Computational identification of Plasmodium falciparum RNA pseudouridylate synthase as a viable drug target, its physicochemical properties, 3D structure prediction and prediction of potential inhibitors

An integrated theoretical study on natural alkaloids as SARS-CoV-2 main protease inhibitors: a step toward discovery of potential drug candidates with anti-COVID-19 activity

Background: in the twenty-first century, the emergence of COVID-19 as a highly transmissible pandemic disease caused by SARS-CoV-2 posed a significant threat to humanity. Aims & Objectives: the disease spreads through small respiratory droplets, necessitating the use of various compounds for treatment, with alkaloids being recognized as particularly crucial owing to their diverse pharmaceutical properties. Methodology: in this study, a dataset comprising 100 natural alkaloids obtained from the literature was transformed into 2D chemical structures using Chem Draw 19.1. Subsequently, 3DQSAR studies were conducted on the dataset, resulting in the automatic screening of 50 compounds from the initial pool of 100 compounds. The values of q 2 and r 2 of the validated field-based 3DQSAR model were 0.7186 and 0.971, respectively. The validated atom-based 3DQSAR model has q 2 and r 2 scores of 0.6025 and 0.9845, respectively. Based on the obtained results, 10 compounds with exceptionally active predictive IC50 values were selected for further analysis. Docking experiments were then performed on the selected compounds, and the top three compounds with the highest docking scores were identified as diazepinomicin, (+)-N-methylisococlaurine, and hymenocardine-H. After docking, MM-GBSA was performed on the complexes of diazepinomicin, (+)-N-methylisococlaurine and hymenocardine-H with their corresponding proteins, which resulted in the authentication of the molecular docking scores. MD simulations were also performed to check the flexibility, stability and compactness of these complexes for revalidation of docking scores. Results: finally, ADMET experiments revealed that (+)-N-methylisococlaurine exhibited the most favourable properties among these three compounds.

Integrative Network Pharmacology, Molecular Docking, and Dynamics Simulations Reveal the Mechanisms of Cinnamomum tamala in Diabetic Nephropathy Treatment: An In Silico Study

Diabetic nephropathy (DN) is a serious diabetes-related complication leading to kidney damage. Cinnamomum tamala (CT), traditionally used in managing diabetes and kidney disorders, has shown potential in treating DN, although its active compounds and mechanisms are not fully understood. This study aims to identify CT's bioactive compounds and explore their therapeutic mechanisms in DN. Active compounds in CT were identified using the Indian Medicinal Plants, Phytochemicals and Therapeutics database, and their potential targets were predicted with PharmMapper. DN-related targets were sourced from GeneCards, and therapeutic targets were identified by intersecting the compound-target and disease-target data. Bioinformatics analyses, including the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment studies, were performed on these targets. A protein-protein interaction network was constructed using STRING and Cytoscape. Molecular docking and dynamics simulations validated the most promising compound-target interactions. Six active compounds in CT were identified, along with 347 potential therapeutic targets, of which 70 were DN-relevant. Key targets like MMP9, EGFR, and AKT1 were highlighted, and the PPAR and PI3K-AKT signaling pathways were identified as the primary mechanisms through which CT may treat DN. CT shows promise in treating DN by modulating key pathways related to cellular development, inflammation, and metabolism.

Emerging roles of the epitranscriptome in parasitic protozoan biology and pathogenesis

RNA modifications (epitranscriptome) - such as N6-methyladenosine (m6A), 5-methylcytosine (m5C), and pseudouridine (Ψ) - modulate RNA processing, stability, interaction, and translation, thereby playing critical roles in the development, replication, virulence, metabolism, and life cycle adaptations of parasitic protozoa. Here, we summarize potential homologs of the major human RNA modification regulatory factors in parasites, outline current knowledge on how RNA modifications affect parasitic protozoa, highlight the regulation of RNA modifications and their crosstalk, and discuss current progress in exploring RNA modifications as potential drug targets. This review contributes to our understanding of epitranscriptomic regulation of parasitic protozoa biology and pathogenesis and provides new perspectives for the treatment of parasitic diseases.

Multi-target mechanism of Solanum xanthocarpum for treatment of psoriasis based on network pharmacology and molecular docking

Solanum xanthocarpum (SX) has been used to treat a variety of diseases, including skin disorders like psoriasis (PSO). SX possesses many pharmacological activities of anti-inflammatory, anti-cancer, immunosuppressive, and healing qualities. However, the multi-target mechanism of SX on PSO still needs clarity. Materials and methods: The Indian Medicinal Plants, Phytochemicals and Therapeutics (IMPPAT) database and the Swiss Target Prediction online tool were used to find the active phytochemical components and their associated target proteins. OMIM and GeneCards databases were used to extract PSO-related targets. A Venn diagram analysis determined the common targets of SX against PSO. Subsequently, the protein-protein interaction (PPI) network and core PPI target analysis were carried out using the STRING network and Cytoscape software. Also, utilising the online Metascape and bioinformatics platform tool, a pathway enrichment analysis of common targets using the Kyoto Encyclopaedia of Genes and Genome (KEGG) and Gene Ontology (GO) databases was conducted to verify the role of targets in biological processes, cellular components and molecular functions with respect to KEGG pathways. Lastly, molecular docking simulations were performed to validate the strong affinity between components of SX and key target receptors. Results: According to the IMPPAT Database information, 8 active SX against PSO components were active. According to the PPI network and core targets study, the main targets against PSO were EGFR, SRC, STAT3, ERBB2, PTK2, SYK, EP300, CBL, TP53, and AR. Moreover, molecular docking simulations verified the binding interaction of phytochemical SX components with their PSO targets. Last but not least, enrichment analysis showed that SX is involved in several biological processes, including peptidyl-tyrosine phosphorylation, peptidyl-tyrosine modification, and peptidyl-serine modification. The relevant KEGG signalling pathways are the PI3K-AKT signalling pathway, the EGFR tyrosine kinase inhibitor resistance pathway, and the MAPK signalling pathway. Conclusion: The network pharmacology technique, which is based on data interpretation and molecular docking simulation techniques, has proven the multi-target function of SX phytoconstituents.

Structure-based pharmacophore modeling, virtual screening, and molecular dynamics simulation studies for identification of Plasmodium falciparum 5-aminolevulinate synthase inhibitors

Plasmodium falciparum (Pf) 5-aminolevulinic acid synthase (5-ALAS) is an essential enzyme with high selectivity during liver stage development, signifying its potential as a prophylactic antimalarial drug target. The aim of this study was to identify important potential lead compounds which can serve as inhibitors of Pf 5-ALAS using pharmacophore modeling, virtual screening, qualitative structural assessment, in silico ADMET (Absorption, Distribution, Metabolism, Excretion and Toxicity) evaluation and molecular dynamics simulation. The best model of the tertiary structure of Pf 5-ALAS was obtained using MolProbity, while the following databases were explored for the pharmacophore-based virtual screening: CHEMBL, ChemDiv, ChemSpace, MCULE, MCULE-ULTIMATE, MolPort, NCI Open Chemical Repository, LabNetwork and ZINC databases. 2,621 compounds were screened against the modeled Pf 5-ALAS using AutoDock vina. The post-screening analysis was carried out using Discovery Studio while molecular dynamics simulation was performed on the best hits using NAMD-VMD and Galaxy Europe platform. Compound CSMS00081585868 was observed as the best hit with a binding affinity of -9.9 kcal/mol and predicted Ki of 52.10 nM, engaging in seven hydrogen bonds with the target's active site amino acid residues. The in silico ADMET prediction showed that all ten best hits possessed relatively good pharmacokinetic properties. The qualitative structural assessment of the best hit, CSMS00081585868, revealed that the presence of two pyridine scaffolds bearing hydroxy and fluorine groups linked by a pyrrolidine scaffold contributed significantly to its ability to have a strong binding affinity with the receptor. The best hit also showed stability in the active site of Pf 5-ALAS as confirmed from the RMSD obtained during the MD simulation.

Epitranscriptomics in parasitic protists: Role of RNA chemical modifications in posttranscriptional gene regulation

"Epitranscriptomics" is the new RNA code that represents an ensemble of posttranscriptional RNA chemical modifications, which can precisely coordinate gene expression and biological processes. There are several RNA base modifications, such as N6-methyladenosine (m6A), 5-methylcytosine (m5C), and pseudouridine (Ψ), etc. that play pivotal roles in fine-tuning gene expression in almost all eukaryotes and emerging evidences suggest that parasitic protists are no exception. In this review, we primarily focus on m6A, which is the most abundant epitranscriptomic mark and regulates numerous cellular processes, ranging from nuclear export, mRNA splicing, polyadenylation, stability, and translation. We highlight the universal features of spatiotemporal m6A RNA modifications in eukaryotic phylogeny, their homologs, and unique processes in 3 unicellular parasites-Plasmodium sp., Toxoplasma sp., and Trypanosoma sp. and some technological advances in this rapidly developing research area that can significantly improve our understandings of gene expression regulation in parasites.