Plant-mediated Silver Nanoparticles Research Articles

Optimization of green silver nanoparticles as nanofungicides for management of rice bakanae disease

Rice bakanae, a devastating seed-borne disease caused by Fusarium species requires a more attractive and eco-friendly management strategy. The optimization of plant-mediated silver nanoparticles (AgNPs) as nanofungicides by targeting Fusarium species may be a rational approach. In this study, Azadirachta indica leaf aqueous extract-based AgNPs (AiLAE-AgNPs) were synthesized through the optimization of three reaction parameters: A. indica leaf amount, plant extract-to-AgNO3 ratio (reactant ratio), and incubation time. The optimized green AgNPs were characterized using ultraviolet–visible light (UV–Vis) spectroscopy, field emission scanning electron microscopy (FESEM) with energy dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), and powder X-ray diffraction (XRD) techniques. The optimal conditions for producing spherical, unique, and diminutive-sized AgNPs ranging from 4 to 27 nm, with an average size of 15 nm, were 2 g AiLAE at a 1:19 ratio (extract-to-AgNO3) and incubated for 4 h. Fusarium isolates collected from infected soils and identified as F. fujikuroi (40) and F. proliferatum (58 and 65) by PCR were used for seed infestation. The AgNPs exhibited concentration-dependent mycelial growth inhibition with EC50 values ranging from 2.95 to 5.50 μg/mL. The AgNPs displayed exposure time-dependent seed disinfectant potential (complete CFU reduction in F. fujikuroi (40) and F. proliferatum (58) was observed at a concentration of 17.24 μg/mL). The optimized green AgNPs were non-toxic to germinating seeds, and completely cured bakanae under net-house conditions, suggesting their great nano-fungicidal potency for food security and sustainable agriculture.

Preparation and Application of Sustained-Release Antibacterial Alginate Hydrogels by Loading Plant-Mediated Silver Nanoparticles

Preparation and Application of Sustained-Release Antibacterial Alginate Hydrogels by Loading Plant-Mediated Silver Nanoparticles

Biosynthesis, characterization, and antifungal activity of plant-mediated silver nanoparticles using Cnidium monnieri fruit extract.

The present study describes a novel method for green synthesis of silver nanoparticles using Cnidium monnieri (CM-AgNPs). Cnidium monnieri fruit is an excellent anti tinea drug that can be used externally to treat superficial fungal infections in the human body. The aqueous ethanolic extract of Cnidium monnieri fruit was prepared and employed in the synthesis of stable silver nanoparticles via biological reduction method. The synthesis conditions of CM-AgNPs was systematically optimized using Box-Behnken design. CM-AgNPs were well characterized by UV-spectroscopy and X-ray powder diffraction (XRD), and it was confirmed that the synthesized particles were AgNPs. The possible functional groups required for the reduction and stabilization of CM-AgNPs in the extract were identified through FTIR spectrum. The size of CM-AgNPs structure was confirmed to be approximately 44.6 nm in polydisperse spherical shape through scanning electron microscopy (SEM), transmission electron microscopy (TEM), and laser dynamic light scattering (DLS). Further, the minimum inhibitory concentration 90% (MIC90) ratios values of Cm-AgNPs against Trichophyton rubrum (7 d), T. mentagrophytes (7 d) and Candida albicans (24 h) were 3.125, 3.125, and 0.78125 μg/mL, respectively, determined by the broth micro dilution method. Finally, the result was concluded that the synthesized AgNPs could be further evaluated in large scale as a potential human topical antifungal agent.

Therapeutic applications and mechanism of action of plant-mediated silver nanoparticles

Therapeutic applications and mechanism of action of plant-mediated silver nanoparticles

Green synthesis of silver nanoparticles derived from lemon and pomegranate peel extracts to combat multidrug-resistant bacterial isolates

BackgroundMultidrug-resistant (MDR) bacteria are acknowledged as one of the main factors contributing to chronic illnesses and fatalities globally. Numerous diseases, including bloodstream infections, pneumonia, urinary tract infections, and surgical site infections, can be brought on by MDR bacteria. Therefore, a crucial topic of continuing research is the development of a novel and different treatment for MDR microbial pathogens. This work is introduce an alternative method for elimination of MDR bacterial isolates which are causative agents of urinary tract infection among people in Egypt. In our study, we need a novel strategy to combat MDR bacteria by green-synthesized metal nanoparticles (MNPs). That is due to the ability of MNPs to penetrate the cell wall and the cell membrane of gram-positive and gram-negative bacteria. MethodsClinical isolates of MDR bacteria had their antibiotic susceptibility assessed before being molecularly identified using 16 s rRNA, sequencing, and phylogenetic analysis. Also, genetic profiles of isolated strains were performed using ISSR and SDS-PAGE. Finally, characterized plant-mediated silver nanoparticles derived from lemon and pomegranate peel extracts were evaluated against isolated multidrug-resistant bacterial stains. ResultsIn our present trial, one-hundred urine samples were collected from 71 females and 29 males complaining of UTI (urinary tract infection) symptoms. One-hundred microbial isolates were isolated, including 88-g negative and only 8-g positive bacteria in addition to four yeast isolates (Candida species). A total of 72% of the isolated bacteria showed MDR activity. The most prevalent MDR bacterial isolates (Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus faecalis, and Klebsiella pneumoniae) were identified through 16S rDNA PCR sequencing as with accession numbers OP741103, OP741104, OP741105, OP741106, and OP741107, respectively. Lemon and pomegranate-mediated silver nanoparticles [Ag-NPs] were characterized by UV spectroscopy, FTIR, XRD, and TEM with average size 32 and 28 nm, respectively. Lemon and pomegranate-mediated silver nanoparticles [Ag-NPs] showed an inhibitory effect on the selected five MDR isolates at MIC 50 and 30 µg/mL, respectively. These common bacterial isolates were also genetically examined using ISSR PCR, and their total protein level was evaluated using SDS-PAGE, showing the presence of distinct genetic and protein bands for each bacterial species and emphasizing their general and protein composition as a crucial and essential tool in understanding and overcoming MDR behavior in UTI patients. ConclusionsLemon and pomegranate-mediated silver nanoparticles [Ag-NPs] were found to have an inhibitory effect on MDR isolates. Therefore, the study suggests that [Ag-NPs] could be a potential treatment for MDR UTI infections caused by the identified bacterial species.

Antimicrobial and Apoptotic Efficacy of Plant-Mediated Silver Nanoparticles.

Phytogenically synthesised nanoparticle (NP)-based drug delivery systems have promising potential in the field of biopharmaceuticals. From the point of view of biomedical applications, such systems offer the small size, high surface area, and possible synergistic effects of NPs with embedded biomolecules. This article describes the synthesis of silver nanoparticles (Ag-NPs) using extracts from the flowers and leaves of tansy (Tanacetum vulgare L.), which is known as a remedy for many health problems, including cancer. The reducing power of the extracts was confirmed by total phenolic and flavonoid content and antioxidant tests. The Ag-NPs were characterised by various analytical techniques including UV-vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), Fourier transform infrared (FT-IR) spectroscopy, and a dynamic light scattering (DLS) system. The obtained Ag-NPs showed higher cytotoxic activity than the initial extracts against both human cervical cancer cell lines HeLa (ATCC CCL-2) and human melanoma cell lines A375 and SK-MEL-3 by MTT assay. However, the high toxicity to Vero cell culture (ATCC CCL-81) and human fibroblast cell line WS-1 rules out the possibility of their use as anticancer agents. The plant-mediated Ag-NPs were mostly bactericidal against tested strains with MBC/MIC index ≤4. Antifungal bioactivity (C. albicans, C. glabrata, and C. parapsilosis) was not observed for aqueous extracts (MIC > 8000 mg L-1), but Ag-NPs synthesised using both the flowers and leaves of tansy were very potent against Candida spp., with MIC 15.6 and 7.8 µg mL-1, respectively.

Photocatalytic and antibacterial activities of green-mediated Khaya senegalensis-silver nanoparticles and oxidized carbon nanotubes

This study investigated the photocatalytic and antibacterial activities of plant-mediated silver nanoparticles (AgNPs) from a medicinal plant extract of Khaya senegalensis (K. senegalensis) and oxygen functionalized carbon nanotubes (oCNTs), respectively. The CNTs were functionalized using acid treatment. The green synthesized AgNPs from K. senegalensis (KS-AgNPs) and oCNTs were characterized by UV–Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission emission microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The formation of KS-AgNPs was confirmed by the UV–Vis absorption spectra, which showed an absorption band at 427 nm with a color change from yellow to brown. The morphology of KS-AgNPs was spherical in shape, with an average particle size of 9.30 nm. The FTIR analyses revealed distinctive functional groups, such as, hydroxyl (O-H), amines (N-H), and carbonyl (C-O), which were directly involved in the synthesis and stability of AgNPs. The XRD spectra was distinctive with five intense peaks at 2theta angles of 38.12°, 44.28°, 64.43°, 77.48°, and 81.54o while oCNTs gave intense peaks at 2theta angles of 26.43o, 42.36o, 44.46o, 54.51o, 59.98o, and 77.40o. The photocatalytic property of green synthesized KS-AgNPs was determined to be 40.7 % higher than that of oCNTs when applied for treatment of industrial waste water. The ability of green-mediated KS-AgNPs to inhibit against gram-positive and gram-negative bacteria was observed to be that gram (-) bacteria (E. coli) was more susceptible to KS-AgNPs than the gram (+) bacteria (S. aureus), in which case their susceptibility was least in oCNTs for both bacteria, respectively.

Green Silver Nanoparticles Synthesized from Taverniera couneifolia Elicits Effective Anti-Diabetic Effect in Alloxan-Induced Diabetic Wistar Rats.

Background: Using a variety of chemical compounds and biomolecules, researchers have been working on new antidiabetic drugs for many years. Anti-diabetic research is increasingly using nanomaterials because of their unique qualities, such as their tiny size, biocompatibility, and ability to penetrate cell membranes for drug delivery. Using extract of T. couneifolia coated with silver nanoparticles as a model for diabetes mellitus research was one of the goals of this work. Methods: Uv-Vis spectroscopy was used to measure the TAgNPs surface plasmon resonance. FTIR spectroscopy confirmed the attached functional groups, XRD analysis confirmed the size and crystallinity, scanning electron microscopy revealed that the majority of the particles were spherical, and EDX performed the elemental analysis. For 21 days, alloxan-induced diabetic Wistar rats (N = 25, n = 5/group) were administered 10 mg/kg body weight of photosynthesized AgNPs as a standard animal model, while those in the untreated normal control group C, received distilled water as a control, diabetics who were treated with 0.5 mg/kg of body weight of glibenclamide, 10 mg/kg of methanolic T. couneifolia extract, and diabetics who were given 10 mg/kg of body weight of synthetic AgNPs derived from T. couneifolia in the DAgNPs group. At the conclusion of the treatment, lipid, liver and kidney profiles were re-examined to determine whether or not the treatment had been effective (day 21). Oral glucose doses of 2 g/kg of body weight were administered to each group, and blood glucose levels were measured at various intervals (day 21). Fasting glucose levels were measured using a glucometer. Each animal’s urine was tested for leukocytes, nitrites, and bilirubin using lab-made prepared assay kits. One-way ANOVA and Dunnett’s test were used for statistical analysis. Results: The surface plasmon resonance effect was examined with UV-vis, it showed a sharp peak at 412 nm. X-ray diffraction measurements indicated that the produced nanoparticles were between 15 to 31.44 nm in size. Alloxan-induced diabetic rats were fed AgNPs derived from phytosynthesized AgNPs, compared to diabetic control rats, diabetic rats treated with AgNPs showed a considerable improvement in their dyslipidemia status. Over the course of the days, it also lowered blood glucose levels. A reduction in blood glucose levels, a rise in body weight, and significant improvements in the lipid, liver, and renal profiles were also seen. Conclusions: The present findings revealed that plant mediated silver nanoparticles significantly improved the alloxan induced diabetic changes in various treated rats and might be used for the treatment of diabetes.

Global mapping of research trends on antibacterial activity of green silver nanoparticles

Over the years, the quest for antibacterial agents from green nanoparticles has attracted great attention due to the global rise in the prevalence of multi-drug resistant bacteria. Although several studies on the antibacterial activity of plant-mediated silver nanoparticles have been documented, no bibliometric studies on the subject have been reported to date. As a result, the present study aimed to assess the global research trends on the antibacterial activity of green silver nanoparticles from 2000 to 2020. In the present study, we explored Science Citation Index Expanded (SCIE) to extract research articles written in English on the subject within the specified period. Two hundred and sixty-nine (269) eligible research articles were included in the bibliometric analysis and R-package “bibliometrix” was used to analyse the documents for annual scientific publications, authors’ impact, most relevant institutions, countries productivity, frequent words, co-occurrence network, co-citation network and authors/institutions/countries collaboration networks. Based on the analysis, the top three (3) authors, journals, institutions and countries were Kumar V (n = 5), Zangeneh MM (n = 5) and Oh BT (n = 4); King Saud University, Banaras Hindu University and Islamic Azad University; Journal of Cluster Science (n = 10), Applied Organometallic Chemistry (n = 8) and Microbial Pathogenesis (n = 8); India, Iran, and Korea. The study findings highlighted the gaps in a research collaboration that negate productivity. Therefore, we are optimitic that this study would enlighten researchers in the field about the research lapses and the need for research collaboration in future studies.

The efficacy of Ximenia americana plant mediated silver nanoparticles against dengue vector mosquito larvae [Aedes (Stegomyia) aegypti (Linnaeus, 1762) (Diptera: Culicidae)

Nanotechnology is an emerging technology and day to day expanding its roots of knowledge to various branches of Science and fulfilling human conveniences. To manage vector populations, new tools have been emerging through nanotechnology. Nanoparticles possess peculiar toxicity mechanisms due to surface volume ratio, and this may actively contribute to their excellent larvicidal potential against Aedes aegypti mosquito. Dengue is a mosquito borne disease and making major public health issue worldwide. Aedes (Stegomyia) aegypti (Linnaeus, 1762) prefers to bread in artificial containers, and anti-larval measures with Ximenia americana L. (Olacaceae) leaf mediated silver nanoparticles (AgNPs) proves to be a potential substitute for the existing organophosphorus insecticides like temephos, malathion and fenthion etc., for mosquito control programme. Larvae were exposed to varying concentrations of plant extracts and synthesized silver nanoparticles for 24 hours. From the results, it was found that plant extracts showed moderate larvicidal effects (LC50 at 179.87 and LC90 at 376.77 ppm) but, the synthesized silver nanoparticles had found to be toxic to larvae at LC50 (0.63 ppm) and LC90 (1.20 ppm). This research highlighted that, the Ximenia americana leaf mediated AgNPs are an efficient and eco-friendly agents against Ae. aegypti mosquito, though the laboratory studies have shown the promising results, yet their efficacy in the field is to be tested for effective mosquito larval control.

Copperpod Plant Synthesized AgNPs Enhance Cytotoxic and Apoptotic Effect in Cancer Cell Lines

The utilization of biological resources on the manufacture of nano silver has attracted the interest of researchers to develop an eco-friendly, cost-effective technology in nanomaterials production. In the present study, plant-mediated silver nanoparticles (AgNPs) were synthesized using aqueous leaf extracts of the Copperpod plant, which was well characterized. The ultraviolet-visible spectrophotometric study showed a maximum absorbance peak at 425 nm, and the observation of transmission electron microscopic features revealed that the nanoparticles size ranged between 20 and 70 nm. The synthesized AgNPs were tested for in vitro cytotoxic effects against cancerous cells, such as HepG2, A549 and MCF-7 cells. The findings showed that the IC50 values of AgNPs against cancerous cells viz., HepG2, MCF-7 and A549 cells, were observed to be 69 µg/mL, 62 µg/mL and 53 µg/mL, respectively. In addition, the apoptosis property was analysed using propidium iodide and acridine orange-ethidium bromide via the DNA fragmentation technique. Thus, the outcomes of the current analysis presume that the plant mediated AgNPs obtained from a synthesized Copperpod plant possess significant anti-cancer properties against various cancerous cells.

Investigation of Catalytic Property of Plant Mediated Silver Nanoparticles as Degradation of Toxic Dyes in Water

Nowadays, silver nano-compounds mediated by plant materials are widely used material in daily life chemistry as well as across the industries, medical, electronics, ceramics, and in all research fields, because it has some specific characteristics such as non-toxic, inexpensive, nature-friendly, heat resistant, catalytic activity, high electric conductivity and so on. In the present work we reported the photo-catalytic dye degradation of green synthesized silver nanoparticles of size 43.75 nm by using the flowers extract of Rhododendron campanulatum tree. Synthesized AgNPs have worked as a strong nano-catalyst for the degradation of toxic dyes such as malachite green (MG), and acridine orange (AO). As a catalyst, synthesized AgNPs degraded the malachite green (MG) dye 47.22 % within 90 min, and acridine orange (AO) dye 66.16 % in 4 h of solar irradiation, while in the absence of nanocatalyst, MG and AO dye degraded upto 22.13 % in 90 min and 46.75 % in 4 h of photo-irradiation respectively. Synthesized nano material (AgNPs) may be applicable as a strong catalytic agent for the degradation of toxic dyes, water purifying agent as well as a good antioxidant agent.

Plant Mediated Silver Nanoparticles and Mode of Action in Cancer Therapy: A Review.

Cancer is a widespread fatal disease associated with the abnormal growth of cells in the body. This article represents applications of biologically synthesized silver nanoparticles and their mode of action in cancer therapy. Nanomedicines have been proved to be an effective therapy in the treatment of the disease because of a wide range of applications. Due to the small shape and size, these nanoparticles are emerging to be of novel importance. They are abundantly found in various resources with easy extraction. Biologically synthesized silver nanoparticles are safe for humans as well as for the environment. They may replace the harmful therapies like chemotherapy, etc. used in cancer treatment due to the severe side effects associated with it. Sometimes patient may die because of the side effects. These green nanoparticles have great potential to treat and diagnose different cancers. This article laid a research opportunity for the diagnosis and treatment of cancer.

Synthesis of ipomoea staphylina plant extract mediated silver nanoparticles

Metallic nanoparticles are being consumed in every phase of science along with engineering including medical fields and are still charming the scientists to explore new dimensions for their respective worth which is generally attributed to their corresponding small sizes. The upcoming researchers have proven their significance of nonlinear optical properties. Among the several noble metal nanoparticles, silver nanoparticles have gotten a special attention. Traditionally silver nanoparticles are produced by chemical method using chemicals as reducing agents then it’s become accountable for various biological risks due to their general toxicity. In this manner, to fathom the goal; natural methodologies are coming up to fill the void; for example green amalgamations utilizing organic atoms got from plant sources as concentrates showing prevalence over compound as well as natural techniques These plant based biological molecules undergo highly controlled assembly for making them suitable for the metal nanoparticle syntheses. The current audit investigates the colossal plant decent variety to be used towards quick and single step convention preliminary technique with green standards over the regular ones and depicts the good stability properties. The Ipomoea staphylina Plant mediated silver nanoparticles is characterized using UV–Visible spectroscopy (UV–Vis.), Fourier transform infra-red spectroscopy (FTIR), High Resolution Transmission Electron Microscope (HRTEM) and Powder X-ray diffraction (XRD). The average particle size of synthesized silver nanoparticles is found by using Scherrer’s formula as 20 nm, which is approximately similar as the size obtained in HRTEM Analysis 22 nm.

Biosynthesis, characterization, and anticancer effect of plant-mediated silver nanoparticles using Coptis chinensis.

BackgroundTremendous growth in nanotechnology has opened up new frontiers in fundamental and applied aspects, including the synthesis of nanoscale matter and understanding/utilizing its exotic physicochemical and optoelectronic properties. Green-synthesis methods employing either biological microorganisms or plant extracts have emerged as a simple and alternative to chemical synthesis.MethodsIn our present study, we aimed to synthesize silver nanoparticles (AgNPs) in combination with an aqueous extract of Coptis chinensis (CC) using a suitable ecofriendly green-synthesis way.ResultsIn our results, ultraviolet-visible spectroscopy revealed a near-absorbance peak at 450 nm, which confirmed the AgNP synthesis. The crystalline nature of the AgNPs was revealed with X-ray diffraction. Transmission electron-microscopy analysis showed spherically dispersed nanoparticles of 6–45 nm diameter. We analyzed the elementary mechanism across A549 lung carcinoma cells ahead of treatment with doses of CC-AgNPs (10 µg/mL and 25 µg/mL). The antiproliferative effect of CC-AgNPs revealed a significant decline in cell viability. Antibacterial assays with both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria exhibited a higher zone of inhibition against S. aureus.ConclusionFurthermore, CC-AgNPs regulated apoptosis using the intrinsic pathway to inhibit A549-cell proliferation. Proliferation migration and invasion were notably inhibited by CC-AgNPs, which promoted apoptosis in lung adenocarcinoma cells by regulating the apoptotic pathway.

Attenuation of diethylnitrosamine (DEN) - Induced hepatic cancer in experimental model of Wistar rats by Carissa carandas embedded silver nanoparticles.

Hepatic cancer is well known, and leading cancer around the world and remain asymptomatic diseases. Carissa carandas possess anti-proliferative, antioxidant, hepatoprotective property and used in hepatic cancer. The current study deals to evaluate the chemoprotective and therapeutic property of Carissa carandas embedded silver nanoparticles (CCAgNPs) against diethylnitrosamine (DEN) -induced hepatic cancer. Wistar rats were divided into six groups and hepatic cancer was induced with diethylnitrosamine at the dose of 200 mg/kg BW. The animals were gastrogavaged with standard drug and CCAgNPs for 16 weeks. Serum biomarkers, haematological profile, antioxidants enzymes, inflammatory markers and membrane bound enzymes were assessed to find the anti-proliferative potential of silver nanoparticles. Histological evaluation and microscopic characterizations were also performed to authenticate the outcomes of the present work. Biosynthesized CCAgNPs significantly down-regulated the serum marker enzymes of hepatic and non-hepatic parameter, elevated the levels of enzymatic and non-enzymatic antioxidant profile, elevation in membrane bound enzymes and diminish the levels of inflammatory markers (IL-6, TNF-α, and IL-1β) via NF-κB pathway. Histopathological features also showed recovery of a hepatic architecture in cancer-induced rats in a dose-dependent manner. Our consequences established that such plant mediated silver nanoparticles shown a defensive impact against DEN-induced hepatocarcinogenesis, and serves as a better option to ameliorate the clinical results against hepatocellular carcinoma.

Plant-Mediated Synthesis of Silver Nanoparticles – A Critical Review

Nanomedicine is a revolutionary science nanoparticles of size 1 - 100nm designed for the utilization in disease diagnostics and therapeutics, targeted drug delivery of drugs which have difficulty in solubility and bioavailability and also to be applied in numerous fields. The present critical review aims at enumerating the advantages, synthesis and characterization methods, as well as diversified applications of green silver nanoparticles. Silver nanoparticles is an attractive proposition due to their distinctive physical, chemical and biological properties including a high electrical as well as thermal conductivity, surface-enhanced Raman scattering, chemical stability, catalytic activity and non linear optical behavior which enables them of potential value in inks, microelectronics, and medical imaging. Plant mediated synthesis of silver nanoparticles (AgNPs) is now-a-day’s gaining enormous interest as it is cost effective, ecofriendly and has less side effects since there is no addition of external stabilizing or capping agents as the plant itself acts as stabilizing or capping agent. The secondary metabolites and other plant products like proteins, metabolites like alkaloids, terpinoids, saponins, glycosides etc are known to act as external stabilizing or capping agents. The plant mediated silver nanoparticles are known to show uniform particles characteristics and morphology. The bottom to top end approach of synthesis is effective to achieve desired particles size, shape and morphology. The synthesized green silver nanoparticles are characterized by UVVis spectroscopy, SEM/TEM analysis, EDAX/EDS, FTIR and other methods zeta potential measurement, thermo gravimetric analysis, Raman scattering. The plant mediated synthesized silver nanoparticles (green silver nanoparticles) are effective in delivering pharmacological activities like antimicrobial, anticancer, larvicidal etc. Also green Silver nanoparticles have diverse applications acting as biosensors, as targeted drug delivery candidates, in diagnostics and therapeutics, in medical and consumer products, as anti pollutant and in agriculture. The future perspective holds promising results in green synthesis of silver nanoparticles involving plants. This review projects a collective sequence of information for synthesizing and evaluation of green silver nanoparticles and scope of its pharmacological actions.

Biosynthesis, characterisation and therapeutic applications of plant-mediated silver nanoparticles

Nanotechnology is one of the most studied domains, and nanoparticle synthesis, especially of silver nanoparticles, has gained special importance due to their properties, biocompatibility and applications. Today, the processes of nanoparticles synthesis tend toward the development of inexpensive, simple, non-toxic and environmentally friendly methods. Thus, the use of plants in the synthesis of silver nanoparticles has attracted considerable interest because biomolecules can act as both reducing and stabilizing agents. This survey aims at discussing the conditions for obtaining silver nanoparticles using plants and their characterization by several methods, such as FTIR and UV?Vis spectroscopy, X-ray diffraction, and scanning and transmission electron microscopy. In addition, it examines some of the most common biological uses of silver nanoparticles: antibacterial, antioxidant and cytotoxic.

A study to evaluate the effect of phyto silver nano-particles synthesized using Azadiracta indica leaf extract on extracellular fungal amylase and cellulase

In the present study, an attempt has been made to evaluate the effect of plant mediated silver nano-particles against two enzymes i.e. Amylase and Cellulase produced by Aspergillus niger through submerged fermentation under optimum condition and the crude enzyme thus obtained was incubated with the respective substrate in presence of phyto silver nano-particles. The enzyme activity was determined with different concentration of nano-particles. Silver nano-particles were fabricated using leaf extract of Azadiracta indica. The bio-reduction was monitored by UV-Vis spectrophotometer, the possible biomolecules responsible for bioreduction, capping and efficient stabilization were identified using Fourier transform infrared spectroscopy, while the size and shape of the synthesized silver nano-particles was determined using scanning electron microscopy (SEM). The synthesized silver nano-particles were found to be potentially active in enhancing the activity of fungal amylases and cellulase. The study thereby concludes utilization of plant material for a rapid, simple, cost-effective and ecofriendly alternative for nano-particles synthesis and these silver nano-particles may have potential application in processes that requires amylolytic and cellulolytic activity at commercial or industrial levels. The “green nanotechnology” thus aims to exploit plant materials to generate products and processes that are energy efficient as well as economically and environmentally sustainable.

Differential Phytotoxic Impact of Plant Mediated Silver Nanoparticles (AgNPs) and Silver Nitrate (AgNO3) on Brassica sp.

Continuous formation and utilization of nanoparticles (NPs) have resulted into significant discharge of nanosized particles into the environment. NPs find applications in numerous products and agriculture sector, and gaining importance in recent years. In the present study, silver nanoparticles (AgNPs) were biosynthesized from silver nitrate (AgNO3) by green synthesis approach using Aloe vera extract. Mustard (Brassica sp.) seedlings were grown hydroponically and toxicity of both AgNP and AgNO3 (as ionic Ag+) was assessed at various concentrations (1 and 3 mM) by analyzing shoot and root length, fresh mass, protein content, photosynthetic pigments and performance, cell viability, oxidative damage, DNA degradation and enzyme activities. The results revealed that both AgNPs and AgNO3 declined growth of Brassica seedlings due to enhanced accumulation of AgNPs and AgNO3 that subsequently caused severe inhibition in photosynthesis. Further, the results showed that both AgNPs and AgNO3 induced oxidative stress as indicated by histochemical staining of superoxide radical and hydrogen peroxide that was manifested in terms of DNA degradation and cell death. Activities of antioxidants, i.e., ascorbate peroxidase (APX) and catalase (CAT) were inhibited by AgNPs and AgNO3. Interestingly, damaging impact of AgNPs was lesser than AgNO3 on Brassica seedlings which was due to lesser accumulation of AgNPs and better activities of APX and CAT, which resulted in lesser oxidative stress, DNA degradation and cell death. The results of the present study showed differential impact of AgNPs and AgNO3 on Brassica seedlings, their mode of action, and reasons for their differential impact. The results of the present study could be implied in toxicological research for designing strategies to reduce adverse impact of AgNPs and AgNO3 on crop plants.