GC–MS analysis of bioactive components and synthesis of gold nanoparticle using Chloroxylon swietenia DC leaf extract and its larvicidal activity

Biosynthesis, characterization, and multifaceted applications of Elytraria acaulis synthesized silver and gold nanoparticles: Anticancer, antibacterial, larvicidal, and photocatalytic activities

Green synthesis of metal nanoparticles using plant extracts has emerged as an eco-friendly alternative to conventional methods, offering potential applications in biomedicine and environmental remediation. This study demonstrates the successful biosynthesis of silver nanoparticles (SNPs) and gold nanoparticles (GNPs) using Euphorbia acaulis leaf extract as a reducing and capping agent. The nanoparticles were thoroughly characterized using UV-Vis spectroscopy, HR-SEM, EDX, TEM, AFM, XRD, and FTIR analyses, confirming their successful synthesis and revealing their predominantly spherical morphology with sizes ranging from 1 to 100 nm. SNPs and GNPs exhibited significant anticancer activity against MCF-7 breast cancer cells, with IC50 values of 59.87 μg/mL and 91.074 μg/mL, respectively. The nanoparticles induce apoptosis and DNA damage in cancer cells, as evidenced by propidium iodide staining, DAPI staining, and comet assay. In antibacterial studies, SNPs demonstrated superior activity against both E. coli (17.00 mm zone of inhibition) and S. aureus (10.77 mm zone of inhibition) compared to GNPs. The nanoparticles also showed promising larvicidal activity against Aedes aegypti, with SNPs exhibiting higher potency (LC50: 20.81 mg/L) than GNPs (LC50: 51.10 mg/L). Histopathological analysis revealed significant tissue damage in SNP-treated larvae, particularly in the midgut, hindgut, muscles, and nerve ganglia. Additionally, both nanoparticles demonstrated photocatalytic activity in degrading methylene blue dye, with SNPs showing superior performance. These findings suggest that biofunctionalized SNPs and GNPs synthesized using E. acaulis possess multiple biological applications, making them promising candidates for various biomedical and environmental applications.

Sustainable fabrication of dimorphic plant derived ZnO nanoparticles and exploration of their biomedical and environmental potentialities

Although, different plant species were utilized for the fabrication of polymorphic, hexagonal, spherical, and nanoflower ZnO NPs with various diameters, few studies succeeded in synthesizing small diameter ZnO nanorods from plant extract at ambient temperature. This work sought to pioneer the ZnO NPs fabrication from the aqueous extract of a Mediterranean salt marsh plant species Limoniastrum monopetalum (L.) Boiss. and assess the role of temperature in the fabrication process. Various techniques have been used to evaluate the quality and physicochemical characteristics of ZnO NPs. Ultraviolet-visible spectroscopy (UV-VIS) was used as the primary test for formation confirmation. TEM analysis confirmed the formation of two different shapes of ZnO NPs, nano-rods and near hexagonal NPs at varying reaction temperatures. The nano-rods were about 25.3 and 297.9 nm in diameter and in length, respectively while hexagonal NPs were about 29.3 nm. The UV-VIS absorption spectra of the two forms of ZnO NPs produced were 370 and 365 nm for nano-rods and hexagonal NPs, respectively. FT-IR analysis showed Zn-O stretching at 642 cm-1 and XRD confirmed the crystalline structure of the produced ZnO NPs. Thermogravimetric analysis; TGA was also used to confirm the thermal stability of ZnO NPs. The anti-tumor activities of the two prepared ZnO NPs forms were investigated by the MTT assay, which revealed an effective dose-dependent cytotoxic effect on A-431 cell lines. Both forms displayed considerable antioxidant potential, particularly the rod-shaped ZnO NPs, with an IC50 of 148.43 µg mL-1. The rod-shaped ZnO NPs were superior candidates for destroying skin cancer, with IC50 of 93.88 ± 1 µg mL-1 ZnO NPs. Thus, rod-shaped ZnO NPs are promising, highly biocompatible candidate for biological and biomedical applications. Furthermore, both shapes of phyto-synthesized NPs demonstrated effective antimicrobial activity against various pathogens. The outcomes highlight the potential of phyto-synthesized ZnO NPs as an eco-friendly alternative for water and wastewater disinfection.

Bio-fabrication of silver nanoparticles using Commelina erecta, L.: a mechanistic approach on synthesis, optimization, antibacterial, and antioxidant potential

The ongoing exploration of economical, sustainable, and environment-friendly methods for synthesizing monodisperse colloidal metal nanoparticles is growing day by day due to their potential application in various fields. The use of plant derivatives in nanoparticle synthesis and their suitability as sustainable catalysts have emerged as significant areas of research. In this study, silver nanoparticles were synthesized using an aqueous extract obtained from the commonly found weed Commelina erecta, L. Extensive study is conducted to optimize various synthesis parameters such as pH, reducing agent concentration, silver nitrate concentration, and temperature. The plant extract utilized in the synthesis process contained variety of antioxidants, including malic acid, phenol, benzoic acid, and catechol, which played a crucial role in both reduction and capping during the synthesis process, thereby making them suitable for biomedical applications. The optimized synthesis process yielded silver nanoparticles with a particle size of 16.2 ± 3.1 nm. These nanoparticles exhibited excellent stability and demonstrated remarkable antibacterial activity compared to the standard antibacterial agent, streptomycin. In addition, the silver nanoparticles displayed promising antioxidant activity attributed to the presence of antioxidant functional groups on their surface. This study reports, for the first time, the synthesis of silver nanoparticles using antioxidant compounds present in C. erecta, L. plant extract. The antioxidant compounds identified through GC-MS belong to phenols, phenolic acids, and carboxylic acid groups. Furthermore, the exceptional antimicrobial and antioxidant properties exhibited by the synthesized silver nanoparticles offer new possibilities for their potential applications.

New weapons against the disease vector Aedes aegypti: From natural products to nanoparticles

Despite the global burden of viral diseases transmitted by Aedes aegypti, there is a lack of effective means of prevention and treatment. Strategies for vector control include chemical and biological approaches such as organophosphates and Bacillus thuringiensis var. israelensis (Bti), among others. However, important concerns are associated, such as resistance in mosquito larvae and deleterious effects on non-target organisms. In this scenario, novel approaches against A. aegypti have been investigated, including natural products (e.g. vegetable oil and extracts) and nanostructured systems. This review focuses on potential strategies for fighting A. aegypti, highlighting plant-based materials and nanomaterials able to induce toxic effects on egg, larva, pupa and adult mosquitoes. Issues including aspects of conventional vector control strategies are presented, and finally new insights on development of eco-friendly nanoformulations against A. aegypti are discussed.

Comparative assessment of the biological activity of the green synthesized silver nanoparticles and aqueous leaf extract of Perilla frutescens (L.)

Green synthesized nanoparticles (GSNPs) display fascinating properties compared to physical and chemical synthesized ones. GSNPs are currently used in numerous applications such as food packaging, surface coating agents, environmental remediation, antimicrobial, and medicine. In the present study, the aqueous leaf extract of Perilla frutescens L. having suitable capping, reducing, and stabilizing compounds was used for green synthesis of silver nanoparticles (Pf-AgNPs). The bioreductant capacity of aqueous leaf extract of P. frutescens for Pf-AgNPs was determined by different confirmatory techniques including UV-Visible spectroscopy, XRD, FESEM, EDX, zeta potential, DLS, SERS, and FTIR analysis. The results exhibited that Pf-AgNPs had optimal size (< 61 nm), shape (spherical), and stability (- 18.1 mV). The antioxidant activity of Pf-AgNPs with both DPPH and FRAP assays was significantly higher compared to P. frutescens extract. Furthermore, Pf-AgNPs had high antimicrobial activity against Escherichia coli and Staphylococcus aureus (MIC = 0.78 mg/mL), and Candida albicans (MIC = 8 mg/mL) while the plant extract showed low antimicrobial activity against both bacterial strains and the fungus tested. Pf-AgNPs and P. frutescens extract also exhibited moderate toxicity on MCF-7 cancer cells with IC₅₀ values of 346.2 and 467.4 µg/mL, respectively. The results provide insights into using the biosynthesized Pf-AgNPs as an eco-friendly material for a wide range of biomedical applications.

Moringa oleifera gum capped MgO nanoparticles: Synthesis, characterization, cyto- and ecotoxicity assessment

Nano-based drug delivery research is increasing due to the therapeutic applications for human health care. However, traditional chemical capping-based synthesis methods lead to unwanted toxicity effects. Hence, there is an urgent need for green synthesis-based and biocompatible synthesis methods. The current work describes for the first time the green synthesis of Moringa gum-capped MgO nanoparticles (Mgm-MgO NPs). Their antioxidant activity, hemolysis potential, cytotoxicity, phytotoxicity, toxicity by chorioallantoic membrane (CAM) chick embryo assay and in vivo toxicity in zebrafish embryos were described. The Mgm-MgO NPs exhibited significant antioxidant activity. The Mgm-MgO NPs at 500 μg/ml produced significant hemolysis (72.54 %), while lower concentrations did not. Besides, the cytotoxicity assessment of the Mgm-MgO NPs was conducted in PA-1 cells from human ovarian teratocarcinoma by MTT assay. The Mgm-MgO NPs (0.1-500 μg/ml) considerably reduced the viability of PA-1 cells. Furthermore, Mgm-MgO NPs had no significant effect on seed germination but had a significant effect on root and shoot length of mungbean (Vigna radiata). Additionally, the CAM assay was used to analyze the antiangiogenic potential of Mgm-MgO NPs, exhibiting no significant alterations after 72 h. Finally, the zebrafish embryotoxicity assay revealed that the Mgm-MgO NPs (0.1-500 μg/ml) did not affect morphology, mortality or survival rate.

Green synthesis of zinc oxide nanoparticles using Sea Lavender (Limonium pruinosum L. Chaz.) extract: characterization, evaluation of anti-skin cancer, antimicrobial and antioxidant potentials

In the present study, a green, sustainable, simple and low-cost method was adopted for the synthesis of ZnO NPs, for the first time, using the aqueous extract of sea lavender, Limonium pruinosum (L.) Chaz., as a reducing, capping, and stabilizing agent. The obtained ZnO NPs were characterized using ultraviolet-visible spectroscopy (UV-VIS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The UV-Vis spectra of the green synthesized ZnO NPs showed a strong absorption peak at about 370 nm. Both electron microscopy and XRD confirmed the hexagonal/cubic crystalline structure of ZnO NPs with an average size ~ 41 nm. It is worth noting that the cytotoxic effect of the ZnO NPs on the investigated cancer cells is dose-dependent. The IC₅₀ of skin cancer was obtained at 409.7 µg/ml ZnO NPs. Also, the phyto-synthesized nanoparticles exhibited potent antibacterial and antifungal activity particularly against Gram negative bacteria Escherichia coli (ATCC 8739) and the pathogenic fungus Candida albicans (ATCC 10221). Furthermore, they showed considerable antioxidant potential. Thus, making them a promising biocompatible candidate for pharmacological and therapeutic applications.

Retrospective analysis of the key molecules involved in the green synthesis of nanoparticles

Emerging nanotechnology leads to success in synthesizing and applying nanoparticles (NPs) using the green-chemistry approach. NPs synthesized using naturally derived materials are a potential alternative to chemical and physical methods because they are simple, cost-effective, eco-friendly, and lower the possibility of hazardous residues being released into the environment. Furthermore, NPs synthesized using the green synthesis approach are stable and biocompatible. However, because natural extracts contain a diverse spectrum of bioactive components, it is difficult to pinpoint the specific component involved in NP formation. Furthermore, the bioactive component contained in the extract changes based on a number of environmental factors; therefore, several studies began with the synthesis of NPs using a pure compound isolated from diverse natural sources. Hence, the present review paper makes an effort to retrospectively analyze the key compounds of the extracts which are responsible for the synthesis of the NPs. The analysis was carried out based on the physicochemical characteristics and biological activities of NPs synthesized from either the extract or the pure compounds. These pure-compound-based NPs were studied for their antimicrobial, antibiofilm, anti-inflammatory, anticancer, and antioxidant properties. In addition, the present review also describes progress in the study of pure compound-based numerous biological activities and the underlying mechanisms of action.

Green synthesis of gold nanoparticles using Gracilaria crassa leaf extract and their ecotoxicological potential: Issues to be considered

The use of vegetal species for gold nanoparticles (AuNPs) biosynthesis can constitute an alternative to replacing the extensive use of several hazardous chemicals commonly used during NPs synthesis and, therefore, can reduce biological impacts induced by the release of these products into the natural environment. However, the "green nanoparticles" and/or "eco-friendly nanoparticles" label does not ensure that biosynthesized NPs are harmless to non-target organisms. Thus, we aimed to synthesize AuNPs from seaweed Gracilaria crassa aqueous extract through an eco-friendly, fast, one-pot synthetic route. The formation of spherical, stable, polycrystalline NPs with a diameter of 32.0 nm ± 4.0 nm (mean ±SEM) was demonstrated by UV-vis spectroscopy, field emission scanning electron microscopy, and high-resolution transmission electron microscopy, energy-dispersive X-ray and X-ray diffraction measurement, and Fourier-transform infrared spectroscopy analysis. In addition, different phytocomponents were identified in the biosynthesized AuNPs, using Gas Chromatography-Mass Spectrometry (GC-MS). However, both G. crassa aqueous extract and the biosynthesized AuNPs showed high ecotoxicity in Anopheles stephensi larvae exposed to different concentrations. Therefore, our study supports the potential of seaweed G. crassa as a raw material source for AuNPs biosynthesis while also shedding light on its ecotoxicological potential, which necessitates consideration of its risk to aquatic biota.

Cichorium intybus bio-callus synthesized silver nanoparticles: A promising antioxidant, antibacterial and anticancer compound

Cichorium intybus, commonly called chicory, has been widely used as a coffee substitute. It display a wide range of natural compounds and medicinally uses in treatment of gastrointestinal disorders. This study synthesized silver nanoparticles (Ci-AgNPs) using C. intybus leaf-derived callus extract to evaluate phytochemical content, antibacterial, antioxidant and anti-proliferative activities against human breast cancer cells (MDA-MB231). The optimal shape, size and stability of Ci-AgNPs was confirmed using UV-visible spectrophotometry, FESEM, EDX, XRD, DLS, Zeta potential, FTIR and sp-ICP-MS studies. The antibacterial activity of Ci-AgNPs was assessed using disk diffusion method against Staphylococcus aureus and Escherichia coli, and they displayed distinct zones of inhibition. Colorimetric phytochemical analysis of Ci-AgNPs revealed their higher total phenolic (TP) and total flavonoid (TF) content. Ci-AgNPs also indicated a high level of antioxidant activity using FRAP and DPPH assays. The Ci-AgNPs were investigated for their anticancer activities on the cancerous MDA-MB231 cells viability and apoptosis using MTT and flow cytometry, respectively. Ci-AgNPs showed dose dependent cytotoxicity against MDA-MB231 cells with IC50 value of 187.6 μg/mL at 48 h through induction of apoptosis. The biocompatibility test showed that Ci-AgNPs induced neglectable cytotoxicity (lower than 3 %) toward human erythrocytes. This is the first study that reports the bio-callus mediated synthesis of silver nanoparticle using C. intybus callus extract which provided a promising anticancer activity against human breast cancer MDA-MB231 cells and therefore could be used as an alternative and interesting benign strategy for biosynthesis of silver nanoparticles useful in cancer therapy.

Green synthesized Ag-nanoparticles using Scutellaria multicaulis stem extract and their selective cytotoxicity against breast cancer

Scutellaria multicaulis is a medicinal herb which has been extensively prescribed in Iranian traditional medicine for treatment of infections, constipation, wounds, and also as medication for anxiety. To evaluate biological activities of biosynthesized silver nanoparticles (Sm-AgNPs), Sm-AgNPswere synthesized using S. multicaulis stem extract as capping and reducing agent. Characterization studies using UV-vis, XRD, DLS, Zeta potential, FESEM, EDX, TEM, FTIR, RAMAN and TGA assays indicated that Sm-AgNPs had optimal shape, size (∼60 nm) and stability (-46.4 mV) to be used as a drug. Findings also demonstrated that Sm-AgNPs display higher Total Phenolics and Total Flavonoids Content and possesses higher antioxidant activity. HPLC-MSn analysis of constituents in the S. multicaulis stem extract and Sm-AgNPs-free supernatant in negative ion mode showed that flavonoids, mainly jaceidin, skullcapflavon II, wogonin, oroxylin A and dihydroxy, trimethoxyflavone from extract have contributed to the synthesis of Sm-AgNPs. Additionally, Sm-AgNPs demonstrated effective anticarcinogenic properties on MDA-MB231 cells proliferation with IC50 value of 81.2 μg/mL at 48 h by inducing cell apoptosis. Overall, results confirmed the potential role of S. multicaulis stem extract as a potential raw material for synthesis of biologically active Sm-AgNPs, for development of new antitumor agents which could be utilized to combat breast cancer.

Green Nano-Biotechnology: A New Sustainable Paradigm to Control Dengue Infection

Dengue is a growing mosquito-borne viral disease prevalent in 128 countries, while 3.9 billion people are at high risk of acquiring the infection. With no specific treatment available, the only way to mitigate the risk of dengue infection is through controlling of vector, i.e., Aedes aegypti. Nanotechnology-based prevention strategies like biopesticides with nanoformulation are now getting popular for preventing dengue fever. Metal nanoparticles (NPs) synthesized by an eco-friendly process, through extracts of medicinal plants have indicated potential anti-dengue applications. Green synthesis of metal NPs is simple, cost-effective, and devoid of hazardous wastes. The recent progress in the phyto-synthesized multifunctional metal NPs for anti-dengue applications has encouraged us to review the available literature and mechanistic aspects of the dengue control using green-synthesized NPs. Furthermore, the molecular bases of the viral inhibition through NPs and the nontarget impacts or hazards with reference to the environmental integrity are discussed in depth. Till date, major focus has been on green synthesis of silver and gold NPs, which need further extension to other innovative composite nanomaterials. Further detailed mechanistic studies are required to critically evaluate the mechanistic insights during the synthesis of the biogenic NPs. Likewise, detailed analysis of the toxicological aspects of NPs and their long-term impact in the environment should be critically assessed.

Chloroxylon swietenia (Roxb.) DC induces cell death and apoptosis by down-regulating the NF-κB pathway in MCF-7 breast cancer cells: In vitro and in vivo investigations

Background

Natural products with targeted bioactivity have gained major attention in the field of cancer research owing to emerging anti‐cancer drug resistance and off target toxicities. Chloroxylon swietenia (Roxb.) DC is recognized as a folklore medicinal plant and has numerous therapeutic benefits in the folklore medicine system, however the anti‐cancer potential of this plant and its mechanism of action is poorly understood.

Aims

The aim of the study was to investigate the anti‐breast cancer efficacy of C. swietenia leaves methanol extract (CSLME) against MCF‐7 hormone dependent human breast cancer cell line with possible mechanism of action.

Methods and results

The anti‐breast cancer activity of CSLME against MCF‐7 cells was assessed by evaluating its efficacy toward cytotoxicity, cell migration, colony formation, DNA fragmentation, apoptosis, cytoskeleton, angiogenesis, cell cycle regulation, and animal toxicity. The preliminary screening of CSLME against MCF‐7 cells revealed the cytotoxicity (IC₅₀ 20 μg/ml), inhibited cell migration, colony formation, and angiogenesis. It was observed that CSLME induces apoptosis by nuclear fragmentation and disruption of cytoskeleton by actin derangement. The results of Annexin V‐FITC assay and cell cycle analysis by flow cytometry clearly pointed out the sizable fraction of apoptotic cells, and arrested the cells at G2/M phase of cell cycle. The results of the immunoblotting experiments showed that CSLME activates intrinsic pathway of apoptosis with down regulation of anti‐apoptotic marker like Bcl2, up regulation of pro‐apoptotic markers like Bax & Bad, along with successful cleavage of Caspase‐9 and PARP‐1. Further, western blot analysis revealed the possible down regulation of NF‐κB pathway by CSLME, which may be responsible for anti‐cancer activity in MCF‐7 cells. In vivo animal model studies using NOD‐SCID mice demonstrated impressive anti‐tumor activity with significant reduction in tumor volume of MCF‐7 tumor xenograft. Of note, in‐vivo acute oral toxicity study as per Organization for Economic Cooperation and Development 423 revealed the nontoxic nature of CSLME.

Conclusion

The in vitro and in vivo findings clearly outline the potential of CSLME as inhibitor of growth and proliferation of MCF‐7 cells. Mechanistically, CSLME seems to activate intrinsic pathway of apoptosis, arrest cell cycle, target actin cytoskeleton, inhibit growth, colony formation, migration, and angiogenesis, with down regulation of NF‐κB pathway leading to cell death.

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.

Botanical insecticide-based nanosystems for the control of Aedes (Stegomyia) aegypti larvae

Aedes (Stegomyia) aegypti is a cosmopolitan species that transmits arbovirus of medical importance as dengue, Zika, and chikungunya. The main strategy employed for the control of this mosquito is the use of larvicidal agents. However, the overuse of synthetic chemical larvicides has led to an increase in resistant insects, making management difficult. Therefore, the use of botanical insecticide-based nanosystems as an alternative to the use of synthetic agents for the control of Ae. aegypti has gained more considerable attention in the last years, mainly due to the advantages of nanostructured delivery systems, such as (a) controlled release; (b) greater surface area; (c) improvement of biological activity; (d) protection of natural bioactive agents from the environment and thus achieving stability; and (e) lipophilic drugs are easier dispersed even in aqueous vehicles. This review summarizes the current knowledge about botanical insecticide-based nanosystems as larvicidal against Ae. aegypti larvae. The majority of papers used metallic nanoparticles (NPs) as larvicidal agents, mainly silver nanoparticles (AgNPs), showing potential for their use as an alternative, followed by nanoemulsions containing vegetable oils, most essential oils, nanosystems that allow the dispersion of this high hydrophobic product in water, the environment of larval development. The final section describes scientific findings about the mode of action of these NPs, showing the gap about this subject in literature.

A Review of Resistance Mechanisms of Synthetic Insecticides and Botanicals, Phytochemicals, and Essential Oils as Alternative Larvicidal Agents Against Mosquitoes

Mosquitoes are a serious threat to the society, acting as vector to several dreadful diseases. Mosquito management programes profoundly depend on the routine of chemical insecticides that subsequently lead to the expansion of resistance midst the vectors, along with other problems such as environmental pollution, bio magnification, and adversely affecting the quality of public and animal health, worldwide. The worldwide risk of insect vector transmitted diseases, with their associated illness and mortality, emphasizes the need for effective mosquitocides. Hence there is an immediate necessity to develop new eco-friendly pesticides. As a result, numerous investigators have worked on the development of eco-friendly effective mosquitocidal compounds of plant origin. These products have a cumulative advantage of being cost-effective, environmentally benign, biodegradable, and safe to non-target organisms. This review aims at describing the current state of research on behavioral, physiological, and biochemical effects of plant derived compounds with larvicidal effects on mosquitoes. The mode of physiological and biochemical action of known compounds derived from various plant families as well as the potential of plant secondary metabolites, plant extracts, and also the essential oils (EO), as mosquitocidal agents are discussed. This review clearly indicates that the application of vegetal-based compounds as mosquito control proxies can serve as alternative biocontrol methods in mosquito management programes.

Green synthesis and bactericidal activities of isotropic and anisotropic spherical gold nanoparticles produced using Peganum harmala L leaf and seed extracts

Shape, size, and homogeneity affect the biological activity of gold nanoparticles (AuNPs) in nanomedicine and catalytic applications. Here we biosynthesized monodispersed isotropic and polydispersed anisotropic spherical AuNPs from leaf and seed extract broths of the medicinal plant Peganum harmala L. (Ph. L). Synthesized AuNPs were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy (FT-IRS), field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The antimicrobial activity of AuNPs against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) human pathogens was also assessed. Leaf- and seed-derived AuNPs had characteristic localized surface plasmon resonances of 530 and 578 nm, respectively. TEM, FE-SEM, EDX, and XRD revealed the formation of elemental face-centered cubic spherical monodispersed isotropic AuNPs of average size 43.44 nm and polydispersed anisotropic AuNPs of average size 52.04 nm from leaf and seed extract broths, respectively. FT-IR revealed polyphenols and alcohols as responsible for AuNP capping, reduction, and protection. Anisotropic AuNPs showed no antibacterial activity, whereas isotropic AuNPs showed good inhibition of both E. coli and S. aureus. This represents a simple and ecofriendly protocol for the green synthesis of monodispersed isotropic spherical AuNPs, which may have value in a variety of applications.

A repertoire of biomedical applications of noble metal nanoparticles

The emerging properties of noble metal nanoparticles are attracting huge interest from the translational scientific community. In this feature article, we highlight recent advances in the adaptation of noble metal nanomaterials and their biomedical applications in therapeutics, diagnostics and sensing.

Novel synthesis of gold nanoparticles using Artemisia vulgaris L. leaf extract and their efficacy of larvicidal activity against dengue fever vector Aedes aegypti L

The Aedes aegypti L. mosquito transmits dengue and yellow fever, which cause millions of death every year. Dengue is a mosquito-borne viral disease that has rapidly spread worldwide particularly in countries with tropical and subtropical climates areas. The present study denotes a simple and eco-friendly biosynthesis of gold nanoparticles using Artemisia vulgaris L. leaf extract as reducing agent. The synthesized gold nanoparticles were characterized by UV-Visible Spectroscopy, X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Dynamic Light Scattering (DLS), Zeta Potential (ZP), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectroscopy (EDX). Solid state ¹³C NMR was utilized to confirm the presence of larvicidal compound Beta caryophyllene in the synthesized AuNPs. Larvicidal activity of the synthesized AuNPs was measured against A. aegypti over 12 and 24h exposure periods and compared with essential oil in various concentrations (25ppm, 50ppm, 100ppm, 200ppm and 400ppm). After a 12h exposure period, the larvicidal activity of 3^rd instar larva by AuNPs showed LC₅₀=156.55ppm and LC₉₀=2506.21ppm, while and essential oil displayed LC₅₀=128.99ppm and LC₉₀=1477.08ppm. Larvicidal activity of 4^th instar larva by AuNPs showed LC₅₀=97.90ppm and LC₉₀=1677.36ppm, while essential oil displayed LC₅₀=136.15ppm and LC₉₀=2223.55ppm. After a 24h of exposure period, larvicidal activity of 3^rd instar larva by AuNPs showed LC₅₀=62.47ppm and LC₉₀=430.16ppm and essential oil showed LC₅₀=111.15ppm and LC₉₀=1441.51ppm. The larvicidal activity of 4^th instar larva and AuNPs displayed LC₅₀=43.01ppm and LC₉₀=376.70ppm and for essential oil LC₅₀=74.42ppm, LC₉₀=858.36ppm. Histopathology of A. aegypti with AuNPs for 3^rdand 4^th stage larvae after 24h exposure at the highest mortality concentration (400ppm) showed that the area of the midgut, epithelial cells and cortex were highly affected. The present findings demonstrate that the biosynthesis of AuNPs using A. vulgaris leaf extracts could be an eco-friendly, safer nanobiopesticide and treatment against A. aegypti which could be used to combat of dengue fever.

Green synthesis of gold nanoparticles using a cheap Sphaeranthus indicus extract: Impact on plant cells and the aquatic crustacean Artemia nauplii

The impact of green-fabricated gold nanoparticles on plant cells and non-target aquatic species is scarcely studied. In this research, we reported an environment friendly technique for the synthesis of gold nanoparticles (Au NPs) using the Sphaeranthus indicus leaf extract. The formation of the metal NPs was characterized by UV-Visible and FT-IR spectroscopy, XRD, SEM and TEM analyses. The UV-Visible spectra of Au NPs showed a surface plasmon resonance peak at 531nm. FT-IR analysis indicated functional bio-molecules associated with Au NPs formation. The crystalline nature of Au nanoparticles was confirmed by their XRD diffraction pattern. TEM revealed the spherical shape with a mean particle size of 25nm. Au NPs was tested at 0, 1, 3, 5, 7 and 10% doses in mitotic cell division assays, pollen germination experiments, and in vivo toxicity trials against the aquatic crustacean Artemia nauplii. Au NPs did not show any toxic effects on plant cells and aquatic invertebrates. Notably, Au NPs promoted mitotic cell division in Allium cepa root tip cells and germination of Gloriosa superba pollen grains. Au NPs showed no mortality on A. nauplii, all the tested animals showed 100% survivability. Therefore, these Au NPs have potential applications in the development of pollen germination media and plant tissue culture.

Lantana camara Linn root extract-mediated gold nanoparticles and their in vitro antioxidant and cytotoxic potentials

The Lantana camara Linn root extract derived gold nanoparticles (Au NPs) were characterized by Ultraviolet-Visible spectroscopy, X-ray diffraction, fourier transform-infrared, high resolution transmission electron microscopy, selected area electron diffraction pattern and energy dispersive X-ray analyses. In DPPH assay, the inhibitory concentration (IC₅₀) of Au NPs and gallic acid was 24.17 and 5.39 μg/ml, whereas, for cytotoxicity assay, the IC₅₀ of Au NPs was 17.72 and 32.98 μg/ml on MBA-MB-231 and Vero cells, respectively. Thus, the Au NPs possess significant in vitro antioxidant and cytotoxic properties which could be considered as potential alternate for the development of anticancer drug in future.

Biosynthesis of gold nanoparticles using green roof species Portulaca grandiflora and their cytotoxic effects against C6 glioma human cancer cells

Leaf and stem extracts of popular green roof vegetation, Portulaca grandiflora, were used for the synthesis of gold nanoparticles. The synthesized gold nanoparticles were characterized using UV–visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. FTIR results indicated the presence of proteins and polyphenols in plant extracts which were responsible for the reduction and stabilization of gold nanoparticles. SEM and TEM images confirmed the formation of spherical, rhombus, triangular, tetragonal, pentagonal, rods and hexagonal shaped gold nanoparticles. The size of the particles was in the range of 8 and 72 nm. The antiproliferative effects of synthesized gold nanoparticles were assessed using C6 glioma human cancer cells. Results indicated that gold nanoparticles synthesized using leaf extracts (150 µg/mL) and stem extracts (200 µg/mL) of P. grandiflora decreased the viability of C6 glioma cell lines up to 50%. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1732–1740, 2016