Middle East respiratory syndrome coronavirus (MERS-CoV) is a highly infectious zoonotic virus first reported into the human population in September 2012 on the Arabian Peninsula. The virus causes severe and often lethal respiratory illness in humans with an unusually high fatality rate. The N-terminal domain (NTD) of receptor-binding S1 subunit of coronavirus spike (S) proteins can recognize a variety of host protein and mediates entry into human host cells. Blocking the entry by targeting the S1-NTD of the virus can facilitate the development of effective antiviral drug candidates against the pathogen. Therefore, the study has been designed to identify effective antiviral drug candidates against the MERS-CoV by targeting S1-NTD. Initially, a structure-based pharmacophore model (SBPM) to the active site (AS) cavity of the S1-NTD has been generated, followed by pharmacophore-based virtual screening of 11,295 natural compounds. Hits generated through the pharmacophore-based virtual screening have re-ranked by molecular docking and further evaluated through the ADMET properties. The compounds with the best ADME and toxicity properties have been retrieved, and a quantum mechanical (QM) based density-functional theory (DFT) has been performed to optimize the geometry of the selected compounds. Three optimized natural compounds, namely Taiwanhomoflavone B (Amb23604132), 2,3-Dihydrohinokiflavone (Amb23604659), and Sophoricoside (Amb1153724), have exhibited substantial docking energy >−9.00 kcal/mol, where analysis of frontier molecular orbital (FMO) theory found the low chemical reactivity correspondence to the bioactivity of the compounds. Molecular dynamics (MD) simulation confirmed the stability of the selected natural compound to the binding site of the protein. Additionally, molecular mechanics generalized born surface area (MM/GBSA) predicted the good value of binding free energies (ΔG bind) of the compounds to the desired protein. Convincingly, all the results support the potentiality of the selected compounds as natural antiviral candidates against the MERS-CoV S1-NTD.

The local medicinal plant Rhazya stricta Decne is reviewed for its folkloric medicinal, phytochemical, pharmacological, biological, and toxicological features. R. stricta has been used widely in different cultures for various medical disorders. The phytochemical studies performed on the R. stricta extract revealed many alkaloidal and fatty acid compounds. Moreover, several flavonoid and terpenoid compounds were also detected. Pharmacological activates of R. stricta extracts are approved to possess antimicrobial, antioxidant, anticancer, antidiabetic, and antihypertensive activities. Additionally, R. stricta extract was found to hold biological activates such as larvicidal and phytoremediation activates R. stricta extract was found to be toxic, genotoxic, and mutagenic. R. stricta contains novel phytochemical compounds that have not been investigated pharmacologically. Further research is needed through in vitro and in vivo experiments to pave the road for these compounds for medical, veterinary, and ecological uses.

Influenza viruses have developed resistance to the current classes of drugs, which means they could eventually become more virulent and cause more mortality and hospitalization. Our study aims to investigate the antiviral activity of Rhazya stricta Decne leaves extract in vitro and search for new promising drugs from R. stricta identified compounds in silico. The study was performed in vitro by utilizing Madin-Darby Canine Kidney cell line (MDCK) as a substrate for the influenza virus and estimating the inhibition performance of the plant leaves extract. Additionally, in silico screening was conducted to explore the antiviral activity of R. stricta phytochemicals. We investigated the cytotoxicity of R. stricta leaves extract and its antiviral activity against influenza virus (A/Puerto Rico/8/34 (H1N1)) using the MTT assay. The mode of action of the plant leaves extract during the viral life cycle was tested using time-of-addition assay. In silico analyses were performed, including molecular docking, drug-likeness analysis, and toxicity risk assessment, to state the leading compounds to be developed into an anti-influenza virus drug. The 50% cytotoxicity concentration of the leaves extract was CC50: 184.6 µg/mL, and the 50% inhibition concentration was CI50: 19.71 µg\mL. The time of addition assay revealed that R. stricta leaves extract exerted its activity in the late step of the influenza virus replication cycle. In comparison to Oseltamivir, the leading compounds showed better binding affinity and can be developed into oral drugs with low toxicity risk. Isolation and purification of the leading compounds and testing their antiviral activity in vitro and in vivo are required.

Parkinson’s disease (PD) is one of the most rapidly growing neurological disorders globally. The molecular relationship between common respiratory infections (RIs) and idiopathic Parkinson’s disease (iPD) remains a controversial issue. Multiple studies have linked acute respiratory infections to PD, but the molecular mechanism behind this connection is not significantly defined. Therefore, the aim of our study was to investigate potential molecular interactions between RIs and PD. We retrieved eight publicly available RNA-seq datasets from the NCBI Gene Expression Omnibus (NCBI GEO) and performed extensive bioinformatics analysis, including differential gene expression (DGE) analysis, the identification of overlapped differentially expressed genes (DEGs), weighted gene co-expression network analysis (WGCNA), pathway and functional enrichment analysis, the construction of protein–protein networks, and the identification of hub genes. Additionally, we applied a machine learning method, a Random Forest model (RF), to external RIs datasets to identify the most important genes. We found that ribosomal subunits, mitochondrial complex proteins, proteasome subunits, and proteins encoding ubiquitin are simultaneously downregulated and co-expressed in RIs and PD. Dysregulation of these proteins may disturb multiple pathways, such as those responsible for ribosome biogenesis, protein synthesis, autophagy, and apoptosis; the ubiquitin–proteasome system (UPS); and the mitochondrial respiratory chain. These processes have been implicated in PD’s pathology, namely in the aggregation of α-synuclein, mitochondrial dysfunction, and the death of dopaminergic neuron cells. Our findings suggest that there are significant similarities in transcriptional responses and dysfunctional molecular mechanisms between RIs, PD, and aging. RIs may modulate PD-relevant pathways in an age- or immune-dependent manner; longitudinal studies are needed to examine the RIs risk factor. Therefore, future studies should experimentally investigate the influence of age, vaccination status, infection type, and severity to clarify the role of RIs in PD’s pathogenesis.

Influenza virus developed resistance to the currently class of drugs, which eventually becoming more virulent and cause more mortality and hospitalization. Our study aims to search new candidate drugs from the plant source. We investigated the cytotoxicity of R. stricta euouaes extract and its antiviral activity against influenza virus (A/Puerto Rico/8/34 (H1N1)) using MTT assay. The mode of action of the plant extract was tested using time of addition assay. in silico study was performed including molecular docking, ADME assay and toxicity risk assessment to investigate the best compound to be developed into anti-influenza virus drug. The cytotoxicity concentration 50% of the extract was (CC50: 184.6µg/ml) and the Inhibitory concentration was (CI50: 19.71 µg\ml and SI 9.37. The time of addition assay revealed that, R. stricta extract exerted its activity in the late step of the influenza virus replication cycle. The in silico study demonstrated that some compounds can be subjected to in vitro study. Therefore, isolation and purification of the candidate compounds and testing their antiviral activity are recommended.