Priscila Goes Camargo

Breast cancer (BC) is the most common cancer in women worldwide. Natural compounds have been studied to improve chemotherapy efficiency. Cafestol and kahweol (C&K) are diterpenes from coffee lipid fraction, with potential anticancer activity, whose effects and association with chemotherapeutic drug doxorubicin in BC cells are still unknown. Here, we evaluated the synergistic cytotoxic effects of the C&K with doxorubicin and their molecular mechanisms in BC cells. Cell viability was assessed by the MTT assay. Flow cytometry was used to analyze apoptosis, cell cycle, and NF‐κB levels. The microarray assay was performed to identify altered signaling pathways, and molecular docking was utilized to predict the interaction between C&K and TNF‐α. In addition, TCGA data were explored to evaluate the clinical association between the expression of C&K‐regulated genes and TNF‐α/NF‐κB pathway genes. C&K was cytotoxic and increased the doxorubicin cytotoxicity, augmented the sub‐G0/G1 phase, downregulated TNF‐α/NF‐κB pathway, decreased NF‐κB protein levels, and showed affinity for TNF‐α by molecular docking. Moreover, considering the C&K‐modulated genes, BLOC1S1 acted as a protective factor for BC, and these genes were negatively correlated with TNF‐α/NF‐κB genes. Our data suggest that C&K have cytotoxic properties by inhibiting TNF‐α/NF‐κB pathway and interacting synergistically with doxorubicin in BC cells.

Dysregulation of the phosphoinositide 3-kinase-alpha (PI3Kα) pathway is implicated in the development of post-CoViD-19 pulmonary fibrosis, highlighting the need for effective therapeutic agents. This study aimed to identify novel PI3Kα inhibitors by computationally repurposing FDA-approved drugs. We employed a hybrid approach that combines machine learning with molecular modeling. A random forest (RF) classification model was built and validated using a curated data set of 4,023 known PI3Kα inhibitors from the ChEMBL database, demonstrating robust predictive performance. The RF model was applied to screen the subset of FDA-approved drugs available in the DrugBank database to identify potential candidates. The top-ranked compounds were subsequently evaluated through molecular docking, extensive 200 ns molecular dynamics simulations (MDS), and binding free energy calculations using the molecular mechanics/Poisson–Boltzmann surface area (MM/PBSA) method. Our virtual screening identified five promising drugs, with simeprevir and ceritinib demonstrating the most favorable free energy binding affinities (ΔG _bind = −33.0 ± 3.2 kcal/mol and −25.2 ± 2.4 kcal/mol, respectively) and stable interactions within the enzyme’s kinase domain. These findings highlight simeprevir and ceritinib as strong candidates for PI3Kα inhibition, warranting further experimental investigation for their potential use in treating post-CoViD-19 fibrotic conditions.

We investigated statin-based peptidomimetic compounds as inhibitors of SARS-CoV-2 papain-like protease (PLpro) by in silico methods, including molecular docking/dynamic simulations and ADMET prediction, as well as enzymatic in vitro assays. Five compounds (LQMed 426, 428, 430, 431, and 432) were identified as having promising interactions with the active site and an allosteric site of PLpro. The docking poses in the active site revealed that the compounds interacted with the catalytic triad (Cys111, His272, and Asp286). Compound 426 stood out for forming significant hydrophobic interactions and hydrogen bonds. In molecular dynamic (MD) simulations, there was a tendency for the compounds to migrate to a pocket in the ubiquitin-like (Ubl) domain region, indicating possible allosteric inhibition. Principal component analysis (PCA) and free energy landscape (FEL) plot showed significant differences in the conformational stability of protein-ligand complexes. Complex 432 had the highest stability (PC1: 24.9%, PC2: 10.5%) with restricted movements, while complex 430 had the lowest stability and the highest PC1, indicating broader movements. Complexes 426 and 428 had intermediate stability. FEL analysis confirmed that complex 432 had multiple minimum energy clusters, suggesting a greater likelihood of stable enzyme-ligand complex. In vitro assays demonstrated that all compounds inhibited PLpro activity by at least 50%, with IC₅₀ values ranging from 0.85 µM to 4.06 µM. Compounds 426 and 432 were the most promising, with IC₅₀ of 0.85 µM and 1.46 µM, respectively, values comparable to the GRL-0617 reference inhibitor. Binding free energy analysis indicated that compounds 430 and 431 showed significant affinity for the allosteric site (-27 kcal/mol and − 14 kcal/mol, respectively), while compound 428 showed reduced stability. In addition, in silico pharmacokinetics and toxicity (ADMET) prediction revealed that statine-based compounds are promising compared to GRL-0617 due to the low potential of inhibition of CYP’s family and toxicity risk. Overall, the tested compounds, especially 426 and 432, showed potential as inhibitors of SARS-CoV-2 PLpro and may act by non-competitive or mixed mechanisms, making them promising candidates for developing antivirals against CoViD-19.

Based on the in vitro trypanocidal efficacy of previously synthesized N-aryl-1,10-phenanthroline-2-amines (Phen1-20) (aryl = R-phenyl, 1- or 2-naphthyl), we explored the potential interactions of these derivatives as ligands of our comparative model of T. cruzi GP63 (TcGP63). This surface metalloprotease plays a crucial role in parasite adhesion to host cells and aids in cell invasion during T. cruzi infection in Chagas disease. Ligand-protein consensus docking simulations using four GOLD scoring functions revealed that N-(R-phenyl) derivatives (R = CH₃, OCH₃, CF₃, CN, NO₂, F, Cl, and Br) presented poses with higher fitness scores than the N-naphthyl ones, with the six para-substituted derivatives (Phen4, p-CH₃; Phen7, p-OCH₃; Phen10, p-CN; Phen14, p-F; Phen17, p-Cl; and Phen18, p-Br) being more favorable than the ortho or meta ones. Subsequent aqueous molecular dynamics simulation (GROMACS package, CHARMM36 force field, and TIP3P water model) of the ligand-protein complexes for these six top-ranking compounds showed persistent interactions within the TcGP63 active site, primarily through coordination with Zn(II)-cofactor, and H-bonding with catalytic Glu221 and zinc-binding His224. RMSD and RMSF analyses confirmed the stability of these interactions, particularly for compounds with electron-withdrawing groups by inductive effect as R-substituents, such as p-OCH₃ (Phen7) and p-CN (Phen10). Binding free energy calculations by the linear interaction energy (LIE) approach corroborated the favorable interactions observed in simulations, highlighting Phen7 and Phen10 as the most promising candidates. This study underscores the potential of N-phenyl-1,10-phenanthroline-2-amines as putative inhibitors targeting the T. cruzi GP63 enzyme.

Introdução: A doença de Chagas (DC), causada pelo Trypanosoma cruzi, representa grandes desafios para a comunidade médica e científica, principalmente devido à limitada eficácia das intervenções terapêuticas existentes. Novas drogas para tratar DC são necessárias. Objetivo: Investigar o derivado benzoiltiouréia 1p (BTU-1p) quanto à sua capacidade tripanocida e quanto à ativação de macrófagos para atividades anti-T. cruzi in vitro. Avaliar em camundongos a toxicidade do BTU-1p, e os efeitos no parasitismo cardíaco em animais infectados. Métodos: In vitro foram utilizados macrófagos derivados da medula óssea de camundongos Balb/c (BMDM) e tripomastigotas de cultura de T. cruzi cepa Y, sendo os tratamentos com BTU-1p (15, 30 e 60 μM) realizados sempre após a infecção e por 48h. Avaliou-se a viabilidade dos BMDM após tratamento com BTU-1p por MTT e o efeito tripanocida do BTU-1p sobre tripomastigotas por resazurina. Em BMDM infectados e tratados com BTU-1p avaliou-se o número de amastigotas intracelulares pela coloração com Giemsa, a cinética de liberação de tripomastigotas em BMDM infectados e tratados até o 8º dia pós-infecção e quantificação de nitrito. In vivo, Balb/c machos foram tratados (v.o.) com BTU-1p (12.5, 25 e 50 mg/kg) durante 30 dias (controles receberam água; DMSO 2% - veículo). Avaliou-se enzimas hepáticas e renais, assim como massa corporal, do fígado e rins. Em camundongos infectados com 500 formas tripomastigotas sanguíneas de T. cruzi (i.p) e tratados (v.o.) com BTU-1p (12.5 mg/kg) e Benzonidazol (BZ - 25 mg/kg) por 15 dias o parasitismo

Tuberculosis (TB) remains a primary global health concern, necessitating the discovery and development of new anti-TB drugs, mainly to combat drug-resistant strains. In this context, thiourea derivatives have emerged as promising candidates in TB drug discovery due to their diverse chemical structures and pharmacological properties. This review aimed to explore this potential, identifying and exploring molecular targets for thiourea derivatives in Mycobacterium tuberculosis (Mtb) and the potential application of virtual screening techniques in drug discovery. We have compiled a comprehensive list of possible molecular targets of thiourea derivatives in Mtb. The enzymes are primarily involved in the biosynthesis of various cell wall components, including mycolic acids, peptidoglycans, and arabinans, or targets in the branched-chain amino acid biosynthesis (BCAA) pathway and detoxification mechanisms. We discuss the potential of these targets as critical constituents for the design of novel anti-TB drugs. Besides, we highlight the opportunities that virtual screening methodologies present in identifying potential thiourea derivatives that can interact with these molecular targets. The presented findings contribute to the ongoing efforts in TB drug discovery and lay the foundation for further research in designing and developing more effective treatments against this devastating disease.

Leishmaniasis is a disease caused by a protozoan of the genus Leishmania, affecting millions of people, mainly in tropical countries, due to poor social conditions and low economic development. First-line chemotherapeutic agents involve highly toxic pentavalent antimonials, while treatment failure is mainly due to the emergence of drug-resistant strains. Leishmania arginase (ARG) enzyme is vital in pathogenicity and contributes to a higher infection rate, thus representing a potential drug target. This study helps in designing ARG inhibitors for the treatment of leishmaniasis. Py-CoMFA (3D-QSAR) models were constructed using 34 inhibitors from different chemical classes against ARG from L. (L.) amazonensis (LaARG). The 3D-QSAR predictions showed an excellent correlation between experimental and calculated pIC₅₀ values. The molecular docking study identified the favorable hydrophobicity contribution of phenyl and cyclohexyl groups as substituents in the enzyme allosteric site. Molecular dynamics simulations of selected protein–ligand complexes were conducted to understand derivatives’ interaction modes and affinity in both active and allosteric sites. Two cinnamide compounds, 7g and 7k, were identified, with similar structures to the reference 4h allosteric site inhibitor. These compounds can guide the development of more effective arginase inhibitors as potential antileishmanial drugs.

Scientists and researchers have been searching for drugs targeting the main protease (Mpro) of SARS-CoV-2, which is crucial for virus replication. This study employed a virtual screening based on molecular docking to identify benzoylguanidines from an in-house chemical library that can inhibit Mpro on the active site and three allosteric sites. Molecular docking was performed on the LaSMMed Chemical Library using 88 benzoylguanidine compounds. Based on their RMSD values and conserved pose, three potential inhibitors (BZG1, BZG2, and BZG3) were selected. These results indicate that BZG1 and BZG3 may bind to the active site, while BZG2 may bind to allosteric sites. Molecular dynamics data suggest that BZG2 selectively targets allosteric site 3. In vitro tests were performed to measure the proteolytic activity of rMpro. The tests showed that BZG2 has uncompetitive inhibitory activity, with an IC₅₀ value of 77 µM. These findings suggest that benzoylguanidines possess potential as Mpro inhibitors and pave the way towards combating SARS-Cov-2 effectively.