Current applications, procedural and 1-year outcomes of Rotatripsy for the treatment of calcified coronary lesions.

BACKGROUND: Intravascular lithotripsy (IVL) combined with rotational atherectomy (RA), known as Rotatripsy, is used to treat severe coronary artery calcification (CAC), though data on efficacy, midterm safety and use sequence is limited. We aimed to identify indicators for Rotatripsy use and to assess its safety and success rates, both acutely and at 1-year follow-up. METHODS: Patients undergoing Rotatripsy for severe CAC across six centers from May 2019 to December 2023 were included. Demographic, clinical, procedural and follow-up data were collected. Efficacy endpoints included device success (delivery of the RA-burr and IVL-balloon across the target lesion and administration of therapy without related complications), technical success (TIMI 3 flow and residual stenosis <30% by quantitative coronary analysis) and procedural success [composite of technical success with absence of in-hospital major adverse cardiovascular events (MACE: cardiac death, myocardial infarction or target vessel revascularization). Safety endpoints comprised Rotatripsy-related complications and MACE at 1-year follow-up. RESULTS: A total of 114 patients (75 ± 9 years, 78% male) underwent Rotatripsy for 120 lesions. In the majority of procedures RA was followed by IVL, mostly electively (n = 68, 57%) but also for balloon underexpansion (n = 37, 31%) and stent crossing failure (n = 1, 1%). Diverse and complex target lesions were addressed with an average SYNTAX score of 24.6 ± 13.0. Device, technical and procedural success were 97%, 94% and 93%, respectively. Therapy-related complications included two (2%) coronary perforations, one (1%) coronary dissection and one (1%) burr entrapment. At 1-year follow-up(present in 77(67%) patients), MACE occurred in 7(9%) cases. CONCLUSIONS: Over a 1-year follow-up period, Rotatripsy was safe and effective, predominantly using RA electively before IVL.

The repertoire of iron superoxide dismutases from Leishmania infantum as targets in the search for therapeutic agents against leishmaniasis.

Species of Leishmania and Trypanosoma genera are the causative agents of relevant parasitic diseases. Survival inside their hosts requires the existence of a potent antioxidant enzymatic machinery. Four iron superoxide dismutases have been described in trypanosomatids (FeSODA, FeSODB1, FeSODB2, and FeSODC) that hold a potential as therapeutic targets. Nonetheless, very few studies have been developed that make use of the purified enzymes. Moreover, FeSODC remains uncharacterised in Leishmania. In this work, for the first time, we describe the purification and enzymatic activity of recombinant versions of the four Leishmania FeSOD isoforms and establish an improved strategy for developing inhibitors. We propose a novel parameter [(V*cyt. c - Vcyt. c)/Vcyt. c] which, in contrast to that used in the classical cytochrome c reduction assay, correlates linearly with enzyme concentration. As a proof of concept, we determine the IC50 values of two ruthenium carbosilane metallodendrimers against these isoforms.

New Phosphoramidates Containing Selenium as Leishmanicidal Agents.

This work reports the synthesis and characterization by Fourier transform infrared spectroscopy (FTIR), 1H, 13C, and 79Se nuclear magnetic resonance (NMR), mass spectrometry, and elemental analysis techniques as well as the in vitro evaluation of the leishmanicidal activity of 13 new selenophosphoramidate derivatives. Among the new compounds, four of them (compounds 1f, 1g, 2f, and 2g), which exhibited the best profiles, were tested against infected macrophages and were selected for further studies related to their leishmanicidal mechanism. In this regard, trypanothione redox system alteration was determined. Compound 1g, under similar conditions, was more effective than the corresponding references. In addition, theoretical calculations showed that this compound also presents most physicochemical and pharmacokinetic properties within the ranges expected for orally available drugs. It is believed that selenophosphoramidate functionalities may represent a scaffold to be explored toward the development of new agents for leishmania treatment.

New Amides Containing Selenium as Potent Leishmanicidal Agents Targeting Trypanothione Reductase.

Two new series of 28 selenocyanate and diselenide derivatives containing amide moieties were designed, synthesized, and evaluated for their leishmanicidal activity against Leishmania infantum axenic amastigotes, and selectivity was assessed in human THP-1 cells. Eleven compounds exhibited excellent leishmanicidal activity with EC50 values lower than the reference drug miltefosine (EC50 = 2.84 µM). In addition, for six of them the selectivity index ranged from 9 to >1,442, greater than both references used. The most potent and selective compounds were compounds 2h, 2k, and 2m that displayed EC50 values of 0.52, 1.19, and 0.50 µM, respectively, and a high selectivity index (SI) when tested against THP-1 monocytic cells (SI = >1,442, >672, and >1,100, respectively). These derivatives showed an efficacy similar to that of the reference drugs but much better SI values. They also showed interesting activity values against infected macrophages. Trypanothione reductase (TryR) activity and intracellular thiol level measurement assays were performed for the three best compounds in an attempt to elucidate their mechanism of action. Despite that the new analogs exhibited comparable or better inhibitory activities than the reference TryR inhibitors, more studies are necessary to confirm this result. In summary, our findings suggest that the three compounds described here could constitute leading leishmanicidal drug candidates.

Activity of steroid 4 and derivatives 4a-4f as inhibitors of the enzyme 5α-reductase 1.

It is known that the growth of prostate metastatic bone tumor depends on androgens, and tumor formation can start from migratory malignant cells produced in that organ. These cells exhibit grater type 1 5α-reductase (5α-R1) activity than type 2 5α-reductase. Noteworthy, both isozymes convert testosterone (T) to the more active androgen dihydrotestosterone (DHT) in the target tissues. Thus, in order to potentially improve the prognosis of this disease, in this work, seven derivatives of 17-(1H-benzimidazol-1-yl)-16-formillandrosta-5,16-dien-3ß-yl benzoate (4a-f) and 17-(1H-benzimidazol-1-yl)-3-hydroxy-16-formylandrost-5,16-diene (4) were synthesized, characterized and identified as inhibitors of type 1 5α-reductase (5αR1). These derivatives having the advantage of improved plasma half-life. The inhibitory activity of the compounds towards 5α-R1 isoenzyme was determined by conversion of T into DHT in the presence or absence of compounds 4, 4a-f. Further, in vivo experiments were also carried out, treating gonadectomized hamsters with T and/or 4, 4a-f and evaluating their effect on the diameter of hamster flank organs and on the weight of the prostatic and seminal vesicles. Results indicated that compounds 4, 4b, 4c, served as in vitro inhibitors of the enzyme 5α-R1 and pharmacological experiments showed that 4 and derivatives 4a-f decreased the diameter of the flank glands, the weight of the prostate and seminal vesicles of treated hamsters without any appreciable toxicity during observation. Noteworthy the fact that compound 4 is the product, in all cases, of the hydrolysis of the series of esters 4a-f, thus they can serve as precursors (prodrugs) of the active form 4.

Synthesis of new derivatives of 21-imidazolyl-16-dehydropregnenolone as inhibitors of 5α-reductase 2 and with cytotoxic activity in cancer cells.

The aim of this study was to synthesize several 16-dehydropregnenolone derivatives containing an imidazole ring at C-21 and a different ester moiety at C-3 as inhibitors of 5α-reductase 1 and 2 isoenzymes. Their binding capacity to the androgen receptor (AR) was also studied. Additionally, we evaluated their pharmacological effect in a castrated hamster model and their cytotoxic activity on a panel of cancer cells (PC-3, MCF7, SK-LU-1). The results showed that only the derivatives with an alicyclic ester at C-3 showed 5α-R2 enzyme inhibition activity, the most potent of them being 21-(1H-imidazol-1-yl)-20-oxopregna-5,16-dien-3ß-yl-cyclohexanecarboxylate with an IC50 of 29nM. This is important because prostatic benign hyperplasia is directly associated with the presence of 5α-R2. However, all the derivatives failed to inhibit 5α-R1 or bind to the AR. These alicyclic ester derivatives decreased the weight and size of androgen-dependent glands in the hamster, indicating they are very active in vivo and are not toxic. In addition, the 21-(1H-imidazol-1-yl)-20-oxopregna-5,16-dien-3ß-yl-acetate derivative showed the highest cytotoxic activity on the three cancer cell lines studied. It is therefore important in the synthesis of steroidal compounds to consider the size of the ester moiety at C-3 of the steroid skeleton, which is key in obtaining biological activity, as observed in this experiment.

Synthesis and biological evaluation of esters of 16-formyl-17-methoxy-dehydroepiandrosterone derivatives as inhibitors of 5α-reductase type 2.

In this study, we investigated the in vitro effect of 16-formyl-17-methoxy dehydroepiandrosterone derivatives on the activity of 5α-reductase type 2 (5α-R2) obtained from human prostate. The activity of different concentrations of these derivatives was determined for the conversion of labelled testosterone to dihydrotestosterone. The results indicated that an aliphatic ester moiety at the C-3 position of these derivatives increases their in vitro potency as inhibitors of 5α-R2 activity compared to finasteride®, which is considered to be a potent inhibitor of 5α-R2. In this case, the augmentation of the lipophilicity of these dehydroepiandrosterone derivatives increased their potency as inhibitors of 5α-R2. However, the presence of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl rings as the cycloaliphatic ester moiety at C-3 of the formyl methoxy dehydroepiandrosterone scaffold did not inhibit the activity of this enzyme. This may be due to the presence of steric factors between the enzyme and the spatial structure of these derivatives.

Novel dehydroepiandrosterone benzimidazolyl derivatives as 5α-reductase isozymes inhibitors.

5α-R isozymes (types 1 and 2) play an important role in prostate gland development because they are responsible for intraprostatic dihydrotestosterone (DHT) levels when the physiological serum testosterone (T) concentration is low. In this study, we synthesized seven novel dehydroepiandrosterone derivatives with benzimidazol moiety at C-17, and determined their effect on the activity of 5α-reductase types 1 and 2. The derivatives with an aliphatic ester at C-3 of the dehydroepiandrosterone scaffold induced specific inhibition of 5α-R1 activity, whereas those with a cycloaliphatic ester (cyclopropyl, cyclobutyl, or cyclopentyl ring) or an alcohol group at C-3 inhibited the activity of both isozymes. Derivatives with a cyclohexyl or cycloheptyl ester at C-3 showed no inhibitory activity. In pharmacological experiments, derivatives with esters having an alcohol or the aliphatic group or one of the three smaller cycloaliphatic rings at C-3 decreased the diameter of male hamster flank organs, with the cyclobutyl and cyclopentyl esters exhibiting higher effect. With exception of the cyclobutyl and cyclopentyl esters, these compounds reduced the weight of the prostate and seminal vesicles.

Biological activity of pyrazole and imidazole-dehydroepiandrosterone derivatives on the activity of 17ß-hydroxysteroid dehydrogenase.

The enzyme type 5 17ß-hydroxysteroid dehydrogenase 5 (17ß-HSD5) catalyzes the transformation of androstenedione (4-dione) to testosterone (T) in the prostate. This metabolic pathway remains active in cancer patients receiving androgen deprivation therapy. Since physicians seek to develop advantageous and better new treatments to increase the average survival of these patients, we synthesized several different dehydroepiandrosterone derivatives. These compounds have a pyrazole or imidazole function at C-17 and an ester moiety at C-3 and were studied as inhibitors of 17ß-HSD5. The kinetic parameters of this enzyme were determined for use in inhibition assays. Their pharmacological effect was also determined on gonadectomized hamsters treated with Δ(4)-androstenedione (4-dione) or testosterone (T) and/or the novel compounds. The results indicated that the incorporation of a heterocycle at C-17 induced strong 17ß-HSD5 inhibition. These derivatives decreased flank organ diameter and prostate weight in castrated hamsters treated with T or 4-dione. Inhibition of 17ß-HSD5 by these compounds could have therapeutic potential for the treatment of prostate cancer and benign prostatic hyperplasia.

Synthesis and activity of novel 16-dehydropregnenolone acetate derivatives as inhibitors of type 1 5α-reductase and on cancer cell line SK-LU-1.

Testosterone (T) plays a crucial role in prostate growth. In androgen-dependent tissues T is reduced to dihydrotestosterone (DHT) because of the presence of the 5α-reductase enzyme. This androgen is more active than T, since it has a higher affinity for the androgen receptor (AR). When this mechanism is altered, androgen-dependent diseases, including prostate cancer, could result. The aim of this study was to synthesize several 16-dehydropregnenolone acetate derivatives containing a triazole ring at C-21 and a linear or alicyclic ester moiety at C-3 of the steroidal skeleton. These steroids were designed as potential inhibitors of the activity of both types (1 and 2) of 5α-reductase. The cytotoxic activity of these compounds was also evaluated on a panel of PC-3, MCF7, and SK-LU-1 human cancer cell lines. The results from this study showed that with the exception of steroids 20-oxo-21-(1H-1,2,4-triazole-1-yl)pregna-5,16-dien-3ß-yl-propionate and 20-oxo-21-(1H-1,2,4-triazole-1-yl)pregna-5,16-dien-3ß-yl-pentanoate, the compounds exhibit a lower inhibitory activity for both isoenzymes of 5α-reductase than finasteride. Furthermore the 3ß-hydroxy-21-(1H-1,2,4-triazole-1-yl)pregna-5,16-dien-20-one and 20-oxo-21-(1H-1,2,4-triazole-1-yl)pregna-5,16-dien-3ß-yl-acetate derivatives display 80% cytotoxic activity on the SK-LU-1 cell line. These results also indicated that the triazole derivatives, which have a hydroxyl or acetoxy group at C-3, could have an anticancer effect, whereas the derivatives with a alicyclic ester group at C-3 do not show biological activity.

Synthesis and Identification of Pregnenolone Derivatives as Inhibitors of Isozymes of 5α-Reductase.

Hyperplasia of the prostate gland and prostate cancer have been associated with high levels of serum 5α-dihydrotestosterone. This steroid is formed from testosterone by the activity of the enzyme 5α-reductase (5α-R) present in the prostate. Thus, inhibition of this enzyme could be a goal for therapies to treat these diseases. This study reports the synthesis and effects of five different 21-esters of pregnenolone derivatives as inhibitors of 5α-R types 1 and 2. The activity of these steroidal compounds was determined using in vivo and in vitro experiments. The results indicate that of the five steroids studied, the 21(p-fluoro)benzoyloxypregna-4,16-diene-3,6,20-trione derivative, whose structure has not yet been reported, has the best molecular conformation to inhibit the in vitro activity of both types of 5α-R. In addition, this steroid also displayed activity in vivo. Apparently, its pharmacological effect was increased by the presence of a keto group at C-6, because this group decreased the possibility that the steroid would be metabolized by hepatic enzymes. In addition, the double bond present at C-4 of this compound also enhanced its inhibitory activity on 5α-R, and the C-21 ester moiety increased its liphophilicity. Therefore, its solubility in the cell membrane and its pharmacological activity were both increased.

Effect of dehydroepiandrosterone derivatives on the activity of 5α-reductase isoenzymes and on cancer cell line PC-3.

It is well known that testosterone (T) under the influence of 5α-reductase enzyme is converted to dihydrotestosterone (DHT), which causes androgen-dependent diseases. The aim of this study was to synthesize new dehydroepiandrosterone derivatives (3a-e, 4a-i, 6 and 7) having potential inhibitory activity against the 5α-reductase enzyme. This paper also reports the in vivo pharmacological effect of these steroidal molecules. The results from this study showed that all compounds exhibited low inhibitory activity for 5α-reductase type 1 and 2 enzymes and they failed to bind to the androgen receptor. Furthermore, in the in vivo experiment, steroids 3b, 4f, and 4 g showed comparable antiandrogenic activity to that of finasteride; only derivatives 4d and 7 produced a considerable decrease in the weight of the prostate gland of gonadectomized hamsters treated with (T). On the other hand, compounds 4a, f and h showed 100% inhibition of the growth of prostate cancer cell line PC-3, with compound 4 g having a 98.2% antiproliferative effect at 50 µM. The overall data indicated that these steroidal molecules, having an aromatic ester moiety at C-3 (4f-h), could have anticancer properties.

Effect of carbamates on mRNA encoding lipid enzymes in hamster flank organs.

Flank organs are an androgen-dependent pilosebaceous complex present in male and female hamsters. These organs have been used for the evaluation of antiandrogenic drugs, which could be used for the treatment of androgen-dependent afflictions. This study demonstrated the role of four different steroidal carbamates 7-10 in the expression of mRNAs coding for different enzymes involved in the lipid metabolism in flank organs. To determine the biological effects of compounds 7-10 on the expression of mRNA coding for lipid enzymes, steroids 7-10, testosterone (T), progesterone (P), and/or 7-10 were applied on the flank organs. Later, the mRNA expression for the enzymes was determined by polymerase chain reaction. The binding of 8 and 9 to the progesterone receptor (PR) as well as their effects on the activity of 5α-reductase were also evaluated. Treatments with T, P, and 7-10 increased the mRNA expression for glycerol 3-phosphate acyl transferase (GPAT), ß-hydroxy-ß-methylglutaryl-CoA synthase (HMG-CoA-S), ß-hydroxy-ß-methylglutaryl-CoA reductase (HMG-CoA-R), phosphatidylinositol synthase (PI-S), and squalene-synthase (SQ-S). However, the combined treatments with P + 7-10 decreased the expression of GPAT, HMG-CoA-S, and HMG-CoA-R. Expression of mRNA for all enzymes was variable under treatment with T + 7-10. Data showed that these carbamates did not bind to the PR, but inhibited the activity of 5α-reductase. Carbamates 7-10 changed the mRNA expression model induced by T and P in flank organs.

Absence and Distortion in the Self-Representation of LGBTQ+ Narratives.

This research uses a mixed quantitative and descriptive approach to analyze the representation of LGBTQ+ people in YouTube fiction produced by Singaporean filmmakers. It observes the general characteristics of such portrayals with a particular focus on the characters' gender and identity expressions. Simultaneously, a qualitative study analyzes these observations in greater depth by means of discourse analysis on two levels. A macro level identifies the ideas conveyed by the narratives and a micro level identifies the portrayal of stereotypes, types of masculinity, visibility of sexual orientation and affective/sexual relations. The results show that Singaporean LGBTQ+ filmmakers depict homonormative characters and follow cis-heteronormative canons. They do not advocate for the normalization of LGBTQ+ realities, and instead present distorted constructions of LGBTQ+ people that do little to encourage their acceptance. This does not contribute to any improvement in sociocultural views of non-normative sexual and gender orientations and negatively impacts the LGBTQ+ identity. Moreover, LGBTQ+ people from the country's ethnic minorities are ignored. These results inform academia, audiovisual industries and regulators about the representation of LGBTQ+ people in fictional products in countries where queer populations still face stigmatization and marginalization.

Procedural and clinical impact of intravascular lithotripsy for the treatment of peri-stent calcification.

BACKGROUND: Use of intravascular lithotripsy (IVL) for treating peri-stent calcification is increasing. However, this indication remains 'off-label'. We aimed to investigate the efficacy and clinical outcomes of in-stent IVL. METHODS: Patients from five European centers who underwent in-stent IVL were included between 2019 and 2023. Demographic, clinical, procedural and follow-up data were collected from electronic hospital records. Angiographic and intracoronary imaging (ICI) data were analyzed in a centralized core-laboratory. RESULTS: Of 101 patients (71.2 ± 9.2 years), 56(55 %) received in-stent IVL for late stent failure (median 109 days post-PCI) due to calcific neoatherosclerosis or extra-stent calcification(late-IVL), while 45(45 %) underwent bail-out IVL due to stent infraexpasion (immediate-IVL). Both late-IVL and immediate-IVL significantly improved angiographic %diameter stenosis (73.7[59.6-89.8]% to 16.4 [10.4-26.9]%;p < 0.0001 and 28.6[22.5-43.3]% to 14.1[10.3-29.4]%;p < 0.0001, and minimum lumen area (MLA) (3.4 ± 1.2 to 8.6 ± 2.5 mm2;p < 0.002 and 5.4 ± 1.9 to 7.3 ± 1.9;p < 0.0001).Device(98 %) and procedural success(80 %) were high. MACE rates in-hospital (2 %), 30-days (3 %),6-months(5 %) and 1-year(7 %) were low and comparable in both groups. Acute diameter gain was lower in immediate-IVL (2.1 ± 0.7 mm vs. 0.5 ± 0.4 mm;p < 0.0001). This, however, was explained by significant differences in pre-IVL angiographic and ICI parameters (%diameter stenosis 73.7[59.6-89.8] vs. 28.6[22.5-43.3]%; p < 0.0001 and MLA (3.4 ± 1.2 vs 5.4 ± 1.9 mm2; p < 0.0001), whereas post-IVL percentage diameter stenosis (16.4(10.4-26.9) vs. 14.1(10.3-29.4);p = 0.914) and MLA (8.6 ± 2.5vs. 7.4 ± 1.9 mm2;p = 0.064) in late- and immediate-IVL were comparable. CONCLUSIONS: IVL in-stent due to peri-stent calcification is an effective strategy, both late and immediately after stent implantation. Overall, MACE rates at short- and mid-term were low and comparable in both groups, although clinical findings should be taken with caution.

A comparison of simplified or conventional antithrombotic regimens after left atrial appendage closure in patients at high bleeding risk: the PLATEBRISK study.

BACKGROUND: Antithrombotic treatment (ATT) post-left atrial appendage occlusion (LAAO) remains controversial. Furthermore, most of the patients undergoing LAAO are at a very high bleeding risk. AIMS: This study aimed to compare a simplified versus conventional ATT after LAAO in very high bleeding risk patients. METHODS: This is a multicentre, retrospective study including very high bleeding risk patients, according to the Bleeding Academic Research Consortium (BARC) definition, who underwent LAAO. These included patients at >4% risk of BARC 3 to 5 bleeding or >1% risk of intracranial bleeding after the procedure. Two groups were established based on the discharge ATT. The simplified group included single antiplatelet treatment or no treatment, and the conventional group comprised dual antiplatelet treatment or anticoagulation (combined or not with antiplatelet therapy). RESULTS: A total of 1,135 patients were included. The mean CHA2DS2-VASc and HAS-BLED scores were 4.5±1.5 and 3.7±1.0, respectively. There were no differences in the composite endpoint (death, stroke, transient ischaemic attack, device-related thrombus or major bleeding) between the 2 groups (hazard ratio [HR] 0.81, 95% confidence interval [CI]: 0.59-1.11; p=0.188). Although the rate of major bleeding during the first year was numerically lower in the simplified group, it did not reach statistical significance (HR 0.67, 95% CI: 0.41-1.10; p=0.104). Nonetheless, patients with previous major bleeding presented a significantly lower rate of major bleeding when using the simplified treatment (HR 0.61, 95% CI: 0.36-0.99; p=0.049). CONCLUSIONS: In patients with very high bleeding risk, a simplified ATT after LAAO seems to be as effective as conventional protocols. Furthermore, patients with a history of major bleeding experienced a lower risk of major bleeding with the simplified ATT.

Catheter-directed therapy for acute pulmonary embolism: results of a multicenter national registry.

INTRODUCTION AND OBJECTIVES: Catheter-directed therapy (CDT) for acute pulmonary embolism (PE) is an emerging therapy that combines heterogeneous techniques. The aim of the study was to provide a nationwide contemporary snapshot of clinical practice and CDT-related outcomes. METHODS: This Investigator-initiated multicenter registry aimed to include consecutive patients with intermediate-high risk (IHR) or high-risk (HR), acute PE eligible for CDT. The primary outcome of the study was in-hospital all-cause death. RESULTS: A total of 253 patients were included, of whom 93 (36.8%) had HR-PE, and 160 (63.2%) had IHR-PE with a mean age of 62.3±15.1 years. Local thrombolysis was performed in 70.8% and aspiration thrombectomy in 51.8%, with 23.3% of patients receiving both. However, aspiration thrombectomy was favored in the HR-PE cohort (80.6% vs 35%; P<.001). Only 51 patients (20.2%) underwent CDT with specific PE devices. The success rate for CDT was 90.9% (98.1% of IHR-PE patients vs 78.5% of HR-PE patients, P<.001). In-hospital mortality was 15.5%, and was highly concentrated in the HR-PE patients (37.6%) and significantly lower in IHR-PE patients (2.5%), P<.001. Long-term (24-month) mortality was 40.2% in HR-PE patients vs 8.2% in IHR-PE patients (P<.001). CONCLUSIONS: Despite the high success rate for CDT, in-hospital mortality in HR-PE is still high (37.6%) compared with very low IHR-PE mortality (2.5%).

In vivo and in vitro effect of androstene derivatives as 5α-reductase type 1 enzyme inhibitors.

The aim of these studies was to synthesize twelve ester derivatives of dehydroepiandrosterone with therapeutic potential. The effect of 1-12 was demonstrated in the flank organs of gonadectomized hamsters treated with testosterone and the synthesized steroids. In vitro studies were carried out determining the IC50 values for the inhibition of the activity of 5α-reductase type 1 and 2, which are present in rat liver and human prostate respectively. The binding of 1-12 to the androgen receptors (AR) was determined using rat's prostate cytosol. Steroids 1-12 containing different substituents in the phenyl group of the ester moiety in C-3 reduced the flank organs and inhibited the activity of 5α-R type 1; however only steroids 1 and 2 inhibited 5α-R type 2. 1-12 did not bind to the AR. The modification of one atom of the substituents in the phenyl group of the ester moiety in C-3 changed their biological potency (IC50).

Biological evaluation of androstene derivatives.

The effect of several new dihydroepiandrosterone ester derivatives A2-A6 was demonstrated using female cycling mice, which were synchronized for estrus with luteinizing hormone-releasing hormone (LHRH) and injected with the steroids. The binding to the progesterone receptor (PR), was obtained from the cytosol of uteri from adult estrogen-primed rabbits. A1 binds to the PR and inhibited the ovulation in cycling mice stimulated with LHRH. The activity of the endometrium and mammary glands in these mice was markedly reduced as compared to the control. A2, A4, and A5 were not active; nevertheless, A3 binds to the PR with high affinity. However, this steroid did not produce any effect as compared to that observed for the control in the endometrial and mammary glands. A6 binds to the PR with the highest affinity and induces a synergistic activity with progesterone in these tissues. Furthermore, A6 inhibited the ovulation in the same manner as A1. These results suggested that A1 and A6 are blocking the gonadotropin secretion. A1 inhibited the conversion of progesterone to 5α-progesterone. As a result of this, a blockage of the ductal and alveolar epithelial cell proliferation in the mammary and endometrial glands, which depends on 5α-progesterone, was also observed.

Identification of L. infantum trypanothione synthetase inhibitors with leishmanicidal activity from a (non-biased) in-house chemical library.

Redox homeostasis in trypanosomatids is based on the low-molecular-weight trypanothione, an essential dithiol molecule that is synthetized by trypanothione synthetase (TryS) and maintained in its reduced state by trypanothione disulfide reductase (TryR). The fact that both enzymes are indispensable for parasite survival and absent in the mammalian hosts makes them ideal drug targets against leishmaniasis. Although many efforts have been directed to developing TryR inhibitors, much less attention has been focused on TryS. The screening of an in-house library of 144 diverse molecules using two parallel biochemical assays allowed us to detect 13 inhibitors of L. infantum TryS. Compounds 1 and 3 were characterized as competitive inhibitors with Ki values in the low micromolar range and plausible binding modes for them were identified by automated ligand docking against refined protein structures obtained through computational simulation of an entire catalytic cycle. The proposed binding site for both inhibitors overlaps the polyamine site in the enzyme and, additionally, 1 also occupies part of the ATP site. Compound 4 behaves as a mixed hyperbolic inhibitor with a Ki of 0.8 µM. The activity of 5 is clearly dependent on the concentration of the polyamine substrate, but its kinetic behavior is clearly not compatible with a competitive mode of inhibition. Analysis of the activity of the six best inhibitors against intracellular amastigotes identified 5 as the most potent leishmanicidal candidate, with an EC50 value of 0.6 µM and a selectivity index of 35.