Biological synthesis of silver nanoparticles (AgNPs) is a green, simple, cost-effective, time-efficient, and single-step method. This study mainly focused on the synthesis of silver nanoparticles (AgNPs) using essential oil of Laggera tomentosa (LTEO) and investigates their potential applications. Ultraviolet-Visible (UV-Vis) result showed the characteristic Surface Plasmon Resonance (SPR) peak of LTEO-AgNPs at 420 nm. Fourier transform infrared (FT-IR) spectroscopy indicated the functional groups present in LTEO and LTEO-AgNPs. Scanning electron microscope (SEM) image depicted the synthesized AgNPs mainly has spherical shapes with average nanoparticles size 89.59 ± 5.14 nm. Energy dispersive X-ray (EDX) peak at 3.0 keV showed the presence of Ag element in LTEO-AgNPs. The X-ray diffraction (XRD) peaks at 38°, 44° and 67° are assigned to (111), (200), and (220), respectively which displays the crystal nature of LTEO-AgNPs. The average particle size and zeta potential of LTEO-AgNPs were determined as 94.98 nm and −49.6 mV, respectively. LTEO-AgNPs were stable for six months against aggregation at room temperature. LTEO-AgNPs solutions exhibited potential activities for the treatment of some pathogenic bacteria species, agricultural productivity growth, determination of metallic ions, and catalytic reduction. This study is the first work to report nanoparticles synthesis using L. tomentosa extracts and evaluate their potential applications.

In East Africa, Dodonaea angustifolia (L.f.) is a well-known medicinal herb. Its leaf is primarily studied in light of its ethnobotanical use. In terms of phytochemistry and biological activity, its flower is not studied. In a prior study, our team looked into phytochemical screening, antioxidant activity, and total phenolic levels. This study aims to compare the profiles and biological activities of the leaf and flower samples of D. angustifolia and to present therapeutic alternatives. The leaf and flower sample powders were extracted with methanol using ultrasound-assisted extraction (UAE). HPTLC profile was obtained using CAMAG—HPTLC equipped with VisionCATS software. Antimicrobial agar well diffusion assay and minimum inhibition concentration (MIC) were determined. The leaf and flower extracts of D. angustifolia showed antibacterial activity with a MIC value of 20 µg/mL against Enterococcus faecalis and Listeria monocytogenes. Similarly, 40 µg/mL was found to be effective against Aspergillus flavus. D. angustifolia flower is a rich source of flavonoids and phenolic acids. Because of its antibacterial properties and profile, which are almost the same, the flower is emerging as a viable option for medicinal alternatives.

It can be argued that in silico studies do not receive enough attention despite being a key part of addressing the limitations of our laboratory facilities, the high cost of chemicals, and the equipment required for wet laboratory activities. Natural product studies are demanding higher costs of chemicals, reagents, and varied laboratory facilities. This becomes a serious limitation in getting data from natural product studies. In silico studies use chemical structures as inputs as well as software and online web servers to generate data to support, predict, and validate wet laboratory activities. Interaction studies use computational tools to calculate binding energies and other associated properties. Predictions are based on the structure-activity relationships derived from previously conducted preclinical and clinical studies. As a main component of in silico studies, the physicochemical and pharmacokinetic properties of small molecules can be determined using online web servers such as SwissADME and absorption, distribution, metabolism, excretion, and toxicity web servers. An interaction study uses molecular docking software such as AutoDock, AutoDock Vina, GOLD, and online servers such as SwissDock. Furthermore, the stabilities of complexes considered in interaction studies can be confirmed using molecular dynamics simulation software such as VMD. Prediction of activity spectra for substances (PASS) is widely used to predict biological activities for molecules based on multilevel neighborhoods of atom descriptors. In silico studies have played an important role in medicinal chemistry, pharmacology, and related research for screening, interaction studies, prediction, and other related purposes. Results of in silico predictions will not be far from wet lab activities as in most cases these studies consider previously attempted clinical and preclinical biological activities. Some examples are presented here to encourage the use of in silico studies. Received: 15 July 2024 | Revised: 27 August 2024 | Accepted: 25 October 2024 Conflicts of Interest The authors declare that they have no conflicts of interest to this work. Data Availability Statement The data that support this work are available upon reasonable request to the corresponding author. Author Contribution Statement Fekade Beshah Tessema: Conceptualization, Methodology, Writing - original draft, Visualization. Tilahun Belayneh Asfaw: Validation, Writing - review & editing. Mesfin Getachew Tadesse: Resources, Visualization, Supervision. Yilma Hunde Gonfa: Validation, Writing - review & editing. Rakesh Kumar Bachheti: Resources, Visualization, Supervision.

In this study, essential oil of the aerial part of Pluchea ovalis (POEO) was isolated and employed for the synthesis of AgNPs (POEO-AgNPs). Then, larvicidal activities of POEO and PEO-AgNPs were evaluated against the larvae of fall armyworm (FAW), Spodoptera frugiderda (J. E. Smith); (Lepidoptera: Noctuidae). The potential medicinal values of P. ovalis and the lack of scientific reports on the applications of essential oils and nanoparticles of the plant species from the ecology of Ethiopia motivated the authors to carry out this research activity. The hydrodistillation technique was used for the isolation of POEO. Characterization of samples was done using gas chromatography/mass spectrometry (GC/MS), ultraviolet–visible spectroscopy (UV–Vis), scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and zeta nanoanalyzer instruments. GC/MS analysis showed that sesquiterpenes (91.27%) are the dominant chemical constituents of POEO. The characteristic UV–Vis spectra absorption of POEO-AgNPs is observed at 428 nm. SEM imaging reveals that POEO-AgNPs have a dominantly spherical shape. A strong peak of EDX at 3.0 keV shows the existence of Ag element in POEO-AgNPs. XRD analysis determines the diffraction peaks of POEO-AgNPs at 2θ of 38.2°, 44.1°, 64.6°, and 77.8° which are indexed to (111), (200), (220), and (311), respectively. The average particle size and surface potential of POEO-AgNPs are 132 nm and −64.7 mV, respectively. POEO-AgNPs were stored at room temperature and 4 °C and showed good stability for about 6 months without aggregation or dissolution. The larvicidal activity was tested at 500, 250, and 125 µg/mL of POEO solution and 100% (full strength = 0.083 g/mL), 50%, and 25% POEO-AgNPs solution against 2^nd instar larvae of S. frugiderda for 3 consecutive days. LC₅₀ and LC₉₀ are determined as 154.88 and 11,749.00 µg/mL for POEO and 69.18 and 1318.26% for POEO-AgNPs solutions, respectively. This finding will benefit the applications of POEO and POEO-AgNPs for a sustainable eco-friendly crop pest management method.

Shigellosis is one of the major causes of death in children worldwide. Flavonoids and phenolic acids are expected to demonstrate anti-shigellosis activity and anti-diarrheal properties. The aerial part of A. integrifolia is commonly used against diarrhea. This study aimed to identify flavonoids and phenolic acids responsible for this therapeutic purpose. Antioxidant activity, total phenol content, and total flavonoid content were determined. The antibacterial activity of the aerial part against Shigella spp. was also tested using the agar well diffusion method. HPLC analysis was performed using UHPLC-DAD for different extracts of the aerial part. Autodock Vina in the PyRx platform was used to screen responsible components. Ciprofloxacin was used as a reference drug. An enzyme taking part in pyrimidine biosynthesis was used as a target protein. Molecular docking results were visualized using Discovery Studio and LigPlot1.4.5 software. Antioxidant activity, total phenol content, and total flavonoid content are more significant for the aerial part of A. integrifolia. From HPLC analysis, the presence of the flavonoids, quercetin, myricetin, and rutin and the phenolic acids gallic acid, chlorogenic acid, and syringic acid were identified from the aerial part of A. integrifolia. Regarding the antibacterial activity, the aerial part shows considerable activity against Shigella spp. Binding energies, RMSD and Ki values, interaction type, and distance are considered to identify the components most likely responsible for the therapeutic effects and observed activity. Antioxidant activity, total phenol content, and total flavonoid content of the aerial part are in line with anti-shigellosis activity. The top five components that are most likely potentially responsible for therapeutic purposes and anti-shigellosis activity are chlorogenic acid, rutin, dihydroquercetin, dihydromyricetin, and kaempferol.

Background. Dodonaea angustifolia is a known medicinal plant across East Arica. The flower of D. angustifolia is not well investigated in terms of phytochemistry and biological activities. This study aims to investigate the presence of flavonoids and phenolic acids in the flower of D. angustifolia and its antioxidant activity. Methods. Preliminary phytochemical screening was carried out using the standard protocols. Antioxidant activity evaluation using DPPH assay and total phenol content (TPC) and total flavonoid content (TFC) determinations in the flower extract were compared with the values of the leaf extract. UHPLC-DAD analysis was managed to develop the profile of the flower extract. Prediction of biological activity spectra for substances (PASS) was done using an online server for antioxidant and related activities. Results. Preliminary phytochemical screening and TPC and TFC values confirmed the presence of flavonoids and phenolic acids. From the HPLC analysis of flavonoids, quercetin, myricetin, rutin, and phenolic acids such as chlorogenic acid, gallic acid, and syringic acid were detected and quantified. The biological activity spectrum was predicted for the detected and quantified polyphenols. Conclusions. D. angustifolia flower is a rich source of flavonoids and phenolic acids, which are extractable and can be checked for further biological activity. It was possible to identify and quantify phenolic compounds through HPLC analysis in the methanol extract of D. angustifolia flower. The PASS biological activity prediction results showed that there were stronger antioxidant activities for the identified flavonoids. Future work will emphasize the isolation and characterization of active principles responsible for bioactivity.