Effect of green synthesized ZnO nanoparticles using Paspalum scrobiculatum grains extract in biological applications

Withania coagulans-mediated green synthesis of silver nanoparticles: characterization and assessment of their phytochemical, antioxidant, toxicity, and antimicrobial activities

BACKGROUND

In this study, we report the biofabrication of silver nanoparticles (Ag-NPs) using aqueous leaf extracts of Withania coagulans, which act as both reducing and capping agents. The goal was to synthesize and characterize the silver nanoparticles and evaluate their biological properties.

RESULTS

The silver nanoparticles were characterized by multiple techniques including UV-visible spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), zeta potential, dynamic light scattering (DLS), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). A surface plasmon resonance peak was observed at 420 nm, and the XRD pattern indicated highly crystalline Ag-NPs with a crystallite size of 39.76 nm. SEM and HRTEM revealed irregular morphology with an average particle diameter of 26.63 nm. Zeta potential of -21.4 mV indicated relatively stable nanoparticles. FTIR spectra displayed significant peaks at 3269, 2921, 1628, 1513, and 1385 cm⁻1. Thermal stability was confirmed via TGA and DSC. Bioassays including total phenolics, total flavonoids, ferric reducing antioxidant power, and DPPH assays showed higher antioxidant potential in Ag-NPs compared to extracts, though phenolic and flavonoid content was lower. Biocompatibility tests such as hemolysis (IC₅₀ = 141.466 μg/mL) and brine shrimp lethality assay (IC₅₀ = 721.76 μg/mL) indicated moderate cytotoxicity. Phytotoxicity assays revealed higher toxicity of Ag-NPs against radish compared to control. Significant antibacterial activity was observed against Klebsiella pneumoniae and Salmonella typhi (29 ± 0.01 mm and 28 ± 1.00 mm inhibition zones at 25 μg/mL, respectively).

CONCLUSIONS

The Withania coagulans leaf-extract-mediated silver nanoparticles exhibit remarkable antioxidant, phytochemical, and antimicrobial properties, suggesting potential for commercial applications in various biomedical and agricultural fields.

Biogenic synthesis of titanium nanoparticles by Streptomyces rubrolavendulae for sustainable management of Icerya aegyptiaca (Douglas)

Biosynthesized nanoparticles have a variety of applications, and microorganisms are considered one of the most ideal sources for the synthesis of green nanoparticles. Icerya aegyptiaca (Douglas) is a pest that has many generations per year and can affect 123 plant species from 49 families by absorbing sap from bark, forming honeydew, causing sooty mold, and attracting invasive ant species, leading to significant agricultural losses. The purpose of this work was to synthesize titanium dioxide nanoparticles (TiO2-NPs) from marine actinobacteria and evaluate their insecticidal effects on Icerya aegyptiaca (Hemiptera: Monophlebidae), in addition to explaining their effects on protein electrophoresis analysis of SDS‒PAGE proteins from control and treated insects after 24, 72 and 120 h of exposure. In all, seven actinobacterial isolates, the most potent of which has the potential to produce titanium hydroxide-based nanoparticles (TiO2-NP2), have DNA sequences that are 99.9% like those of Streptomyces rubrolavendulae (MCN2) according to nucleotide alignment and a phylogenetic tree. The produced TiO2-NPs were verified by UV examination and characterized by FT-IR, XRD, TEM, EDX, and DLS analyses. Toxicological results revealed that TiO2-NPs have insecticidal effects and high mortality rates reaching 55, 62.5, 80 and 95% at TiO2-NPs dose 120,250,500 and 1000 ppm respectively. Compared with the control, TiO2-NP spraying caused changes in the protein pattern of I. aegyptiaca, as indicated by the disappearance of normal bands and the appearance of other bands, as well as quantitative and qualitative changes in protein content after 24, 72 and 120 h of exposure. The application of TiO2-NPs by MNC2 offers a new alternative strategy to control I. aegyptiaca and is considered a modern approach to nanotechnology.

Green synthesis of selenium nanoparticles from Cassia javanica flowers extract and their medical and agricultural applications

Nanostructured materials are advantageous within numerous fields of medicine owing to their intriguing qualities, which include their size, reactive surface, bioactivity, potential for modification, and optical characteristics. Cassia javanica flower extract was used as a chelating agent in an environmentally friendly process to create SeNPs FTIR, XRD, and TEM, SAED were utilized to analyze and characterize the synthesized. The findings showed that the MIC of Se NPs against B. subtilis and S. aureus was 500 µg/ml. Conversely, the MIC for P. aeruginosa, E. coli, and C. albicans were 125, 250, and 62.5 µg/ml, respectively. Hence, SeNPs considerably reduced the activity; the inhibition peaked at 77.6% at 250 µg/ml to reach 49.04% at 7.8 µg/ml. Which showed the greatest suppression of MRSA biofilm formation without affecting bacterial growth. SeNPs showed an intriguing antioxidant capacity, achieving an IC50 of 53.34 µg/ml. This study looked how soaking seeds before sowing them with Se NPs at 50, 100, and 200 ppm affected the plants' development in different parameters, as well as their yield of Vicia faba L. The growth conditions were effectively increased by soaking application of various quantities of Se NPs. The highest values of dry weight/pod (g), number of seeds/plant, weight of 100 seeds (g), and number of pods/plant were caused by high concentrations of Se NPs, by 28.43, 89.60, 18.20, and 94.11%, respectively.

Anticancer, antimicrobial and antioxidant activity of CuO-ZnO bimetallic nanoparticles: green synthesised from Eryngium foetidum leaf extract

In the present study, green synthetic pathway was adapted to synthesize CuO-ZnO bimetallic nanoparticles (BNPs) using Eryngium foetidum leaf extract and their anti-cancer activity against MCF7 breast cancer cell lines, anti-microbial activity and in vitro anti-oxidant activity were evaluated. Various bio-active compounds present in leaf extract were responsible for the reduction of CuO-ZnO NPs from respective Cu2+ and Zn2+ metal precursors. In the present study, the involvement of bio-active compounds present in E. foetidum extract before and after green synthesis of BNPs were evaluated for the first time. Rod-shaped and spherical structural morphology of synthesized BNPs were revealed by using FESEM, TEM, and XRD analysis with particle size ranged from 7 to 23 nm with an average size of 16.49 nm. The distribution of Cu and Zn were confirmed by elemental mapping. The green synthesized CuO-ZnO NPs showed significant cytotoxic effect with the inhibition rate 89.20 ± 0.03% at concentration of 500 μg/mL. Again, good antioxidant activity with IC50; 0.253 mg/mL and antimicrobial activity of BNPs were also evaluated with the increasing order of MIC; E. coli (7.81 μg/mL) < B. subtilis (62.5 μg/mL) < S. aureus (31.25 μg/mL).

Biogenic synthesis, characterization, and in vitro biological investigation of silver oxide nanoparticles (AgONPs) using Rhynchosia capitata

The current research aimed to study the green synthesis of silver oxide nanoparticles (AgONPs) using Rhynchosia capitata (RC) aqueous extract as a potent reducing and stabilizing agent. The obtained RC-AgONPs were characterized using UV, FT-IR, XRD, DLS, SEM, and EDX to investigate the morphology, size, and elemental composition. The size of the RC-AgONPs was found to be ~ 21.66 nm and an almost uniform distribution was executed by XRD analysis. In vitro studies were performed to reveal biological potential. The AgONPs exhibited efficient DPPH free radical scavenging potential (71.3%), reducing power (63.8 ± 1.77%), and total antioxidant capacity (88.5 ± 4.8%) to estimate their antioxidative power. Antibacterial and antifungal potentials were evaluated using the disc diffusion method against various bacterial and fungal strains, and the zones of inhibition (ZOI) were determined. A brine shrimp cytotoxicity assay was conducted to measure the cytotoxicity potential (LC50: 2.26 μg/mL). In addition, biocompatibility tests were performed to evaluate the biocompatible nature of RC-AgONPs using red blood cells, HEK, and VERO cell lines (< 200 μg/mL). An alpha-amylase inhibition assay was carried out with 67.6% inhibition. Moreover, In vitro, anticancer activity was performed against Hep-2 liver cancer cell lines, and an LC50 value of 45.94 μg/mL was achieved. Overall, the present study has demonstrated that the utilization of R. capitata extract for the biosynthesis of AgONPs offers a cost-effective, eco-friendly, and forthright alternative to traditional approaches for silver nanoparticle synthesis. The RC-AgONPs obtained exhibited significant bioactive properties, positioning them as promising candidates for diverse applications in the spheres of medicine and beyond.