYPOTHESIS: OCs with increased progestin-to-estrogen ratios will (1) increase ACL collagen expression, (2) decrease ACL matrix metalloproteinase expression, and (3) increase ACL strength. STUDY DESIGN: Controlled laboratory study. METHODS: Untreated female rats were compared with rats treated with 1 of 5 clinically used OCs: norethindrone (NE) only, NE plus ethinylestradiol (EE), etynodiol diacetate (ED) plus EE, norgestimate (NG) plus EE, and drospirenone (DS) plus EE. Doses were scaled from human doses to account for differences in bioavailability and body weight, and OCs were administered daily via oral gavage for 4 rat estrous cycles (20 days). A total of 36 rats were then sacrificed (6 rats/group). ACLs underwent biomechanical testing to assess ACL strength, stiffness, and maximum load before failure. ACL specimens were also isolated for quantitative real-time polymerase chain reaction analysis to assess collagen, matrix metalloproteinase, and relaxin receptor-1 expression. RESULTS: While the primary structural property of interest (ACL maximum load before failure) was not significantly improved by OC treatment, the main material property of interest (ACL strength) in rats treated with NE only, DS + EE, ED + EE, and NE + EE was significantly increased compared with untreated controls (P = .001, P = .004, P = .004, and P = .04, respectively). The order from strongest to weakest ACLs, which was also the same order as the highest to lowest progestin-to-estrogen ratios, was groups treated with NE only, DS + EE, ED + EE, NE + EE, and lastly NG + EE. Higher ratio formulations also increased the expression of type I collagen (P = .02) and decreased the expression of matrix metalloproteinase-1 (P = .04). CONCLUSION: OC formulations with higher progestin-to-estrogen ratios may be more protective for the ACL than formulations with lower ratios. CLINICAL RELEVANCE: OC formulations with high progestin-to-estrogen ratios may benefit female athletes by reducing their ACL injury risk by decreasing the effects of relaxin on the ACL.

Molecular insights into how SHBG dimerization exerts changes on ligand molecular recognition.

Sex hormone binding globulin (SHBG) is a homodimeric glycoprotein and is the major carrier protein for sex steroids in plasma, regulating sex hormone availability in most vertebrate groups. Although it was initially thought that human dimeric SHBG bound a single ligand at the homodimer interface, studies demonstrated that dimeric SHBG binds a ligand to each subunit with similar affinity. In fact, the findings from recent experimental studies suggest that ligand binding to the SHBG dimer involves a complex allosteric mechanism involving conformational changes that limit observations of the presence of allosteric regulation. Therefore, we combined structural data with molecular dynamics simulations using Molecular Mechanics Generalized-Born Surface Area (MMGBSA) to dissect the structural and energetic basis for molecular recognition between five ligands whose affinities and binding positions on SHBG are known, i.e., 3ß,17α-diol; 3ß,17ß-diol; DHT; norgestrel (NOG); and estradiol (E2), and monomeric and dimeric SHBG. Protein-ligand complexes, involving dimeric SHBG saturated with two ligands on each subunit, reproduce the experimental affinity tendency and allow the observation that dimerization exerts disparate effects on binding affinity, characteristic of negative cooperativity for E2, DHT, and NOG, whereas 3ß-17α-diol and 3ß-17ß-diol lack allostery.

Norgestrel, a Progesterone Analogue, Promotes Significant Long-Term Neuroprotection of Cone Photoreceptors in a Mouse Model of Retinal Disease.

Purpose: Retinitis pigmentosa (RP) refers to a group of inherited blinding retinal diseases, whereby the death of mutated rod photoreceptors is followed closely by the death of cone photoreceptors. Cone cell death can be hugely debilitating as color/daytime vision becomes impaired. Thus, treatments that are effective against cone cell death are urgently needed. Our research has been working toward development of a neuroprotective treatment for RP. We have previously demonstrated significant neuroprotective properties of norgestrel, a progesterone analogue, in the mouse retina. The current study further investigates the potential of norgestrel as a treatment for RP, with a focus on long-term preservation of cone photoreceptors. Methods: Using the well-established rd10 mouse model of RP, we administered a norgestrel-supplemented diet at postnatal day (P)30, following widespread loss of rod photoreceptors and at the outset of cone degeneration. We subsequently assessed cone cell morphology and retinal function at P50, P60, and P80, using immunohistochemistry, electroretinograph recordings, and optomotor testing. Results: While cone cell degeneration was widespread in the untreated rd10 retina, we observed profound preservation of cone photoreceptor morphology in the norgestrel-treated mice for at least 50 days, out to P80. This was demonstrated by up to 28-fold more cone arrestin-positive photoreceptors. This protection transpired to functional preservation at all ages. Conclusions: This work presents norgestrel as an incredibly promising long-term neuroprotective compound for the treatment of RP. Crucially, norgestrel could be used in the mid-late stages of the disease to protect remaining cone cells and help preserve color/daytime vision.

A Multi-Center, Open-Label, Pharmacokinetic Drug Interaction Study of Erenumab and a Combined Oral Contraceptive in Healthy Females.

BACKGROUND: Erenumab is a human anti-calcitonin gene-related peptide monoclonal antibody developed for migraine prevention. Migraine predominately affects women of childbearing age; thus, it is important to determine potential drug-drug interactions between a common oral contraceptive and drugs used to treat migraine. OBJECTIVES: We sought to evaluate potential drug-drug interactions between erenumab and a common oral contraceptive. METHODS: Healthy women received three cycles of a norgestimate/ethinyl estradiol-containing oral contraceptive with a single 140-mg subcutaneous dose of erenumab during cycle three. Norgestimate metabolites (norgestrel and norelgestromin) and ethinyl estradiol pharmacokinetics were evaluated in the absence and presence of erenumab. Primary endpoint was peak plasma concentration (Cmax) and area under concentration-time curve from time 0 to 24 h (AUCtau). Luteinizing hormone, follicle-stimulating hormone, and progesterone concentrations were evaluated as pharmacodynamic markers. RESULTS: Erenumab did not influence the pharmacokinetics of norelgestromin, norgestrel, or ethinyl estradiol. Least-squares mean estimates (90% confidence interval) for Cmax ratios were 1.05 (0.90-1.23), 1.06 (0.97-1.16), and 1.04 (0.88-1.22) for norelgestromin, norgestrel, and ethinyl estradiol, respectively. Respective AUCtau ratios were 1.02 (0.94-1.12), 1.03 (0.96-1.10), and 1.02 (0.91-1.14). Luteinizing hormone, follicle-stimulating hormone, and progesterone concentrations were similar after exposure to oral contraceptive alone and with erenumab. CONCLUSION: Erenumab did not alter the pharmacokinetics of the active components of an estrogen/progestin combination oral contraceptive. Thus, no change in contraceptive efficacy is expected with erenumab. TRIAL REGISTRATION: ClinicalTrials.gov NCT02792517.

Reproductive effects of synthetic progestin norgestrel in zebrafish (Danio rerio).

The aim of this study was to assess the adverse effects of synthetic progestin norgestrel (NGT) on the reproduction of zebrafish by measuring the egg production, histology and transcriptional expression profiles along the hypothalamic-pituitary-gonadal (HPG) axis in adult zebrafish. After a pre-exposure period of 7 days, adult zebrafish were exposed to 6, 29 and 69 ng L-1 NGT for 21 days. The results showed that exposure to 69 ng L-1 NGT led to a significant up-regulation of follicle stimulating hormone, beta polypeptide (fshb), luteinizing hormone, beta polypeptide (lhb), progesterone receptor (pgr), estrogen receptor 1 (esr1) and androgen receptor (ar) genes in the brains, as well as significant up-regulation of hydroxysteroid 20-beta dehydrogenase (hsd20b) and hydroxysteroid 11-beta dehydrogenase 2 (hsd11b2) genes and down-regulation of 11-beta-hydroxylase (cyp11b) gene in the ovaries of females. In the testes of males, an overall down-regulation of steroidogenic acute regulatory protein (star), cytochrome P450-mediated side-chain cleavage enzyme (cyp11a1), cyp11b, hsd20b, hydroxysteroid 17-beta dehydrogenase type 3 (hsd17b3), hsd11b2 and ar genes were observed following exposure to different treatments of NGT. These transcriptional alterations imply that NGT could exhibit the potent progestogenic and androgenic activities in zebrafish. Egg production as well as histology in the ovaries and testes was not affected by NGT. Taken together, the overall results demonstrated that NGT could significantly affect transcriptional expression levels of genes related to HPG axis in zebrafish, and whether that change translates to additional physiological effects is needed further research.

Microglial-induced Müller cell gliosis is attenuated by progesterone in a mouse model of retinitis pigmentosa.

Norgestrel, a progesterone analogue, has demonstrated neuroprotective effects in a mouse model of retinitis pigmentosa. Neuroprotection is achieved in part through Norgestrels anti-inflammatory properties, alleviating detrimental microglial activity. Gliosis is a feature of many neurodegenerative diseases of the retina, including retinitis pigmentosa. Müller glia, a type of macroglia found in the retina, are major contributors of gliosis, characterized by the upregulation of glial fibrillary acidic protein (GFAP). Microglia-Müller glia crosstalk has been implicated in the initiation of gliosis. In the rd10 retina, increased microglial activity and gliotic events are observed prior to the onset of photoreceptor loss. We hypothesized that Norgestrels dampening effects on harmful microglial activity would consequently impact on gliosis. In the current study, we explore the role of microglia-Müller glia crosstalk in degeneration and Norgestrel-mediated neuroprotection in the rd10 retina. Norgestrels neuroprotective effects in the rd10 retina coincide with significant decreases in both microglial activity and Müller cell gliosis. Using a Müller glial cell line, rMC-1, and isolated microglia, we show that rd10 microglia stimulate GFAP production in rMC-1 cells. Norgestrel attenuates gliosis through direct actions on both microglia and Müller glia. Norgestrel reduces the release of harmful stimuli from microglia, such as interferon-γ, which might otherwise signal to Müller glia and stimulate gliosis. We propose that Norgestrel also targets Müller cell gliosis directly, by limiting the availability of pSTAT3, a known transcription factor for GFAP. These findings highlight an important aspect to Norgestrels neuroprotective effects in the diseased retina, in combating Müller cell gliosis.

Thromboembolic adverse event study of combined estrogen-progestin preparations using Japanese Adverse Drug Event Report database.

Combined estrogen-progestin preparations (CEPs) are associated with thromboembolic (TE) side effects. The aim of this study was to evaluate the incidence of TE using the Japanese Adverse Drug Event Report (JADER) database. Adverse events recorded from April 2004 to November 2014 in the JADER database were obtained from the Pharmaceuticals and Medical Devices Agency (PMDA) website (www.pmda.go.jp). We calculated the reporting odds ratios (RORs) of suspected CEPs, analyzed the time-to-onset profile, and assessed the hazard type using Weibull shape parameter (WSP). Furthermore, we used the applied association rule mining technique to discover undetected relationships such as the possible risk factors. The total number of reported cases in the JADER contained was 338,224. The RORs (95% confidential interval, CI) of drospirenone combined with ethinyl estradiol (EE, Dro-EE), norethisterone with EE (Ne-EE), levonorgestrel with EE (Lev-EE), desogestrel with EE (Des-EE), and norgestrel with EE (Nor-EE) were 56.2 (44.3-71.4), 29.1 (23.5-35.9), 42.9 (32.3-57.0), 44.7 (32.7-61.1), and 38.6 (26.3-56.7), respectively. The medians (25%-75%) of the time-to-onset of Dro-EE, Ne-EE, Lev-EE, Des-EE, and Nor-EE were 150.0 (75.3-314.0), 128.0 (27.0-279.0), 204.0 (44.0-660.0), 142.0 (41.3-344.0), and 16.5 (8.8-32.0) days, respectively. The 95% CIs of the WSP-ß for Ne-EE, Lev-EE, and Nor-EE were lower and excluded 1. Association rule mining indicated that patients with anemia had a potential risk of developing a TE when using CEPs. Our results suggest that it is important to monitor patients administered CEP for TE. Careful observation is recommended, especially for those using Nor-EE, and this information may be useful for efficient therapeutic planning.

Pro-survival redox signalling in progesterone-mediated retinal neuroprotection.

Retinitis pigmentosa (RP) is a group of hereditary retinal diseases, characterised by photoreceptor cell loss. Despite a substantial understanding of the mechanisms leading to cell death, an effective therapeutic strategy is sought. Our laboratory has previously demonstrated the neuroprotective properties of Norgestrel, a progesterone analogue, in the degenerating retina, mediated in part by the neurotrophic factor basic fibroblast growth factor (bFGF). In other retinal studies, we have also presented a pro-survival role for reactive oxygen species (ROS), downstream of bFGF. Thus, we hypothesized that Norgestrel utilises bFGF-driven ROS production to promote photoreceptor survival. Using the 661W photoreceptor-like cell line, we now show that Norgestrel, working through progesterone receptor membrane complex 1 (PGRMC1); generates an early burst of pro-survival bFGF-induced ROS. Using the rd10 mouse model of RP, we confirm that Norgestrel induces a similar early pro-survival increase in retinal ROS. Norgestrel-driven protection in the rd10 retina was attenuated in the presence of antioxidants. This study therefore presents an essential role for ROS signalling in Norgestrel-mediated neuroprotection in vitro and demonstrates that Norgestrel employs a similar pro-survival mechanism in the degenerating retina.

Transcriptional alterations induced by binary mixtures of ethinylestradiol and norgestrel during the early development of zebrafish (Danio rerio).

Synthetic estrogens and progestins are commonly used in human and veterinary medicine. After use, they reach aquatic environments via discharge of wastewaters from human and animals, thus posing potential risks to organisms. So far, very little is known about their combined effects in aquatic organisms. The aim of this study was to investigate the effects of binary mixtures of ethinylestradiol (EE2) and norgestrel (NGT) on embryonic zebrafish (Danio rerio) by measuring transcriptional alterations. Zebrafish embryos were exposed to EE2 and NGT alone or in combination at concentrations between 36 and 5513ngL-1 for 96h post-fertilization (hpf). The results showed that most of gene transcriptions of hypothalamic-pituitary-gonadal axis (e.g., Pgr, Mprα, Esr1, Esr2a, Vtg1, Ar, Cyp11b, Star, Gnrh3 and Fshb) and circadian rhythm signaling (e.g., Cry1a, Cry2a, Cry2b, Per3, Arntl1b, Arntl2, Clock1a, Cry3 and Cry4) displayed most pronounced alterations in the mixtures as compared to single EE2 and NGT exposures. This finding suggests exposure to the binary mixtures of EE2 and NGT produced significantly enhanced effects in fish as compared to single chemical exposures, and their coexistence could have significant environmental implications.

Fractalkine-CX3CR1 signaling is critical for progesterone-mediated neuroprotection in the retina.

Retinitis pigmentosa (RP) encompasses a group of retinal diseases resulting in photoreceptor loss and blindness. We have previously shown in the rd10 mouse model of RP, that rd10 microglia drive degeneration of viable neurons. Norgestrel, a progesterone analogue, primes viable neurons against potential microglial damage. In the current study we wished to investigate this neuroprotective effect further. We were particularly interested in the role of fractalkine-CX3CR1 signaling, previously shown to mediate photoreceptor-microglia crosstalk and promote survival in the rd10 retina. Norgestrel upregulates fractalkine-CX3CR1 signaling in the rd10 retina, coinciding with photoreceptor survival. We show that Norgestrel-treated photoreceptor-like cells, 661Ws, and C57 explants modulate rd10 microglial activity in co-culture, resulting in increased photoreceptor survival. Assessment of Norgestrel's neuroprotective effects when fractalkine was knocked-down in 661 W cells and release of fractalkine was reduced in rd10 explants confirms a crucial role for fractalkine-CX3CR1 signaling in Norgestrel-mediated neuroprotection. To further understand the role of fractalkine in neuroprotection, we assessed the release of 40 cytokines in fractalkine-treated rd10 microglia and explants. In both cases, treatment with fractalkine reduced a variety of pro-inflammatory cytokines. These findings further our understanding of Norgestrel's neuroprotective properties, capable of modulating harmful microglial activity indirectly through photoreceptors, leading to increased neuroprotection.

Nonoral combined hormonal contraceptives and thromboembolism: a systematic review.

BACKGROUND: Combined hormonal contraceptives (CHCs), containing estrogen and progestin, are associated with an increased risk of venous thromboembolism (VTE) and arterial thromboembolism (ATE) compared with nonuse. Few studies have examined whether nonoral formulations (including the combined hormonal patch, combined vaginal ring and combined injectable contraceptives) increase the risk of thrombosis compared with combined oral contraceptives (COCs). OBJECTIVES: The objectives were to examine the risk of VTE and ATE among women using nonoral CHCs compared to women using COCs. METHODS: We searched the PubMed database for all English language articles published from database inception through May 2016. We included primary research studies that examined women using the patch, ring or combined injectables compared with women using levonorgestrel-containing or norgestimate-containing COCs. Outcomes of interest included VTE (deep venous thrombosis or pulmonary embolism) or ATE (acute myocardial infarction or ischemic stroke). We assessed the quality of each individual piece of evidence using the system developed by the United States Preventive Services Task Force. RESULTS: Eight studies were identified that met inclusion criteria. Of seven analyses from six studies examining VTE among patch users compared with levonorgestrel- or norgestimate-containing COC users, two found a statistically significantly elevated risk among patch users (risk estimates 2.2-2.3), one found an elevated risk that did not meet statistical significance (risk estimate 2.0), and four found no increased risk. Of three studies examining VTE among ring users compared with levonorgestrel COC users, one found a statistically significantly elevated risk among patch users (risk estimate 1.9) and two did not. Two studies did not find an increased risk for ATE among women using the patch compared with norgestimate COCs. We did not identify any studies examining combined injectable contraceptives. CONCLUSION: Limited Level II-2 good to fair evidence demonstrated conflicting results on whether women using the patch or the ring have a higher risk of VTE than women using COCs. Evidence did not demonstrate an increased risk of ATE among women using the patch. Overall, any potential elevated risk likely represents a small number of events on a population level. Additional studies with standard methodology are needed to further clarify any associations and better understand mechanisms of hormone-induced thrombosis among users of nonoral combined hormonal contraception.