The current study focused on the synthesis of doped silver nanoparticles (doped AgNPs) with yttrium (Y), gadolinium (Gd), and chromium (Cr) from pine needle leaf extract (PNLE). X-ray diffraction (XRD) was performed to assess the phase formation, detecting 61.83% from Ag and 38.17% for secondary phases of AgCl, AgO, Y, Cr-, and Gd phases. The size and shape of the NPs were determined by transmission electron microscopy (TEM), showing a spherical shape with an average particle size of 26.43 nm. X-ray photoelectron spectroscopy (XPS) detected the oxidation state of the presented elements. The scanning electron microscope (SEM) and the energy-dispersive X-ray analysis (EDX) determined the morphology and elemental composition of the NPs, respectively. Fourier transform infrared spectroscopy (FTIR) determined the different functional groups indicating the presence of Ag, Y, Gd, Cr, and other groups. Photoluminescence (PL) spectroscopy showed the optical properties of the NPs. A vibrating sample magnetometer (VSM) revealed the ferromagnetic behavior of the doped AgNPs. The antibacterial activity of the doped AgNPs was tested against six uro-pathogenic bacteria (Staphylococcus aureus, Staphylococcus haemolyticus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa) using the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) microdilution assays, agar well diffusion assay, time–kill test, and antibiofilm screening assays, revealing significant activity, with MICs ranging between 0.0625 and 0.5 mg/mL and antibiofilm activity between 40 and 85%. The antioxidant activity was determined by the 1,1, diphenyl 1-2 picrylhydrazyl (DPPH) radical scavenging assay with a potential of 61.3%. The docking studies showed that the doped AgNPs had the potential to predict the inhibition of crucial enzymes such as penicillin-binding proteins, LasR-binding proteins, carbapenemase, DNA gyrase, and dihydropteroate synthase. The results suggest that the doped AgNPs can be applied in different medical domains.

Green nanoparticles are synthesized using environmentally friendly methods, and natural materials hold significant importance. This makes the process environmentally sustainable and reduces the production of harmful waste by-products. Green nanoparticles exhibit reduced toxicity which is crucial for biomedical applications. The current study suggested that yttrium nanoparticles (YNPs) should be synthesized, characterized, and evaluated for their diverse biological applications due to the rise in antibacterial resistance. The YNPs were prepared using a pine needle leaf extract (PNLE). The structural and morphological features have been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–vis), and vibrating sample magnetometry (VSM). The XRD pattern demonstrated the presence of yttrium oxide and yttrium nitrate phases. The crystallite size and particle size of the synthesized YNPs measured 1.696 nm and 24.55 nm, respectively. The XPS peaks showed two components with binding energies at 530.940 eV and 532.18 eV due to the bond between O–Y and OH–Y, respectively. Additionally, the ferromagnetic nature of the YNPs was confirmed by VSM analysis. The YNPs were tested for antibacterial activity on six uropathogenic bacteria (S. aureus, S. haemolyticus, E. faecalis, E. coli, K. pneumonia, and P. aeruginosa) using the microdilution assays, to find the minimum inhibitory concentration (MIC) as well as the minimum bactericidal concentration (MBC), the agar well diffusion assay, and antibiofilm screening assays, where they showed bacteriostatic action against all isolates (0.5–1 mg/mL MIC) and significant inhibition of biofilm formation (80% inhibition rate). The antioxidant capacity assessed by 1,1, diphenyl-2-picrylhydrazyl (DPPH) radical scavenging revealed 50% DPPH scavenging. Moreover, docking studies exhibited that YNPs inhibit crucial bacterial enzymes, including DNA gyrase, penicillin-binding proteins, carbapenemase, LasR-binding protein, and dihydropteroate synthase. These findings may explain the mechanisms responsible for the observed antibacterial effects of YNPs. Overall, these findings underscore YNPs as promising candidates for antioxidant and antibacterial applications.

This study focused on testing the antibacterial and antifungal activity of Origanum syriacum (O. syriacum) and Cimbopogon winterianus (C. winterianus) extracts and their essential oils (EOs). The bacteria were isolated from urine samples and identified by a VITEK assay, and the fungi were isolated from spoiled food samples and further identified by MALDI-TOF. The susceptibility of the microbial isolates was assessed by determining the bacteriostatic and bactericidal/fungicidal effects by the minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) broth microdilution assay and time-kill test. The antibiofilm activities were assessed by the antibiofilm screening assays. The bacterial isolates included three Gram-negative isolates (Escherichia coli, Klebsiella pneumonia, and Citrobacter freundii) and two Gram-positive isolates (Staphylococcus aureus and Streptococcus intermedius). The fungal isolates included Candida albicans and Aspergillus niger. The O. syriacum and C. winterianus extracts exhibited bacteriostatic and fungistatic activities (MIC 1.25–2.5 mg/mL for the bacterial isolates and 2.5–5 mg/mL for the fungal isolates). However, their EOs exhibited bactericidal (MBC 5–20%) and fungicidal (MFC 1.25–10%) activities, meaning that the EOs had a better antimicrobial potential than the extracts. The antibiofilm activities of the mentioned extracts and their EOs were relatively weak. The O. syriacum extract inhibited S. aureus, S. intermedius, and K. pneumonia biofilms at a concentration of 0.3125 mg/mL and C. albicans and A. niger biofilms at 0.625 mg/mL. No antibiofilm activity was recorded for C. winterianus extract. In addition, the packaging of grapes with C. winterianus extract preserved them for about 40 days. The results reflect the significant antimicrobial activity of O. syriacum and C. winterianus extracts and their EOs, thus suggesting their potential in food packaging and preservation.

Background/Objectives: Conventional cancer treatments such as radiation therapy, chemotherapy, and surgery often severely reduce a patient’s quality of life due to their side effects. This underscores the urgent need to develop less toxic and more effective alternative therapies. Medicinal plants and their derivatives represent a valuable source for discovering such agents. In this study, we investigated the anticancer and antibacterial properties of ethanolic (EE), methanolic (ME), and aqueous (AE) leaf extracts from the Lebanese Eucalyptus camaldulensis. Methods: The cytotoxicity of the extracts and cis-diamminedichloroplatinum(II) (CDDP) was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against four human cancer cell lines: two breast cancer lines (MCF-7 and MDA-MB-231), colorectal carcinoma cells (HCT-116), and lung carcinoma epithelial cells (A-549). Morphological changes in the cells were observed via inverted phase-contrast microscopy. The antibacterial potential was determined through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) broth microdilution assays, agar well diffusion, and time-kill tests. The antibiofilm activity of the extracts against Staphylococcus haemolyticus, Streptococcus intermedius, Escherichia coli, and Leclercia adecarboxylata was assessed using antibiofilm screening. Results: All three extracts demonstrated significant anticancer activity against the four cell lines, with particular potency against A-549 cells. The AE showed the greatest cytotoxic effect, with IC50 values ranging from 97.1 to 163.3 µg/mL after 24 h of treatment. Furthermore, all extracts induced notable morphological changes in the cancer cells. The MIC and MBC results indicated a bactericidal effect for the EE (MBC range: 1.5625–50%), ME (MBC range: 6.25–50%), and AE (MBC range: 3.125–100%). Agar well diffusion assays revealed inhibition zones of 8.1 to 20.1 mm, while time-kill tests showed bacterial inhibition within 1 to 24 h of incubation. The antibiofilm assays demonstrated that the extracts inhibited biofilm production and eradicated 50% of pre-formed biofilms. Conclusions: These findings suggest that Lebanese Eucalyptus camaldulensis leaf extracts are a promising source of bioactive compounds with both antibacterial and anticancer properties.

(1) Background: This study evaluated the efficacy of magnesium nanoparticles (MgNPs) synthesized through a green method utilizing bacterial metabolites (BMs) produced by Escherichia coli. (2) Methods: BMs were tested for total phenolic content by high-performance liquid chromatography. MgNPs were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, photoluminescence, and ultraviolet–visible spectroscopy. MgNPs and BMs were tested for antibacterial and antibiofilm potentials against multidrug-resistant clinical isolates by agar well diffusion, minimum inhibitory and bactericidal concentration assays, time–kill test, and inhibition of biofilm formation and destruction of pre-formed biofilm assays. Furthermore, they were tested for antioxidant potential by 2,2-diphenyl-1-picryhydrazyl radical scavenging assay. (3) Results: BMs included carbohydrates, reducing sugars, and phenols (gallic acid and catechin) with a total phenolic content of 0.024 mg GAE/g. MgNPs showed a pure crystalline structure with a spherical shape, 17.8 nm in size, and a 4.19 eV energy gap. Bacteria included Streptococcus pneumonia, Enterococcus faecium, Klebsiella pneumonia, and Salmonella Typhimurium. The antibacterial results showed inhibition zones ranging between 7.2 and 10.4 mm, a bactericidal effect of MgNPs, a bacteriostatic effect of BMs, and growth inhibition after 3 h. The antibiofilm results demonstrated significant inhibition of biofilm formation (inhibition percentages of 64.931% for MgNPs and 71.407% for BMs). However, the assays revealed modest biofilm destruction (eradication percentages of 48.667% for MgNPs and 37.730% for BMs). Antioxidant capacity revealed notable scavenging activity of MgNPs (scavenging activity of 41.482%) and weak activity of BMs (scavenging activity of 16.460%). (4) Conclusions: These findings support the application of MgNPs in biomedical fields.