Antibacterial Activity Of AgNPs Research Articles

Silver Nanoparticles Loaded with Bark Extract of Sterculia foetida: Their Green Synthesis, Characterization, and Anti-bacterial Activity Evaluation

Sterculia foetida is a subject of interest in many scientific fields as researchers look for novel treatments because of its varied medicinal qualities and chemical richness. Terpenoids are aromatic and aliphatic chemicals with anti-bacterial properties and can prevent free radical damage. They are present in S. foetida extract. Moreover, it possesses immunomodulatory, hepatoprotective, antiviral, antioxidant, anti-inflammatory, and antifungal properties. This work aims to green synthesize, characterize, and evaluate the anti-bacterial activity of Sterculia foetida bark extract-loaded silver nanoparticles. Chemicals like Methanol, Petroleum Ether, and water have been used to extract the phytoconstituents from the plant bark. AgNO3 and Silver have been used to synthesize the nanoparticles. Instruments like ATR-IR Spectrophotometer, UV- spectrophotometer, DLS, and SEM instruments have been used to characterize the nanoparticles. Bacterial strains like Staphylococcus aureus (ATCC-6538), Escherichia coli (ATCC 25922), saline water, AMX30, swab stick, inoculation loop, susceptibility scale have been used for studying the anti-bacterial activity. DLS and zeta potential analysis demonstrated the creation of stable nanoparticles with a particle size of 79 nm. The anti-bacterial activity of AgNPs with the methanolic bark extract showed significant anti-bacterial activity compared to the standard marketed drug AMX30. The highest zone of inhibition was observed against gram-positive bacteria S.aureus (1.68 cm) and gram-negative bacteria E.coli (1.74 cm), respectively, at 500 μg/ml concentration. The study concludes that greenly synthesized S. foetida bark extract containing nanoparticles is a potential anti-bacterial agent, especially against gram-negative bacteria. Further, in vivo studies are needed to establish its potential. Keywords: Sterculia foetida, Green synthesis, Silver Nanoparticles (AgNPs), ATR-IR, DLS, SEM, Zeta-potential, Anti-bacterial.

Panicum maximum Jacq. mediated green synthesis of silver nanoparticles: synthesis, characterization, and biological activities supported by molecular docking

This study uses the aerial parts of Panicum maximum total extract (PMTE) to synthesize silver nanoparticles (AgNPs) in an environmentally friendly manner. TEM, SEM, FTIR, X-ray powder diffraction (XRD), Zeta potential, UV, and FTIR were used to characterize the green silver nanoparticles (PM-AgNPs). PM-AgNPs were evaluated as anticancer agents compared to (PMTE) against breast (MCF-7), lung (A549), and ovary adenocarcinoma (SKOV3) human tumour cells. The antibacterial activity of AgNPs was assessed against Staphylococcus aureus isolates. The PM-AgNPs had an absorbance of 418 nm, particle size of 15.18 nm, and zeta potential of −22.4 mV, ensuring the nanosilver’s stability. XRD evaluated the crystallography nature of the formed PM-AgNPs. The cytotoxic properties of PM-AgNPs on MCF-7 and SKOV 3 were the strongest, with IC50s of 0.13 ± 0.015 and 3.5 ± 0.5 g/ml, respectively, as compared to A549 (13 ± 3.2 µg/mL). The increase in the apoptotic cells was 97.79 ± 1.61 and 96.6 ± 1.91% for MCF-7 and SKOV3 cell lines, respectively. PM-AgNPs were found to affect the membrane integrity and membrane permeability of 50 and 43.75% of the tested isolates, respectively. Also, PM-AgNPs have recorded a reduction in the biofilm formation of S. aurues. These results suggest using PM-AgNPs to treat breast and ovarian cancers.

Green Synthesis of Antimicrobial Silver Nanoparticles using Green Tea Extract: The Role of Concentration and pH

ABSTRACTGreen synthesis for silver nanoparticles (AgNPs) is the process of reducing Ag+ ions to Ag0 by using plant bioactive compounds. Green synthesis is safer, environmentally friendly and cost-effective. Plant bioactive compounds from Camellia sinensis L. (green tea) extract containing polyphenols can be used as a reducer in the formation of silver nanoparticles. This study aims to determine the effect of pH (8, 9, and 10), at 1,5mM AgNO3 concentration and 0,75% green tea extract concentration on the physical characteristics and antibacterial activity of silver nanoparticles prepared by green synthesis method. The synthesized results were evaluated by UV-Vis Spectrophotometer, Dynamic Light Scattering (DLS), SEM, and FTIR. The optimal AgNP synthesis process resulted from the AgNO3 concentration of 1.5 mM with 0.75% green tea extract at pH 10 which showed an absorbance value of 4,420 at λ 435,3 nm, with a particle size of 47,1 nm and a PDI of 0,243. The formation of AgNPs was observed by a change in color to brownish yellow. Antibacterial activity of AgNPs using liquid diffusion method. The results obtained AgNPs for Staphylococcus aureus bacteria has had inhibition at a concentration of 0,187mM and Escherichia coli at a concentration of 0,375mM.Keywords: Silver nanoparticles; green synthesis; green tea extract; pH; antibacterial activity

Green Synthesis of Silver Nanoparticles with Extracts from Kalanchoe fedtschenkoi: Characterization and Bioactivities.

In this work, the hexane, chloroform, and methanol extracts from Kalanchoe fedtschenkoi were utilized to green-synthesize silver nanoparticles (Kf1-, Kf2-, and Kf3-AgNPs). The Kf1-, Kf2-, and Kf3-AgNPs were characterized by spectroscopy and microscopy techniques. The antibacterial activity of AgNPs was studied against bacteria strains, utilizing the microdilution assay. The DPPH and H2O2 assays were considered to assess the antioxidant activity of AgNPs. The results revealed that Kf1-, Kf2-, and Kf3-AgNPs exhibit an average diameter of 39.9, 111, and 42 nm, respectively. The calculated ζ-potential of Kf1-, Kf2-, and Kf3-AgNPs were -20.5, -10.6, and -7.9 mV, respectively. The UV-vis analysis of the three samples demonstrated characteristic absorption bands within the range of 350-450 nm, which confirmed the formation of AgNPs. The FTIR analysis of AgNPs exhibited a series of bands from 3500 to 750 cm-1, related to the presence of extracts on their surfaces. SEM observations unveiled that Kf1- and Kf2-AgNPs adopted structural arrangements related to nano-popcorns and nanoflowers, whereas Kf3-AgNPs were spherical in shape. It was determined that treatment with Kf1-, Kf2-, and Kf3-AgNPs was demonstrated to inhibit the growth of E. coli, S. aureus, and P. aeruginosa in a dose-dependent manner (50-300 μg/mL). Within the same range, treatment with Kf1-, Kf2-, and Kf3-AgNPs decreased the generation of DPPH (IC50 57.02-2.09 μg/mL) and H2O2 (IC50 3.15-3.45 μg/mL) radicals. This study highlights the importance of using inorganic nanomaterials to improve the biological performance of plant extracts as an efficient nanotechnological approach.

Green synthesis of silver nanoparticles and evaluation of their effects on the Porphyromonas gingivalis bacterial biofilm formation.

This study aimed to evaluate the impact of silver nanoparticles (AgNPs) synthesized from propolis on the formation of Porphyromonas gingivalis biofilms. AgNPs were synthesized from propolis, and their inhibitory effect on P. gingivalis biofilm formation was assessed. Different concentrations of AgNPs (0.1%, 0.3%, and 0.5%) were tested to determine the dose-dependent antibacterial activity. The results of this study indicated that AgNPs exhibited an inhibitory effect on P. gingivalis biofilm formation. The antibacterial activity of AgNPs was dose-dependent, with concentrations of 0.1%, 0.3%, and 0.5% showing effectiveness. Notably, the concentration of 0.5% demonstrated the most significant anti-biofilm formation activity. The results of this study suggest that AgNPs synthesized from propolis have potential as an effective option for enhancing periodontal treatment outcomes. The inhibitory effect of AgNPs on P. gingivalis biofilm formation highlights their potential as alternative antimicrobial agents in the management of periodontal diseases.

Synthesis of sustainable silver nanoparticles using plant extract and their antimicrobial, anticancer, and photocatalytic dye degradation efficiency analysis

The green synthesis of noble metal nanoparticles has gained a lot of interest in the area of nanotechnology, because of its high therapeutic properties. The present study focussed on the synthesis of the silver nanoparticles (Ag-NPs) using Ceropegia debilis leaf extract and characterized by various physio-chemical techniques and surface morphological studies. The prepared Ag-NPs exhibit a face-centred cubic structure, spherical morphology, and high purity as shown by XRD, SEM, and EDS analyses. The average size of the Ag-NPs was confirmed by TEM study as 18.6 ± 7.5 nm. The synthesized Ag-NPs show remarkable antioxidant activity of 72.1% compared to standard BHT 86.9%. Furthermore, Ag-NPs show remarkable cytotoxic properties against MCF 7 and A 549 cell line of 37.19% and 33.33%, respectively at 250 µg/mL. The antibacterial activity of Ag-NPs was investigated against the human pathogen and intestinal pathogen Staphylococcus aureus and Escherichia coli by agar disc diffusion method. Moreover, the synthesised Ag-NPs exhibit good antifungal properties against the fungal specimen Trichoderma viride assessed by well diffusion technique. In addition, Ag-NPs serve as an excellent nanocatalyst in the removal of toxic methylene blue dye (93.2%) from industrial wastewater under sunlight irradiation.

Green synthesis of silver nanoparticles using five varieties of Cordyline fruticosa sp. leaves and reviewing their antimicrobial, antioxidant and photocatalytic properties

The biological synthesis of nanoparticles using plants or microorganisms has gained attention in the recent past, mainly due to its eco-friendly nature and because they can be used in a vast variety of fields such as medicine, agriculture and textiles. The current study focuses on the green synthesis of silver nanoparticles (AgNPs) using five varieties of Cordyline fruticosa (candy cane, waihee rainbow, exotica, pink cascade and pink diamond) leaves, and assessing their antioxidant, photocatalytic and antimicrobial activities. SEM analysis of pink cascade-AgNPs shows they are spherical and in the range of 40-50nm. Band gap energy calculations reveal that synthesized AgNPs can act as semiconductors. Total flavonoid content, total phenolic content and total antioxidant capacity were analyzed and the DPPH-free radical scavenging assay was performed. These showed that AgNPs had higher antioxidant activity compared to aqueous extracts. The antibacterial activity of AgNPs and aqueous extracts was assessed using cultures of Escherichia coli and Staphylococcus aureus. Extracts and AgNPs showed better bactericidal effect on S.aureus. Photocatalytic activity of synthesized AgNPs was assessed using malachite green as a model dye and significant degradation of the dye was observed when AgNPs were added together with catalyst NaBH4. According to the results obtained from this study, it can be seen that AgNPs synthesized using Cordyline fruticosa have potential in different aspects including treatment of free-radical mediated diseases, overcoming antibiotic resistance, treatment of bacterial diseases and overcoming environmental pollution.

Synthesis of Silver Nanoparticles from Extract of Epiphytic Shrub Leaves (Ficus heteropleura Blume) on Oil Palm Plant and Evaluation of Their Antibacterial Activity Against Escherichia coli

Silver nanoparticles are silver metal particles with a size of less than 100 nm. Extract of epiphytic shrub leaves (Ficus heteropleura Blume) serves as a bioreductant in producing silver nanoparticles, which are utilized for their antibacterial properties against Escherichia coli. This study aims to synthesize silver nanoparticles and assess their activity against Escherichia coli. Silver nanoparticles (AgNPs) were synthesized using the green synthesis method with Ficus heteropleura leaf extract with silver nitrate (AgNO3). AgNPs were synthesized using a 1 mM solution of AgNO3 and different concentrations (2, 4, 6, 8, and 10%) of Ficus heteropleura extract. The AgNPs were characterized using UV-Vis spectrophotometer, FTIR, and PSA. UV-Vis analysis revealed that AgNPs at concentrations ranging from 2% to 10% exhibited absorbance peaks within the wavelength range of 201.2–473.5 nm. FTIR analysis identified functional groups such as OH, CH, C=C, C≡C, C≡N, and CO, which played a role in reducing silver nanoparticles. The size distribution of AgNPs was determined, with AgNPs synthesized at a concentration of 6% exhibiting a size range of 1–100 nm, constituting 40.77% of the total. For AgNPs synthesized at concentrations of 8% and 10%, the percentage of nanoparticles in the 1–100 nm size range was found to be 26.845% and 1.28%, respectively. The antibacterial activity of AgNPs at concentrations of 6% and 8% against Escherichia coli demonstrated moderate effectiveness.

Use of Residual Malt from an Artisanal Beer Brewing Process in the Biosynthesis of Silver Nanoparticles Mediated by Nucleating and Structure-Directing Agents.

Biosynthesized silver nanoparticles (AgNPs) are widely used in varied applications, which are morphology dependent. Consequently, a morphology-controlled synthesis is mandatory. Although there are several studies focused on the plant extract-based biosynthesis of metallic nanoparticles, the use of extracts obtained from agro-wastes is scant. Furthermore, information regarding morphology modification through the use of additional agents is even more scarce. Thus, in this study, AgNPs were synthesized using a malt extract (ME) obtained from an artisanal beer brewing process residue. Additionally, sodium chloride (NaCl), gum arabic (GA), and talc (T) were used in an attempt to modify the morphology of AgNPs. XRD, DLS, SEM, and TEM results demonstrate that stable AgNPs of different sizes and shapes were synthesized. FTIR, HPLC analysis, and the quantification of total proteins, free amino acids, reducing sugars, and total polyphenols before and after AgNPs synthesis showed that ME biomolecules allowed them to act as a source of reducing and stabilizing agents. Therefore, this study provides evidence that ME can be successfully used to biosynthesize AgNPs. Additionally, the antibacterial activity of AgNPs against Gram-negative and Gram-positive bacteria was evaluated. Results indicate that AgNPs show a higher antibacterial activity against Gram-positive bacteria.

Green synthesis, characterization and biological activity of silver nanoparticles of Hypnum cupressiforme Hedw extract

Mosses are one of the oldest land plants that constitute the second largest group of the plant kingdom, are found in almost every region, have known therapeutic effects, are rich in secondary metabolites, can withstand harsh climatic conditions and thirst for a long time. Volatile extracts of Hypnum cupressiforme Hedw. were analyzed by gas chromatography-mass spectrometry in this study, and the presence of 18 different phytocompounds was determined as secondary metabolites. Using these extracts, silver nanoparticles (AgNPs) were synthesized using a green synthesis method. The AgNPs that were created were characterized. The extracts and AgNPs were tested for antibacterial, antibiofilm, antioxidant, mutagenic, and DNA-cleavage activity. The tests revealed no evidence of mutagenicity. Antibiofilm and antibacterial activity of AgNPs against P. vulgaris, P. aeruginosa, and E. faecalis were demonstrated. Both oxidatively and hydrolytically, H. cupressiforme the extract was found to have higher antioxidant properties and high DNA cleavage activity.

Investigating the Antibacterial and Anti-inflammatory Potential of Polyol-Synthesized Silver Nanoparticles.

Silver nanoparticles (Ag-NPs) were synthesized by using the polyol method. The structural and morphological characteristics of Ag-NPs were studied by using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The XRD analysis revealed the formation of single-phase polycrystalline Ag-NPs with an average crystallite size and lattice constant of ∼23 nm and 4.07 Å, respectively, while the FE-SEM shows the formation of a uniform and spherical morphology. Energy-dispersive X-ray spectroscopy confirmed the formation of single-phase Ag-NPs, and no extra elements were detected. A strong absorption peak at ∼427 nm was observed in the UV-vis spectrum, which reflects the surface plasmon resonance (SPR) behavior characteristic of Ag-NPs with a spherical morphology. Fourier-transform infrared (FTIR) spectra also supported the XRD and EDX results with regard to the purity of the prepared Ag-NPs. Anti-inflammatory activity was tested using HRBCs membrane stabilization and heat-induced hemolysis assays. The antibacterial activity of Ag-NPs was evaluated against four different types of pathogenic bacteria by using the disc diffusion method (DDM). The Gram-negative bacterial strains used in this study are Escherichia coli (E. coli), Klebsiella, Shigella, and Salmonella. The analysis suggested that the antibacterial activities of Ag-NPs have an influential role in inhibiting the growth of the tested Gram-negative bacteria, and thus Ag-NPs can find a potential application in the pharmaceutical industry.

Efficiency Evaluation and Characterization of Microbially, Phyto and Chemically Synthesized Silver Nanoparticles

The present research objectives involves the synthesis and characterization of microbially, Phyto- and chemically silver nanoparticles (AgNPs) and evaluation the antimicrobial and cytotoxicity effect. Silver nanoparticles were biosynthesized through Streptomyces clavuligerus and Curcuma extract in addition to chemical reduction method with trisodium citrate as reducing agent silver nitrate as the metal substrate. The syntheses of the silver nanoparticles were characterized using UV-Vis spectroscopy and scanning electron microscopy (SEM). The results of characterization revealed absorption peaks obtained at range from 217-222 nm for all AgNPs types. SEM photographs of biosynthesized AgNPs indicate a narrow size distribution with average 8 nm in ‎spherical with smooth surfaces‎ and serruond protein but, chemical AgNPs showed ‎ without serruond protein. Antibacterial activity of AgNPs was determined using agar well diffusion method against Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginos. Results show similar significant antibacterial activity of microbial and Phyto- biosynthesized silver NPs. On the other hand, the chemically synthesized AgNPs recorded no activity against all tested pathogens. The cytotoxicity of AgNPs was tested in vitro on lung tissue fibroblast (WI-38) using MTT with various concentrations. The results recorded IC50 4.6, 1.25 and 2.18 µgml-1 for microbially, Phyto- and chemically AgNPs respectively. Almost all the microbial synthesis of silver nanoparticles exhibit the beast characteristics that qualify it for application in the pharmaceutical field due to its being the smallest in size, antimicrobial activity, and the less toxic on host cells.

Biosynthesis of silver nanoparticles by banana pulp extract: Characterizations, antibacterial activity, and bioelectricity generation

Here, green banana pulp extract (PE) has been used as a bio-reducing agent for the reduction of silver ions to silver nanoparticles (AgNPs). Bio-synthesized AgNPs were characterized by using UV, XRD, FEEM, TEM, and FTIR analysis. The face-centered cubic structures of AgNPs were formed with an average crystallite size of 31.26 nm and an average particle size of 42.97 nm. In this report, the electrical activities of green synthesized AgNPs have been evaluated along with the antibacterial activities. The antibacterial activities of AgNPs were evaluated against two pathogenic bacteria: Escherichia coli (gram-negative) and Staphylococcus epidermidis (gram-positive). AgNPs were added to the electrochemical cell and results demonstrated the improvement of power of the electrochemical cell. Green synthesized AgNPs showed excellent antibacterial activities against both gram-positive and negative bacteria and most importantly the NPs played an important role as an effective catalyst to enhance the electrical performance of bio-electrochemical cells. These significant findings may help in the advancement of nanotechnology in biomedical applications as well as in the creation of cheap and eco-friendly power generation devices.

Green synthesis of Silver Nanoparticles and their antimicrobial applications

The exceptional antibacterial properties of silver nanoparticles (Ag NPs) and their prospective uses in different fields have attracted a lot of interest in contemporary times. The chemical agents used in the preparation of Ag NPs are hazardous to human health and the environment. In contrast to chemical approaches, green synthesis techniques involve the use of natural resources, which accomplish the principles of green chemistry and sustainable development goals (SDGs). In this regard, this review article delves into a comprehensive analysis of the green synthesis methods employed for the production of Ag NPs and their utilization as diverse antimicrobial agents. In addition to exploring the many antimicrobial uses of Ag NPs production, this article attempts to give a thorough examination of the processes behind the antibacterial activity of Ag NPs. This review provides in-depth mechanisms of antimicrobial action, including rupture of membranes, production of reactive oxygen species (ROS), and disruption of cellular functions. Thus, this article explores recent insights into green synthesis approaches for the preparation of Ag NPs which are effectively utilized as antimicrobial agents.

Antibacterial activity of silver nanoparticles synthesized from Citrus aurantium and its synergistic effect of the combination of silver nanoparticles with ampicillin against Proteus mirabilis

Abstract Background: Proteus mirabilis is one of the most infectious organisms that cause a various infections involving those of the skin, wounds, and urinary tract. This study describes the synthesis of silver nanoparticles (AgNps) and using it as an antibacterial agent. Objective: To determine the activity of AgNps and synergistic effect of combination of AgNps with ampicillin (AMP). Materials and Methods: Out of 205 samples, 32 isolated were identified as P. mirabilis and determine the inhibition zone by using AgNps and its combination with AMP. The AgNps were biosynthesized by Citrus aurantium and then characterized using Ultraviolet (UV)-visible spectroscopy, X-ray diffraction (XRD) and transmission electron microscope (TEM). The antibacterial activity of AgNps was done using well diffusion agar method and the activity was evaluated by calculating the increase in the inhibition zone and reduction in the bacterial growth. Results: The synthesized AgNps was first characterized by UV-visible spectroscopy which showed a peak between 400 and 500 cm–1. The color changes from clear yellow to red or brown color indicate the formation of AgNps. The particle size of AgNps was calculated and found to be 21.24 nm by XRD. The TEM images showed the presence of very regular particles in shape of nanospheres with a particle size in the range of 10–28 nm. Different concentrations (25, 50, 75, 100 µg/mL) were used for determining the activities of AgNps and the combination of AgNps with AMP, and the result showed that the most efficient in inhibition zone was at concentration 100 µg/mL. Conclusion: This study concluded that the green synthesized AgNps from C. aurantium leaves extract have most potential as antibacterial against P. mirabilis.

Synergistic effect of synthesized silver nanoparticles combined with amoxicillin/clavulanic acid against Pseudomonas aeruginosa isolated from clinical samples

Abstract Background: Pseudomonas aeruginosa is one of the most prevalent nosocomial pathogenic microorganisms that affect and cause a life-threatening situation. Objective: The study aimed to investigate the synergistic effect of silver nanoparticles (NPs) with amoxicillin/clavulanic acid antibiotic on P. aeruginosa growth. Materials and Methods: A total of 220 clinical samples were collected. A sample has been subjected to isolation and identification by standard microbiological procedures. The extract of Citrus aurantium was used to synthesize silver NPs. The characterization of silver NPs was achieved at the University of Tehran, by using UV–visible spectrophotometry, X-ray diffraction (XRD), and transmission electron microscope (TEM). The antibacterial activity of AgNPs and combination with amoxicillin/clavulanic acid antibiotic were tested against bacteria using the agar well diffusion method. Results: Out of the 220 samples collected, 33 (15%) isolates were positive for P. aeruginosa. Highest resistance of P. aeruginosa was found to amoxicillin/clavulanic acid in percentage of 100. NPs have been characterized by a UV–visible spectrometer which revealed a broad peak at 426 cm-1. XRD showed the purity of the prepared silver NPs that the particle size was equal to 21.26 nm. TEM measurement showed the presence of sphere-like structures with sizes of 20 nm for regular particles and 40 nm for irregular particles. AgNPs, amoxicillin/clavulanic acid, and mixture (amoxicillin/clavulanic acid + AgNPs) have high inhibition activity of P. aeruginosa in concentration of 100 µg/mL and recorded 21.33 ± 3.06, 13.00 ± 0.00, and 22.00 ± 3.46 mm, respectively. Conclusion: The results supported a green synthesis approach for the synthesis of AgNPs with antimicrobial. P. aeruginosa has synergistic combinations of AgNPs with amoxicillin/clavulanic acid, with a great inhibitory effect on the growth of the bacteria.

An investigation into synthesis and characterization of Ag-nanoparticles using green chemistry, and their antibacterial properties

The quest for new nano-systems is ongoing to provide tailored nanoparticle systems for commercial purposes. The ability to manage their size and morphology leads to an advantage over other characteristics, therefore, a stable generation system is considered critical for their applications. We employed rose plant leaves extract to generate Ag-NPs via silver nitrate (AgNO3) as a basic ingredient in this study. The procedure was executed for multiple concentrations of the plant extract, as well as varying amounts of salt, and for different time periods. All of the different steps resulted in the development of Ag-NPs. The emergence of an absorption peak at 425 nm in UV-Vis spectroscopic spectra, and the presence of spherical particles visualized through SEM provided evidence of the creation of small-sized Ag-NPs. Finally, using the spread plate method, the antibacterial activity of Ag-NPs was investigated, and it was discovered that Ag-NPs exhibit high antibacterial activity against the four bacterial strains.

Green synthesis of silver nanoparticles using Sambucus ebulus leaves extract: Characterization, quantitative analysis of bioactive molecules, antioxidant and antibacterial activities

Sambucus ebulus is a well-known medicinal plant used as a traditional medicine due to its bioactive compound contents. The importance of nanotechnology has increased recently since it has effective and widespread usage areas. In this study, silver nanoparticles (AgNPs@Se) were synthesized using S. ebulus leaf extract and their structures were clarified by spectroscopic analyses including FTIR, UV–Vis, and XRD. The morphology and particle size of AgNPs@Se were determined by SEM analysis. Quantitative analysis of bioactive compounds of S. ebulus leaf extract was defined by HPLC analysis. Antioxidant activity of extract and AgNPs@Se was executed by DPPH•, ABTS•+, and FRAP assays. The antibacterial activity of AgNPs was carried out using agar well diffusion and microdilution broth methods. Quantitative analysis of bioactive compounds in S. ebulus leaf extract was established by HPLC. The average particle size of nanoparticles was calculated as 18.6 nm. Isoquercitrin was found as a major product. AgNPs@Se displayed excellent antioxidant activity, but they revealed a moderate antibacterial effect. The structure of nanoparticles was assigned as a face center cubic unit cell. Hence, nanoparticles could be a favorable agent for the pharmaceutical and food industry.

Antibacterial Efficacy and Mechanical Strength of Direct Dental Composite Resins with Integrated Metal and Metal Oxide Nanoparticles: A Systematic Review of In-Vitro Studies

The present systematic review aimed to evaluate the antibacterial efficacy and mechanical strength of direct dental composite resins with integrated metal/metal oxide nanoparticles (NPs). A review was performed using different electronic databases employing MeSH terms for identifying relevant published literature, without any restrictions on language and date of publication. The antibacterial activity of metal/metal oxide NPs-incorporated composites for the prevention of secondary caries was the primary outcome, whereas the mechanical strength was designated as the secondary outcome. 6 studies used varying amounts of silver (AgNPs); 5 studies used zinc oxide (ZnO-NPs); 1 study used Ag-doped ZnO-NPs. Four studies found a statistically significant (p < 0.05) antibacterial activity of varying amounts of ZnO-NPs, five studies found a statistically significant (p < 0.05) antibacterial activity of AgNPs, two studies reported a statistically non-significant (p > 0.05), however greater antibacterial activity, by the incorporation of AgNPs. All included studies reported that the mechanical strength of the composites was not compromised by the addition of either ZnO-NPs or AgNPs. Metal/metal oxide-modified direct dental composite resins resulted in improved antibacterial efficacy without compromising their mechanical strength as compared to non-modified composite resins. However, it is imperative to determine an equilibrium between the mechanical features and antibacterial activity of these materials, and more in vivo investigations are recommended in this aspect.

Amomum subulatum Fruit Extract Mediated Green Synthesis of Silver and Copper Oxide Nanoparticles: Synthesis, Characterization, Antibacterial and Anticancer Activities

This research presents a straightforward, effective, and eco-friendly method for the production of silver nanoparticles (AgNPs) and copper oxide nanoparticles (CuONPs) using the dried fruit of Amomum subulatum as a reducing, stabilizing, and capping agent. The formation of AgNPs and CuONPs is supported by the presence of a surface plasmon resonance band (SPR) at 440 nm for AgNPs and 245 nm for CuONPs. Additionally, the identification of specific biomolecules responsible for the synthesis of AgNPs and CuONPs was confirmed through FTIR spectra analysis. The Transmission electron microscope (TEM) images demonstrated that AgNPs and CuONPs had spherical shapes, with mean particle diameters of 20.6 nm and 24.7 nm, respectively. X-ray diffraction and selected area electron diffraction (SAED) analyses provided evidence of the crystalline nature of the synthesized AgNPs and CuONPs. Additionally, the presence of silver and copper elements was observed through energy-dispersive X-ray spectroscopy (EDS) analysis. Furthermore, the antibacterial activity of AgNPs was found to be superior to that of CuONPs against human pathogens such as Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The cytotoxic activity of the biosynthesized nanoparticles (NPs) was evaluated in vitro against human cervical cells (HeLa) and human breast cells (MCF-7). In MCF-7 cells, the IC50 value for AgNPs was estimated to be 39.79 µg/mL, while that of CuONPs was 83.89 µg/mL. In HeLa cells, the IC50 value for AgNPs was 45.5 µg/mL, and for CuONPs, it was 97.07 µg/mL. For the first time, an eco-friendly method for the synthesis of AgNPs and CuONPs from fruit extract of Amomum subulatum has been discussed along with their comparative evaluation study. These results highlight the promising applications of the eco-friendly synthesized AgNPs and CuONPs as effective agents against microbial infections and potential candidates for cancer therapy.