Vincent O. Imieje

Plasmodium falciparum malaria, contributing 26.8% of global malaria deaths in 2022, drives Nigeria's health burden, with artemisinin resistance necessitating novel natural product-derived treatments. This study bridges Nigeria's ethnobotanical heritage with modern pharmacognosy to evaluate the extracts of Alchornea cordifolia (Ogwu obi) and Enantia chlorantha (Awopa). This study aims to assess the antiplasmodial potential of a combined A. cordifolia and E. chlorantha extract via molecular docking against P. falciparum Plasmepsin II and evaluate its acute toxicity in mice. Leaves of A. cordifolia and stem bark of E. chlorantha were extracted with methanol, freeze-dried, and concentrated using a rotary evaporator at 40℃, respectively. Molecular docking targeted Plasmepsin II (PDB ID: 1LEE) using PyRx 0.9.8, with dihydroartemisinin (standard antimalarial drug) and R36 (co-crystallized ligand) as comparators. Compounds with binding affinities ≤ -6.5 kcal/mol were prioritised. Acute toxicity was assessed in Swiss mice using Lorke's method (10–5000 mg/kg). Drug-likeness was evaluated via SwissADME 2025.2 and ProTox-3.0. Binding affinity trends were analysed descriptively. Docking revealed 10 A. cordifolia compounds (e.g., CID:236432, -9.1 kcal/mol) and 15 E. chlorantha compounds (e.g., CID:91710667, -8.6 kcal/mol) with binding affinities ≤ -6.5 kcal/mol, comparable to dihydroartemisinin (-7.1 kcal/mol) and R36 (-10.0 kcal/mol), indicating strong Plasmepsin II inhibition. No toxicity was observed at a dose of 5000 mg/kg. Most compounds showed favourable drug-likeness.

The outbreak of COVID-19, caused by SARS-CoV-2, has created an urgent need for new and more effective antiviral agents, particularly those derived from natural sources. Andrographis paniculata (Burm.f.) Nees (Acanthaceae), commonly known as the King of bitters, is a medicinal plant valued for its antiviral and immunomodulatory properties. This study aimed to investigate the therapeutic potential of phytochemicals from Andrographis paniculata as inhibitors of the SARS-CoV-2 virus (PDB ID:7BV2) using molecular docking and ADMET predictions. The 3D structure of the SARS-CoV-2 protein was obtained from the RCSB PDB. Amino acids at the binding site of the protein were identified using PLIP. The protein was prepared for docking in BIOVIA Discovery Studio. Phytochemicals isolated from the plant and identified using GC-MS were downloaded from PubChem as SDF files and imported into PyRx for molecular docking. Post-docking interaction was analysed in BIOVIA Discovery Studio. The ADMET predictions of the phytochemicals were done using the Swiss ADME web server and ProTox-3.0. Molecular docking results from 90 isolated compounds and 23 compounds from GC-MS analysis revealed 27 isolated compounds with a binding affinity range of -6.9 to -8.5 kcal/mol against the target protein, as compared to the standard drug (Remdesivir Triphosphate) and co-crystallized ligand (F86) with binding affinities of -7.7 and -6.8 kcal/mol, respectively. These 27 compounds were selected for post-docking analysis and ADMET profiling. Andrographis paniculata (Burm.f.) Nees (Acanthaceae) possesses phytoconstituents with potential inhibitory activity against the SARS-CoV-2 protein. Methyl 3,4-dicaffeoylquinate, identified as the top compound, along with 5-Hydroxy-7,2',6'-trimethoxyflavone, 5,7,2',6'- Tetrahydroxyflavone, and Apigenin showed good absorption, distribution, metabolism, elimination (ADME), and a comparatively safe toxicity profile. Therefore, further experimental validation is required to confirm their therapeutic potential as antiviral agents against SARS-CoV-2

COVID-19 is an infectious disease caused by the SARS-CoV-2 virus, which triggered a global pandemic in 2019. Phytochemicals such as diosmin and quercetin, which are present in and/or structurally similar to compounds found in Bryophyllum pinnatum, have demonstrated antiviral and anti-inflammatory effects against SARS-CoV-2 in preclinical and in silico studies and remain promising candidates for further drug development. This study aims to explore the anti-SARS-CoV-2 potential of compounds in Bryophyllum pinnatum using GC-MS and in silico methods. Ninety-nine phytochemicals from Bryophyllum pinnatum (38 isolated compounds from literature and 61 from GC-MS analysis of extracts) were evaluated. The 3D structure of the SARS-CoV-2 spike RBD/ACE2 B0AT1 protein complex (PDB ID: 6M17) was retrieved from the Protein Data Bank and prepared by removing water molecules and non-standard residues, adding hydrogen atoms using BIOVIA Discovery Studio. The compounds’ 3D structures were retrieved from the PubChem database. Each compound was docked against the spike RBD/ACE2 complex. Physicochemical, pharmacokinetic (ADME), and toxicological properties were assessed using the SwissADME and ProTox II webservers. Thirty-four phytochemicals, including two identified via GC-MS, exhibited binding affinities below –6.8 kcal/mol. Kaempferitrin showed the highest affinity (–10 kcal/mol), followed by diosmin (–9.5 kcal/mol). Post-docking and ADMET analyses indicated that some of these compounds possess favourable ADME profiles and acceptable toxicity. Bryophyllum pinnatum shows selective anti-SARS-CoV-2 potential. Taraxasterol and taraxerol displayed favorable binding and safety profiles, whereas kaempferitrin, diosmin, and bersaldegenin orthoacetate, despite stronger binding, may be limited by toxicity and warrant further optimization.

SARS-CoV-2, an RNA virus from the Coronaviridae family, remains a global threat due to its rapid variant evolution and immune evasion. Artemisia annua is used traditionally to treat malaria and has documented antiviral activity. This study assesses the inhibitory potential of A. annua extracts against the SARS-CoV-2 helicase 5RMM responsible for viral replication using computational and biochemical methods. Phytoconstituents present in this plant were obtained from literature sources as well as GC-MS analysis. Their 3D structures were obtained from PubChem; the protein helicase (5RMM) was retrieved from the Protein Data Bank (PDB) and processed using Biovia Discovery Studio 2025. Molecular docking was performed using PyRx. Post-docking analysis was done using Biovia Discovery Studio 2025, and ADMET profiling was conducted using the Swiss ADME web server and Pro-Tox 3.0 virtual lab. Eighteen (18) phytoconstituents from the isolated compounds showed low ΔG energy ˂-7 kcal/mol. Others have ΔG energy <-6.5 kcal/mol. Post-docking analysis and ADMET profiling of the ligands showed that Quercimeritrin and Rhamnetin were identified as putative drug molecules based on their high binding affinity and hydrogen-bond interactions with the target protein's active-site amino acid residues. deoxyartemisinin from the n-Hexane extract and 3H- Cyclodeca[b]furan-2-one,4,9-dihydroxy-6-methyl-3,10-dimethylene-3a,4,7,8,9,10,11,11a- octahydro- from the dichloromethane extract were also highlighted for their high binding affinity scores. Isolated compounds, especially flavonols from Artemisia annua, demonstrate notable in- silico antiviral activity against SARS-CoV-2. Findings suggest the therapeutic potential of these compounds. Further investigation is required to confirm the compounds’ efficacy, elucidate their molecular mechanisms of action, and assess their safety across diverse biological systems