Antibacterial and cytotoxic potential of silver nanoparticles synthesized using latex of Calotropis gigantea L

Updates on Biogenic Metallic and Metal Oxide Nanoparticles: Therapy, Drug Delivery and Cytotoxicity

The ambition to combat the issues affecting the environment and human health triggers the development of biosynthesis that incorporates the production of natural compounds by living organisms via eco-friendly nano assembly. Biosynthesized nanoparticles (NPs) have various pharmaceutical applications, such as tumoricidal, anti-inflammatory, antimicrobials, antiviral, etc. When combined, bio-nanotechnology and drug delivery give rise to the development of various pharmaceutics with site-specific biomedical applications. In this review, we have attempted to summarize in brief the types of renewable biological systems used for the biosynthesis of metallic and metal oxide NPs and the vital contribution of biogenic NPs as pharmaceutics and drug carriers simultaneously. The biosystem used for nano assembly further affects the morphology, size, shape, and structure of the produced nanomaterial. The toxicity of the biogenic NPs, because of their pharmacokinetic behavior in vitro and in vivo, is also discussed, together with some recent achievements towards enhanced biocompatibility, bioavailability, and reduced side effects. Because of the large biodiversity, the potential biomedical application of metal NPs produced via natural extracts in biogenic nanomedicine is yet to be explored.

Polianthes tuberosa-Mediated Silver Nanoparticles from Flower Extract and Assessment of Their Antibacterial and Anticancer Potential: An In Vitro Approach

Plant-mediated metallic nanoparticles have beenreported for a diversified range of applications in biological sciences. In the present study, we propose the Polianthes tuberosa flower as a reducing and stabilizing agent for the synthesis of silver nanoparticles (PTAgNPs). The PTAgNPs were exclusively characterized using UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy, zeta potential, and transmission electron microscopy (TEM) studies. In a biological assay, we investigated the antibacterial and anticancer activity of silver nanoparticles in the A431 cell line. The PTAgNPs demonstrated a dose-dependent activity in E. coli and S. aureus, suggesting the bactericidal nature of AgNPs. The PTAgNPs exhibited dose-dependent toxicity in the A431 cell line, with an IC₅₀ of 54.56 µg/mL arresting cell growth at the S phase, as revealed by flow cytometry analysis. The COMET assay revealed 39.9% and 18.15 severities of DNA damage and tail length in the treated cell line, respectively. Fluorescence staining studies indicate that PTAgNPs cause reactive oxygen species (ROS) and trigger apoptosis. This research demonstrates that synthesized silver nanoparticles have a significant effect on inhibiting the growth of melanoma cells and other forms of skin cancer. The results show that these particles can cause apoptosis or cell death in malignant tumor cells. This suggests that they could be used to treat skin cancers without harming normal tissues.

Synthesis of Green Engineered Silver Nanoparticles through Urtica dioica: An Inhibition of Microbes and Alleviation of Cellular and Organismal Toxicity in Drosophila melanogaster

Plant fractions have a diversity of biomolecules that can be used to make complicated reactions for the bioactive fabrication of metal nanoparticles (NPs), in addition to being beneficial as antioxidant medications or dietary supplements. The current study shows that Urtica dioica (UD) and biologically synthesized silver nanoparticles (AgNPs) of UD have antibacterial and antioxidant properties against bacteria (Escherichia coli and Pseudomonas putida) and Drosophila melanogaster (Oregon R+). According to their ability to scavenge free radicals, DPPH, ABTS, TFC, and TPC initially estimated the antioxidant potential of UD and UD AgNPs. The fabricated AgNPs were analyzed (UV−Vis, FTIR, EDS, and SEM) to determine the functional groups (alcohol, carboxylic acids, phenol, proteins, and aldehydes) and to observe the shape (agglomerated crystalline and rod-shaped structure). The disc diffusion method was used to test the antimicrobial properties of synthesized Ag-NPs against E. coli and P. putida. For 24 to 120 h, newly enclosed flies and third instar larvae of Drosophila were treated with UD and UD AgNPs. After exposure, tests for biochemical effects (acetylcholinesterase inhibition and protein estimation assays), cytotoxicity (dye exclusion), and behavioral effects (jumping and climbing assays) were conducted. The results showed that nanoparticles were found to have potent antimicrobial activity against all microbial strains tested at various concentrations. In this regard, ethno-medicinal characteristics exhibit a similar impact in D. melanogaster, showing (p < 0.05) significantly decreased cellular toxicity (trypan blue dye), enhanced biochemical markers (AChE efficacy and proteotoxicity), and improved behavioral patterns in the organism treated with UD AgNPs, especially in comparison to UD extract. The results of this study may help in the utilization of specific plants as reliable sources of natural antioxidants that may have been beneficial in the synthesis of metallic NPs, which aids in the production of nanomedicine and other therapeutic applications.

A Review on Green Synthesis of Silver Nanoparticles and its Role Against Cancer

Cancer is a fatal disease, with a collection of related diseases in various body parts. The conventional therapies cannot show the desired results of treatment due to their imprecise targeting, deprived drug delivery, and side effects. Therefore, it is required to make the drug engineered in such a way that it can target only cancerous cells and can inhibit its growth and proliferation. Nanotechnology is a technology that can target and differentiate between cancerous cells and the normal cells of the body. Silver itself is a good anticancer and antibacterial agent and employing it with phytochemicals having anticancer properties, and nanotechnology can give the best approach for the treatment. The synthesis of silver nanoparticles using plant extracts is an economical, energy-efficient, low-cost approach and it doesn't need any hazardous chemicals. In the present review, we discussed different methods of synthesis of silver nanoparticles using herbal extracts and their role against cancer therapy along with the synergistic role of silver and plant extracts against cancer in the formulation.

Impact of Nano Preparation of Phytoconstituents in Medulloblastoma

The conventional cancer treatment strategies from chemotherapy to surgery often lead to inadequate results which in some cases lead to relapsing of the tumor being treated. Medulloblastoma witness 30% relapse rate which is universally fatal among children. Although the treatment of primary medulloblastoma is well established including surgical excision, postsurgical irradiation, and, more recently, chemotherapy, there is no established treatment for its recurrence. Despite efforts to improve its therapy, frequent long-haul survivors have been recorded in the world's medical literature. In this book chapter, we have attempted to focus light on the nano preparation of phytoconstituents as an alternative approach as it has advantage of providing better bioavailability of the compound in terms of crossing the blood-brain barrier and an additional benefit in terms of limited adverse effects of the natural product over the traditional chemotherapeutic approaches. In recent times, biological methods or green approaches in the case of plants have received immense attention due to its safety and lack of contamination in the process. In this chapter, we will explore some plant products that have been incorporated into nanocarriers to improve their bioavailability in this tumor treatment.

Gold Nanoparticles: Biosynthesis and Potential of Biomedical Application

Gold nanoparticles (AuNPs) are extremely promising objects for solving a wide range of biomedical problems. The gold nanoparticles production by biological method ("green synthesis") is eco-friendly and allows minimization of the amount of harmful chemical and toxic byproducts. This review is devoted to the AuNPs biosynthesis peculiarities using various living organisms (bacteria, fungi, algae, and plants). The participation of various biomolecules in the AuNPs synthesis and the influence of size, shapes, and capping agents on the functionalities are described. The proposed action mechanisms on target cells are highlighted. The biological activities of "green" AuNPs (antimicrobial, anticancer, antiviral, etc.) and the possibilities of their further biomedical application are also discussed.

Recent advances in anticancer and antimicrobial activity of silver nanoparticles synthesized using phytochemicals and organic polymers

Development of eco-friendly synthetic methods has resulted in the production of biocompatible Ag NPs for applications in medical sector. To overcome the prevailing antibiotic resistance in bacteria, Ag NPs are being extensively researched over the past few years due to their broad spectrum and robust antimicrobial properties. Silver nanoparticles are also being studied widely in advanced anticancer therapy as an alternative anticancer agent to combat cancer in an effective manner. Keeping this backdrop in consideration, this review aims to provide an extensive coverage of the recent progresses in the green synthesis of Ag NPs specifically using plant derived reducing agents such phytochemicals and numerous other biopolymers. Current development in antimicrobial activity of Ag NPs against various pathogens has been deliberated at length. Recent advances in potent anticancer activity of the biogenic Ag NPs against various cancerous cell lines has also been discussed in detail. Mechanistic details of the synthesis of Ag NPs, their anticancer and antimicrobial action has also been highlighted.

A Systematic Review of Biosynthesized Metallic Nanoparticles as a Promising Anti-Cancer-Strategy

Cancer is one of the foremost causes of death worldwide. Cancer develops because of mutation in genes that regulate normal cell cycle and cell division, thereby resulting in uncontrolled division and proliferation of cells. Various drugs have been used to treat cancer thus far; however, conventional chemotherapeutic drugs have lower bioavailability, rapid renal clearance, unequal delivery, and severe side effects. In the recent years, nanotechnology has flourished rapidly and has a multitude of applications in the biomedical field. Bio-mediated nanoparticles (NPs) are cost effective, safe, and biocompatible and have got substantial attention from researchers around the globe. Due to their safe profile and fewer side effects, these nanoscale materials offer a promising cure for cancer. Currently, various metallic NPs have been designed to cure or diagnose cancer; among these, silver (Ag), gold (Au), zinc (Zn) and copper (Cu) are the leading anti-cancer NPs. The anticancer potential of these NPs is attributed to the production of reactive oxygen species (ROS) in cellular compartments that eventually leads to activation of autophagic, apoptotic and necrotic death pathways. In this review, we summarized the recent advancements in the biosynthesis of Ag, Au, Zn and Cu NPs with emphasis on their mechanism of action. Moreover, nanotoxicity, as well as the future prospects and opportunities of nano-therapeutics, are also highlighted.

Functional Attributes of Myco-Synthesized Silver Nanoparticles from Endophytic Fungi: A New Implication in Biomedical Applications

To develop a benign nanomaterial from biogenic sources, we have attempted to formulate and fabricate silver nanoparticles synthesized from the culture filtrate of an endophytic fungus Penicillium oxalicum strain LA-1 (PoAgNPs). The synthesized PoAgNPs were exclusively characterized through UV-vis absorption spectroscopy, Fourier Transform Infra-Red spectroscopy (FT-IR), X-ray powder diffraction (XRD), and Transmission Electron Microscopy (TEM) with energy dispersive X-ray spectroscopy (EDX). The synthesized nanoparticles showed strong absorbance around 430 nm with surface plasmon resonance (SPR) and exhibited a face-centered cubic crystalline nature in XRD analysis. Proteins presented in the culture filtrate acted as reducing, capping, and stabilization agents to form PoAgNPs. TEM analysis revealed the generation of polydispersed spherical PoAgNPs with an average size of 52.26 nm. The PoAgNPs showed excellent antibacterial activity against bacterial pathogens. The PoAgNPs induced a dose-dependent cytotoxic activity against human adenocarcinoma breast cancer cell lines (MDA-MB-231), and apoptotic morphological changes were observed by dual staining. Additionally, PoAgNPs demonstrated better larvicidal activity against the larvae of Culex quinquefasciatus. Moreover, the hemolytic test indicated that the as-synthesized PoAgNPs are a safe and biocompatible nanomaterial with versatile bio-applications.

The Effect of Silver Nanoparticles on Pyocyanin Production of Pseudomonas aeruginosa Isolated From Clinical Specimens

BACKGROUND

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen causing a wide range of human infections. The organism is resistant to a wide range of antibiotics. The purpose of this study was to investigate the effect of AgNPs on pyocyanin pigment production of P. aeruginosa bacteria isolated from clinical specimens.

METHODS

In this study, 15 clinical isolates of P. aeruginosa were collected from different specimens of hospitalized patients. P. aeruginosa was detected by biochemical and molecular (detection of pbo1 gene by colony PCR method) methods and the MIC and MBC of AgNPs were determined by agar dilution method. Inhibition of P. aeruginosa pyocyanin production at AgNPs concentrations of 0, 0.3, 0.5, 1 and 1.5 mg/ml of was studied with OD of 520 nm.

RESULTS

The mean MIC and MBC of AgNPs were 1.229 and 1.687 mg/ml, respectively. Pyocyanin production was investigated for all isolates at different concentrations of nanoparticles, and their comparison showed that with increasing nanoparticle concentration, pyocyanin production significantly decreased (p<0.05).

CONCLUSION

According to the results of this study, AgNPs had an inhibitory effect on P. aeruginosa and its pigment production and with increasing nanoparticles concentration, pigment production decreased; therefore, it seems that the nanoparticles can be used to treat and prevent diseases caused by P. aeruginosa.

Green synthesis of silver nanoparticles using plant extracts and their antimicrobial activities: a review of recent literature

Synthesis of metal nanoparticles using plant extracts is one of the most simple, convenient, economical, and environmentally friendly methods that mitigate the involvement of toxic chemicals. Hence, in recent years, several eco-friendly processes for the rapid synthesis of silver nanoparticles have been reported using aqueous extracts of plant parts such as the leaf, bark, roots, etc. This review summarizes and elaborates the new findings in this research domain of the green synthesis of silver nanoparticles (AgNPs) using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015. While highlighting the recently used different plants for the synthesis of highly efficient antimicrobial green AgNPs, we aim to provide a systematic in-depth discussion on the possible influence of the phytochemicals and their concentrations in the plants extracts, extraction solvent, and extraction temperature, as well as reaction temperature, pH, reaction time, and concentration of precursor on the size, shape and stability of the produced AgNPs. Exhaustive details of the plausible mechanism of the interaction of AgNPs with the cell wall of microbes, leading to cell death, and high antimicrobial activities have also been elaborated. The shape and size-dependent antimicrobial activities of the biogenic AgNPs and the enhanced antimicrobial activities by synergetic interaction of AgNPs with known commercial antibiotic drugs have also been comprehensively detailed.

Biogenic nanoparticles: a comprehensive perspective in synthesis, characterization, application and its challenges

BACKGROUND

Translating the conventional scientific concepts into a new robust invention is a much needed one at a present scenario to develop some novel materials with intriguing properties. Particles in nanoscale exhibit superior activity than their bulk counterpart. This unique feature is intensively utilized in physical, chemical, and biological sectors. Each metal is holding unique optical properties that can be utilized to synthesize metallic nanoparticles. At present, versatile nanoparticles were synthesized through chemical and biological methods. Metallic nanoparticles pose numerous scientific merits and have promising industrial applications. But concerning the pros and cons of metallic nanoparticle synthesis methods, researchers elevate to drive the synthesis process of nanoparticles through the utilization of plant resources as a substitute for use of chemicals and reagents under the theme of green chemistry. These synthesized nanoparticles exhibit superior antimicrobial, anticancer, larvicidal, leishmaniasis, wound healing, antioxidant, and as a sensor. Therefore, the utilization of such conceptualized nanoparticles in treating infectious and environmental applications is a warranted one.

CONCLUSION

Green chemistry is a keen prudence method, in which bioresources is used as a template for the synthesis of nanoparticles. Therefore, in this review, we exclusively update the context of plant-based metallic nanoparticle synthesis, characterization, and applications in detailed coverage. Hopefully, our review will be modernizing the recent trends going on in metallic nanoparticles synthesis for the blooming research fraternities.

Calotropis gigantea assisted green synthesis of nanomaterials and their applications: a review

Background

Nanotechnology has been receiving wonderful impetus in the current emerging technological era by opening a pool of scientific ideas to compete with the daily challenges of developing technology. So far, numerous properties and countless applications of nanomaterials have been explored which have been even proved to be based on characteristic shape, size, surface area and surface chemistry.

Main content

By the time, several attempts have been made for green synthesis of nanomaterials, using plant extracts. Calotropis gigantiea (L.) R. Br is the plant belonging to Apocynaceae, have been screened and proved to possess various pharmacological activities, due to different polar phytochemicals like flavonoids, lignans and terpenoids. This review focus on phytochemicals so far reported from different parts of the plant; pharmacological activities exhibited; green synthesis of nanomaterials, particularly metallic nanoparticles green synthesised by facilitating reaction of metallic ion donor molecule/salt and aqueous extract of leaves or flowers of C. gigantiea and their biological or non-biological applications. The use of C. gigantea in the fabrication of nanomaterials is an eco-friendly and safe approach. Secondary metabolites present act as a stabilizing agent for nanomaterials. Cadmium sulphide, titanium dioxide, nickel and nickel oxide nanoparticles synthesised using C. gigantea exerted better anti-microbial action, compared to extracts. Nanoencapsulated magnesium oxide nanoparticles avoided biochemical degradation of MgO; increase its bioavailability and proved beneficial in type II diabetes mellitus. Cupric oxide nanoparticles got applied in dye-sensitised solar cell. Silver nanoparticles showed better cytotoxicity in HeLa cells. Biomaterial-supported zero-valent iron and stannic oxide nanoparticles proved to have utilities in water purification. Green synthesised Eu3+ doped Y2SiO5 nanophosphors had significant chromaticity coordinates and average correlated colour temperature, hence find application in displays.

Conclusion

Variety of nanomaterials including nanoparticles and nanophophors could successfully be biosynthesised using Calotropis gigantean extract or its latex. These green synthesised nanomaterials have several applications in the healthcare system and technology.

Graphical Abstract

Green Chemistry Synthesis of Silver Nanoparticles and Their Potential Anticancer Effects

Nanobiotechnology has grown rapidly and become an integral part of modern disease diagnosis and treatment. Biosynthesized silver nanoparticles (AgNPs) are a class of eco-friendly, cost-effective and biocompatible agents that have attracted attention for their possible biomedical and bioengineering applications. Like many other inorganic and organic nanoparticles, such as AuNPs, iron oxide and quantum dots, AgNPs have also been widely studied as components of advanced anticancer agents in order to better manage cancer in the clinic. AgNPs are typically produced by the action of reducing reagents on silver ions. In addition to numerous laboratory-based methods for reduction of silver ions, living organisms and natural products can be effective and superior source for synthesis of AgNPs precursors. Currently, plants, bacteria and fungi can afford biogenic AgNPs precursors with diverse geometries and surface properties. In this review, we summarized the recent progress and achievements in biogenic AgNPs synthesis and their potential uses as anticancer agents.

Effective Inhibition of Candidiasis Using an Eco-Friendly Leaf Extract of Calotropis-gigantean-Mediated Silver Nanoparticles

The approaches used for the green biosynthesis of nanoparticles with clinical applications have been widely used in nanotechnology due to their potential to provide safe, eco-friendly, cost effective, high-stability, and high-loading-capacity nanoparticles. This study aimed to evaluate the anti-candidal activity of silver nanoparticles (AgNPs) biosynthesized using the aqueous leaf extract of Calotropis gigantea (CG) alone or in a combination with the plant extract of CG (AgNPs/CG). AgNPs were characterized using UV-Vis spectrophotometry, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The results of the standard disk diffusion method revealed that AgNPs alone displayed anti-candidal activity (11.33-mm inhibition zone), while AgNPs/CG displayed a strong synergistic anti-candidal activity (17.76-mm inhibition zone). Similarly, AgNPs/CG completely inhibited the growth of C. albicans after 4 h of incubation, as measured using the time-kill assay. In addition, AgNPs/CG inhibited the dimorphic transition of C. albicans and suppressed both the adhesion and the biofilm formation of C. albicans by 41% and 38%, respectively. The treatment of Candida. albicans with AgNPs/CG showed a significant inhibition of the production of several antioxidant enzymes. Interestingly, AgNPs/CG did not show any cytotoxicity in animal cells, including the MCF-7 cell line and primary mouse bone marrow-derived mesenchymal stem cells (mBMSCs), at the concentration used to completely inhibit the dimorphic transition of C. albicans. In conclusion, we identified AgNPs/CG as a promising natural-product-based nanoparticle that can potentially be used as an anti-candidal drug.

Antimicrobial activity of green silver nanoparticles from endophytic fungi isolated from Calotropis procera (Ait) latex

Endophytes, a potential source of bioactive secondary metabolites, were isolated from the widely used medicinal plant Calotropis procera Ait. Approximately 675 segments from 15 Calotropis procera plants and 15 latex samples were assessed for the presence of endophytic fungi. Finally, eight fungal species were isolated and identified based on their macro- and micro-morphology. The endophytic fungal filtrates were screened for their antimicrobial activity against 11 important pathogenic micro-organisms. The filtrates of nanoparticles were from three of the eight isolated endophytic fungi, namely, Penicillium chrysogenum, Aspergillus fumigatus and Aspergillus flavus, and were highly effective against the tested bacteria, while the remaining endophytic fungal filtrates displayed low activity.

Use of agricultural waste (coconut shell) for the synthesis of silver nanoparticles and evaluation of their antibacterial activity against selected human pathogens

Green synthesis of silver nanoparticles (AgNPs) is environmentally satisfactory because of their low cost and safe to nature. In the present study, extract of an agricultural waste, coconut (Cocos nucifera) shell is used to synthesize AgNPs and their antibacterial effect was investigated against selected human pathogens Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium. The AgNPs synthesized using coconut shell extract (CSE-AgNPs) were characterized using UV-Visible spectroscopy (absorption peak at 432 nm), Transmission Electron Microscopy (spherical shaped particles size of 14.2-22.96 nm), Fourier-Transform Infrared Spectroscopy indicating the CSE capping around the AgNPs (Peaks 1384, 1609 and 3418 corresponds to organic molecules) and X-Ray Diffraction (Peak at 32.078 and 2-Theta). CSE-AgNPs exhibited zone of inhibition against S. aureus (15 mm), E. coli (13 mm), S. typhimurium (13 mm) and L. monocytogenes (10 mm) and minimum inhibitory concentration (MIC) of 26, 53, 106 and 212 μg/ml, respectively. Growth curve assay showed the effectiveness of CSE-AgNPs to inhibit the selected pathogens when compared to amphicillin control and extract. Scanning electron microscopy results indicated that the cell wall degradation might be the possible mechanism of antibacterial action of CSE-AgNPs. Different concentrations of AgNPs (0.078-2.5 mg/ml) showed no toxicity against human PBMC cell line. Hence, such highly effective CSE-AgNPs could be explored as antibacterial agent.

Potential anti-proliferative activity of AgNPs synthesized using M. longifolia in 4T1 cell line through ROS generation and cell membrane damage

To overcome the problem of breast cancer, silver nanoparticles (AgNPs) synthesized using Indian medicinal plant Madhuca longifolia could be explored as an alternative anticancer medicine. Synthesized AgNPs were studied their characteristics and their anti-proliferative property was investigated in breast cancer cell line (4T1). Based on zeta sizer analysis, the size of the AgNPs was 103.5 nm and potential -9.57 eV. Fe-SEM results showed particle size of 69.4-99.4 nm while TEM images indicated the particle size of 18-24 nm. In dose-dependent study, AgNPs showed 93% of anti-proliferative activity at 50 μg/ml whereas the methanolic extract of M. longifolia showed 80% activity only at 10-fold increased concentration (500 μg/ml). AgNPs exhibited higher level of cytotoxicity in breast cancer cell line than extract through cell wall degradation and ROS generation. Such effective AgNPs could be investigated further through in vivo models with a view to develop anticancer drug.

One pot green fabrication of metallic silver nanoscale materials using Crescentia cujete L. and assessment of their bactericidal activity

In this study, the leaf extract of an important medicinal plant Crescentia cujete L. (CC) was employed as a green reducing agent to synthesise highly-stable C. cujete silver nanoparticles (CCAgNPs). The reduction of Ag+ to Ag0 nanoparticles was initially observed by a colour change which generates an intense surface plasmon resonance peak at 417 nm using a UV-Vis spectrophotometer. Various optimisation factors such as temperature, pH, time and the stoichiometric proportion of the reaction mixture were performed, which influence the size, dispersity and synthesis rate of CCAgNPs. In addition, surface chemistry of synthesised CCAgNPs through Fourier transform infrared spectroscopy reveals the reducing/stabilising agent present in the aqueous extract of C. cujete and synthesised CCAgNPs. Transmission electron microscopy analysis features the spherical shape of CCAgNPs with an average size of 39.74 nm. Furthermore, an X-ray diffraction study confirms that the synthesised CCAgNPs were face-centred cubic crystalline in nature. The CCAgNPs display tremendous bactericidal activity against human pathogens Bacillus subtilis, Staphylococcus epidermidis, Rhodococcus rhodochrous, Salmonella typhi, Mycobacterium smegmatis, Shigella flexneri and Vibrio cholerae via penetrating into the bacterial cell membrane and causing failure of an internal chain reaction.

Green synthesis of silver nanoparticles with the Arial part of Dorema ammoniacum D. extract by antimicrobial analysis

Silver nanoparticles (SNPs) were synthesised by using the Arial part extract of Dorema ammoniacum D. and characterised by employing UV-visible spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction techniques. Transmission electron microscopy and field emission scanning electron microscopy were applied to investigate the morphological structure of the bio-synthesised SNPs. The antimicrobial activity of SNPs was studied against Gram positive (Bacillus cereus and Staphylococcus aureus) and Gram-negative (Escherichia coli and Salmonella typhimurium) bacteria by employing the disk diffusion agar process. An extremely antimicrobial effect was observed for SNPs. Utilising D. ammoniacum D. as a mediator for the synthesis of SNPs helped to save time and cost.

Nanosilver: new ageless and versatile biomedical therapeutic scaffold

Silver nanotechnology has received tremendous attention in recent years, owing to its wide range of applications in various fields and its intrinsic therapeutic properties. In this review, an attempt is made to critically evaluate the chemical, physical, and biological synthesis of silver nanoparticles (AgNPs) as well as their efficacy in the field of theranostics including microbiology and parasitology. Moreover, an outlook is also provided regarding the performance of AgNPs against different biological systems such as bacteria, fungi, viruses, and parasites (leishmanial and malarial parasites) in curing certain fatal human diseases, with a special focus on cancer. The mechanism of action of AgNPs in different biological systems still remains enigmatic. Here, due to limited available literature, we only focused on AgNPs mechanism in biological systems including human (wound healing and apoptosis), bacteria, and viruses which may open new windows for future research to ensure the versatile application of AgNPs in cosmetics, electronics, and medical fields.

Carica papaya (Papaya) latex: a new paradigm to combat against dengue and filariasis vectors Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae)

This study manifests the larvicidal efficacy of Carica papaya latex extract and silver nanoparticles (CPAgNPs) synthesized using latex, against developing immature juveniles of Aedes aegypti and Culex quinquefasciatus. Briefly, the latex was collected and fractioned with different solvents such as chloroform, methanol and aqueously. The obtained crude extracts were subjected to larvicidal activity in the dose-dependent method. After 24 h, the mortality rate was calculated and statistically analyzed. From the results, it was demonstrated that the chloroform extract displayed prominent activity in IInd and IIIrd instar larvae of A. aegypti and C. quinquefasciatus with better LC50 values followed by methanol and aqueous extract. Subsequently, we profiled the qualitative analysis of a chloroform extract through biochemical tests; Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry. Moreover, we authenticated the major secondary metabolites and activated larvicidal compound present in the extract. Further, we synthesized CPAgNPs using aqueous latex extract and challenged with IInd and IIIrd instar larvae of A. aegypti and C. quinquefasciatus. Noticeably, the synthesized nanoproducts were showed 100% mortality in a 24-h treatment with significant LC50 values. Hence, this study has opened up new vistas in the field of parasitological research to develop Carica papaya latex as a new stratagem in the insect vector management program.

Biosynthesis of silver nanoparticles formation from Caesalpinia pulcherrima stem metabolites and their broad spectrum biological activities

The present work illustrates eco-friendly, rapid and cost effective method of AgNPs synthesis using C. pulcherrima stem extract. Initially, various physico chemical factors were optimized. Characterization was done by different spectroscopic and microscopic analysis. AgNPs were spherical in shape with an average size of 8 nm. AgNPs showed good synergistic antimicrobial, antibiofilm and antioxidant activity. The cytotoxicity effect against HeLa cancer cell line was dose dependent while genotoxic study revealed the non toxic nature of AgNPs at lower concentration. The results suggest that AgNPs from C. pulcherrima stem extract have great potential in biomedical applications.

Plant extracts as green reductants for the synthesis of silver nanoparticles: lessons from chemical synthesis

From conventional synthesis to green transformations: a brief literature overview and insight for the synthesis of Ag nanoparticles.

Low-temperature biosynthesis of silver nanoparticles using mango leaf extract: catalytic effect, antioxidant properties, anticancer activity and application for colorimetric sensing

Aqueous mango leaf extract was used as a reducing and capping agent for the biosynthesis of silver nanoparticles (AgNPs)viaa single-step, low cost and green process.

Green Synthesized Zinc Oxide (ZnO) Nanoparticles Induce Oxidative Stress and DNA Damage in Lathyrus sativus L. Root Bioassay System

Zinc oxide nanoparticles (ZnONP-GS) were synthesised from the precursor zinc acetate (Zn(CH₃COO)₂) through the green route using the milky latex from milk weed (Calotropis gigantea L. R. Br) by alkaline precipitation. Formation of the ZnONP-GS was monitored by UV-visible spectroscopy followed by characterization and confirmation by energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Both the ZnONP-GS and the commercially available ZnONP-S (Sigma-Aldrich) and cationic Zn²⁺ from Zn(CH₃COO)₂ were tested in a dose range of 0–100 mg·L⁻¹ for their potency (i) to induce oxidative stress as measured by the generation reactive oxygen species (ROS: O₂^•−, H₂O₂ and ^•OH), cell death, and lipid peroxidation; (ii) to modulate the activities of antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), guaiacol peroxidase (GPX), and ascorbate peroxidase (APX); and (iii) to cause DNA damage as determined by Comet assay in Lathyrus sativus L. root bioassay system. Antioxidants such as Tiron and dimethylthiourea significantly attenuated the ZnONP-induced oxidative and DNA damage, suggesting the involvement of ROS therein. Our study demonstrated that both ZnONP-GS and ZnONP-S induced oxidative stress and DNA damage to a similar extent but were significantly less potent than Zn²⁺ alone.

Green synthesis of copper nanoparticles using Eclipta prostrata leaves extract and their antioxidant and cytotoxic activities

The present study outlines the development of a method to synthesize copper nanoparticles (CuNPs) by mixing copper acetate solution with leaf extract of Eclipta prostrata without using any surfactant or external energy. E. prostrata leaf extract function as an excellent reducing agent of copper ions, and the biosynthesized CuNPs are safer for the environment. The powder X-ray diffraction (XRD) pattern provided evidence for the formation of face-centered cubic structure ranging from 23 to 57 nm, with an average size of 31±1.2 nm. Fourier transform infrared spectroscopy (FTIR) was used to identify the biomolecules and capping reagents in the E. prostrata leaf extract that may be responsible for the reduction of copper ions and the stability of the bioreduced nanoparticles. The biosynthesized CuNPs displayed considerable antioxidant capacity. Similarly, in vitro anticancer studies demonstrated the cytotoxicity value of synthesized CuNPs against tested HepG2 cells. The findings of the present study suggested that biosynthesized CuNPs that utilize extracts of E. prostrata may be used for therapeutic application, and thus are a promising nanomaterial.

Plant-Mediated Synthesis of Silver Nanoparticles: Their Characteristic Properties and Therapeutic Applications

Interest in "green nanotechnology" in nanoparticle biosynthesis is growing among researchers. Nanotechnologies, due to their physicochemical and biological properties, have applications in diverse fields, including drug delivery, sensors, optoelectronics, and magnetic devices. This review focuses on the green synthesis of silver nanoparticles (AgNPs) using plant sources. Green synthesis of nanoparticles is an eco-friendly approach, which should be further explored for the potential of different plants to synthesize nanoparticles. The sizes of AgNPs are in the range of 1 to 100 nm. Characterization of synthesized nanoparticles is accomplished through UV spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy. AgNPs have great potential to act as antimicrobial agents. The green synthesis of AgNPs can be efficiently applied for future engineering and medical concerns. Different types of cancers can be treated and/or controlled by phytonanotechnology. The present review provides a comprehensive survey of plant-mediated synthesis of AgNPs with specific focus on their applications, e.g., antimicrobial, antioxidant, and anticancer activities.