Multitarget anti-parasitic activities of isoquinoline alkaloids isolated from Hippeastrum aulicum (Amaryllidaceae).

BACKGROUND: Chagas disease and leishmaniasis affect a significant portion of the Latin American population and still lack efficient treatments. In this context, natural products emerge as promising compounds for developing more effective therapies, aiming to mitigate side effects and drug resistance. Notably, species from the Amaryllidaceae family emerge as potential reservoirs of antiparasitic agents due to the presence of diverse biologically active alkaloids. PURPOSE: To assess the anti-Trypanosoma cruzi and anti-Leishmania infantum activity of five isolated alkaloids from Hippeastrum aulicum Herb. (Amaryllidaceae) against different life stages of the parasites using in silico and in vitro assays. Furthermore, molecular docking was employed to evaluate the interaction of the most active alkaloids. METHODS: Five natural isoquinoline alkaloids isolated in suitable quantities for in vitro testing underwent preliminary in silico analysis to predict their potential efficacy against Trypanosoma cruzi (amastigote and trypomastigote forms) and Leishmania infantum (amastigote and promastigote forms). The in vitro antiparasitic activity and mammalian cytotoxicity were investigated with a subsequent comparison of both analysis (in silico and in vitro) findings. Additionally, this study employed the molecular docking technique, utilizing cruzain (T. cruzi) and sterol 14α-demethylase (CYP51, L. infantum) as crucial biological targets for parasite survival, specifically focusing on compounds that exhibited promising activities against both parasites. RESULTS: Through computational techniques, it was identified that the alkaloids haemanthamine (1) and lycorine (8) were the most active against T. cruzi (amastigote and trypomastigote) and L. infantum (amastigote and promastigote), while also revealing unprecedented activity of alkaloid 7­methoxy-O-methyllycorenine (6). The in vitro analysis confirmed the in silico tests, in which compound 1 presented the best activities against the promastigote and amastigote forms of L. infantum with half-maximal inhibitory concentration (IC50) 0.6 µM and 1.78 µM, respectively. Compound 8 exhibited significant activity against the amastigote form of T. cruzi (IC50 7.70 µM), and compound 6 demonstrated activity against the trypomastigote forms of T. cruzi and amastigote of L. infantum, with IC50 values of 89.55 and 86.12 µM, respectively. Molecular docking analyses indicated that alkaloids 1 and 8 exhibited superior interaction energies compared to the inhibitors. CONCLUSION: The hitherto unreported potential of compound 6 against T. cruzi trypomastigotes and L. infantum amastigotes is now brought to the forefront. Furthermore, the acquired dataset signifies that the isolated alkaloids 1 and 8 from H. aulicum might serve as prototypes for subsequent structural refinements aimed at the exploration of novel leads against both T. cruzi and L. infantum parasites.

First Description of Marinoquinoline Derivatives' Activity against Toxoplasma gondii.

Toxoplasmosis is a globally prevalent zoonotic disease with significant clinical implications, including neurotoxoplasmosis, a leading cause of cerebral lesions in AIDS patients. The current pharmacological treatments for toxoplasmosis face clinical limitations, necessitating the urgent development of new therapeutics. Natural sources have yielded diverse bioactive compounds, serving as the foundation for clinically used derivatives. The exploration of marine bacteria-derived natural products has led to marinoquinolines, which feature a pyrroloquinoline core and demonstrate in vitro and in vivo anti-Plasmodium activity. This study investigates the in vitro anti-Toxoplasma gondii potential of six marinoquinoline derivatives. Additionally, it conducts absorption, distribution, metabolism, excretion, and toxicity (ADMET) predictions, and evaluates the in vivo efficacy of one selected compound. The compounds displayed half-maximal effective concentration (EC50) values between 1.31 and 3.78 µM and half-maximal cytotoxic concentration (CC50) values ranging from 4.16 to 30.51 µM, resulting in selectivity indices (SI) from 3.18 to 20.85. MQ-1 exhibiting the highest in vitro SI, significantly reduced tachyzoite numbers in the peritoneum of RH-infected Swiss mice when it was orally administered at 12.5 mg/kg/day for eight consecutive days. Also, MQ-1 significantly reduced the cerebral parasite burden in chronically ME49 infected C57BL/6 mice when it was orally administered at 25 mg/kg/day for 10 consecutive days. These findings underscore the promising anti-T. gondii activity of marinoquinolines and their potential as novel therapeutic agents against this disease.

Natural Phenolic Compounds with Antithrombotic and Antiplatelet Effects: A Drug-likeness Approach.

BACKGROUND: Thrombosis is one of the major causes of morbidity and mortality in a wide range of vessel diseases. Several studies have been conducted to identify antithrombotic agents from medicinal plants, and phenolic compounds (PCs) have been shown to effectively inhibit plasma coagulation and platelet aggregation. OBJECTIVES: This study aimed to conduct a survey of the natural PCs with proven antithrombotic and antiplatelet activities, as well as to evaluate by computational modeling the physicochemical and toxicological properties of these compounds using drug-likeness approaches. METHODS: The data were collected from the scientific database: 'Web of Science', 'Scifinder', 'Pubmed', 'ScienceDirect' and 'Google Scholar', the different classes of PCs with antithrombotic or antiplatelet effects were used as keywords. These molecules were also evaluated for their Drug-Likeness properties and toxicity to verify their profile for being candidates for new antithrombotic drugs. RESULTS: In this review, it was possible to register 85 lignans, 73 flavonoids, 28 coumarins, 21 quinones, 23 phenolic acids, 8 xanthones and 8 simple phenols. Activity records for tannins were not found in the researched databases. Of these 246 compounds, 213 did not violate any of Lipinski's rules of five, of which 125 (59%) showed non-toxicity, being promising candidates for new potential antithrombotic drugs. CONCLUSION: This review arouses interest in the isolation of phenolic compounds that may allow a new approach for the prevention of both arterial and venous thrombosis, with the potential to become alternatives in the prevention and treatment of cardiovascular diseases.

Mechanisms Involved in the Therapeutic Effect of Cannabinoid Compounds on Gliomas: A Review with Experimental Approach.

INTRODUCTION: Brain tumors have high morbidity and mortality rates, accounting for 1.4% of all cancers. Gliomas are the most common primary brain tumors in adults. Currently, several therapeutic approaches are used; however, they are associated with side effects that affect patients'quality of life. Therefore, further studies are needed to develop novel therapeutic protocols with a more favorable side effect profile. In this context, cannabinoid compounds may serve as potential alternatives. OBJECTIVE: This study aimed to review the key enzymatic targets involved in glioma pathophysiology and evaluate the potential interaction of these targets with four cannabinoid derivatives through molecular docking simulations. METHODS: Molecular docking simulations were performed using four cannabinoid compounds and six molecular targets associated with glioma pathophysiology. RESULTS: Encouraging interactions between the selected enzymes and glioma-related targets were observed, suggesting their potential activity through these pathways. In particular, cannabigerol showed promising interactions with epidermal growth factor receptors and phosphatidylinositol 3- kinase, while Δ-9-tetrahydrocannabinol showed remarkable interactions with telomerase reverse transcriptase. CONCLUSION: The evaluated compounds exhibited favorable interactions with the analyzed enzymatic targets, thus representing potential candidates for further in vitro and in vivo studies.

Derivative of 7-hydroxycoumarin has antifungal potential against Candida species and low cytotoxicity against human cells: In silico studies and biological evaluation.

This study investigates the antifungal and cytotoxic properties of 7-(pentyloxy)-2H-chromen-2-one. Through molecular docking and dynamics simulations, we explored the compound's interactions with fungal cell protein targets. Notably, it exhibited strong affinities for 1,3ß-glucan synthase, squalene epoxidase, δ-14-sterol reductase, 14-α-demethylase, and thymidylate synthase, with binding energies ranging from -100.39 to -73.15 kcal/mol. Molecular dynamics simulations confirmed its stable binding at active targets. The MIC and MFC values ranged from 67.16 µM (15.6 µg/mL) to 537.28 µM (125.0 µg/mL). The compound displayed promising antifungal effects, inhibiting fungal growth for at least 24 hours. Fungal plasma membrane function alteration likely contributed to these antifungal mechanisms. Additionally, the combination of the compound with nystatin, fluconazole, and caspofungin showed indifferent effects on antifungal activity. Cytotoxicity assessment in human keratinocyte cells (HaCaT) revealed an IC50 of 100 µM, which was approximately 1.5 times higher than the MIC for C. krusei. Thus, the compound exhibited strongly in silico and in vitro antifungal activity with low cytotoxicity in HaCaT cells. These findings support its potential as a candidate for further development as an antifungal compound.

Cleomin Exerts Acute Antinociceptive Effects in Mice via GABAB and Muscarinic Receptors.

Cleomin, a 1,3-oxazolidine-2-thione, was recently isolated from Neocalyptrocalyx longifolium, a species traditionally used for treating painful conditions. Reports about the pharmacological activities of cleomin are lacking. Here, the antinociceptive effects of cleomin were investigated using mice models of pain, namely the formalin, the cold plate, and the tail flick tests. Motor integrity was assessed in the rota-rod test. Antagonism assays and in silico docking analyses were performed to investigate the putative mechanisms of action. Cleomin (12.5-25 mg/kg), at doses that did not induce motor impairment, induced dose-dependent antinociception in both early and late phases of the formalin test and reduced nociceptive behaviors in both the cold plate and tail flick tests. Pretreatments with phaclofen and atropine attenuated the antinociceptive effects of cleomin, implicating the involvement of GABAB and muscarinic receptors. In silico docking studies suggested satisfactory coupling between cleomin and GABAB and M2 receptors, hence corroborating their role in cleomin's activity. Pretreatments with naloxone, yohimbine, bicuculline, and methysergide did not affect the antinociception of cleomin. In silico pharmacokinetics prediction showed a good drug ability profile of cleomin. In conclusion, cleomin promoted antinociception mediated by GABAB and muscarinic receptors. These findings support further investigation of the analgesic potential of cleomin.

The Essential Oil from Conyza bonariensis (L.) Cronquist (Asteraceae) Exerts an In Vitro Antimelanoma Effect by Inducing Apoptosis and Modulating the MAPKs, NF-κB, and PKB/AKT Signaling Pathways.

The characterization and cytotoxicity of the essential oil from Conyza bonariensis (L.) aerial parts (CBEO) were previously conducted. The major compound was (Z)-2-lachnophyllum ester (EZ), and CBEO exhibited significant ROS-dependent cytotoxicity in the melanoma cell line SK-MEL-28. Herein, we employed the Molegro Virtual Docker v.6.0.1 software to investigate the interactions between the EZ and Mitogen-Activated Protein Kinases (MAPKs), the Nuclear Factor kappa B (NF-κB), and the Protein Kinase B (PKB/AKT). Additionally, in vitro assays were performed in SK-MEL-28 cells to assess the effect of CBEO on the cell cycle, apoptosis, and these signaling pathways by flow cytometry and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using MAPKs inhibitors. CBEO induced a significant increase in the sub-G1 peak, as well as biochemical and morphological changes characteristic of apoptosis. The in-silico results indicated that EZ interacts with Extracellular Signal-Regulated Kinase 1 (ERK1), c-Jun N-terminal Kinase 1 (JNK1), p38α MAPK, NF-κB, and PKB/AKT. Moreover, CBEO modulated the ERK1/2, JNK, p38 MAPK, NF-κB, and PKB/AKT activities in SK-MEL-28 cells. Furthermore, CBEO's cytotoxicity against SK-MEL-28 cells was significantly altered in the presence of MAPKs inhibitors. These findings support the in vitro antimelanoma effect of CBEO through apoptosis induction, and the modulation of ERK, JNK, p38 MAPK, NF-κB, and PKB/AKT activities.

Proposition of In silico Pharmacophore Models for Malaria: A Review.

In the field of medicinal chemistry, the concept of pharmacophore refers to the specific region of a molecule that possesses essential structural and chemical characteristics for binding to a receptor and eliciting biological activity. Understanding the pharmacophore is crucial for drug research and development, as it allows the design of new drugs. Malaria, a widespread disease, is commonly treated with chloroquine and artemisinin, but the emergence of parasite resistance limits their effectiveness. This study aims to explore computer simulations to discover a specific pharmacophore for Malaria, providing new alternatives for its treatment. A literature review was conducted, encompassing articles proposing a pharmacophore for Malaria, gathered from the "Web of Science" database, with a focus on recent publications to ensure up-to-date analysis. The selected articles employed diverse methods, including ligand-based and structurebased approaches, integrating molecular structure and biological activity data to yield comprehensive analyses. Affinity evaluation between the proposed pharmacophore and the target receptor involved calculating free energy to quantify their interaction. Multiple linear regression was commonly utilized, though it is sensitive to multicollinearity issues. Another recurrent methodology was the use of the Schrödinger package, employing tools such as the Phase module and the OPLS force field for interaction analysis. Pharmacophore model proposition allows threedimensional representations guiding the synthesis and design of new biologically active compounds, offering a promising avenue for discovering therapeutic agents to combat Malaria.

Convergent QSAR Models for the Prediction of Cruzain Inhibitors.

Chagas disease is a parasitosis caused by Trypanosoma cruzi. Cruzain, the major cysteine protease from T. cruzi, is an excellent therapeutic target in the search for antichagasic drugs. It is important in the role of cell invasion, replication, differentiation, and metabolism of the parasite. In this work, we developed and assessed multiple quantitative structure-activity relationship (QSAR) models for a set of 61 cruzain inhibitors. These models include two-dimensional (2D) QSAR, three-dimensional (3D) QSAR, such as comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA), and Hologram QSAR (HQSAR). In total, we generated 10 major and 114 minor model variations. Molecular docking was used to successfully align the molecules. All CoMFA and CoMSIA models, which incorporate multiple fields, demonstrated robustness in our analysis. Steric fields exhibited satisfactory convergence in the contour maps, while the electrostatic field converged into a single small region. The HQSAR model taking into consideration only Atoms and Connectivity, with fragment sizes ranging from two to five atoms, was considered the best of the HQSAR variations, despite exhibiting a higher level of deviance. In total, 78 model variations meet the minimum requirements to be considered acceptable. We found that using as few as five descriptors it is possible to obtain robust results with 2D-QSAR. Models such as Random Forest, Tree Ensemble, Linear Regression, and HQSAR are recommended for working with large data sets, while the 3D-QSAR models are intended to study the geometry of the ligands, to optimize them into new and better performing antichagasics. Virtual Screening of a set of hydrazones, guided by the top-performing models, identified promising candidates for experimental validation. Among them, dv007 and dv015 exhibited consistently high predicted pIC50 values (7.26 and 7.24, respectively), making them compelling candidates for further drug development.

Anti-Toxoplasma gondii screening of MMV pandemic response box and evaluation of RWJ-67657 efficacy in chronically infected mice.

Toxoplasmosis is a significant public health concern with limited therapeutic options. The medicines for malaria venture (MMV) developed the pandemic response box (PRB) containing 400 drug-like molecules with broad pathogen activity. The aim of this work is to evaluate PRB compounds for their anti-Toxoplasma gondii activity and identify promising candidates for further evaluation. Screening identified 42 selective compounds with half effective concentration (EC50) ranging from 2.4 to 913.1 nm and half cytotoxic concentration (CC50) ranging from 6 µm to >50 µm. Selectivity index (SI) values (CC50/EC50) ranged from 11 to 17 708. Based on its in silico and in vitro profile and its commercial availability, RWJ-67657 was selected for further studies. Molecular docking analysis showed RWJ-67657 is predicted to bind to T. gondii p38 mitogen-activated protein kinase (TgMAPK). Oral administration of RWJ-67657 (20 mg kg day−1/10 days) significantly reduced parasite burden in chronically infected mice compared to mock-treated group (P < 0.01). These findings highlight the PRB as a promising source for anti-T. gondii compounds, with several showing favourable drug properties, including MMV1634492, MMV002731, MMV1634491, MMV1581551, MMV011565, MMV1581558, MMV1578577, MMV233495 and MMV1580482, firstly described here as anti-T. gondii agents. RWJ-67657 emerges as a valuable drug candidate for experimental chronic cerebral toxoplasmosis therapy.

Methyleugenol Has an Antidepressant Effect in a Neuroendocrine Model: In Silico and In Vivo Evidence.

Major depressive disorder is a severe mood disorder characterized by different emotions and feelings. This study investigated the antidepressant activity of the phenylpropanoid methyleugenol (ME) in adult female mice exposed to a stress model induced by dexamethasone. The animals were randomly divided into groups containing eight animals and were pre-administered with dexamethasone (64 µg/kg subcutaneously). After 165 and 180 min, they were treated with ME (25, 50 and 100 mg/kg intraperitoneally) or imipramine (10 mg/kg intraperitoneally) after 45 min and 30 min, respectively; they were then submitted to tests which were filmed. The videos were analyzed blindly. In the tail suspension test, ME (50 mg/kg) increased latency and reduced immobility time. In the splash test, ME (50 mg/kg) decreased grooming latency and increased grooming time. In the open field, there was no statistical difference for the ME groups regarding the number of crosses, and ME (50 mg/kg) increased the number of rearing and time spent in the center. Regarding in silico studies, ME interacted with dopaminergic D1 and α1 adrenergic pathway receptors and with tryptophan hydroxylase inhibitor. In the in vivo evaluation of the pathways of action, the antidepressant potential of ME (50 mg/kg) was reversed by SCH23390 (4 mg/kg intraperitoneally) dopaminergic D1 receptor, Prazosin (1 mg/kg intraperitoneally) α1 adrenergic receptor, and PCPA (4 mg/kg intraperitoneally) tryptophan hydroxylase inhibitor. Our findings indicate that ME did not alter with the locomotor activity of the animals and shows antidepressant activity in female mice with the participation of the D1, α1 and serotonergic systems.

The potential of Acmella oleracea as a nutraceutical source for the symptomatic treatment of Burning Mouth Syndrome.

This study analysed the phytochemical profile of Acmella oleracea extract and the molecular interactions of its main compounds with TRPV1 and CB2, target receptors in the Burning Mouth Syndrome (BMS) pathogenesis. The phytochemical profile of A. oleracea's floral buds extract treated with activated charcoal (TCEE) was analysed by High-Performance Liquid Chromatography (HPLC) coupled to Mass Spectrometry (LC-MS). The quantification of spilanthol was analysed by HPLC coupled to a Diode-Array Detector (HPLC-DAD). The phytochemical analysis revealed the presence of nine alkylamides and phenolic compounds. The TCEE showed a significant increase in spilanthol content compared to the crude extract (CEE), going from 28.33 mg/g to 117.96 mg/g. The molecular docking indicated a behaviour of the alkylamides as partial TRPV1 agonists and CB2 agonists and, for the first time, indicates the action of these compounds in the symptomatic management of BMS.

Virtual Screening of Different Subclasses of Lignans with Anticancer Potential and Based on Genetic Profile.

Cancer is a multifactorial disease that continues to increase. Lignans are known to be important anticancer agents. However, due to the structural diversity of lignans, it is difficult to associate anticancer activity with a particular subclass. Therefore, the present study sought to evaluate the association of lignan subclasses with antitumor activity, considering the genetic profile of the variants of the selected targets. To do so, predictive models were built against the targets tyrosine-protein kinase ABL (ABL), epidermal growth factor receptor erbB1 (EGFR), histone deacetylase (HDAC), serine/threonine-protein kinase mTOR (mTOR) and poly [ADP-ribose] polymerase-1 (PARP1). Then, single nucleotide polymorphisms were mapped, target mutations were designed, and molecular docking was performed with the lignans with the best predicted biological activity. The results showed more anticancer activity in the dibenzocyclooctadiene, furofuran and aryltetralin subclasses. The lignans with the best predictive values of biological activity showed varying binding energy results in the presence of certain genetic variants.

Structure-based design, optimization of lead, synthesis, and biological evaluation of compounds active against Trypanosoma cruzi.

Chagas' disease affects approximately eight million people throughout the world, especially the poorest individuals. The protozoan that causes this disease-Trypanosoma cruzi-has the enzyme cruzipain, which is the main therapeutic target. As no available medications have satisfactory effectiveness and safety, it is of fundamental importance to design and synthesize novel analogues that are more active and selective. In the present study, molecular docking and the in silico prediction of ADMET properties were used as strategies to optimize the trypanocidal activity of the pyrimidine compound ZN3F based on interactions with the target site in cruzipain. From the computational results, eight 4-amino-5-carbonitrile-pyrimidine analogues were proposed, synthesized (5a-f and 7g-h) and, tested in vitro on the trypomastigote form of the Tulahuen strain of T. cruzi. The in silico study showed that the designed analogues bond favorably to important amino acid residues of the active site in cruzipain. An in vitro evaluation of cytotoxicity was performed on L929 mammal cell lines. All derivatives inhibited the Tulahuen strain of T. cruzi and also exhibited lower toxicity to L929 cells. The 5e product, in particular, proved to be a potent, selective (IC50 = 2.79 ± 0.00 µM, selectivity index = 31.3) inhibitor of T. cruzi. The present results indicated the effectiveness of drugs based on the structure of the receptor, revealing the potential trypanocidal of pyrimidines. This study also provides information on molecular aspects for the inhibition of cruzipain.

Repurposing the Medicines for Malaria Venture's COVID Box to discover potent inhibitors of Toxoplasma gondii, and in vivo efficacy evaluation of almitrine bismesylate (MMV1804175) in chronically infected mice.

Toxoplasmosis, caused by the obligate intracellular parasite Toxoplasma gondii, affects about one-third of the world's population and can cause severe congenital, neurological and ocular issues. Current treatment options are limited, and there are no human vaccines available to prevent transmission. Drug repurposing has been effective in identifying anti-T. gondii drugs. In this study, the screening of the COVID Box, a compilation of 160 compounds provided by the "Medicines for Malaria Venture" organization, was conducted to explore its potential for repurposing drugs to combat toxoplasmosis. The objective of the present work was to evaluate the compounds' ability to inhibit T. gondii tachyzoite growth, assess their cytotoxicity against human cells, examine their absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties, and investigate the potential of one candidate drug through an experimental chronic model of toxoplasmosis. Early screening identified 29 compounds that could inhibit T. gondii survival by over 80% while keeping human cell survival up to 50% at a concentration of 1 µM. The Half Effective Concentrations (EC50) of these compounds ranged from 0.04 to 0.92 µM, while the Half Cytotoxic Concentrations (CC50) ranged from 2.48 to over 50 µM. Almitrine was chosen for further evaluation due to its favorable characteristics, including anti-T. gondii activity at nanomolar concentrations, low cytotoxicity, and ADMET properties. Administering almitrine bismesylate (Vectarion®) orally at dose of 25 mg/kg/day for ten consecutive days resulted in a statistically significant (p < 0.001) reduction in parasite burden in the brains of mice chronically infected with T. gondii (ME49 strain). This was determined by quantifying the RNA of living parasites using real-time PCR. The presented results suggest that almitrine may be a promising drug candidate for additional experimental studies on toxoplasmosis and provide further evidence of the potential of the MMV collections as a valuable source of drugs to be repositioned for infectious diseases.

Targets Involved in Skin Aging and Photoaging and their Possible Inhibitors: A Mini-review.

BACKGROUND: Skin aging is a natural process resulting from intrinsic (hormonal and genetic) and extrinsic (environmental) factors. Photoaging occurs due to prolonged exposure of the skin to ultraviolet radiation, accounting for 80% of facial aging. INTRODUCTION: Characteristics of aging skin include reduced elasticity, the appearance of fine wrinkles, uneven tone, and dryness. Clinical signs of photoaging involve the presence of deeper wrinkles, rough texture, dyschromia and a greater loss of elasticity compared to chronological aging. METHODS: This work reported several scientific articles that used computational techniques, such as molecular docking, molecular dynamics and quantitative structure-activity relationship (QSAR) to identify natural products and their derivatives against skin aging and photoaging. RESULTS: The in silico analyses carried out by the researchers predicted the binding affinity and interactions of the natural products with the targets matrix metalloproteinase-1, matrix metalloproteinase- 3, matrix metalloproteinase-9 and tyrosinase. Furthermore, some studies have reported the stability of the protein-ligand complex and the physicochemical properties of the studied compounds. Finally, this research proposes promising molecules against the targets. CONCLUSION: Thus, studies like this one are relevant to guide new research related to skin aging and photoaging.

In Silico Studies on Natural Products and Derivatives Against Different Types of Cancer.

According to the World Health Organization (WHO), cancer is the second cause of death worldwide, responsible for almost 10 million deaths and accounting for one in every six deaths. It is a disease that can affect any organ or tissue with rapid progression to the final stage, which is metastasis, in which the disease spreads to different regions of the body. Many studies have been carried out to find a cure for cancer. Early diagnosis contributes to the individual achieving the cure; however, deaths are increasing considerably due to late diagnosis. Thus, this bibliographical review discussed several scientific research works pointing to in silico analyses in the proposition of new antineoplastic agents for glioblastoma, breast, colon, prostate, and lung cancer, as well as some of their respective molecular receptors involved in molecular docking simulations and molecular dynamics. This review involved articles describing the contribution of computational techniques for the development of new drugs or already existing drugs with biological activity; thus, important data were highlighted in each study, such as the techniques used, results obtained in each study, and the conclusion. Furthermore, 3D chemical structures of the molecules with the best computational response and significant interactions between the tested molecules and the PDB receptors were also presented. With this, it is expected to help new research in the fight against cancer, the creation of new antitumor drugs, and the advancement of the pharmaceutical industry and scientific knowledge about studied tumors.

Anticancer Activity of Chalcones and Its Derivatives: Review and In Silico Studies.

Chalcones are direct precursors in the biosynthesis of flavonoids. They have an α,ß-unsaturated carbonyl system which gives them broad biological properties. Among the biological properties exerted by chalcones, their ability to suppress tumors stands out, in addition to their low toxicity. In this perspective, the present work explores the role of natural and synthetic chalcones and their anticancer activity in vitro reported in the last four years from 2019 to 2023. Moreover, we carried out a partial least square (PLS) analysis of the biologic data reported for colon adenocarcinoma lineage HCT-116. Information was obtained from the Web of Science database. Our in silico analysis identified that the presence of polar radicals such as hydroxyl and methoxyl contributed to the anticancer activity of chalcones derivatives. We hope that the data presented in this work will help researchers to develop effective drugs to inhibit colon adenocarcinoma in future works.

Multitargeted molecular docking and dynamics simulation studies of flavonoids and volatile components from the peel of Citrus sinensis L. (Osbeck) against specific tumor protein markers.

Citrus sinensis (L.) Osbeck (Rutaceae), commonly known as the sweet orange, is a popular and widely consumed fruit with several medicinal properties. The present study aimed to perform the in silico screening of 18 flavonoids and eight volatile components from the peel of C. sinensis against apoptotic and inflammatory proteins, metalloprotease, and tumor suppressor markers. Flavonoids obtained higher probabilities than volatile components against selected anti-cancer drug targets. Hence, the data from the binding energies against the essential apoptotic and cell proliferation proteins substantiate that they may be promising compounds in developing effective candidates to block cell growth, proliferation, and induced cell death by activating the apoptotic pathway. Further, the binding stability of the selected targets and the corresponding molecules were analyzed by 100 ns molecular dynamics (MD) simulations. Chlorogenic acid has the most binding affinity against the important anti-cancer targets iNOS, MMP-9, and p53. The congruent binding mode to different drug targets focused on cancer shown by chlorogenic acid suggests that it may be a compound with significant therapeutic potential. Moreover, the binding energy predictions indicated that the compound had stable electrostatic and van der Waal energies. Thus, our data reinforce the medicinal importance of flavonoids from C. sinensis and expand the need for more studies, seeking to optimize results and amplify the impacts of further in vitro and in vivo studies. Communicated by Ramaswamy H. Sarma.

Kaurane-Type Diterpenoids as Potential Inhibitors of Dihydrofolate Reductase-Thymidylate Synthase in New World Leishmania Species.

The bifunctional enzyme Dihydrofolate reductase-thymidylate synthase (DHFR-TS) plays a crucial role in the survival of the Leishmania parasite, as folates are essential cofactors for purine and pyrimidine nucleotide biosynthesis. However, DHFR inhibitors are largely ineffective in controlling trypanosomatid infections, largely due to the presence of Pteridine reductase 1 (PTR1). Therefore, the search for structures with dual inhibitory activity against PTR1/DHFR-TS is crucial in the development of new anti-Leishmania chemotherapies. In this research, using the Leishmania major DHFR-TS recombinant protein, enzymatic inhibitory assays were performed on four kauranes and two derivatives that had been previously tested against LmPTR1. The structure 302 (6.3 µM) and its derivative 302a (4.5 µM) showed the lowest IC50 values among the evaluated molecules. To evaluate the mechanism of action of these structures, molecular docking calculations and molecular dynamics simulations were performed using a DHFR-TS hybrid model. Results showed that hydrogen bond interactions are critical for the inhibitory activity against LmDHFR-TS, as well as the presence of the p-hydroxyl group of the phenylpropanoid moiety of 302a. Finally, additional computational studies were performed on DHFR-TS structures from Leishmania species that cause cutaneous and mucocutaneous leishmaniasis in the New World (L. braziliensis, L. panamensis, and L. amazonensis) to explore the targeting potential of these kauranes in these species. It was demonstrated that structures 302 and 302a are multi-Leishmania species compounds with dual DHFR-TS/PTR1 inhibitory activity.