A Review on the Synthesis, Formation Mechanisms, Antimicrobial Activities, and Toxicities of Phytochemical-Mediated Biosynthesized Silver Nanoparticles for Incorporation in Acne-Related Cosmetic Products

Background: Citrus aurantifolia juice has been useful for the treatment of various infections and green synthesis of silver nanoparticle using lime juice may offer added advantages.Objective: The phytochemical composition and comparative evaluation of antimicrobial activities of the crude juice extract and biosynthesized Silver nanoparticle (SNPs) from Citrus aurantifolia juice was investigated.Materials and methods: Phytochemical, antimicrobial evaluation (agar well diffusion) and biosynthesis of SNPs was done using Crude extract of Citrus aurantifolia. The SNPs were characterized by colour changes, spectroscopy and Fourier-Transform Infrared (FTIR) Spectroscopy.Results: The juice extract contained bioactive compounds such as flavonoids (710mg/100g), tannins (525mg/100g), phenols (65mg/100g) and terpenes (56mg/100g). Changes in colour, UV-Vis Spectroscopy at 300-550nm ranges and FTIR revealed the functional groups present in the biosynthesized SNPs. The crude extract and SNPs exhibited varying antimicrobial activities against some selected pathogens including Streptococcus pyogenes ATCC 19615, Klebsiella pneumoniae ATCC 10031, Bacillus sp, Actinobacillus sp., Pseudomonas aeruginosa and Staphylococcus aureus. The crude extract has more antibacterial potential against the tested pathogens than the biosynthesized SNPs. The crude extract also had higher antimicrobial activities against Streptococcus pyogenes which were resistant to ciprofloxacin. The result revealed that the crude extract was more effective than the SNPs produced and the Minimum Inhibitory concentration (MIC) also showed increasing activities with an increase in the concentration of the juice extract and SNPs.Conclusion: Crude extract of Citrus aurantifolia contain bioactive compound with potent antimicrobial potential and the extract was more effective than the biosythesized SNPs.Keywords: Citrus aurantifolia juice, Silver nanoparticle, phytochemical, antimicrobial activities, minimum inhibitory concentration.

<h2>Abstract</h2>\n<p><strong>Objectives:</strong> To evaluate the efficacy of edible mushroom, Macrocybe gigantea for the biosynthesis of silver nanoparticles, antioxidant property and antibacterial property. <strong>Methods:</strong> M. gigantea pure culture was isolated using tissue culture in a petri-plate comprising potato dextrose agar (PDA) medium, spawn was prepared using sorghum grains and mushrooms were grown indoors using paddy straw in an uniquely designed environment for mushroom growth. The green synthesis of silver nanoparticles with AgNO3, antioxidant activity and antibacterial potential against a few food-borne bacteria were all investigated. The formation of AgNPs was further confirmed using a UV-Visible spectrophotometer. The silver nanoparticles were examined using Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The disc diffusion method was used to test the bacteriostatic and bactericidal activity of synthesised silver nanoparticles against selected food-borne bacteria such as Escherichia coli, Bacillus subtilis and Streptococcus mutans. <strong>Findings:</strong> The existence of phytochemicals such as alkaloids, terpenoids, phenols, flavonoids, proteins, and carbohydrates was revealed. Furthermore, the AgNPs produced from M.gigantea demonstrated absorbance at 420nm in a UV-Visible spectrophotometer. According to the SEM pictures, AgNPs appear spherical with diameters ranging from 50 to 70nm. At 100g/mL, the DPPH antioxidant assay exhibited the maximum percentage of inhibition of 67.94%, with an IC50 value of 57.07g/mL. The produced AgNPs also inhibited bacterial growth significantly. Green synthesised AgNPs from M.gigantea were produced in an environmentally friendly, quick and simple technique that functions as an antibacterial agent against certain food-borne pathogens such as E. coli, Bacillus subtilis, and Streptococcus mutans. The antibacterial screening demonstrates the biocidal ability of AgNPs from M.gigantea, which could be employed in the food processing and packaging industries. <strong>Novelty:</strong> This study is regarded as the first attempt to synthesise AgNPs from M.gigantea for use against food-borne bacteria.</p>\n<p><strong>Keywords:</strong> Macrocybe gigantea; Agnps; MycoNanoparticle; Antibacterial Activity; DPPH And Antioxidant</p>

The present study reports the green synthesis of silver and gold nanoparticles (NPs) from their respective precursors AgNO3 and HAuCl4, using root bark extract of Mammea suriga. Further, it describes the influence of various reaction parameters, such as pH, temperature, precursor concentration, and volume of the extract, on the morphology and size of the newly synthesized NPs. The biosynthesized NPs were characterized using UV–Vis spectroscopy, SEM, EDX, XRD, and FTIR. The formation of Ag and Au NPs was confirmed by their UV–Vis spectra. Ag NPs were efficiently synthesized at pH 10, with precursor concentration of 1 mM of AgNO3 and a reaction temperature of 80 °C, while Au NPs were successfully obtained at pH 8, with precursor concentration of either 1 or 3 mM HAuCl4, and the reaction was maintained at room temperature. The SEM study revealed that the particle size decreases with an increase in the extract volume used in the reaction. The XRD analysis confirmed the formation of metallic Ag and Au NPs having an average size of 50 and 22 nm, respectively. Further, the FTIR spectral data established the role of various functional groups of biomolecules involved in bioreduction as well as capping of NPs. The in vitro antibacterial screening results indicated that the NPs are potential antibacterial agents. Conclusively, the overall study showed that the root bark extract of M. suriga is an excellent eco-friendly and non-toxic source for the synthesis of biologically active Ag and Au NPs at optimal conditions.

Metal nanoparticles have attained much popularity due to their low toxicity, economic feasibility, and eco-friendly nature. The present study focuses on the synthesis of silver and zinc nanoparticles from Vitex altissima leaf extract, further characterized by UV/Vis spectral analysis, Powder-x-ray diffraction (XRD), FE-SEM, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential. Synthesized silver and zinc nanoparticles were screened for antioxidant, anti-inflammatory, antibacterial, and anti-biofilm activities. AgNPs exhibited moderate antioxidant activities compared to ZnNPs, which were studied using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and ABTS assays. The anti-inflammatory effect was assessed using membrane stabilization and human red blood cell methods. Furthermore, both types of nanoparticles, AgNPs and ZnNPs, exhibited anti-biofilm activity against four MDR bacterial strains: Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Synthesized nanoparticles show antibacterial activity. Our data suggest that silver nanoparticles exhibited moderate activity compared to ZnNPs. These nanoparticles could act as potential antioxidant, anti-inflammatory, and antibacterial agents.

Globularia alypum methanolic extract improves burn wound healing process and inflammation in rats and possesses antibacterial and antioxidant activities.

Plants have been widely adopted as an alternative medicine for different diseases. Recent studies show that various parts of Theobroma cacao have been used to treat some diseases or disorders. For example, individuals in rural areas have been using the exocarp of T. cacao as an alternative medicine for furuncle. However, there was no scientific study that was conducted related to this. Several studies about cocoa beans have shown antimalarial, antioxidant, anti-cough, anti-influenza, anti-diabetic, and anti-hypertensive activities. However, there was no study about the fruit exocarp cacao. This study investigated the phytochemical composition, antibacterial potential, and anti-inflammatory activity of the fruit exocarp of Theobroma cacao. The different activities were done using the standard methods with some slight modifications. Antibacterial activity was done using the disc diffusion method and Human Red Blood Cell (HRBC) membrane stabilization method for anti-inflammatory activity. Results of the study have shown no antibacterial activity for the plant extract; however, the plant exhibits anti-inflammatory activity. The 500 ?g/ml concentration of cacao extract shows a lower percentage of hemolysis and a higher percentage of protection of the Human Red Blood Cell membrane. The observed anti- inflammatory activity shows to be dose-dependent of the extract in that the higher the concentration used, the lower the number of hemolysis and the higher the number of protections that occurs. Phytochemical screening of the exocarp of T. cacao has shown the highest content of flavonoids, tannins, and steroids. Further studies on the antioxidant activity may be conducted, for this activity is the most studied one attributed to flavonoids. Keywords : alternative medicines, disc diffusion method, furuncle, HRBC membrane stabilization method, phytochemical composition

<strong>Objective(s):</strong> Among herbal oils, cinnamon bark oil has several advantages such as anti-inflammatory and antimicrobial activity. It is already reported that particle size of oil droplets affects their properties such as their antibacterial activity. In this study, we investigated inhibitory activity of cinnamon oil products including bulk, microemulsion (ME) and nanoemulsion (NE). <strong>Methods: </strong>ME and NE were prepared by low energy methods. Physicochemical characterization of cinnamon oil ME (COME) and NE (CONE) were investigated. Bulk, ME and NE of cinnamon oil were evaluated for antibacterial inhibitory activity against <em>Escherichia coli</em> and <em>Staphylococcus aureus</em> by microdilution method. <strong>Results:</strong> Average particle size of COME and CONE was found to be 2040 nm and 30.4 nm, respectively. Results showed that both CONE and COME had increased inhibitory activity (p<0.05) against bacterial infection compared with ablank control group, of which COME had highest antibacterial effects. <strong>Conclusions:</strong> Our findings suggested COME and CONE as potential green antibacterial agents.

Aim and Objective: We reported in this manuscript, synthesis of novel pyrazolopyrazinothienopyrimidines. The o-amino-thienopyrazolopyrazine-carbonitrile 4 was used as a versatile precursor for synthesis of new heterocyclic compounds. Due to development of resistance to the current antimicrobial therapy and non-steroidal anti-inflammatory drugs (NSAIDs), continues research for more effective agents is interesting. Hence, the suspected promising biological activities of pyrazolopyrazine compounds persuaded us to study the anti-microbial and anti-inflammatory activities in comparison with standard drugs. Materials and Methods: The chemical structures of the newly synthesized compounds were confirmed by elemental and spectral analyses. Activities of the synthesized compounds against a number of Gram-negative and Gram-positive bacterial strains were investigated. The fungal strains were obtained from some cases of human dermatophytosis. The antimicrobial activities were determined according to the Kwon-Chung and Bennett method. Anti-inflammatory activity was evaluated using carrageenan induced paw edema method. Results: The antibacterial screening of the synthesized compounds represented that the o-amino-carbonitrile 4 and triazepinone 11 have the highest activity towards E. coli &amp; S. aureus and S. pneumonia. The amino-imino 6 was very effective against E. coli. Ring closure of 6 to triazolopyrimidine 7 increases the antibacterial activity against E. coli &amp; K. pneumonia, their inhibition zones were higher than ciprofloxacin. Also, the triazolopyrimidines 7 and 10 exhibited high antifungal activity against all tested strains. Compounds 6 and 11 revealed high antifungal activity against S. racemosum and T. rubrum. The anti-inflammatory activity data indicated that all the tested compounds 4, 6, 7, 10 &amp; 11 revealed the highest anti-inflammatory effect after 4 hrs. of carrageenan injection. Conclusion: we found that most of the examined novel thieno- pyrazolopyrazine compounds exhibited promising antibacterial, antifungal and anti-inflammatory activities which can be used as potential antibacterial, antifungal and anti-inflammatory drugs.

Globally, silver nanoparticles (SNP) were created using a biologically activated green synthesis process that has raised substantial awareness of medical science and illness therapy. A new method of synthesising SNPs based on a bottom-up, "green" approach is described here Guazuma ulmifolia Lam. leaf aqueous extract in addition to assess their antibacterial, anti-inflammatory also anticancer in vitro properties. By using well diffusion method, the antibacterial activity possessed by nanoparticles against Staphylococcus aureus, Staphylococcus gallinarium, Bacillus subtilis, Pseudomonas stuberia, in addition to Escherichia coli was examined. Subsequently, these GUSNPs (Guazuma ulmifolia Silver Nanoparticles) were investigated for anticancer activity assessed by MTT assay utilizing HepG2 carcinoma cell line, and anti-inflammatory activity assessed by HRBC stabilization assay protein denaturation assays. In dosage of 10 μg/ml, the GUSNPs had the maximum antibacterial activity against the following bacteria: Staphylococcus aureus (7.1 mm), Staphylococcus gallinarium (5.2 mm), Bacillus subtilis (6.7 mm), Pseudomonas stuberia (6.3 mm), and Escherichia coli (4.7 mm), respectively. Membrane stabilization of HRBCs had a substantial anti-inflammatory activity (73.27±0.89%), whereas the GUSNPs had the best protection of protein denaturation (79.35±0.42%) at 1000 μg/ml. The best cytotoxicity activity of GUSNPs against HepG2 cell line was found in 500 μg/ml concentration with 24.32 percent of cell viability. The current study of GUSNPs has good antibacterial, anti-inflammatory, and anticancer activities.

Group IIA secreted phospholipase A(2) (sPLA2) is known to display potent Gram-positive bactericidal activity in vitro and in vivo. We have analyzed the bactericidal activity of the full set of recombinant murine and human groups I, II, V, X, and XII sPLA2s on Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli. The rank order potency among human sPLA2s against Gram-positive bacteria is group IIA > X > V > XII > IIE > IB, IIF (for murine sPLA2s: IIA > IID > V > IIE > IIC, X > IB, IIF), and only human group XII displays detectable bactericidal activity against the Gram-negative bacterium E. coli. These studies show that highly basic sPLA2s display potent bactericidal activity with the exception of the ability of the acidic human group X sPLA2 to kill Gram-positive bacteria. By studying the Bacillus subtilis and S. aureus bactericidal potencies of a large panel of human group IIA mutants in which basic residues were mutated to acidic residues, it was found that: 1) the overall positive charge of the sPLA2 is the dominant factor in dictating bactericidal potency; 2) basic residues on the putative membrane binding surface of the sPLA2 are modestly more important for bactericidal activity than are other basic residues; 3) relative bactericidal potency tracks well with the ability of these mutants to degrade phospholipids in the bacterial membrane; and 4) exposure of the bacterial membrane of Gram-positive bacteria by disruption of the cell wall dramatically reduces the negative effect of charge reversal mutagenesis on bactericidal potency.

Background: Drug-resistant bacteria are a major threat for hospitals, complicating hospital-acquired infections. Objective: To promote medicinal plants as alternative therapeutics to current conventional antibacterial agents which are increasingly tolerated by bacteria, the present investigation assessed the antibacterial potentials of the hydroethanolic extract recovered from dried leaves of Cajanus cajan (L.) Millsp., on multidrug-resistant bacteria isolated from a healthcare facility environment. Methods: For this purpose, multidrug-resistant (MDR) bacteria were isolated from specimens collected from the “Université des Montagnes” Teaching Hospital environment, where local bacterial flora were previously found to express high rates of resistance to conventional antibacterial agents and to disinfectants. The antibacterial potential was investigated through the determination of the minimal inhibitory and bactericidal concentrations of the extract from which a few groups of secondary metabolites were screened. Results: Qualitative phytochemical screening revealed the presence of flavonoids, polyphenols, quinones, tannins and terpenes in the extract used. On a pool of 64 multidrug-resistant bacteria isolates (Gram-positive rods: 23; Gram-positive cocci: 20; Gram-negative rods: 21), the minimal inhibitory and bactericidal concentrations of the hydroethanolic extract from dried leaves of Cajanus cajan (L.) Millsp. ranged from 1.465 through 93.75 mg/mL, and from 6.25 through 175 mg/mL, respectively. Gram-positive rods exhibited the highest tolerance (MIC = 69.4185±17.4405 mg/mL; MBC = 116.8478±35.677 mg/mL), while Gram-positive cocci were most susceptible (MIC = 3.2663±1.6854 mg/mL; MBC = 12.0701±5.7882 mg/mL). Amongst the Gram-negative rods, higher resistance was observed with Pseudomonas (MIC = 43.2292±3.0725 mg/mL; MBC = 73.9583±11.2962 mg/mL), and Enterobacteriaceae (MIC = 12.2342±3.6743 mg/mL; MBC = 22.1153±6.3016 mg/mL). Eventually, this extract expressed a bactericidal potential on 78.125% of subjected isolates. Conclusion: The antibacterial assays revealed a significant antibacterial activity against MDR Gram-positive cocci and Gram-negative rods, which are due to bioactive compounds present in the plant as revealed by the phytochemical screening. Hence, the current findings indicate that this extract could effectively serve in controlling environmental antibiotic-resistant bacteria which are threat in healthcare settings and to public health at large.

Introduction and Aim: The present study investigated the biosynthesis of silver nanoparticles (AgNPs) using aqueous stem extract of Tinospora sinensis under the influence of sunlight irradiation. Materials and Methods: For the biosynthesis of AgNPs 90 ml of 10-3 M AgNO3 was mixed with 10 ml of the aqueous stem extract of Tinospora sinensis and the solution was kept under sunlight. The formation of AgNPs were monitored using UV-Vis spectroscopy. Furthermore, the characterization of the synthesized AgNPs were accomplished using X-ray diffraction (XRD), Fourier transforms infr ared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy Dispersive X-ray (EDX), Dynamic Light Scattering (DLS). Results: The reaction mixture changes its colour from pale yellow to dark brown within 30 minutes. The UV-Vis spectra of AgNPs showed an absorption peak at 445 nm, which indicated the formation of AgNPs. The SEM and the DLS analysis revealed the spherical shape of the AgNPs with an average particle size of 74.2 nm. The XRD analysis confirmed the crystalline nature of the AgNPs. Furthermore, the synthesized silver nanoparticles act as a catalyst in degradation of 4-nitrophenol by NaBH4. Moreover, the biosynthesized AgNPs showed antibacterial activity against three bacterial strains viz. Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027) and Staphylococcus aureus (ATCC 6538P). Conclusion: In the present study, AgNPs have been successfully synthesized using aqueous stem extract of Tinospora sinensis under the influence of sunlight irradiation. The synthesized AgNPs exhibits catalytic as well as antibacterial properties that makes it suitable for environmental remediation. Keywords: Silver nanoparticles; Tinospora sinensis; sunlight irradiation; antibacterial; dye degradation.

The silver nanoparticles (AgNPs) green synthesis has been investigated by selecting naturally occurred reduction and stabilizing/capping agents. In this work, Ilex paraguariensis aqueous extract in the one-step biosynthesis of AgNPs is reported. The synthesis was carried out at room temperature under different pH (5.0, 6.8 and 8.5) and extract concentrations (2.5, 5.0 and 7.5% v v−1) resulting in average diameters ranging from 34 to 144 nm and polydispersity index (PDI) up to 0.51. The morphological characterization was performed by Transmission Electron Microscopy, associated with the UV–Vis Spectroscopy, showing that at higher pH the shape of AgNPs was more spherical rather than ellipsoidal. X-ray diffraction (XRD) pattern of AgNPs exhibited 2θ values corresponding to silver nanocrystals. Colloidal AgNPs solution synthesized with pH 8.5 and extract concentration of 2.5% v v−1 remained stable for 10 months of storage at ambient temperature. Fourier Transform Infrared Spectroscopy suggested that the polyphenols were responsible for the AgNPs formation. AgNPs presented bacteriostatic and bactericidal activity. AgNPs presented in vitro rat brain acetylcholinesterase (AChE) activity, with higher inhibition potential at 200 µL. So, it is concluded that AgNPs were synthesized with success, the pH and extract concentration influences in AgNPs size and morphology, consequently in its antimicrobial and AChE activity.

Background: Silver nitrate AgNPs nanoparticles have garnered significant attention for their unique antibacterial properties, making them a valuable addition to the medical field. Extracellular biosynthesis of AgNPs was performed by employing an aqueous extract of Eriobotrya japonica seeds to reduce silver nitrate ions in a short period. Objectives: We aimed to prepare AgNPs from the aqueous extract of fruit seeds and detect its antibacterial effect. Materials and Methods: AgNP formation was attested by altering the color of the plant extracts’ single-nucleotide polymorphisms (SNPs) to coffee and several spectroscopic and microscopic analyses. The AgNP formation was also confirmed by spectroscopy. These silver nanoparticles of plant origin were tested for antibacterial activities using the disk-diffusion method, with three concentrations of 50, 100, 150 mg/mL, using Klebsiella, Escherichia coli, and Streptococcus mutans. Results: The inhibitory antimicrobial property of silver nanoparticles was assessed by measuring the area of inhibition. Dishes treated with silver nanoparticles made from extracts of E. japonica seeds encountered toxicity. It yielded the highest inhibition diameters at a concentration of 150 mg/mL toward E. coli and Klebsiella, which were 20 mm, whereas the growth of S. mutans was 15 mm. The antibacterial activity of silver was magnified by SNPs synthesized from the seed extract compared with that of anti-penicillin; the results suggested that AgNPs may have a good antibacterial advantage over conventional antibiotics. Conclusion: Antibacterial research on the E. japonica seed extract shows its potential as a natural antimicrobial. The study indicated that higher seed extract concentrations are more effective in limiting bacterial growth. The extract showed broad-spectrum antibacterial activity against Klebsiella, E. coli, and S. mutans, suggesting that E. japonica may be a good alternative or supplement to antibiotics. These findings suggest that E. japonica seed extract can be used to create novel antibacterial medicines, especially given the issue of antibiotic resistance. The study also shows that addition of natural ingredients can promote synthesis of physiologically active nanoparticles.

In this study, we explored the green synthesis of metal nanoparticles (Ag-NPs, Au-NPs, and Pd-NPs) using Moringa oleifera seed (MOS) extract, which is known for its nutrient density, antioxidant properties, anti-inflammatory effects, and potential benefits in managing cholesterol, blood sugar levels, as well as promoting digestion, skin, and hair health. The nanoparticles’ size was controlled by varying the concentration of MOS extract. The successful formation of Au-NPs and Ag-NPs was confirmed through surface plasmon resonance (SPR), while the absence of absorption at 420 nm indicated the reduction of Pd2+ ions to Pd0, affirming the synthesis of Pd-NPs. The nanoparticles exhibited mono-dispersed, spherical shapes with confirmed crystallinity. Sizes were determined as 28 nm for Pd-NPs, 5 nm for Au-NPs, and 19 nm for Ag-NPs. The MOS extract’s phenols and proteins played a crucial role in reducing and stabilising Ag-NPs, Au-NPs, and Pd-NPs. Notably, the synthesised nanoparticles demonstrated strong antimicrobial activity, particularly against Salmonella typhi, making them potential antibacterial agents. The catalytic efficiency of Au-NPs, Ag-NPs and Pd-NPs was studied using the reduction of 4-Nitrophenol (4-NP) by NaBH4 to 4-Aminophenol. Additionally, Au-NPs showed enhanced photocatalytic degradation rate constant and catalytic reaction rate constant of 0.0038/min and 0.261/min respectively, due to their small size and increased surface area. By combining a green synthesis approach with an in-depth analysis of properties and diverse applications, this study provides valuable insights into the immense potential of MOS-assisted metal nanoparticles for various technological and environmental advancements.