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Biological agents are getting a noticeable concern as efficient eco-friendly method for nanoparticle fabrication, from which fungi considered promising agents in this field. In the current study, two fungal species (Embellisia spp. and Gymnoascus spp.) were isolated from the desert soil in Saudi Arabia and identified using 18S rRNA gene sequencing then used as bio-mediator for the fabrication of silver nanoparticles (AgNPs). Myco-synthesized AgNPs were characterized using UV–visible spectrometry, transmission electron microscopy, Fourier transform infrared spectroscopy and dynamic light scattering techniques. Their antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae were investigated. In atrial to detect their possible antibacterial mechanism, Sodium dodecyl sulfate (SDS-PAGE) and TEM analysis were performed for Klebsiella pneumoniae treated by the myco-synthesized AgNPs. Detected properties of the fabricated materials indicated the ability of both tested fungal strains in successful fabrication of AgNPs having same range of mean size diameters and varied PDI. The efficiency of Embellisia spp. in providing AgNPs with higher antibacterial activity compared to Gymnoascus spp. was reported however, both indicated antibacterial efficacy. Variations in the protein profile of K. pneumoniae after treatments and ultrastructural changes were observed. Current outcomes suggested applying of fungi as direct, simple and sustainable approach in providing efficient AgNPs. [ABSTRACT FROM AUTHOR]

This study was conducted to develop an approach for reducing severe damage to grains caused by various insect pests using the biological control agent Cypovirus1 and silver nanoparticles, both alone and in combination. Four types of beetles that infest stored products, including drugstore beetle (Stegobium paniceum), saw-toothed grain beetle (Oryzaephilus surinamensis), warehouse beetle (Trogoderma variabile), and Cowpea weevil (Callosobruchus maculates), were collected from seven different areas in the Kingdom of Saudi Arabia, specifically Mecca regions. We determined the morphological characteristics of the pests in various grains. Corn borer pupae and larvae of corn plants infected with Cypovirus1 were collected from the stems of live and dead maize plants in fields in Mecca regions to isolate Cypovirus1. Infected samples were examined using triple antibody sandwich-enzymelinked immunosorbent assay (TAS-ELIZA) and reverse transcription-polymerase chain reaction (RT-PCR). Transmission electron microscopy (TEM) analysis revealed virus-containing occlusion bodies inside infected cells of corn borer larvae with irregular shapes and dimensions of 2.2-4.9 μm. The effects of different concentrations of the virus activated by synthetic spherical silver nanoparticles with an average diameter of 36.32 nm on the larva of grain pests taken were evaluated, and all treatments led to an increased mortality percentage after 72 h compared to at 48 h. The treatment mixture consisting of 10/100 viral and 400 μg/kg AgNPs led to the highest average death rates of the four insect larvae at 72 h after treatment. Protein bands that were present in the virus-infected larvae of the four pests were absent from healthy larvae, indicating viral infection. [ABSTRACT FROM AUTHOR]

The present work aimed at differentiating five Amaranthus species from Saudi Arabia according to their morphology and the ability in nanoparticle formulation. Biogenic silver nanoparticles (AgNPs) were synthesized from leaf extracts of the five Amaranthus species and characterized by different techniques. Fourier-transform infrared spectroscopy (FT-IR) was used to identify the phyto-constituents of Amaranthus species. The nanoparticles (NPs) were characterized by UV-visible spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). The antibacterial activity of the synthesized NPs was tested against Staphylococcus aureus, E. coli, Klebsiella pneumoniae and Pseudomonas aeruginosa using the agar well diffusion method. Spherical NPs varying in size and functional groups from the five plant species were demonstrated by TEM, DLS and FTIR analysis, respectively. Variations in NPs characteristics could be related to the phytochemical composition of each Amaranthus species since they play a significant role in the reduction process. EDX confirmed the presence of Ag in plant fabricated AgNPs. Antibacterial activity varied among the species, possibly related to the NPs characteristics. Varied characteristics for the obtained AgNPs may reflect variations in the phytochemical composition type and concentration among Amaranthus species used for their fabrication. [ABSTRACT FROM AUTHOR]

Background: The most commonly available drugs for leishmaniasis are pentavalent antimony compounds; whereas the recent studies showed various complications and limitations of these drugs. We aimed to green synthesized silver nanoparticles (AgNPs) and study the promising antileishmanial and synergic effects of green synthesized silver nanoparticles alone and combined with glucantime. Methods: The precipitation technique was used to drop silver ions via an extract of Astragalus spinosus to AgNPs at Department of Biological Sciences, Faculty of Science and Humanities, Shaqra University, Saudi Arabia in 2022. Then, its anti-amastigotes, caspase-3-like activity, triggering the nitric oxide (NO) as well as its cytotoxicity effects on macrophage cells as well as effects on leishmaniasis in BALB/c mice infected by L. major were measured. Results: The size of the AgNPs were ranging from 30-40 nm. The IC50 value for AgNPs, AgNPs+ meglumine antimoniate (MA), and MA was 59.3, 18.6, and 51.2 μg/mL, respectively. The determined FIC value for AgNPs and MA was found to be 0.31 and 0.36, respectively; demonstrating the synergistic potency of AgNPs when combined with MA. The diameter of CL lesions treated with various doses of AgNPs and AgNPs+MA notably (p<0.001) decreased. AgNPs, particularly at the concentrations of ½ IC50 and IC50, considerably triggered the caspase-3 activation. The calculated CC50 of AgNPs and MA was 612.5 and 789.8 μg/mL, respectively. Green synthesized AgNPs, especially in combination with MA had synergic antileishmanial effects and displayed a promising drug candidate for treating L. major CL. Conclusion: We found satisfactory findings in the parasite reduction in both in vitro and animal models. Still, more studies are expected to explain the precise action mechanisms of AgNPs and their efficacy in humans. [ABSTRACT FROM AUTHOR]

Background: Artemisia sieberi (mugwort) is a member of the daisy family Asteraceae and is widely propagated in Saudi Arabia. A. sieberi has historical medical importance in traditional societies. The current study aimed to assess the antibacterial and antifungal characteristics of the aqueous and ethanolic extracts of A. sieberi. In addition, the study investigated the effect of silver nanoparticles (AgNPs) synthesized from the A. sieberi extract. Methods: The ethanolic and aqueous extracts and AgNPs were prepared from the shoots of A. sieberi. The characteristics of AgNPs were assessed by UV–visible spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS). The antibacterial experiments were performed against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. The fungal species used were Candida parapsilosis, Candida krusei, Candida famata, Candida rhodotorula, and Candida albicans. The antibacterial and antifungal characteristics were evaluated by measuring the diameter of growing organisms in Petri dishes treated with different concentrations of either extracts or AgNPs compared to the untreated controls. Furthermore, TEM imaging was used to investigate any ultrastructure changes in the microbes treated with crude extracts and AgNO3. Results: The ethanolic and aqueous extracts significantly decreased the growth of E. coli, S. aureus, and B. subtilis (p < 0.001), while P. aeruginosa was not affected. Unlike crude extracts, AgNPs had more substantial antibacterial effects against all species. In addition, the mycelial growth of C. famata was reduced by the treatment of both extracts. C. krusei mycelial growth was decreased by the aqueous extract, while the growth of C. parapsilosis was affected by the ethanolic extract and AgNPs (p < 0.001). None of the treatments affected the growth of C. albicans or C. rhodotorula. TEM analysis showed cellular ultrastructure changes in the treated S. aureus and C. famata compared to the control. Conclusion: The biosynthesized AgNPs and extracts of A. sieberi have a potential antimicrobial characteristic against pathogenic bacterial and fungal strains and nullified resistance behavior. [ABSTRACT FROM AUTHOR]

Introduction: Diabetes mellitus is a chronic metabolic disorder that exhibited great expansion all over the world. It is becoming an epidemic disease adding a major burden to the health care system, particularly in developing countries. Methods: The plant under investigation in the current study Phragmanthera austroarabica A. G. Mill and J. A. Nyberg is traditionally used in Saudi Arabia for the treatment of diabetes mellitus. The methanolic extract (200 mg/kg) of the plant and pure gallic acid (40 mg/kg), a major metabolite of the plant, as well as their silver nanoparticle formulae (AgNPs) were evaluated for their antidiabetic activity. Results and Discussion: The results showed a decrease in body fat, obesity, an improvement in lipid profiles, normalization of hyperglycemia, insulin resistance, and hyperinsulinemia, and an improvement in liver tissue structure and function. However, the results obtained from AgNPs for both extract and the pure gallic acid were better in most measured parameters. Additionally, the activity of both the crude extract of the plant and its AgNPs were evaluated against a number of gram-positive, gram-negative bacteria and fungi. Although the activity of the crude extract ranged from moderate to weak or even non-active, the AgNPs of the plant extract clearly enhanced the antimicrobial activity. AgNPs of the extract demonstrated remarkable activity, especially against the Gram-negative pathogens Proteus vulgaris (MIC 2.5 µg/ml) and Pseudomonas aeruginosa (MIC 5 µg/ml). Furthermore, a promising antimicrobial activity was shown against the Gram-positive pathogen Streptococcus mutants (MIC 1.25 µg/ml). [ABSTRACT FROM AUTHOR]

The use of nanoparticles for various purposes, including pest control, has become increasingly popular because of their cost and environmental safety. In the present study, gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) were synthesized in an extract of Senna alexandrina Miller leaves with the aim of use against vectors of disease such as Culex pipiens L. (the filarial vector in Saudi Arabia). The nanoparticles were characterized by scanning electron microscopy and spectroscopic techniques. The larvicidal activity of the nanoparticles against Cx. pipiens was evaluated according to the protocol of the World Health Organization. According to the lethal concentration LC50, the result shows differentiation in the sensitivity on mosquitoes. The AuNPs (51.383 ppm) the best one followed by AgNPs (52.525 ppm) while S. alexandrina leaf extract alone (355.25 ppm), the lowest effectiveness. Generally, the Cx. pipiens mosquito larvae proved to be more susceptible to AuNPs and AgNPs than leaf extract alone by about 6.91 and 6.76 times, respectively. [ABSTRACT FROM AUTHOR]

Aspergillus sydowii is a mesophilic soil saprobe that is a food contaminant as well as a human pathogen in immune-compromised patients. The biological fabrication of silica and silver nanoparticles provides advancements over the chemical approach, as it is eco-friendly and cost-effective. In the present study, Aspergillus sydowii isolates were collected from the soil fields of six different sites in the western area of Saudi Arabia and then identified using the PCR technique following sequencing analysis by BLAST and phylogenetic analysis. Then, applied silica and silver nanoparticles were synthesized by biological methods, using Aspergillus niger as a reducer. Silver and silica nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The antifungal activity of silver and silica nanoparticles against Aspergillus sydowii isolates was evaluated using the disc diffusion method and the minimum inhibitory concentration (MIC). The physiochemical results emphasized the fabrication of silver and silica nanoparticles in spherical shapes with a diameter in the range of 15 and 40 nm, respectively, without any aggregation. MIC of Ag-NPs and Si-NPs against Aspergillus sydowii isolates were 31.25 and 62.5 µg/mL, respectively. Finally, the aim of the study is the use of silver as well as silica nanoparticles as antifungal agents against Aspergillus sydowii. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance is one of the crucial public health challenges that we need to combat. Thus, in concern over public health and the economy, controlling the emergence of infectious diseases is critical worldwide. One of the ways to overcome the influences of antimicrobial resistance is by developing new, efficient, and improved antimicrobial agents. Medicinal plant-derived silver nanoparticles (AgNPs) are under intensive examination for a variety of therapeutic purposes and targeted applications in nanomedicine and nanotechnology. Plants belonging to the genus Thevetia [Syn. Casabela], which is known for its medicinal uses and has rarely been applied for the synthesis of AgNPs, is an attractive alternative as they have a high content of secondary metabolites. Herein, using aqueous leaf extract of Cascabela thevetia, which was locally found in the Makkah region, Saudi Arabia, green synthesis of AgNPs is reported. Active components of Cascabela thevetia aqueous leaf extract were sufficient to reduce AgNO3 into AgNPs and stabilize them as this was confirmed through UV-Visible absorption, Fourier transforms infrared (FTIR), X-ray diffraction (XRD), filed emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) studies. UV-Visible, HPLC, and FTIR analysis demonstrated the presence of gallic acid in aqueous extract and solution of C-AgNPs. The spherical Cascabela thevetia derived C-AgNPs with an average diameter in the range of 20–30 nm were highly dispersed, as seen from FESEM and TEM images, and demonstrated the high antibacterial and antifungal activities when incubated with Gram-positive bacteria Methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus (S. aureus), Enterococcus faecalis (E. faecalis), Gram-negative bacteria Escherichia coli (E. coli), Salmonella typhimurium (S. typhimurium), Klebsiella pneumoniae (K. pneumoniae), Pseudomonas aeruginosa (P. aeruginosa) and fungi Candida albicans (C. albicans) and Candida parapsilosis (C. parapsilosis). The lowest MIC values of C-AgNPs versus S. aureus, E. faecalis, and E. coli were found. Finally, the antioxidant activity and catalytic property of C-AgNPs were assessed by neutralizing DPPH free radical and reducing methylene blue and rhodamine B dyes, respectively. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) are widely used for medical applications particularly as antimicrobial agents against multidrug-resistant microbial strains. Some plants stimulate the reduction of Ag ions to AgNPs. In this study, we prepared AgNPs via the green synthesis approach using fenugreek leaves grown in Saudi Arabia. Furthermore, we characterized these AgNPs and evaluated their antimicrobial activities against pathogenic yeast, bacteria, and fungi. The ultraviolet-visible peak at 380 nm confirmed the biosynthesis of NPs. Transmission electron microscopy analyses revealed particle size in the range of 9–57 nm with a spherical shape. Dynamic light scattering results confirm slight aggregation as the average particle size was shown as 68.71 nm and a polydispersity index of 0.083. The energy-dispersive X-ray spectroscopy results showed an intense peak at 3 keV, indicating the presence of elemental AgNPs. The synthesized AgNPs efficiently inhibit the growth of both Gram-positive and Gram-negative bacteria; however, varying degree of inhibition was shown toward fungi. The potent antimicrobial ability of the synthesized NPs can be attributed to their small size and round shape. Among all test organisms, the growth of Candida albicans and Helminthosporium sativum was remarkably affected by AgNPs treatment. [ABSTRACT FROM AUTHOR]

A study was carried out on soil samples collected from coastal area of Red Sea and from El-Souda Mountains, KSA. Biological, physical and chemical properties of each soil type had been investigated using X-ray fluorescence spectrometer, X-ray diffraction, scanning electron microscopy, UV–Vis-spectrophotometer, conductivity bridge, AgNO3 titration, electronic pH meter, well diffusion and hydrometer methods. It was found that the Red Sea coastal soils contain major components of Ca (39.74%) in (site 1) at 3 meters height, whereas the sandy soil (site 2) has Si (47.61%) at 4 m height. Site 3 at 2640 m height has Si (29.62%), whereas site 4 at 2928 m height has high amount of Fe (62.25%). Except soils of site 2, all other sites are fall into the grains category of a micrometer scale. The pH value of the soil extract was decreased gradually from (7.75 ± 0.08) in site 1 to (6.52 ± 0.09) in site 4. Electrical conductivity was found to be very high in site 1 (9.84 ± 0.03 mS) and less in site 2 (2.35 ± 0.01 mS) and in sites 3 and 4 were very low. Chloride amount was very high in site 1 (2929 ± 1.52 ppm) and in site 2 (692 ± 1.54 ppm) and no traces found in sites 3 and 4. Site 4 had the highest amount of clay 80%. XRD pattern showed there was a remarkable difference in crystalline nature, phase identification and in grain size. Synthesized nanoparticles from all soils showed promising antimicrobial activities against all tested pathogenic microbial strains. [ABSTRACT FROM AUTHOR]

Ochradenus arabicus is a significant therapeutic plant which grows in desert zones of Saudi Arabia. It has antimicrobial, anticancer, cancer prevention, antidiabetic, allopathic and pabulum properties. The present study evaluated the biosynthesis of silver nanoparticles (AgNPs) utilizing the leaf concentrate of plant O. arabicus having novel ethnomedicinal potential. The incorporated AgNPs were visualized utilizing UV-Visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The antimicrobial impact of AgNPs delivering O. arabicus was considered utilizing distinctive pathogenic microorganisms, for example, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Streptococcus mutans. From the plate dispersion results, the incorporated silver nanoparticles demonstrated potent antibacterial properties and high antimicrobial action contrasted with the ionic silver. Supplemental data for this article is available online at https://doi.org/10.1080/13102818.2021.1961609. [ABSTRACT FROM AUTHOR]

Sidr honey is used as food and medicine in many countries. Study of immunomodulatory and anticancer activity of Sidr honey did not tested before. The aim of this work was to study the anticancer activity and immunomodulatory as well as antimicrobial potential of Sidr honey and its synthesized silver nanoparticles (AgNPs). Sidr honey from three sources (two from Kingdom of Saudi Arabia (KSA) and one from Pakistan) was diluted to 20% and tested for its biological activities and to synthesize AgNPs. The results demonstrated that honeys could produce AgNPs (spherical shape), modulated the growth of normal splenic cells, and have antimicrobial activities. Sidr honey has anticancer activity against HepG2 but not Hela cells. Sidr honey can be used as antimicrobial agent, but can be used as anticancer agent with care as it stimulated cell growth of some lines (e.g., Hala) and inhibited another (e.g., HepG2). [ABSTRACT FROM AUTHOR]

The Dodonaea viscose was commonly known plant in Al-mukhwah area (Al-baha city in Saudi Arabia) by exhibiting various therapeutic pharmacological properties owing to existence of divers polyphenols and flavonoids in its roots and seeds. Ultrasound-assisted extraction was utilized to extract total phenolic and antioxidant compounds from Dodonaea viscose. The aim of this study is to inspect the solvent type effects, sonication time and dissipated power on the extraction of total phenolic compounds, total flavonoid compounds (TFC) and on the antioxidant capacity: 2,2'-azinobis- 3-ethylbenzothiazoline-6 sulfonic acid (ABTS) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH). The highest TPC was 176.63 mg. g-1 GAE of dry extract), whilst the total flavonoids equal 125.78 mg QE.g-1 of dry extract, the lower value IC50 of DPPH radical scavenging activity was 13.60 μg.g-1 of dry extract and under ABTS radical scavenging assay, IC50 was assessed as 3.58 μg.g-1 of dry extract. These results were observed for the sample extracted with pulsed ultrasound (40%) in Methanol at 15 min which indicated that the extracted compounds contribute to the activity of antioxidant. The natural products which are found in plants extracts, may be considered as a reducing agent as like a stabilizing agent in the formation of metal nanoparticles. Silver nanoparticles (AgNps) were synthesized by aqueous extract through a facile route. Characterizations of nanoparticles were evaluated by the use of UltraViolet-Visible spectroscopy (UV-Vis), Fourier Transform Infra-Red spectroscopy (FT-IR), and Transmission Electron Microscopy. Nanoparticles were found 30.20±19 (nm) by TEM analysis. [ABSTRACT FROM AUTHOR]

Considering the significance of biological and eco-friendly nanomaterials, in the present study, we have synthesized silver nanoparticles from the exopolysaccharide of recently recovered bacterial strain CEES51 from the Red Sea coastal area of Jeddah, Saudi Arabia. 16S ribosomal RNA gene sequencing was used to characterize the isolated bacteria, and it was identified as Mesoflavibacter zeaxanthinifaciens and assigned an accession number MH707257.1 GenBank. The bacterial strain is an excellent exopolysaccharide producer and survived at hypersaline (30%) and high-temperature (50°C) conditions. The bacterial exopolysaccharides were employed for the fabrication of silver nanoparticles at room temperature. UV-visible spectrophotometer optimized the synthesized nanoparticles, and their size was determined by Nanophox particle size analyzer and dynamic light scattering. Additionally, the X-ray powder diffraction and Fourier-transform infrared spectroscopy studies also approved its crystalline nature and the involvement of organic functional groups in their formation. The synthesized nanomaterials were tested for their antibacterial and antibiofilm properties against pathogenic microorganisms Bacillus subtilis and methicillin-resistant Staphylococcus aureus. The antimicrobial property showed time, and dose-dependent response with a maximum of zone inhibition was observed at around 22 and 18 mm at a dose of 50 µg/well against B. subtilis and S. aureus and a minimum inhibitory concentration of 8 and 10 µg/ml, respectively. Furthermore, the synthesized silver nanoparticles possessed a substantial antibiofilm property and were also found to be biocompatible as depicted by red blood cell lysis assay and their interaction with peripheral blood mononuclear cells and human embryonic kidney 293 cells. Therefore, Mesoflavibacter zeaxanthinifaciens is found to be an excellent source for exopolysaccharide synthesis that assists in the silver nanoparticle production. [ABSTRACT FROM AUTHOR]

We report the use of the fungus Fusarium semitectum, isolated from soil from Saudi Arabia, for the extracellular synthesis of silver nanoparticles using silver nitrate solution. Highly stable and crystalline silver nanoparticles were produced in solution by treating the filtrate of the fungus F. semitectum with an aqueous silver nitrate solution. The nanoparticles were characterized by UV-Vis spectrophotometry, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). These analyses revealed that the particles ranged in size from 5 to 35 nm and were mostly spherical in shape. Interestingly, the colloidal suspensions of silver nanoparticles were stable for many weeks. [ABSTRACT FROM AUTHOR]

The Arabian desert is rich in different species of medicinal plants, which approved variable antimicrobial activities. Phoenix dactylifera L. is one of the medical trees rich in phenolic acids and flavonoids. The current study aimed to assess the antibacterial and antifungal properties of the silver nanoparticles (AgNPs) green-synthesized by two preparations (ethanolic and water extracts) from palm leaves. The characteristics of the produced AgNPs were tested by UV-visible spectroscopy and Transmitted Electron Microscopy (TEM). The antifungal activity of Phoenix dactylifera L. was tested against different species of Candida . Moreover, its antibacterial activity was evaluated against two Gram-positive and two Gram-negative strains. The results showed that AgNPs had a spherical larger shape than the crude extracts. AgNPs, from both preparations, had significant antimicrobial effects. The water extract had slightly higher antimicrobial activity than the ethanolic extract, as it induced more inhibitory effects against all species. That suggests the possible use of palm leaf extracts against different pathogenic bacteria and fungi instead of chemical compounds, which had economic and health benefits.

This study aimed to synthesize silver nanoparticles (AgNPs) by pomegranate and orange peel extracts using a low concentration of AgNO3 solution to controlearly blight of tomato caused by Alternaria solani. The pathogen was isolated from infected tomato plants growing in different areas of Saudi Arabia. The isolates of this pathogen were morphologically and molecularly identified. Extracts from peels of pomegranate and orange fruits effectively developed a simple, quick, eco-friendly and economical method through a synthesis of AgNPs as antifungal agents against A. solani. Phenolic content in the pomegranate peel extract was greater than orange peel extract. Phenolic compounds showed a variation of both peel extracts as identified and quantified by High-Performance Liquid Chromatography. The phenolic composition displayed variability as the pomegranate peel extract exhibited an exorbitant amount of Quercitrin (23.62 mg/g DW), while orange peel extract recorded a high amount of Chlorogenic acid (5.92 mg/g DW). Biosynthesized AgNPs were characterized using UV- visible spectroscopy which recorded an average wavelength of 437 nm and 450 nm for pomegranate and orange peels, respectively. Fourier-transform infrared spectroscopy exhibited 32x73.24, 2223.71, 2047.29 and 1972.46 cm−1, and 3260.70, 1634.62, 1376.62 and 1243.76 cm−1 for pomegranate and orange peels, respectively. Transmission electron microscopy showed spherical shape of nanoparticles. Zetasizer analysis presented negative charge values; −16.9 and −19.5 mV with average particle sizes 8 and 14 nm fin case of pomegranate and orange peels, respectively. In vitro, antifungal assay was done to estimate the possibility of biosynthesized AgNPs and crude extracts of fruit peels to reduce the mycelial growth of A. solani. AgNPs displayed more fungal mycelial inhibition than crude extracts of two peels and AgNO3. We recommend the use of AgNPs synthesized from fruit peels for controlling fungal plant pathogens and may be applied broadly and safely in place by using the chemical fungicides, which display high toxicity for humans. [ABSTRACT FROM AUTHOR]

The green biosynthesis of nanoparticles by plant extracts is an attractive and promising technique for medicinal applications. In the current study, we chose one of the daisy plants, Aaronsohnia factorovskyi (which grows in the Najd region, Saudi Arabia), to investigate its anti-microbial efficacy, in combination with silver nanoparticles. The biosynthesized nanoparticles were evaluated for antibacterial activity against Staphylococcus aureus, Bacillussubtilis (Gram-positive), Pseudomonas aeruginosa, and Escherichia coli, (Gram-negative) using the disc diffusion method, while the antifungal activity was assessed against Fusarium oxysporum, Fusarium solani, Helminthosporiumrostratum, and Alternariaalternata. The potential phytoconstituents of the plant extracts were identified by Fourier-transform infrared spectroscopy (FT-IR) techniques, the Field emission scanning electron microscopy (FE-SEM), Chromatography/Mass Spectrometry (GC-MS) techniques, and Zeta potential analysis. The current study revealed the ability of the tested plant extract to convert silver ions to silver nanoparticles with an average diameter of 104–140 nm. Biogenic Aaronsohnia factorovskyi-silver nanoparticles (AF-AgNPs) showed significant antibacterial activity against Staphylococcus aureus with inhibition zone diameter to 19.00 ± 2.94 mm, and antifungal activity against Fusarium solani, which reduced the growth of fungal yarn to 1.5 mm. The innovation of the present study is that the green synthesis of NPs, which is simple, cost-effective, provides stable nano-materials, and can be an alternative for the large-scale synthesis of silver nanoparticles. [ABSTRACT FROM AUTHOR]

Globally, antimicrobial resistance has grown at an alarming rate. To combat the multidrug-resistant (MDR) superbugs, silver nanoparticles (Ag NPs) were synthesized using an aqueous leaf extract of seasonal desert plant Sisymbrium irio obtained from the central region of Saudi Arabia by a simple one-step procedure. The physical and chemical properties of the Ag NPs were investigated through ultraviolet visisble analysis (UV-vis), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) analysis. The UV-vis spectrum showed an absorption band at 426 nm. The XRD results showed a highly crystalline face-centered cubic structure. The surface morphology analyzed using SEM and TEM analyses showed the particle size to be in the range 24 nm to 50 nm. Various concentrations of Ag NPs were tested against MDR Pseudomonas aeruginosa and Acinetobacter baumanii that cause ventilator-associated pneumonia (VAP). American Type Culture Collection (ATCC) Escherichia coli-25922 was used as the reference control strain. The Ag NPs effectively inhibited tested pathogens, even at the lowest concentration (6.25 µg) used. The bacterial inhibitory zone ranged from 11–21 mm. In conclusion, the newly synthesized Ag NPs could be a potential alternative candidate in biomedical applications in controlling the spread of MDR pathogens. [ABSTRACT FROM AUTHOR]

The therapeutic molecules recovered from the marine biological origin are widely used for the treatment of diverse levels of infections caused by microbial pathogens. In addition, the eco-friendly preparations of nanomaterials together with the secondary metabolites' producing active microbial strains effectively suppress the spreading of the pathogenic bacteria. Considering their importance, the present study evaluated the environmental friendly synthesis of Silver nitrate nanomaterials (SNM) from the active marine Streptomyces strain Al-Dhabi-91 isolated from the Dammam region of Saudi Arabia. The obtained SNM was chemically characterized by various spectroscopic techniques such as UV, XRD, FTIR, SEM, TEM and EDAX; and its biological applications such as antimicrobial properties and antioxidant potential were recorded by DPPH methods. Biochemical and micromorphological studies together with the molecular techniques confirmed that the isolate Al-Dhabi-91 belonged to Streptomyces species. The characterization techniques confirmed that the UV spectrum showed maximum absorption peak at 305 nm indicating the plasmodium characteristics. SEM and TEM analyses evidenced 5–2 nm which are agglomerated, cool to form porous asymmetrical networks. Additionally, the FTIR spectrum showed maximum peak at 1194 cm−1 and 1394 cm−1, confirming the presence of aromatic C H bending and aromatic C C bending in the SNM. SNM exhibited prolific antibacterial activity against Gram negative pathogens, K. pneumoniae (28.33 mm) and E. coli (21.66 mm) respectively. The MIC values of SNM were significant with respect to E. faecalis (125 μg/ml), S. aureus (250 μg/ml), P. aeruginosa (125 μg/ml), K. pneumoniae (500 μg/ml) and E. coli (250 μg/ml) respectively. In addition, the antioxidant potential of the SNM was another value added importance. Especially 50 μg/ml of the nanoparticles showed 33% antioxidant potential; similarly in nitric oxide radical inhibition assay the concentration of 50 μg/ml nanoparticles showed 33% of inhibition potential. Overall, the eco-friendly synthesis of SNM from the marine Streptomyces strain Al-Dhabi-91 was an ideal active source for the treatment of infectious disease and health associated disorders. • Silver NPs of Streptomyces sp. Al-Dhabi-91 showed antibacterial and antioxidant activities. • Maximum absorption of the Silver nanoparticles were observed at 310 nm. • TEM and SEM analysis confirmed the size of 9.7 to 20 nm and cubic in appearance. • NPs exhibited Minimum Inhibitory Concentration of 125 μg/ml towards P.aeruginosa. • Silver NPs pronounced significant antioxidant activities. [ABSTRACT FROM AUTHOR]