Antioxidant Activity Of AgNPs Research Articles

Synthesis, Characterization, Phytochemistry, and Therapeutic Potential of Azadirachta indica Conjugated Silver Nanoparticles: A Comprehensive Study on Antidiabetic and Antioxidant Properties.

Nanotechnology has become a major topic of study, particularly in the medical and health domains. Because nanomedicine has a higher recovery rate than other conventional drugs, it has attracted more attention. Green synthesis is the most efficient and sustainable method of creating nanoparticles. The current work used ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray, and X-ray diffraction to thoroughly characterize the synthesized silver nanoparticles (AgNPs) from Azadirachta indica leaf extract. Characterization confirmed the synthesis of the AgNPs along with the possible linkage of the phytochemicals with the silver as well as the quantitative analysis and nature of NPs. The antioxidant activity of AgNPs and neem extract was measured by the 2,2-diphenyl-1-picrylhydrazyl assay using various concentrations (20, 40, 60, 80, and 100µg/ml). Additionally, using diabetic mice that had been given alloxan, the in vivo antidiabetic potential of biosynthesized AgNPs was assessed. Eight groups of mice were used to assess the antidiabetic activity: one control group and seven experimental groups (untreated, extract-treated, AgNPs at low and high doses, standard drug, low dose of AgNPs + drug, and high dose of AgNPs + drug). At days 0, 7, 14, 21, and 28, blood glucose levels and body weight were measured. After 28days, the mice were dissected, and the liver, kidney, and pancreas were examined histologically. The results depicted that the AgNPs showed higher (significant) radical scavenging activity (IC50 = 35.2µg/ml) than extract (IC50 = 93.0µg/ml) and ascorbic acid (IC50 = 64.6µg/ml). The outcomes demonstrated that biosynthesized AgNPs had a great deal of promise as an antidiabetic agent and exhibited remarkable effects in diabetic mice given AgNPs, extract, and drug. Remarkable improvement in the body weight and blood glucose level of mice treated with high doses of AgNPs and drug was observed. The body weight and blood glucose level of diabetic mice treated with a high dose of AgNPs + standard drug showed significant improvement, going from 28.7 ± 0.2 to 35.6 ± 0.3g and 248 ± 0.3 to 109 ± 0.1mg/dl, respectively. Significant regeneration was also observed in the histomorphology of the kidney, liver's central vein, and islets of Langerhans after treatment with biosynthesized AgNPs. Diabetic mice given a high dose of AgNPs and drug displayed architecture of the kidney, liver, and pancreas that was nearly identical to that of the control group. According to the current research, biosynthesized AgNPs have strong antioxidant and antidiabetic potential and may eventually provide a less expensive option for the treatment of diabetes.

Biological Synthesis of Silver Nanoparticles from Lavandula mairei Humbert: Antibacterial and Antioxidant Activities.

Hospital-acquired infections involving carbapenem-resistant Acinetobacter baumannii (A. baumannii) and extended spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae pose significant challenges in the intensive care units. The lack of novel antimicrobial drugs amplifies the urgency to explore innovative management strategies. Nanotechnology, with its ability to generate nanoparticles possessing specific properties beneficial in drug delivery and nanomedicine, stands as a pivotal research domain. The objective of this study was to synthesize, for the first time, biologically silver nanoparticles (Ag-NPs) from Lavandula mairei Humbert (L. mairei) plant. The biosynthesized Ag-NPs were characterized by UV-visible spectral analysis, X-Ray diffraction Analysis, Fourier transform infrared spectroscopy analysis, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy. Subsequently, the antibacterial and antioxidant activities of Ag-NPs were assessed using the micro-dilution method, DPPH test and FRAP assay, respectively. The green-synthesized Ag-NPs exhibited high antibacterial activity against ESBL-producing multidrug-resistant (MDR) strains and against carbapenem-resistant and non-carbapenem-resistant strains of A. baumannii, as well as a very interesting antioxidant activity. The present study suggests that these results hold very promising for the potential application of biologically synthesized Ag-NPs from L. mairei (Ag-LM-NPs) in the invention of novel antibacterial and antioxidant agents.

Biosynthesized Silver Nanoparticles Using Alnus nitida Leaf Extract as a Potential Antioxidant and Anticancer Agent.

Biogenic synthesis of silver nanoparticles (AgNPs) using plant extracts is gaining attention as a substitute to the conventional physical and chemical synthesis methods. This study reports a facile, cost-effective, and ecofriendly synthesis of AgNPs using leaf extract of Alnus nitida (A. nitida) and their antioxidant and antiproliferative activities. The biosynthesized AgNPs were characterized using various analytical techniques including UV-visible spectroscopy, energy-dispersive spectrometry, scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and dynamic light scattering. The antioxidant and cytotoxic potential of the extract and AgNPs was evaluated using different in vitro models. The UV-vis analysis revealed a surface plasmon resonance peak of 400 nm corresponding to the synthesis of AgNPs. SEM analysis confirmed the formation of heterogeneously dispersed particles of nano size, while the XRD and FTIR spectra confirmed the crystallinity and existence of different functional groups that helped in capping and stability of AgNPs. The antioxidant activity of AgNPs and extract, studied by 1,1-diphenyl 2-picryl hydrazyl (DPPH), fluorescence recovery after photobleaching (FRAP), 2, 2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and H2O2 scavenging assays, showed a dose-dependent effect. The AgNPs at 1000 μg/mL significantly scavenged DPPH, FRAP, ABTS, and H2O2 by 66.45, 74.65, 78.81, and 72.56% with an average IC50 value of 33.31, 18.50, 16.46, and 15.65 μg/mL, respectively. The cytotoxic potential investigated by MTT assay revealed promising antiproliferative effects against different cancer cell lines. The IC50 values of AgNPs on MDA-MB-231, A549, and Hep-G2 cells were 14.88, 3.6, and 5.38 μg/mL, respectively. The results showed that AgNPs were more effective against lung and hepatocellular carcinoma. The selectivity index showed that AgNPs remained highly selective in retarding the growth of A549 and Hep-G2 cells as compared to normal cell lines HPAEpiC and HRPTEpiC. Overall, this study showed that biosynthesized AgNPs were associated with considerable antioxidant and cytotoxic effects. Our work suggests that A. nitida-mediated AgNPs should be evaluated further in order to develop safe and effective formulations for the treatment of different degenerative diseases.

Apoptotic, cytotoxic, antioxidant, and antibacterial activities of biosynthesized silver nanoparticles from nettle leaf

Here, we reported the biosynthesis of silver nanoparticles (AgNPs) using Urtica dioica (nettle) leaf extract as green reducing and capping agents and investigate their anticancer and antibacterial, activity. The Nettle-mediated biosynthesized AgNPs was characterized by UV-Vis a spectrophotometer. Their size, shape and elemental analysis were determined with the using of SEM and TEM. The crystal structure was determined by XRD and the biomolecules responsible for the reduction of Ag+ were determined using FTIR analysis. Nettle-mediated biosynthesis AgNPs indicated strong antibacterial activity against pathogenic microorganisms. Again, the antioxidant activity of AgNPs is quite high when compared to ascorbic acid. Anticancer effect of AgNPs, IC50 dose was determined by XTT analysis using MCF-7 cell line and the IC50 value was found to be 0.243 ± 0.014 μg/mL (% w/v).

Silver Nanoparticles from Saudi and Syrian Black Cumin Seed Extracts: Green Synthesis, ADME, Toxicity, Comparative Research, and Biological Appraisal.

The current study's objective is to highlight the value of using plant resources to identify key bioactive molecules and implement green chemistry in research and development to meet market demand. The black cumin seeds (Saudi and Syria originated) were utilized to make silver nanoparticles (Ag-NPs), which were subsequently confirmed using a UV spectrophotometer and color analysis of reaction mixtures. The antibacterial activity of Ag-NPs was tested against E. coli, K. pneumoniae, and S. aureus, and antioxidant activity was measured using the DPPH assay. Swiss-ADME, pkCSM, and ProTox-II were also used to assess the pharmacokinetics, oral bioavailability, toxicity, and safety endpoints of molecules. The antibacterial effect of Ag-NPs from Saudi-origin black cumin seeds was observed higher. In comparison to the standard, the Saudi and Syrian Ag-NPs combined displayed synergistic antibacterial effects and were found to be more susceptible to S. aureus. In comparison to the reference, the antioxidant activity of Ag-NPs indicated 60-85% radical scavenging. All molecules passed the Lipinski rule, the filter (Veber, Egan, and Muegge), PAINS, and the Brenk structural alert (zero violations), and the synthetic score was also found to be in the easy limit (1 to 2). The compounds were found to be non-substrate for p-glycoprotein, high GIA% (>90%), non-inhibitor for CYP3A4, CYP2C19, CYP2C9, CYP2D6 (except 5 and 10), Log Po/w (1.71 to 3.26), TPSA 150 2 and MR 155. The compounds likewise had high Caco2 values (log Papp >0.9) with the exception of 4 and 9 (log Papp 0.9), were non-inhibitors of P-gp-I and II and hERG I and II, and showed no AMES toxicity. Except for molecule 11, no organ damage (hepatotoxicity) or endpoint toxicity (mutagenicity, immunotoxicity, carcinogenicity, and cytotoxicity) was identified in ProTox-II. The current study sheds new light on the significance of bioactive molecules found in black cumin seeds, with molecules 3 and 6 identified as potential leads (highest GIA%, no AMES toxicity, oral rat acute and chronic toxicity, lack of renal OCT2 substrate, high total clearance, and lack of organ toxicity) for further research for a variety of medical applications.

Xanthan gum mediated monowave synthesis of silver nanoparticles: Characterization, anticancer, antimicrobial, antioxidant and catalytic studies

Using a monowave approach, stabilized silver nanoparticles (AgNPs) were synthesized by xanthan gum as a reducing agent. The combination of XG and AgNPs is a cost-effective and environmentally friendly method of synthesis. The effects of various parameters, such as time and concentrations of silver nitrate and xanthan gum, on the formation of AgNPs were also studied. The synthesized AgNPs were analyzed using UV–Vis spectrophotometry, FTIR, X-ray diffractometry, and TEM measurements, revealing the characteristic SPR band for Ag at 420 nm. TEM images indicated that over 70% of the AgNPs were below 10 nm in size. Green-synthesized AgNPs exhibited significant anticancer activity against MCF-7 cells, outperforming Doxorubicin. Antibacterial studies showed that AgNPs possess inhibitory properties against both gram-positive and gram-negative bacteria. The antioxidant activity of AgNPs was evaluated using DPPH assay, and IC50 values of 40.2 µg/mL and 43.4 µg/mL were obtained, indicating significant free radical scavenging activity. Finally, the catalytic activity of AgNPs was studied with respect to the reduction of hexacyanoferrate (III) by sodium borohydride in aqueous solution. These AgNPs exhibited good catalytic activity, and the kinetics of the reaction were found to be pseudo first order with respect to the hexacyanoferrate (III).

One-step synthesized biogenic nanoparticles using Linum usitatissimum: Application of sun-light photocatalytic, biological activity and electrochemical H2O2 sensor

This study aimed to synthesize Ag NPs as a green catalyst for photocatalytic activity and to examine their biological activities. It was determined that they have high activity in catalytic and biological activities. The green synthesis which is an environmentally friendly and inexpensive method was used to synthesize Ag-NPs using Linum usitatissimum as a reducing agent. Transmission electron microscopy (TEM), infrared to Fourier transform infrared (FTIR) spectroscopy, UV-Visible (UV–Vis) spectroscopy, and X-ray diffraction (XRD) were used to characterize the Ag NPs. In UV–Vis examination, Ag-NPs had intense peaks in the 435 nm region. The antibacterial activity of Ag NPs was investigated, and Ag NPs showed a high lethal effect against S. aureus, E. coli, B. subtilis, and MRSA. In addition, Ag NPs were tested for anticancer activity against the HT-29 colon cancer cell line, MDA-MB-231 breast cancer cell line, healthy cell line L929-Murine Fibroblast cell Lines, and MIA PaCa-2 human pancreatic cancer cell line at various concentrations (1–160 μg/mL) and showed a high anticancerogenic properties against MDA-MB-231 cells. Ag NPs showed the ability of DNA cleavage activity. Also, the antioxidant activity of Ag NPs against DPPH was found to be 80% approximately. Furthermore, the photocatalytic activity of Ag NPs against methylene blue (MB) was determined to be 67.13% at the 180th min. In addition, it was observed that biogenic Ag NPs have high electrocatalytic activity for hydrogen peroxide (H2O2) detection. In the sensor based on Ag NPs, linearity from 1 μM to 5 μM was observed with a detection limit (LOD) of 1.323 μM for H2O2. According to these results, we conclude that the biogenic Ag NPs synthesized using Linum usitatissimum extract can be developed as an efficient biological agent as an antibacterial and anticancer also can be used as a photocatalyst for industrial wastewater treatment to prevent wastewater pollution.

Nettle-root extract mediated green synthesis of silver nanoparticles: Characterization and evaluation of its gastric carcinoma properties

This work describes an extremely simplified synthesis of Ag NPs using antioxidant-rich Nettle-root extract as a local natural source. The innate oxygenated phytochemicals facilitated the green reduction of Ag+ ions to corresponding Ag0 NPs and stabilized them by encapsulating them. This modification prevented the as-synthesized Ag NPs towards agglomeration and prepared in uniformly spherical in shape and in the range of 10–20 nm dimension. Physicochemical characteristics of the green synthesized Ag NPs were evaluated by advanced physicochemical techniques like UV–vis and FT-IR spectroscopy, SEM, TEM, EDX and elemental mapping study. Thein vitrocytotoxic and anti-gastric carcinoma effects of biologically synthesized Ag NPs against GC1415, AGS, GC1401, and GC1436 cancer cell lines were assessed. The anticancer properties of the Ag NPs could significantly remove cancer cell lines in a time and concentration-dependent manner by MTT assay. The IC50 of the Ag NPs were 183, 154, 250, and 276 µg/mL against GC1415, AGS, GC1401, and GC1436 cancer cell lines. The antioxidant activity of Ag NPs was determined by DPPH method. The Ag NPs showed the high antioxidant activity according to the IC50 value.

Comparative study of biogenically synthesized silver and gold nanoparticles of Acacia auriculiformis leaves and their efficacy against Alzheimer's and Parkinson's disease

The present article reports the biogenic synthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) from the extract of Acacia auriculiformis (AA) leaves using biogenic approach. Several spectral and morphological studies namely UV–vis, Fourier transform infrared (FT-IR), tunneling electron microscopy along with selected area electron diffraction (TEM/SAED), scanning electron microscopy along with energy dispersive X-ray (SEM-EDX) and X-ray diffraction (XRD) were carried out which ascertains the successful formation of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) starting from Silver nitrate and Chloroauric acid respectively. On the basis of TEM/SAED and SEM-EDX, AgNPs were found to be more regular with smaller particle size and hence they were selected for biological studies. Thermal techniques like thermo gravimetric analysis (TGA) and differential thermal analysis (DTA) were also performed to study the comparative thermal stability of AgNPs and AuNPs where AgNPs were found to be thermally more stable. Several biophysical techniques including Thioflavin T assay, ANS assay, Rayleigh scattering method and turbidity assay were also performed. These assays confirm that AgNPs possess better inhibitory property. Moreover, antioxidant activity of AgNPs was also carried out using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and AgNPs were found to be good antioxidant.

Investigation of Antioxidant and Cytotoxicity Effects of Silver Nanoparticles Produced by Biosynthesis Using Lactobacillus gasseri.

The biosynthesis of silver nanoparticles (AgNPs) is a new approach in nanotechnology which was optimistically implemented in medicine, food control, and pharmacology. The present study aimed to investigate the antioxidant and cytotoxicity effects of AgNPs produced by Lactobacillus gasseri filtrate. Also, changing color from yellow to brown confirmed the production of AgNPs. AgNPs were characterized using ultraviolet-visible spectroscopy, FE-SEM, and Fourier Transform Infrared Spectroscopy (FTIR). The antioxidant activity of AgNPs was tested using the DPPH assay. The scavenging test for DPPH showed 19.3%, 32.6%, 47.6%, 72%, 85.3% at concentrations (6.25, 12.5, 25, 52, 100) µg/ml, respectively, which proved that the scavenging percentage increased with increasing concentration. The effect of AgNPs on the chromosomal pattern was also studied. The results of the experiment of AgNPs against SK-GT-4 cancer cells showed the toxic activity of the used particles against the strains of these human esophageal cancer cells and failed to affect normal cells.

Mycosynthesis of Silver Nanoparticles by Candida albicans Yeast and its Biological Applications.

This study conducted a mycosynthesis of silver nanoparticles (AgNPs) by Candida albicans supernatant. The mycosynthesized AgNPs were identified by color visualization, ultraviolet-visible (UV) spectroscopy device, X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDX), field emission scanning electron microscope (FESEM), and zeta potential analysis. The UV-Vis spectroscopy examination has shown the highest absorbance (λmax) at the wavelength of 429 nanometers, which was the indicator of the creation of AgNPs. Furthermore, XRD showed the crystalline structure of AgNPs, and EDX revealed the weight percentage of silver atoms in the sample (82.4%). According to the FESEM, the morphology of AgNPs was spherical, and its size was 40.19 nanometers. Zeta potential analysis indicated that AgNPs were middling stable in the solution, and the zeta potential of AgNPs mycosynthesized by C. albicans was-23.02 mV. The cytotoxic effect of AgNPs against a human colon cancer cell line using MTT assay has shown the presence of toxic action against the cells, and no cytotoxic effect appears on the normal cells. The antioxidant activity of AgNPs using DPPH assay demonstrated 17.0%, 29.3%, 48.3%, 67.6%, and 83.6% at concentrations of 6.25, 12.5, 25, 50, and 100 µg/ml, respectively. The impact of AgNPs on the chromosomal pattern has also been studied. The importance of this study lies in the possibility of the synthesis of AgNPs using this yeast since most nanoparticle preparation methods utilize molds.

Biosynthesis of silver nanoparticles using Origanum majorana L. and evaluation of their antioxidant activity

The aerial part of Origanum majorana L. was extracted with deionized water and then filtered. The liquid extract was treated with silver nitrate to yield the AgNPs. The maximum absorption was observed at 483 nm in the UV-Vis spectrum. SEM analysis exhibited the spherical shape of silver nanoparticles with an average size of 72.01 nm. The XRD diffraction peaks at 2θ degrees revealed the face-centered cubic crystalline structure. Antioxidant activity of AgNPs and water extract was carried out by DPPH•, ABTS•+, and reducing power assays. AgNPs revealed higher DPPH• scavenging activity (IC50, µg/mL, 12.25) than that of the extract (21.66). Moreover, AgNPs exhibited outstanding ABTS•+ activity (3.87) compared to the standards. The reducing power activity of AgNPs was found (µmol TE/mg extract, 5.09 ± 0.21) the same as the BHT. AgNPs and extract exhibited excellent antioxidant activity promising for usage in food and pharmaceutical applications.

Formulation and characterization of a novel cutaneous wound healing ointment by silver nanoparticles containing Citrus lemon leaf: A chemobiological study

Abstract Introduction Formulating new wound-healing ointments by natural compounds is the first research priority in the developing and developed countries. This study was intended to provide green formulation of Ag-NP ointment containing Citrus lemon leaf aqueous extract and examine its capability of healing cutaneous wounds and its antioxidant and cytotoxicity activities under in vitro and in vivo conditions. Materials and Methods Different techniques, including UV-Vis and FT-IR spectroscopy, were used to characterize Ag-NPs. MTT assay was used to investigate cytotoxicity property of Ag-NPs. Antioxidant activity of Ag-NPs were examined by DPPH in the presence of butylated hydroxytoluene as positive control. Parameters of cutaneous wound healing were measured both histopathologically and biochemically. Results Clear peak at 429 nm shown by UV-Vis spectroscopy indicated formation of Ag-NPs. In FT-IR spectroscopy, presence of many antioxidant compounds provided an excellent condition to reduce silver in Ag-NPs. FE-SEM and TEM images showed spherical Ag-NPs with an average size of 25.1nm. The synthesized silver nanoparticles had excellent cell viability on the HUVECs line and indicated this method was nontoxic. Application of Ag-NP ointment improved wound healing parameters significantly (P ≤ 0.01). Ag-NPs reduced wound areas, total cells, neutrophils and lymphocytes significantly (P ≤ 0.01) and increased wound contracture, vessels, hexosamines, hydroxyl proline, hexuronic acid, fibrocytes, fibroblasts and fibrocyte/ fibroblast ratios significantly (P ≤ 0.01). Conclusions Once our results are verified by clinically experimental studies, Ag-NP ointment can be used as a modern one to treat several types of wounds, especially cutaneous ones, in humans.

Biosynthesis of metal nanoparticles using blue-green algae (Cyanobacteria) and their possible applications: Thesis Abstract

Thesis Abstract Background: Silver nanoparticles has attracted much attention as its appropriate solvent systems and ecological reducing agents so, its synthesis was of wide prominence and were functional in many fields. Aim: The present work was designed for the biosynthesis of AgNPs by seven cyanobacterial species using their filtrate and biomass separately and also their crude phycobiliproteins extract of Nostoc linckia and Spirulina platensis which scored the highest quantities. Results: Appearance of surface plasmon band at 400 nm for filtrate and biomass while at 420 nm crude phycobiliproteins extract that indicated the biosynthesis of AgNPs. FTIR analysis suggested that proteins were responsible for their capping and stabilization. XRD analysis confirmed its spherical crystalline shape. Zeta potential recorded -15.9 mV and -16.8 mV for S. platensis and N. linckia AgNPs, respectively confirming its stability. TEM images revealed that AgNPs had a mean average size of 21.2 and 21.05 nm for S. platensis and N. linckia, respectively. AgNPs showed potent antimicrobial activity against Gram positive, Gram negative bacteria and Candida albicans using the disk diffusion method. The antioxidant activity of AgNPs was promising by using three assays of DPPH radical scavenging activity, total antioxidant capacity and ferric reducing antioxidant power. The cytotoxicity of AgNPs was tested on HepG2 cell line through neutral red assay and the NPs of both species proved to be safe in low concentrations. Significant antiviral activity against HCV (64.976%) was recorded for AgNPs of N. linckia which was comparable to Ribavirin (66.67%) as a standard drug while S. platensis AgNPs recorded 48.3%. Conclusion: Biosynthesis of metal nanoparticles using blue-green algae (Cyanobacteria) can express potenial anti-cancer activities.

Green synthesis of silver nanoparticles from Echinacea purpurea (L.) Moench with antioxidant profile

Nanoparticles reveal unique properties due to their application in many fields. The easy, eco-friendly, and cost-effective method for synthesis of silver nanoparticles (AgNPs) from the aerial part of Echinacea purpurea (L.) Moench was demonstrated in this work. The synthesized AgNPs were elucidated by Ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and Scanning electron microscope (SEM) spectroscopic analyses. The UV-Vis spectrum revealed the maximum absorption at 481 nm and SEM spectral analysis displayed the formation of spherical shape silver nanoparticles with an average size of 68.24 nm. XRD spectral analysis at 2θ degrees of 38.1°, 44.3°, 64.4°, and 77.4° can be indexed to the (111), (200), (220), and (311) Bragg’s reflections of the face-centered cubic crystalline structure. Antioxidant activity of AgNPs and water extract were executed using the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•) scavenging, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS•+) scavenging, and reducing power assays. AgNPs and extract exhibited excellent antioxidant activity that could be promising for food and pharmaceutical utilization.

Antimicrobial, Antioxidant, and Antiviral Activities of Biosynthesized Silver Nanoparticles by Phycobiliprotein Crude Extract of the Cyanobacteria Spirulina platensis and Nostoc linckia

The present work was designed for the biosynthesis of silver nanoparticles (AgNPs) by Spirulina platensis and Nostoc linckia phycobiliprotein extract and for evaluation of their antimicrobial, antioxidant, and antiviral activities. The biosynthesized AgNPs were characterized by UV-Vis spectroscopy, Fourier transform-infrared spectroscopy, transmission electron microscopy, X-ray diffraction analysis, and Zeta potential analysis. The antimicrobial activity of the biosynthesized AgNPs was tested by the disk diffusion method. The antioxidant activity of the nanoparticles was assessed by using DPPH radical scavenging, total antioxidant capacity, and ferric reducing antioxidant assays. The antiviral activity of AgNPs was also challenged with the hepatitis C virus (HCV). The appearance of the surface plasmon resonance band at 420 nm indicated the biosynthesis of AgNPs. TEM images revealed that AgNPs had a mean average size of 21.211 and 21.052 nm for S. platensis and N. linckia, respectively. XRD analysis confirmed its spherical crystalline shape, and FTIR analysis suggested that proteins were responsible for their capping and stabilization. Zeta potential recorded − 15.902 mV and − 16.811 mV for S. platensis and N. linckia AgNPs, respectively, confirming its stability. AgNPs showed potent antimicrobial activity against some bacterial pathogens and Candida albicans. The antioxidant activity of AgNPs was evident by the use of three antioxidant assays. Significant antiviral activity against HCV (64.976%) was recorded for AgNPs of N. linckia, compared with Ribavirin (66.673%) as a standard drug, while S. platensis AgNPs recorded 48.334%. In conclusion, AgNPs biosynthesized from cyanobacterial phycobiliproteins were stable and showed potent antimicrobial, antioxidant, and antiviral activities.

Biosynthesis of silver nanoparticles using Origanum onites extract and investigation of their antioxidant activity

The current study was designed for green synthesis of silver nanoparticles (AgNPs) using Origanum onites extract and evaluation of their antioxidant activity. Origanum onites was extracted with hexane and methanol sequentially and methanol extract was used for synthesis of the AgNPs. The structure of silver nanoparticles was elucidated by UV-Vis, FTIR, XRD, and SEM analyses. Antioxidant activity of AgNPs and extract was carried out using DPPH, ABTS and reducing power assays. The absorption peak at 450 nm in UV-Vis spectrum confirmed the establishment of AgNPs. SEM analysis identified the formation of spherical-shaped nanoparticles with the average size of 54.2 nm. FTIR analysis displayed the possible content of secondary metabolites in silver nanoparticles of crude extract. XRD study displayed the crystalline nature of AgNPs. The AgNPs revealed the significant ABTS•+ scavenging effect (IC50, µg/mL, 5.16 ± 0.07) compared to standard, BHT (IC50, µg/mL, 7.03 ± 0.19). The AgNPs revealed the better activity than the methanol extract. The best activity of extract was observed in ABTS•+ assay (IC50, µg/mL, 6.24 ± 0.04). Due to the importance of O. onites in the pharmacy and food industry, the green synthesized silver nanoparticles could be valuable materials in the bio-medicinal field.

Green synthesized silver nanoparticle from Allium ampeloprasum aqueous extract: Characterization, antioxidant activities, antibacterial and cytotoxicity effects

In the current study for the first time, silver nanoparticles (AgNPs) were biosynthesized by reducing agents from hot water extract of Allium ampeloprasum, an antibacterial and anti-inflammatory edible plant. UV–vis. spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering, X-ray diffractometric, and transmission electron microscopy (TEM) analyses have been applied to confirm the formation of biosynthesized AgNPs. Total phenol content and antioxidant activities of AgNPs and extract together with their antibacterial and cytotoxic properties, were evaluated. According to TEM, AgNPs were spherical with a diameter of 8–50 nm. Total phenolic compounds were 15.58 μg/mL, and 10.94 μg/mL at a concentration of 150 μg/mL for the A. ampeloprasum extract and the biosynthesized AgNPs, respectively. Biosynthesized AgNPs showed significant antioxidant activity (81%) as compared to A. ampeloprasum extract (32%) and were active on multi-drug resistant P. aeruginosa. Besides, the cytotoxic activity response was also demonstrated that AgNPs were more potent than the A. ampeloprasum extract and showed high activity against Hela cell line with an IC50 value of less than 25 µg/mL. In conclusion, AgNPs synthesized by A. ampeloprasum extract with excellent antioxidant and antibacterial effects and acceptable cytotoxicity on cervical cancer cells have the potential to be used in biological applications.

Antioxidant and Antibacterial Activities of Biosynthesized Silver Nanoparticles using Aqueous Terminalia catappa Leaf Extracts as Novel Reducing Agent

In this study, silver nanoparticles (AgNPs) were successfully synthesized from aqueous Terminalia catappa leaf extract that acts as a novel reducing agent. Various parameters, including pH, temperature and reaction time, were determined. The UV-visible spectra showed the main peak at 416 nm, which was the characteristic surface plasmon resonance of AgNPs. The spherical shape and particle size of 49 ± 0.01 nm were observed from SEM, TEM and laser particle size analysis (LPSA). FTIR spectra of the leaf extract exhibited the characteristic functional groups that should be responsible for Ag+ ion reduction. The EDX spectrum proved that the obtained sample is silver. The antioxidant activity of AgNPs treated with the leaf extract as determined by the DPPH assay was higher compared to that of Terminalia catappa leaf extract, and the treated AgNP sample exhibited high antibacterial potential against both Gram-positive and Gram-negative bacteria.

Biogenically Synthesized Silver Nanoparticles Using Endophyte Fungal Extract of Ocimum tenuiflorum and Evaluation of Biomedical Properties

In the present work, AgNPs have been prepared using an extract of Exserohilum rostrata, an endophyte fungus isolated from Ocimum tenuiflorum leaf and characterized using TEM, SEM, DLS, XRD, FT-IR, etc. The FT-IR analysis confirmed the capping of AgNPs with bioactive molecules of endophyte extract, thereby importing addition or enhancing inherent AgNPs therapeutic properties. Both endophyte extract and AgNPs offered significant inhibition in Gram-positive and Gram-negative bacteria. Further, we also demonstrated its ability to inhibit bacterial biofilm formation of P. aeruginosa and S. aureus. Furthermore, we also demontrated excellent antioxidant and anti-inflammatory activity of both endophyte extract and AgNPs. Moreover, we observed ehanced antibacterial, anti-inflammatory, and antioxidant activity of AgNPs which is due to the synergistic effect of the bioactive agent forming the corona of AgNPs and with inhabitant activity of AgNPs. We also demonstrated the antimitotic activity in A. cepa and antiproliferative activity in breast cancer cells. AgNPs have also found to be excellent compatibility with healthy human keratinocyte cells and RBC cells. Hence, we might say that biogenically synthesized AgNPs using endophyte extract possess anti-bacterial, anti-inflammatory, and anti-oxidant ability as well as antiproliferative activity in breast cancer cells and thus possible found its application in the biomedical industry due to it’s eco-friendly and cost-effectiveness.