(1) Background: Malaria fever affects millions of people yearly in Africa and Asia’s tropical and subtropical areas. Because there is no effective vaccine, malaria prevention is solely dependent on avoiding human-vector interaction. (2) Aim: This study examines the interaction between the constituents of Vitex negundo essential oil and Anopheles gambiae Odorant Binding Proteins (OBP) as well as the compositional variation, repellent efficacy, and toxicity profile. (3) Methods: The oils were subjected to GC-MS and mosquito behavioral analysis. OBP–ligand interactions, Anopheles species authentication, and the toxicity profile were determined by molecular docking, PCR assay and in silico ADME/tox tool. Docking protocol validation was achieved by redocking the co-crystallized ligands into the protein binding pocket and root mean square deviation (RMSD) calculation. (4) Results: The oil yields and compositions are climate–soil dependent with ≈71.39% monoterpenes and ≈16.32% sesquiterpene. Optimal repellency is achieved at 15 min at ED₅₀ 0.08–0.48% v/v while the RMSD was estimated to be within 0.24–1.35 Å. Strong affinities were demonstrated by α-pinene (−6.4 kcal/mol), citronellal (−5.5 kcal/mol), linalool (−5.4 kcal/mol), and myrcene (−5.8 kcal/mol) for OBP1, OBP7, OBP4, and OBP; respectively. The hydrophobic interactions involve Leu17 (α-helix 1), Cys35 (α-helix 2), ALA52 (α-helix 3), Leu73, Leu76 (α-helix 4), Ala88, Met91, Lys93, Trp114 (α-helix 5), Phe123 (α-helix 6), and Leu124 (α-helix 7) receptors within the binding cavities, and may cause blocking of the olfactory receptors resulting in disorientation. (5) Conclusion: The ligand efficiency metrics, ADME/tox and repellency screening are within the threshold values; hence, α-pinene, linalool, and myrcene are safe and fit-to-use in the development of a green and novel repellent.

(1) Background: Essential oil from Vitex negundo is known to have repellent and insecticidal properties toward the Anopheles gambiae and this is linked to its monoterpene and sesquiterpene content. In this work, an effort is made to delineate the constitution of V. negundo essential oil (VNEO) and their interaction with odorant-binding proteins (OBPs) of A. gambiae and hence access its repellent efficiency as cost-effective and safer malaria vector control alternatives. (2) Methods: Anopheles species authentication was performed by genomic DNA analysis and was subjected to behavioral analysis. GC-MS profiling was used to identify individual components of VNEO. Anopheles OBPs were obtained from the RCSB protein data bank and used for docking studies. Determination of ligand efficiency metrics and QSAR studies were performed using Hyper Chem Professional 8.0.3, and molecular dynamics simulations were performed using the Desmond module. (3) Results: GC-MS analysis of VNEO showed 28 compounds (monoterpenes, 80.16%; sesquiterpenes, 7.63%; and unknown constituents, 10.88%). The ligand efficiency metrics of all four ligands against the OBP 7 were within acceptable ranges. β-selinene (−12.2 kcal/mol), β-caryophellene (−9.5 kcal/mol), sulcatone (−10.9 kcal/mol), and α-ylangene (−9.3 kcal/mol) showed the strongest binding affinities for the target proteins. The most stable hydrophobic interactions were observed between β-selinene (Phe111 and Phe120), Sulcatone (Phe54 and Phe120), and α-ylangene (Phe111), while only sulcatone (Tyr49) presented H-bond interactions in the simulated environment. (4) Conclusions: Sulcatone and β-caryophyllene presented the best log p values, 6.45 and 5.20, respectively. These lead phytocompounds can be used in their purest as repellent supplement or as a natural anti-mosquito agent in product formulations.

Factors such as Mutation, Gene transfer, Inappropriate use and Diagnostics, and prescription of antibiotics to persistent patient which are yet undiagnosed has significantly led to the emergence of drug resistance in bacteria, which is now hampering our ability in treat infections, and with the decline in development of new antibiotics, scientist and research keep trying to develop/proposed some synergistic combinations of antibiotic with medicinal plant extracts in an effort to boost their antimicrobial activities against drug resistant bacteria. This work aim to develop a cocktail regimen which will be highly susceptible to confirmed drug resistant clinical isolate of Salmonella spp using Tetracycline, Co-trimoxazole, Aspirin, Psidium guajava and Syzygium aromaticum extract alongside minimizing toxicity potential. Twenty four (24) different combinations were made from 10 g/mL of Co-trimoxazole, Tetracycline and Aspirin each with each clove extract and separately again with guava extract, Eighteen (18) out of the 24 were combined in three different stages (6 each) using concentrated Tetraoxosulphate(vi)acid (H2SO4) and 0.1Molar sodium hydroxide (NaOH), 31 antimicrobial disks were prepared and tested on Salmonella spp. The antimicrobial susceptibility test reveals that Scl, a stage 1 combination of Co-trimoxaazole with clove extract, Ac2, a stage 2 combination of Aspirin and clove extract, Ag2, a stage 2 combination of Aspirin and guava leave extract were all susceptible to the confirmed resistant isolate of Salmonella spp. Ag2 had the best zone of inhibition better than Ciprofloxacin inhibition zone at 20 g/mL. Aspirin was the best precursor drug which favourably combines with both clove and guava extract to give a desired cocktail regimen with potential antimicrobial characteristics, hence, the need to identify the compounds obtained in this combinations, isolates, and purify their active principles, and subjected to other pharmacological test to ascertain if they can be used to combat multi-drug resistant bacteria and other pathogenic organisms.

The green synthesis of nanoparticles utilizing an aqueous plant extract as a capping and stabilizing agent has attracted significant attention across diverse fields, particularly in pharmaceuticals and drug delivery. In this investigation, Copper Sulfate Pentahydrate (CuSO4.5H2O) salt served as a precursor for synthesizing copper nanoparticles at pH 4-5 and pH 8, employing Psidium guajava (leaves and fruits) extract for characterization. Fourier Transform Infrared (FTIR) spectroscopy revealed four major functional groups at distinct peaks (3235.3 cm-1, 2109.7 cm-1, 1640.0 cm-1, and 1069.7 cm-1) responsible for capping and stabilizing the synthesized P.g-CuNPs. Scanning Electron Microscopy (SEM) displayed spherical shapes for the synthesized P.g-CuNPs, with an average particle size range of 20-30 nm. Energy-dispersive X-ray (EDX) analysis of the synthesized P.g-CuNPs indicated the presence of pure copper (Cu) at 54.15%, occurring at regions of 1, 8, and 9 keV. P.g-CuNPs synthesized at pH 4-5 exhibited complete growth inhibition of all tested bacterial strains at concentrations of 0.1, 0.25, and 0.5 mg/mL. Serially diluted P.g-CuNPs (pH 5) demonstrated inhibition of Salmonella spp, E.coli, and Streptococcus spp at 100 µg/mL, while serially diluted P.g-CuNPs (pH 8) only showed inhibition of E.coli at 100 µg/mL. The acid-based synthesized P.g-CuNPs exhibited a higher degree of efficacy in the antimicrobial study compared to the alkaline-based synthesized P.g-CuNPs. Based on the study's findings, P.g-CuNPs derived from Psidium guajava can be employed for various biomedical purposes, such as incorporating them as a therapeutic drug for enhanced efficacy against microbial infectious diseases, integrating them into textile coatings for fiber, and employing nanocapsulation for food storage to extend the shelf life of food items.