Stem cell-conditioned medium improves methylation patterns and quality of caprine preantral follicles.

This study investigated the methylation patterns of H3K4me3 and H3K9me3, as well as the mRNA expression of genes encoding the epigenetic regulators KDM1AX1, KDM1AX2, and KDM3A in goat preantral follicles developed in vivo (Uncultured control) or after in vitro culture for 7 days in either the absence (α-MEM+) or presence of conditioned medium (α-MEM+ + CM) from Wharton's jelly mesenchymal stem cells (WJ-MSCs). In the in vivo setting, all follicular categories exhibited similar H3K4me3 and H3K9me3 patterns, and transcripts of KDM1AX1, KDM1AX2, and KDM3A were detected in all samples. During in vitro culture, α-MEM+ + CM enhanced several important aspects. It increased the percentage of normal growing follicles, oocyte diameters across all categories, stromal cell density, and the H3K4me3 methylation pattern in preantral follicles. Simultaneously, it decreased the levels of reduced thiols and reactive oxygen species in the spent media, diminished the presence of lipofuscin aggresomes, lowered granulosa cell apoptotic rates, and reduced the H3K9me3 methylation pattern in preantral follicles. In conclusion, the findings from this study provide compelling evidence that supplementing the in vitro culture medium (α-MEM+) with CM from WJ-MSCs has a protective effect on goat preantral follicles. Notably, CM supplementation preserved follicular survival, as evidenced by enhanced follicular and oocyte growth and increased stromal cell density when compared to the standard culture conditions in the α-MEM+ medium. Furthermore, CM reduced oxidative stress and apoptosis and promoted alterations in H3K4me3 and H3K9me3 patterns.

Human health risks assessment of the fluctuations in mercury levels in seafood from different key regions of Rio de Janeiro, Brazil.

Mercury (Hg) contamination on the Brazilian southeast coast has been highlighted, especially in relation to species of commercial importance. This study aimed to quantify the Hg concentration in species of mussels, fish, and crabs obtained from fishing colonies on the beaches of the west and south of the city of Rio de Janeiro, investigate the possible effect of seasonality, sex, and location sampling, and finally, the risk to consumer health in four different age groups. The difference between cooked and raw commercially available mussel samples was also verified. The main results highlight that the fish presented higher levels of Hg and that the mussel samples sold cooked presented lower levels of Hg when compared to the raw ones. For Micropogonias furnieri, Sardinella brasiliensis, and Callinectes spp., the season variable influenced Hg concentrations, while only for Merluccius merluccius was a difference between the sexes identified, with males having the highest values. Although Hg concentrations in animals were below the permitted limit, consumption of all species exceeded the monthly intake limit for this metal. For the hazard quotient (HQ) calculation, most species presented HQ > 1, especially when ingested by the child population. These results are fundamental for designing consumption strategies for these animals, in order to prioritize the acquisition of some species over others, depending on the location and/or season, for each age group, with the aim of maintaining seafood consumption with minimal risk to the population's health.

Antitumoral activity of different Amaryllidaceae alkaloids: In vitro and in silico assays.

ETHNOPHARMACOLOGY RELEVANCE: The plants of Amaryllidaceae family, such as Amaryllis belladonna L., have been used as herbal remedies for thousands of years to address various disorders, including diseases that might today be identified as cancer. AIM OF THE STUDY: The objective of this work was to evaluate the potential of three Amaryllidaceae alkaloids against four cancer cell lines. MATERIAL AND METHODS: The alkaloids lycorine, 1-O-acetylcaranine, and montanine were evaluated in vitro against colon adenocarcinoma cell line (HCT-116) and breast carcinoma cell lines (MCF-7, MDAMB231, and Hs578T). Computational experiments (target prediction and molecular docking) were conducted to gain a deeper comprehension of possible interactions between these alkaloids and potential targets associated with these tumor cells. RESULTS: Montanine presented the best results against HCT-116, MDAMB231, and Hs578T cell lines, while lycorine was the most active against MCF-7. In alignment with the target prediction outcomes and existing literature, four potential targets were chosen for the molecular docking analysis: CDK8, EGFR, ER-alpha, and dCK. The docking scores revealed two potential targets for the alkaloids with scores similar to co-crystallized inhibitors and substrates: CDK8 and dCK. A visual analysis of the optimal docked configurations indicates that the alkaloids may interact with some key residues in contrast to the other docked compounds. This observation implies their potential to bind effectively to both targets. CONCLUSIONS: In vitro and in silico results corroborate with data literature suggesting the Amaryllidaceae alkaloids as interesting molecules with antitumoral properties, especially montanine, which showed the best in vitro results against colorectal and breast carcinoma. More studies are necessary to confirm the targets and pharmaceutical potential of montanine against these cancer cell lines.

Mercury contamination in seafood from an aquatic environment impacted by anthropic activity: seasonality and human health risk.

Petroleum activity and the dumping of domestic and industrial sewage are important sources of mercury (Hg) contamination in the aquatic environment. Thus, this article aimed to biomonitor the Hg concentration in fish, mussels, and swimming crabs of commercial importance in southeastern Brazil. The quantifications were carried out over a year to verify the influence of seasonality. Finally, a risk assessment was applied to identify whether the concentrations found could lead to long-term damage to the population. Our results indicate that the contaminations were higher in spring, summer, and winter than in autumn, mainly among fish and swimming crabs. The results of quantification in the animal and estimated monthly intake, despite being below the limit established nationally and internationally, were indicative of risk for these two animals after calculating the Hazard quotient. The highest risk values were attributed to the infant population. Based on the data generated by this work, the consumption of mussels is encouraged throughout the year, to the detriment of the other types of seafood studied, especially during summer, spring, and winter. Our work reinforces the importance of risk assessment for a more reliable understanding of the impact of contaminants in seafood on the population's health.

LaSOM 335, active against bladder cancer cells, interferes with Let-60 (hRas) and reduces CD73 expression/activity.

Bladder cancer is the fourth most common malignancy in men. It can present along the entire continuum of severity, from mild to well-differentiated disease to extremely malignant tumors with low survival rates. Human RAS genes are the most frequently mutated oncogenes in human cancers, and the critical role of aberrant Ras protein function in carcinogenesis is well established. Therefore, considerable efforts have been devoted to the development of anti-Ras inhibitors for cancer treatment. This study presents the biphenyl dihydropyrimidinone LaSOM 335 with high activity against T24 bladder cancer cells (IC50 = 10.73 ± 0.53 µM) and selectivity of cytotoxicity for this cancer cell line compared to two non-cancer cell lines investigated. Furthermore, we also show that this compound reduced vulvar development in the mutant let-60 gene of Caenorhabditis elegans. Let-60 is a homolog of the mammalian Ras gene. In addition, we observed that LaSOM 335 inhibits the enzymatic activity of CD73 and decreases CD73 expression. Possibly, this expression decrease is due to downstream EGFR signaling via the Ras-Raf-ERK pathway, that directly regulates CD73 expression via ERK1/2. Evidence suggests that non-immunomodulating functions of CD73 play an equally important role for cancer cell survival, progression, and migration. Regarding we also notice that LaSOM 335 was safe in the in vivo model of C. elegans. The set of these findings makes this biphenyl dihydropyrimidinone a promising candidate for further investigations in the bladder cancer field.

In silico Prediction of ADMET/Drug-likeness Properties of Bioactive Phloroglucinols from Hypericum Genus.

BACKGROUND: Dimeric acylphloroglucinols occurring in species from sections Brathys and Trigynobrathys of the genus Hypericum exhibit acylfilicinic acid and acylphloroglucinol moieties linked by a methylene bridge. However, this chemical feature differs from hyperforin, from H. perforatum (Hypericum section). Some dimeric acylphloroglucinols, such as uliginosin B, display similar pharmacological activities, namely antidepressant and antinociceptive. However, there is no knowledge about the pharmacokinetic profile and no toxicity studies of these compounds in intact mammals. OBJECTIVE: To perform an in silico evaluation of the similarity, pharmacokinetics and toxicity (ADMET) properties of dimeric acylphloroglucinols from species native to Central and South America. METHODS: ADMET prediction of eleven elected phloroglucinols followed by the chemical space evaluation of thirty-five dimeric acylphloroglucinols derivatives labeled according to their prenylation/ geranylation pattern through principal component analysis (PCA). The similarity analysis was performed using the Tanimoto similarity index. ADMET properties were predicted with the opensource software SwissADME and pkCSM-pharmacokinetics. RESULTS: Several compounds showed good human intestinal absorption. However, they may present difficulties in crossing the blood-brain barrier, probably due to the high tPSA values. The predicted toxicity parameters indicated that most compounds have low toxicity. Most non-prenylated phloroglucinols were disposed into Lipinski's rule limits. Uliginosin B, isouliginosin B and japonicin A seem to be druglike compounds. The PCA model explained 77.49% of the total variance, and molecular similarity analyses revealed some expected similarities between isomers and different compounds. CONCLUSION: Dimeric acylphloroglucinols may be promising drug candidates and deserve further pharmacological and medicinal chemistry studies.

Targeting ecto-5'-nucleotidase: A comprehensive review into small molecule inhibitors and expression modulators.

The purinergic signaling has drawn attention from academia and more recently from pharmaceutical industries as a potential therapeutic route for cancer treatment, since ATP may act as chemotactic agent and possess in vitro antineoplastic activity. On the other way, adenosine, produced in extracellular medium by ecto-5'-NT, acts as immunosuppressor and is related to neoangiogenesis, vasculogenesis and evasion to the immune system. Consequently, inhibitors of ecto-5'-NT may prevent tumor progression, reducing adenosine concentrations, preventing escape from the host's immune system and slowing cancer's growth. This review aims to highlight important biochemical and structural features of ecto-5'NT, highlight its expression profile in normal and cancer cell lines detailing compounds which may act as expression regulators and to review the several classes of ecto-5'NT inhibitors developed in the past 12 years, in order to build a general structure-activity relationship model to guide further compound design.

The Role of Alternative Toxicological Trials in Drug Discovery Programs. The Case of Caenorhabditis elegans and Other Methods.

The discovery of a new drug requires over a billion dollars and around 12 years of research efforts, and toxicity is the leading reason for the failure to approve candidate drugs. Many alternative methods have been validated to detect toxicity as early as possible to diminish the waste of resources and efforts in medicinal chemistry research, and in vivo alternative methods are especially valuable for the amount of information they can provide at little cost and in a short time. In this work, we present a review of the literature published between the years 2000 and 2021 on in vivo alternative methods of toxicity screening employed in medicinal chemistry, which we believe will be useful because, in addition to shortening the research time, these studies provide much additional information aside from the toxicity of drug candidate compounds. These in vivo models include zebrafish, Artemia salina, Galleria mellonella, Drosophila melanogaster, planarians, and Caenorhabditis elegans. The most published ones in the last decade were zebrafish, D. melanogaster, and C. elegans due to their reliability, ease, and cost-effectiveness in implementation and flexibility. Special attention is given to C. elegans because of its rising popularity, a wide range of uses, including toxicity screening, and active effects measurement, from antioxidant effects to anthelmintic and antimicrobial activities, and its fast and reliable results. Over time, C. elegans also became a viable high-throughput (HTS) automated drug screening option. Additionally, this manuscript lists briefly the other screening methods used for the initial toxicological analyses and the role of alternative in vivo methods in these scenarios, classifying them as in silico, in vitro and alternative in vivo models that have been receiving a growing increase in interest in recent years.

Exploring the N1 Position of Biginelli Compounds: New Insights and Trends for Chemical Diversity Generation of Bioactive Derivatives.

Dihydropyrimidinones (DHPMs) are heterocycles obtained by the multicomponent Biginelli reaction. Recently, new synthetic protocols have allowed us to explore functionalisation at less explored positions of DHPMs, such as the N1 position. In this context, a full literature survey of N1- substituted DHPMs was performed. We analysed 27 papers and identified 379 compounds with substituents at the N1 position, most of them with alkyl groups, and a total of 28% compounds with aromatic substituents attached at the N1 position. N1-substituted DHPMs were explored mainly due to their effects on cancer cell proliferation via numerous targets, such as kinesin Eg5, heat shock protein 70, heat shock protein 90, and the epidermal growth factor receptor. Similarity analyses were performed using the data of 379 DHPMs from different cheminformatic approaches, i.e., chemical property correlations, principal component analysis, similarity networks, and compound clustering.

Efeito de diferentes intensidades do exercício antagonista no desempenho de repetições dos agonistas em séries pareadas / Effect of different intensities of antagonist exercise on agonist repetitions performance in paired series

O objetivo do presente estudo foi verificar o efeito agudo de diferentes intensidades em séries pareadas agonistas e antagonistas sobre o desempenho de repetições máximas. Participaram de estudo, 12 homens recreacionalmente treinados (idade: 25.83 ± 3.43 anos; peso: 76.33 ± 5.58 kg; altura 1.72 ± 0.04 metros; IMC: 25.95 ± 1.34 kg/m²). Os procedimentos foram separados em cinco sessões: o primeiro encontro constou de anamnese, medidas antropométricas e teste de 10 repetições máximas (RM) nos exercícios rosca bíceps supinada com barra (RB) e tríceps no pulley (TP). Nos demais encontros, os participantes executaram o máximo de repetições no RB com 80% da carga de 10RM após realizarem, de maneira aleatória e em dias separados, um dos 4 protocolos de diferentes intensidades na musculatura antagonista (TP): Protocolo controle (PC), 10 repetições com 40% de 10RM (P40), 10 repetições com 60% de 10RM (P60) e 10 repetições com 80% de 10RM (P80). Para a análise estatística foi realizada uma ANOVA de medidas repetidas e o nível de significância adotado foi de p < 0.05. Os resultados demonstraram que maiores intensidades (P60 = 15.83 ± 0.94 repetições e P80 = 16.42 ± 0.79 repetições) possibilitaram um aumento significativo (p < 0.05) no desempenho de repetições quando comparado ao PC (14.83 ± 0.72 repetições). Além disso, P80 foi também superior ao P40 (15.25 ± 0.97 repetições, p = 0.00), mostrando existir uma dosagem mínima (60% de 10RM) para a melhora de desempenho no método pareado agonista e antagonista. (AU)

The aim of the present study was to verify the acute effect of different intensities of paired agonist and antagonist series on the performance of maximum repetitions. Twelve recreational trained men participated in the study (age: 25.83 ± 3.43 years; weigth: 76.33 ± 5.58 kg; height 1.72 ± 0.04 meters; IMC: 25.95 ± 1.34 kg/m²). The experimental procedure took place over five sessions: the first consisted of anamnesis, anthropometric measurements and a test of 10 maximum repetitions (RM) in the barbell curved supine (RB) and triceps pulley (TP) exercises. nother meetings, the participants performed maximum repetitions in the RB with 80% of the 10RM load after performing, in random order and on separate days, one of the 4 protocols of different intensities in the antagonist musculature (TP): Control protocol (PC), 10 repetitions with 40% of 10RM (P40), 10 repetitions with 60% of 10RM (P60) and 10 repetitions with 80% of 10RM (P80). For the statistical analysis, an ANOVA was performed and the level of significance adopted was p <0.05. The results showed that higher intensities (P60 = 15.83 ± 0.94 repetitions e P80 = 16.42 ± 0.79 repetitions) enabled a significant increase in repetition performance when compared to CP (14.83 ± 0.72 repetitions). In addition, P80 was also superior to P40 (15.25 ± 0.97 repetitions, p = 0.00), showing that there is a minimum dosage (60% of 10RM) to improve performance in the paired agonist and antagonist method. (AU)

New insights into cytotoxic mechanisms of bozepinib against glioblastoma.

Glioblastoma (GBM) is the most frequent and aggressive brain tumor in adults and the current treatments only have a modest effect on patient survival. Recent studies show that bozepinib (BZP), a purine derivative, has potential applications in cancer treatment. The aim of this study was to evaluate the effect of BZP against GBM cells, specially concerning the purinergic system. Thus, GBM cells (C6 and U138 cell lines) were treated with BZP and cell viability, cell cycle, and annexin/PI assays, and active caspase-3 measurements were carried out. Besides, the effect of BZP over the purinergic system was also evaluated in silico and in vitro. Finally, we evaluate the action of BZP against important markers related to cancer progression, such as Akt, NF-κB, and CD133. We demonstrate here that BZP reduces GBM cell viability (IC50 = 5.7 ± 0.3 µM and 12.7 ± 1.5 µM, in C6 and U138 cells, respectively), inducing cell death through caspase-dependent apoptosis, autophagosome formation, activation of NF-κB, without any change in cell cycle progression or on the Akt pathway. Also, BZP modulates the purinergic system, inducing an increase in CD39 enzyme expression and activity, while inhibiting CD73 activity and adenosine formation, without altering CD73 enzyme expression. Curiously, one cycle of treatment resulted in enrichment of GBM cells expressing NF-κB and CD133+, suggesting resistant cells selection. However, after another treatment round, the resistant cells were eliminated. Altogether, BZP presented in vitro anti-glioma activity, encouraging further in vivo studies in order to better understand its mechanism of action.

Characterization and plasticity of wharton's jelly mesenchymal stem cells of goat

Mesenchymal stem cells (MSCs), obtained from several anatomical sites, have already been described, characterized and used in therapeutic models for tissue repair. The umbilical cord mesenchymal stem cells, represented by cells from arteries and veins walls, as well as Wharton's jelly are easy to be obtained, highly available, require no invasive procedure, do not present risk to donors and do not present ethical limitation. The aim of this research was to analyze the plasticity of Wharton's jelly mesenchymal stem cells (WJ-MSCs) of goat, evaluating their behavior in vitro and characterizing them immunophenotypically. Thus, tests were performed on colony forming units, viability and cell growth curve, flow cytometry analysis and plasticity potential. Goat umbilical cord matrix cells exhibited fibroblastoid morphology with colony formation and self-renewal ability, always maintaining their undifferentiated state up to the eighth passage (P8). The growth curve kinetics exhibited the LAG, LOG, and DECAY phases, without displaying a PLATEAU phase. The plasticity assay demonstrated positive differentiation for osteogenic, adipogenic and chondrogenic lines, characterized by the synthesis of intracytoplasmic granules or extracellular matrix with the presence of calcium, lipids and proteoglycans. Flow cytometry demonstrated the expression of CD90 and CD105; absence of CD14 expression. It is concluded that the cell population isolated from the Wharton's jelly of goat constitutes a representative sample of mesenchymal stem cells, with great possibilities in the field of regenerative and reproductive medicine.

Discovery, development, chemical diversity and design of isoxazoline-based insecticides.

Isoxazoline is a 5-membered heterocycle present in the active compounds of many commercial veterinary anti-ectoparasitic products. The molecular target of isoxazolines is the inhibition of GABA-gated chloride channels in insects. These facts have inspired the use of the isoxazoline scaffold in the design of novel insecticide compounds. The main strategies used for isoxazoline synthesis are either the 1,3-dipolar cycloaddition between a nitrile oxide and an alkene or the reaction between hydroxylamine and an α,ß-unsaturated carbonyl compound. This review highlights the utilization of isoxazoline as insecticide: its mode of action, its commercial preparations and its consideration in the design of novel insecticides. Similarity analyses were performed with 235 isoxazoline derivatives in three different cheminformatic approaches - chemical property correlations, similarity network and compound clustering. The cheminformatic methodologies are interesting tools to use in evaluating the similarity between commercial isoxazolines and to clarify the main features explored within their derivatives.

Diagnostic significance of C-reactive protein and hematological parameters in acute toxoplasmosis.

ABSTRACT: Toxoplasmosis is a zoonosis caused by Toxoplasma gondii, which can be acquired by oral contact and may cause severe health problems especially for pregnant (congenital toxoplasmosis) and immunocompromised patients. This study aimed to verify the diagnostic significance of hematological parameters and C-reactive protein (CRP) for toxoplasmosis acute detection. A case-control study was carried out between December 2017 and May 2018, in samples of convenience independent of age and sex. The case group was formed by 25 patients with positive anti-Toxoplasma gondii IgG/IgM antibody and the control group was formed by 21 patients with non-positive anti-Toxoplasma gondii IgG/IgM antibody. The results of the hematological parameters and CRP were analyzed in these patients. The patients with Toxoplasma gondii IgM antibody reagent showed higher lymphocytes counting and lower neutrophils counting than the control group. C-reactive protein levels were not different between the groups case and control. ROC curve analysis highlighted that the cut-off value of > 32.00% for lymphocytes and < 57.50% for neutrophils were able to produce specificity higher than 90% for IgM antibody detection. The Naïve Bayes classifier was considered suitable (AUC ≈ 0.700) to separate both groups according to their white cell counting. Changes in lymphocytes and neutrophils may be useful parameters for toxoplasmosis identification and may be used as a tool in the complementary diagnosis of toxoplasmosis.

Geo-Measures: A PyMOL plugin for protein structure ensembles analysis.

Although molecular dynamics encompasses several applications, studies focusing on biomolecular systems are central issues of this research area. Such simulations require the generation of trajectory files, which provide a path for the analysis and interpretation of results with biological significance. However, although several programs have been developed in Python language for the analyses of molecular dynamics (MD) trajectories, they usually require some knowledge of programming languages in order to write or run the scripts using command lines, which certainly hinders the access of MD simulations to many scientists with the necessary biological background to interpret their results. To ease the access to Python packages focusing on MD trajectory analyses, we built a user-friendly and easy-to-install graphical PyMOL interface. Geo-Measures integrates the PyMOL functionalities with MDTraj, a powerful library of trajectory analyses, allowing the users to access up to 14 different types of analyses. Two sample cases are reported here to demonstrate the use of Geo-Measures. In the first example, which involves the use a MD trajectory file of hemoglobin from the MoDEL MD bank, we exemplified the analyses of the following variables: root mean square deviation, radius of gyration, free energy landscape and principal component analysis. In the second case, we built a trajectory file for the ecto-5'-nucleotidase using the LiGRO program to study the carbon alpha pincer angles, to define the secondary structure of the proteins and to analyze the Modevectors. This user-friendly graphical PyMOL plugin, which can be used to generate several descriptive analyses for protein structures, is open source and can be downloaded at: https://pymolwiki.org/index.php/Geo_Measures_Plugin.

Natural and synthetic coumarins as antileishmanial agents: A review.

The neglected tropical disease leishmaniasis is still a major public health problem that affects millions of people worldwide. Related to poor-living conditions, this vector-borne disease presents multiple clinical manifestations - from asymptomatic to systemic conditions. The protozoans of the genus Leishmania are the etiologic agents transmitted through the bite of sandflies, the main vectors. Current pharmacological interventions are outdated and present several drawbacks, thus the search for new antileishmanial compounds is imperative. Medicinal chemists have been continuously investigating for new alternatives to combat leishmaniasis, and coumarins play a pivotal role in this search. Various biological properties have been described owing to coumarin's structural versatility combined with its unique features, including antileishmanial activity. The aim of this review is to highlight the most relevant studies between 1997 and 2020 and provide a guide for the development of new antileishmanial coumarins. Naturally occurring and synthetically designed coumarins are comprised in this review, along with a structure-activity relationship to provide an insight for further development of coumarins with antileishmanial activity.

New pharmacological findings linked to biphenyl DHPMs, kinesin Eg5 ligands: anticancer and antioxidant effects.

Background: Dihydropyrimidin-2-thiones (DHPMs) are a class of heterocyclic compound which have been intensively investigated mainly due to their anticancer activity as kinesin Eg5 inhibitors. Materials & methods: A library of N1 aryl substituted DHPMs were tested against glioma and bladder cancer cell lines. Quantitative structure-activity relationship (QSAR) investigation was performed in order to identify key elements of DHPMs linked with their antiproliferative effect. The toxicity of most active compounds was investigated using Caenorhabditis elegans as the model. Results & conclusion: DHPMs 9, 13 and 17 have been identified as having improved activity against glioma and bladder cell lines as compared with monastrol. Flow cytometry investigations showed that the new compounds induce cell cycle arrest in phase G2/M and cell death by apoptosis. In addition, compound 13 was able to modulate the reactive oxygen species production in vivo in C. elegans. The biphenyl dihydropyrimidinthiones provided a safety profile in C. elegans.

Novel coumarins active against Trypanosoma cruzi and toxicity assessment using the animal model Caenorhabditis elegans.

BACKGROUND: Chagas disease (CD) is a tropical parasitic disease. Although the number of people infected is very high, the only drugs available to treat CD, nifurtimox (Nfx) and benznidazole, are highly toxic, particularly in the chronic stage of the disease. Coumarins are a large class of compounds that display a wide range of interesting biological properties, such as antiparasitic. Hence, the aim of this work is to find a good antitrypanosomal drug with less toxicity. The use of simple organism models has become increasingly attractive for planning and simplifying efficient drug discovery. Within these models, Caenorhabditis elegans has emerged as a convenient and versatile tool with significant advantages for the toxicological potential identification for new compounds. METHODS: Trypanocidal activity: Forty-two 4-methylamino-coumarins were assayed against the epimastigote form of Trypanosoma cruzi (Tulahuen 2 strain) by inhibitory concentration 50% (IC50). Toxicity assays: Lethal dose 50% (LD50) and Body Area were determined by Caenorhabditis elegans N2 strain (wild type) after acute exposure. Structure-activity relationship: A classificatory model was built using 3D descriptors. RESULTS: Two of these coumarins demonstrated near equipotency to Nifurtimox (IC50 = 5.0 ± 1 µM), with values of: 11 h (LaSOM 266), (IC50 = 6.4 ± 1 µM) and 11 g (LaSOM 231), (IC50 = 8.2 ± 2.3 µM). In C. elegans it was possible to observe that Nfx showed greater toxicity in both the LD50 assay and the evaluation of the development of worms. It is possible to observe that the efficacy between Nfx and the synthesized compounds (11 h and 11 g) are similar. On the other hand, the toxicity of Nfx is approximately three times higher than that of the compounds. Results from the QSAR-3D study indicate that the volume and hydrophobicity of the substituents have a significant impact on the trypanocidal activities for derivatives that cause more than 50% of inhibition. These results show that the C. elegans model is efficient for screening potentially toxic compounds. CONCLUSION: Two coumarins (11 h and 11 g) showed activity against T. cruzi epimastigote similar to Nifurtimox, however with lower toxicity in both LD50 and development of C. elegans assays. These two compounds may be a feasible starting point for the development of new trypanocidal drugs.

Targeting pteridine reductase 1 and dihydrofolate reductase: the old is a new trend for leishmaniasis drug discovery.

Leishmaniasis is one of the major neglected tropical diseases in the world and it is considered endemic in 88 countries. This disease is transmitted by a Leishmania spp. infected sandfly and it may lead to cutaneous or systemic manifestations. The preconized treatment has low efficacy and there are cases of resistance to some drugs. Therefore, the search for new efficient molecular targets that can lead to the preparation of new drugs must be pursued. This review aims to evaluate both Leishmania enzymes PTR1 and DHFR-TS as potential drug targets, highlight their inhibitors and to discuss critically the use of chemoinformatics to elucidate interactions and propose new molecules against these enzymes.

In vitro and in silico Activity of Iridoids Against Leishmania amazonensis.

BACKGROUND: Leishmaniasis reaches millions of people around the world. The control of the disease is difficult due to the restricted access to the diagnosis and medication, and low adherence to the treatment. Thus, more efficient drugs are needed and natural products are good alternatives. Iridoids, natural products with reported leishmanicidal activity, can be exploited for the development of anti- Leishmania drugs. The aim of this study was to isolate and to investigate the in vitro activity of iridoids against Leishmania amazonensis and to compare the activity in silico of these compounds with those reported as active against this parasite. METHODS: Iridoids were isolated by chromatographic methods. The in vitro activity of asperuloside (1) and geniposide (2) from Escalonia bifida, galiridoside (3) from Angelonia integerrima and theveridoside (4) and ipolamiide (5) from Amphilophium crucigerum was investigated against promastigote forms of Leishmania amazonensis. Molecular modeling studies of 1-5 and iridoids cited as active against Leishmania spp. were performed. RESULTS: Compounds 1-5 (5-100 µM) did not inhibit the parasite survival. Physicochemical parameters predicted for 1-5 did not show differences compared to those described in literature. The SAR and the pharmacophoric model confirmed the importance of maintaining the cyclopentane[C]pyran ring of the iridoid, of oxygen-linked substituents at the C1 and C6 positions and of bulky substituents attached to the iridoid ring to present leishmanicidal activity. CONCLUSION: The results obtained in this study indicate that iridoids are a promising group of secondary metabolites and should be further investigated in the search for new anti-Leishmania drugs.