In vivo estrogen bioactivities and in vitro estrogen receptor binding and transcriptional activities of anticoagulant synthetic 17beta-aminoestrogens

Prolame produces anxiolytic- and antidepressant-like effects in middle-aged female rats with less uterotrophic effects than 17β-estradiol

Estrogen hormone replacement therapy (EHRT), improving women's life quality at menopause, reduces anxiety and depression symptoms associated with ovarian hormonal decline. However, its potential adverse effects, like thromboembolism and cancer risk, limit its use. Prolame is a synthetic 17β-amino estrogen with antithrombotic actions that exerts anxiolytic- and antidepressant-like effects on young adult ovariectomized female rats. It is unknown if prolame's effects may be observed in age and endocrine conditions emulating menopause. This study aimed to identify the antidepressant- and anxiolytic-like effects of prolame and E2 (used as a reference estrogen treatment) in middle-aged female rats coursing with irregular cycles, in two different conditions: ovariectomized or gonadally intact. Results were compared with those from young adult ovariectomized rats. Prolame (60 or 120 μg/kg), 17β-estradiol (E2, 40 or 80 μg/kg), or vehicle were chronically administered, and their effects were evaluated in the elevated plus-maze, defensive burying behavior test, open field test, and forced swimming test. Uterotrophic actions were estimated by uterine weight related to body weight. Prolame and E2 produced robust anxiolytic- and antidepressant-like effects in young adult ovariectomized rats, but these effects were absent in gonadally intact middle-aged rats. Interestingly, only prolame induced anxiolytic- and antidepressant-like effects in middle-aged ovariectomized rats. Uterotrophic effects of prolame were weaker than E2 effects, notably in middle-aged females. Altogether, present data support the notion that prolame has the potential to be considered an EHRT with relevant psychoactive actions and with apparently lower adverse-side effects, especially in middle-aged populations.

Sex Hormones and Lung Inflammation

Inflammation is a characteristic marker in numerous lung disorders. Several immune cells, such as macrophages, dendritic cells, eosinophils, as well as T and B lymphocytes, synthetize and release cytokines involved in the inflammatory process. Gender differences in the incidence and severity of inflammatory lung ailments including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), lung cancer (LC), and infectious related illnesses have been reported. Moreover, the effects of sex hormones on both androgens and estrogens, such as testosterone (TES) and 17β-estradiol (E2), driving characteristic inflammatory patterns in those lung inflammatory diseases have been investigated. In general, androgens seem to display anti-inflammatory actions, whereas estrogens produce pro-inflammatory effects. For instance, androgens regulate negatively inflammation in asthma by targeting type 2 innate lymphoid cells (ILC2s) and T-helper (Th)-2 cells to attenuate interleukin (IL)-17A-mediated responses and leukotriene (LT) biosynthesis pathway. Estrogens may promote neutrophilic inflammation in subjects with asthma and COPD. Moreover, the activation of estrogen receptors might induce tumorigenesis. In this chapter, we summarize the most recent advances in the functional roles and associated signaling pathways of inflammatory cellular responses in asthma, COPD, PF, LC, and newly occurring COVID-19 disease. We also meticulously deliberate the influence of sex steroids on the development and progress of these common and severe lung diseases.

Potential Estrogenic Properties of 17β-Hydroxy-ethylimine Estradiol Derivative Targeted to Menopause Stage

BACKGROUND/AIM

Hormone replacement therapy during menopause increases the risk of thromboembolic diseases and cancer, so safety alternative therapeutic strategies are needed. 17β-Aminoestrogens are a synthetic estrogens group that possess mild anticoagulant activity that contrasts with the pro-coagulant effects showed by estradiol's (E₂) in rodents. Being considered an alternative to conventional hormone replacement therapy during menopause without thrombogenic risks producing. The present study aimed to determine the estrogenic profile and anxiolytic activity of 17β-[hydroxy-ethylimine]-1,3,5(10)-estratrien-3-ol (IE₂), a related compound unknown until now.

METHODS

IE₂ was assessed in immature rats by uterotrophic assay administering IE_2, E_2, or vehicle. In ovariectomized adult Wistar rats (Ovx) to facilitating the lordotic behavior compared with E_2, estradiol benzoate, or vehicle. The effect of IE₂ on anxiety was estimated in Ovx animals treated with IE₂, E₂, or vehicle group and evaluated in the elevated plus-maze model.

RESULTS AND CONCLUSION

IE₂ produced an uterotrophic effect, lordotic behavior, and anxiolytic effect in a dose-dependent manner, similar to E₂. IE₂ depicted estrogenicity, indicating potential clinical use as hormone replacement therapy during menopause.

Differential effect of the 17β-aminoestrogens prolame, butolame and pentolame in anxiety and depression models in rats

Estrogens of clinical use produce consistent antidepressant- and anxiolytic-like effects in animal models of menopause. Regulation of the hypothalamic-pituitary-adrenal (HPA) or stress axis, has been proposed as a pathway through which estrogens improve affective-like behaviors. Anticoagulant 17β-aminoestrogens (17β-AEs) butolame and pentolame mimic some effects of estradiol (E2), i.e., on female rodent sexual behavior, with opposite actions on coagulation. However, their psychoactive actions have not been explored. On the basis of similitude with E2's effects, we hypothesized that these 17β-AEs would induce anxiolytic- and antidepressant-like effects, which would be reflected in a reduction of activity in the HPA axis. In ovariectomized female rats, chronic treatment with prolame (60 μg/kg), butolame (65 μg/kg) and pentolame (70 μg/kg) reduced anxiety-like behavior in the elevated plus maze (evidenced by an increase in time in open arms, E2 (40 μg/kg) +176%; prolame +201%; butolame, +237%; and pentolame +295%, in comparison to the control vehicle group 100%). Pentolame also decreased significantly anxiety-like behavior in the burying behavior test. Prolame and E2 produced a significantly antidepressant-like action, which was not induced by butolame and pentolame. Behavioral effects of 17β-AEs (and E2) on anxiety and depression did not follow the same pattern than corticosterone or E2 levels; they also were associated to changes in locomotor activity, evaluated by the open field test. These results constitute the first evidence of specific and selective actions of butolame and pentolame as anxiolytics for females with a hypoestrogenic condition. Results also confirm the potential of prolame as an antidepressant steroid with equivalent actions to E2. Psychoactive properties of 17β-AEs in combinations with reduced adverse effects on coagulation, suggest that 17β-AEs may be a good alternative replacement therapy for women with symptoms associated with menopause.

17β-Aminoestrogens induce guinea pig airway smooth muscle hyperresponsiveness through L-type Ca(2+) channels activation

Therapy with estrogens is frequently used in menopausal women and as hormonal contraception. Because of its thrombotic effects, long term estrogen administration used in hormonal replacement therapy (HRT) and contraception could represent a health hazard. In this regard, 17β-aminoestrogens such as aminoestrol, butolame and pentolame have shown promising HRT potential, because they have a weak agonist estrogenic action and antithrombotic activity. Additionally, estrogens play a protective role in airway smooth muscle, but the effect of 17β-aminoestrogens on the airway smooth muscle has not been tested yet. In guinea pig tracheal smooth muscle pentolame and butolame induced hyperresponsiveness to histamine (His), carbachol (Cch) and KCl. Interestingly, aminoestrol did not show this effect at the highest concentration studied, it even lowered the contraction induced by Cch. The hyperresponsiveness induced by pentolame to His was abolished by nifedipine. In single tracheal myocytes, KCl induced an increment in the intracellular Ca(2+) concentration [Ca(2+)]i, pentolame also showed an increase in [Ca(2+)]i and the addition of KCl in the plateau of this rise further significantly augmented the [Ca(2+)]i response. Additionally, in patch clamp experiments pentolame increased the L-type Ca(2+) currents. Thus, 17β-aminoestrogens such as pentolame and butolame, but not aminoestrol, activate L-type Ca(2+) channel to induced hyperresponsiveness to Cch, His and KCl in guinea pig tracheal smooth muscle. Due to its lack of effect on airways and to its anticoagulant characteristics, aminoestrol seems to be the best alternative in the HRT among the 17β-aminoestrogens studied.

In vivo and in vitro estrogenic profile of 17β-amino-1,3,5(10)estratrien-3-ol

17β-amino-1,3,5(10)estratrien-3-ol (17βAE2), is the 17β-aminoestrogens prototype possessing anticoagulant activity, contrasting with the procoagulant effects of 17β-estradiol (17βE2). Its estrogenicity profile has not been reported, and it was evaluated by uterotrophic assay, estrogen receptor binding affinity and its ability to induce gene transcription of the human estrogen receptor (hER)α mediated in a Saccharomyces cerevisiae yeast expression system. Additionally, 17βAE2 and 17αAE2 were compared with 17βE2 in HeLa cells co-transfected with expression vectors for hERα or hERβ subtypes and for an estrogen-responsive reporter gene. Immature female CD1 mice and Wistar rats (21 days old) were treated for three days with 17βAE2 (10-5000 μg/kg), 17βE2 (0.001-1000 μg/kg) or vehicle (propylenglycol 10 ml/kg) and uterine weights were estimated. 17βAE2 increased uterine weight in a dose-dependent manner. The effective dose (ED)50 uterine weight values: 17βAE2=552 and 764 μg/kg (17βE2=4.8 and 16 μg/kg) and their relative uterotrophic potency were 0.86 and 2.1 (17βE2=100) in mice and rats, respectively. 17βAE2 competed with [(3)H]E2 for the estrogen receptor. The 17βAE2 relative binding affinities (RBAs) were: 0.074; Ki=2.2×10(-6)M (17βE2=100; Ki=1.6×10(-9)M); 0.029 and Ki=3.8×10(-6)M (17βE2=100; Ki=1.1×10(-9)M) for mice and rats uteri respectively. 17βAE2 activated hERα-mediated β-galactosidase transcription activity in the yeast system co-transfected with hERα gene. 17βAE2 effective concentration (EC)50=1.82 μM (17βE2=2.14 nM) with a relative potency of 0.12 (17βE2=100). These transactivation effects were abolished by the antagonist fulvestrant (ICI 182,780), similarly to 17βE2. 17βAE2 and 17αAE2 bind with low relative affinity to hERα and hERβ. Both induced hER-mediated reporter gene transactivation in a dose-response manner. The overall results provide evidence that 17βAE2 has a weak agonist estrogenic action greatly mediated through the hERβ and to a lesser extent the hERα at genomic level.

Isolation and chemical identification of lipid derivatives from avocado (Persea americana) pulp with antiplatelet and antithrombotic activities

Bioassay-guided isolation of acetogenins from avocado pulp within vitroantiplatelet aggregation andin vivoantithrombotic effects in CD1 mice.

Gender differences in response to chronic treatment with 17β-oestradiol and 17β-aminoestrogen pentolame on hemostasis in rats

OBJECTIVES

This work evaluated chronic treatment with 17β-oestradiol (E2) and 17β-aminoestrogen pentolame (AEP) on prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen concentration (FIB). Male (M) and ovariectomized (Ovx) Wistar rats were used to explore gender differences in the pharmacological response.

MATERIALS AND METHODS

Rats (n=12-18) were treated every third day during three months with E2 (1, 10, 100 μg/kg), AEP (1, 10, 100, 500 μg/kg) or vehicle (propylenglycol 1 ml/ kg). PT, aPTT, TT, and FIB were measured using standardized techniques.

RESULTS

Chronic treatment with E2 in male rats increased PT (4-7%; P<0.05), decreased aPTT (9%; 100 μg/kg; P<0.05) and decreased TT (5% at 100 μg/Kg; P<0.05). Chronic treatment with E2 in ovariectomized female rats decreased PT (3-4%; P<0.05), did not induce significant changes on aPTT and decreased TT in a dose dependent manner (12-27%; P<0.05). Chronic treatment with AEP in male rats did not alter PT, increased aPTT in a dose dependent manner (5-16%; P<0.05), and decreased TT (5%; 500 μg/Kg; P<0.05) while in female ovariectomized rats it decreased PT (5-9%; P<0.05), increased aPTT (8-13%; P<0.05) and decreased TT (6-13%; P<0.05). E2 and AEP decreased FIB in M and Ovx animals. Decreases in FIB by E2 were more pronounced in male (15-18% P<0.05) than in ovariectomized rats (10-14% P<0.05). E2 showed more potency than AEP, lowering FIB at 1 and 10 μg/kg doses. Both estrogens decreased FIB in ovariectomized animals (E2, 10-14%, P<0.05; AEP, 9% P<0.05) and were reverted by increasing dosage.

CONCLUSIONS

Gender influenced response to chronic treatment with E2 and AEP on hemostatic parameters. PT and aPTT were the most affected parameters, demonstrating non-equivalence in the pharmacological response of M and Ovx rats.

Estrogenic effects of 17β-aminoestrogens assessed in uteri of rats and mice

Administration of exogenous estrogens has been associated with an increase of thromboembolic events. The 17 beta-aminoestrogens produce anticoagulant effects contrasting with the procoagulant effects of the natural occurring estradiol in rodents. This work compares the estrogenic effects induced by 17 beta-aminoestrogens prolame, butolame, pentolame, and estradiol in vivo models. Dose-response curves were performed using immature CD1 mice and Wistar rats. The animals were injected with estradiol or 17 beta-aminoestrogens (0.01 to 1000 microg/kg), or vehicle. The uterine wet and dry weights were determined. The 17 beta-aminoestrogens increased uterine weight in a dose-dependent manner. The uterotrophic effect produced by estradiol induced lower ED50 (6.5 and 4 microg/kg) and higher E(max) values (+523-350%) in mice as compared with those from the rat, indicating more susceptibility of the mice model. The 17 beta-aminoestrogens are partial estrogenic agonists with a relative uterotrophic effect of estradiol (100%) from 9-86%. Only the ED50 values of 17 beta-aminoestrogens in CD1 mice showed a direct correlation to the length of the amine group substitution in C-17 since their efficacy and potency were in the order: prolame>butolame>pentolame.

Contrasting effects of estradiol and 17β-aminoestrogens on blood clotting time in rats and mice

Estrogens have been associated with thromboembolic events. Our group has described the anticoagulant effect of 17 beta-aminoestrogens in rodents, potentially new alternative estrogenic agents without thrombogenic risk. This work compares the contrasting effects of estradiol and the 17 beta-aminoestrogens (prolame, butolame, and pentolame) on blood clotting time. Ovariectomized CD1 mice received a single injection of 17beta-aminoestrogens, estradiol (20 to 80 mg/kg), or vehicle. Estradiol decreased blood clotting time from -10% to -25% (48 h; P<0.01) and 17 beta-aminoestrogens increased it, differing in latency (approximately 12 h; +48%, P<0.01) and duration (approximately 72 h +58%, P<0.01). In male Wistar rats, similar effects (pentolame +45%; estradiol -31%; P<0.01) were observed 48 h after five consecutive daily injections of 1000 microg/animal/day. The maximum procoagulant effect of estradiol was obtained after 72 h with 10 microg/animal/day (-45%; P<0.01). 17 Beta-aminoestrogens always produced opposite effects to those of estradiol on blood coagulation.

Changes on hemostatic parameters induced by 17beta-estradiol, ethinylestradiol, and the 17beta-aminoestrogen pentolame in the male Wistar rat

Oral contraceptives containing estrogens increases the incidence of thromboembolic events. In contrast, administration of 17beta-aminoestrogens prolonged blood clotting time (BCT) in rodents. We studied the effect of estradiol (E(2)), ethinylestradiol (EE) and pentolame on some screening hemostatic tests. BCT was evaluated 24, 48, 72 and 96 h post-treatment. Rats received subcutaneously (s.c.) for five consecutive days E(2) (0.1-1000 microg), EE (1-1000 microg), pentolame (0.1-1000 microg), or vehicle (propyleneglycol 0.3 ml). At 48 h post-treatment E(2) (1000 microg) diminished BCT (32%, P<0.01), in contrast pentolame (1000 microg) augmented BCT by 41% (P<0.01). After 72 h, E(2) showed procoagulant effects with 10, 100 and 1000 microg doses (-45, -30, and -21%, respectively). Significant effects on BCT of EE were observed 72 h after with 1000 microg (-12%, P<0.05). Animals were treated s.c. for two consecutive days with E(2) (3mg/100g), pentolame (4 mg), or vehicle (0.1 ml). BCT, bleeding time (BT), platelet aggregation (PA), prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen concentration were determined. E(2) produced a significant diminution on BCT (-20%) after 72 h whereas pentolame increased BCT from 24 to 96 h (62%, maximal response at 48 h). APTT and PT coagulation times of the groups treated with E(2) and pentolame were lengthened (33 and 29%; 16 and 24%, respectively; P<0.05). Fibrinogen concentration increased (115%, P<0.01) only in the pentolame-treated group. Pentolame and E(2) produced any effects on BT and PA compared with control groups, indicating that platelet function was not modified. Our results indicate that E(2), EE and pentolame affects the plasmatic phase of the hemostatic mechanism.