Modulating plant-soil microcosm with green synthesized ZnONPs in arsenic contaminated soil

Biogenic nanoparticle (NP), derived from plant sources, is gaining prominence as a viable, cost-effective, sustainable, and biocompatible alternative for mitigating the extensive environmental impact of arsenic on the interplay between plant-soil system. Herein, the impact of green synthesized zinc oxide nanoparticles (ZnONPs) was assessed on Catharanthus roseus root system-associated enzymes and their possible impact on microbiome niches (rhizocompartments) and overall plant performance under arsenic (As) gradients. The application of ZnONPs at different concentrations successfully modified the arsenic uptake in various plant parts, with the root arsenic levels increasing 1.5 and 1.4-fold after 25 and 50 days, respectively, at medium concentration compared to the control. Moreover, ZnONPs gradients regulated the various soil enzyme activities. Notably, urease and catalase activities showed an increase when exposed to low concentrations of ZnONPs, whereas saccharase and acid phosphatase displayed the opposite pattern, showing increased activities under medium concentration which possibly in turn influence the plant root system associated microflora. The use of nonmetric multidimensional scaling ordination revealed a significant differentiation (with a significance level of p < 0.05) in the structure of both bacterial and fungal communities under different treatment conditions across root associated niches. Bacterial and fungal phyla level analysis showed that Proteobacteria and Basidiomycota displayed a significant increase in relative abundance under medium ZnONPs concentration, as opposed to low and high concentrations, respectively. Similarly, in depth genera level analysis revealed that Burkholderia, Halomonas, Thelephora and Sebacina exhibited a notably high relative abundance in both the rhizosphere and rhizoplane (the former refers to the soil region influenced by root exudates, while the latter is the root surface itself) under medium concentrations of ZnONPs, respectively. These adjustments to the plant root-associated microcosm likely play a role in protecting the plant from oxidative stress by regulating the plant's antioxidant system and overall biomass.

Plant-derived nanomaterials (PDNM): a review on pharmacological potentials against pathogenic microbes, antimicrobial resistance (AMR) and some metabolic diseases

Plant-derived nanomaterials (PDNM) have gained significant attention recently due to their potential pharmacological applications against pathogenic microbes, antimicrobial resistance (AMR), and certain metabolic diseases. This review introduces the concept of PDNMs and their unique properties, including their small size, high surface area, and ability to penetrate biological barriers. Besides various methods for synthesizing PDNMs, such as green synthesis techniques that utilize plant extracts and natural compounds, the advantages of using plant-derived materials, such as their biocompatibility, biodegradability, and low toxicity, were elucidated. In addition, it examines the recent and emerging trends in nanomaterials derived from plant approaches to combat antimicrobial resistance and metabolic diseases. The sizes of nanomaterials and their surface areas are vital as they play essential roles in the interactions and relationships between these materials and the biological components or organization. We critically analyze the biomedical applications of nanoparticles which include antibacterial composites for implantable devices and nanosystems to combat antimicrobial resistance, enhance antibiotic delivery, and improve microbial diagnostic/detection systemsIn addition, plant extracts can potentially interfere with metabolic syndrome pathways; hence most nano-formulations can reduce chronic inflammation, insulin resistance, oxidative stress, lipid profile, and antimicrobial resistance. As a result, these innovative plant-based nanosystems may be a promising contender for various pharmacological applications.

Synergism and toxicity of iron nanoparticles derived from Trigonella foenum-graecum against pyrethriod treatment in S. litura and H. armigera (Lepidoptera: Noctuidae)

The tobacco cutworm, Spodoptera litura and cotton bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae) are important pests of various agricultural crops that cause sevier economic loses throughout the world. Indiscriminate and frequent use of insecticide may lead to development of resistance in these pests. Nanotechnology has given an alternative to manage and overcome insecticide resistance for pest management strategies. In the present study the iron nanoparticles derived from Trigonella foenum-graecum leaf extract (FeNPs) was investigated for its ecofriendly management of pyrethroid resistance in two lepidopteron pest species at 24 h, 48 h and 72 h post treatment. The result showed high mortality (92.83% and 91.41%) of S. litura and H. armigera at 72 h treatment upon FeNPs and fenvalerate (Fen + FeNPs) teratment. Probit analysis revealed high LC₅₀ upon Fen + FeNPs treatment (130.31 and 89.32 mg/L) with a synergism ratio of 1.38 and 1.36. Antifeedant activity of six dofferent concentration of FeNPs revelaed increased antifeedant activity with respect to increasing concentration of nanoparticles ranging from 10 to 90% and 20-95% againt both insects (p<0.05). Detoxification activity of carboxylesterase was elevated at 630 μmol/mg protein/min (p<0.05) in fenvalerate treatment, whereas decreased activity was found (392umole/mg protein/min) in FeNPs and Fen + FeNPs treatment (P<0.001). GST and P450 activity was also increased in fenvalerate treatment, whereas decreased activity was observed in FeNPs and Fen + FeNPs. Esterase isoenzyme banding pattern revealed four bands in fenvalerate treatment and two bans (E3 and E4) in Fen + FeNPs combination. Hence the present study concludes that T. foenum-graecum synthesized iron nanoparticles could be an effective alternate for ecofriendly management of S. litura and H. armigera.

Eco-friendly synthesis of Ag-NPs using Endostemon viscosus (Lamiaceae): Antibacterial, antioxidant, larvicidal, photocatalytic dye degradation activity and toxicity in zebrafish embryos

Nanotechnology is a multidisciplinary area of study that has grown significantly in serving many functions and impacting human society. New fields of science have been facilitated by the clean, non-toxic, and biocompatible nature of plant-derived nanoparticles. The present study deals with the first green synthesis of silver nanoparticles (Ag-NPs) using Endostemon viscosus, and their synthesized Ag NPs were characterized by different spectral methods (UV-vis Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction Spectroscopy (XRD), Transmission Electron Microscopy (TEM) and Energy dispersive X-ray Spectroscopy (EDAX). The change initially observed the production of Ag-NPs in color from green to ash and then confirmed by SPR band at 435 nm in UV-vis spectral analysis. The FTIR findings indicate that many functional groups belong to the pharmaceutically useful phytochemicals, which interact as reducing, capping, and stabilizing agents in synthesizing silver nanoparticles. The predominant peaks in the XRD pattern belong to the planes 210°, 111°, 200°, 241°, and 311° and thus demonstrated the Ag-NPs FCC crystal structure. TEM analysis exhibited spherical-shaped particles with an average size of 13 nm, and the EDAX band showed a distinctive metallic silver peak at 3.0 keV. The antibacterial activity of Ag-NPs tested to show a maximum zone of inhibition of 19 mm for Staphylococcus aureus and 15 mm for Escherichia coli at 100 μg/mL, respectively. Bio-fabricated Ag-NPs were assessed for antioxidant activity (DPPH with % inhibition 57.54% and FRAP with % inhibition 70.89%). The biosynthesized Ag-NPs demonstrated potential larvicidal efficacy against Aedes aegypti with more than 90% at 250 μg/mL. Histological profiles were altered while treating with Ag-NPs at 250 μg/mL. The photocatalytic activity of synthesized E. viscosus Ag-NPs was tested against methylene blue (MB) and crystal violet (CV), and the maximum degradation efficiency was found as 90 and 94%, respectively. Furthermore, the toxicity test on zebrafish embryos demonstrated that aberrations have only been induced at concentrations higher than 500 μg/mL. We conclude that the greenly produced Ag-NPs may find use in biomedical applications based on bacteria and cost-effective industrial wastewater treatment.

A green and environmental sustainable approach to synthesis the Mn oxide nanomaterial from Punica granatum leaf extracts and its in vitro biological applications

Pathogenic fungal infections in fruit cause economic losses and have deleterious effects on human health globally. Despite the low pH and high water contents of vegetables and fresh, ripened fruits, they are prone to fungal and bacterial diseases. The ever-increasing resistance of phytopathogens toward pesticides, fungicides and bactericides has resulted in substantial threats to plant growth and production in recent years. However, plant-mediated nanoparticles are useful tools for combating parasitic fungi and bacteria. Herein, we synthesized biogenic manganese oxide nanoparticles (MnONPs) from an extract of Punica granatum (P. granatum), and these nanoparticles showed significant antifungal and antibacterial activities. The production of MnONPs from plant extracts was confirmed by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and UV visible spectroscopy (UV). The surface morphology and shape of the nanoparticles were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Using a detached fruit method, the MnONPs were shown to exhibit significant antimicrobial activities against two bacterial strains, E. coli and S. aureus, and against the fungal species P. digitatum. The results revealed that the MnONPs had a minimum antimicrobial activity at 25 µg/mL and a maximum antimicrobial activity at 100 µg/mL against bacterial strains in lemon (citrus). Furthermore, the MnONPs exhibited significant ROS scavenging activity. Finally, inconclusive results from the green-synthesized MnONPs magnified their significant synergetic effects on the shelf life of tomatoes (Lycopercicum esculantum) and indicated that they could be used to counteract the phytopathological effects of postharvest fungal diseases in fruits and vegetables. Overall, this method of MnONPs synthesis is inexpensive, rapid and ecofriendly. MnONPs can be used as potential antimicrobial agents against different microbial species.

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.

Treatment of Saussurea heteromalla for biofuel synthesis using catalytic membrane reactor

Membrane technology has been adopted as a prospective and promising alternative to the standard technology used for biodiesel production since the time when it had some limitations. During this research project, the inedible seed oil generating feedstock known as Saussurea heteromalla was put through a biodiesel production process that utilized membrane technology with an effort to increase the yield of methyl ester. The transesterification process was mediated by zirconium oxide nanoparticles that were generated using an aqueous extract of Portulaca oleracea leaf. With an oil to methanol ratio of 1:9, a catalyst concentration of 0.88 (wt. %), temperature of 87 °C, and reaction time of 180 min, the highest possible biodiesel yield of 93% was achieved. The findings of the catalyst characterization demonstrated the purity of the zirconium oxide nano particles and their nanoscale nature with average particle size of 31 nm. Using gas chromatography and mass spectrometry (GC/MS), an examination of biodiesel revealed the presence of four different peaks of methyl esters. Using Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance, we were able to verify that the production of methyl esters in the biodiesel sample was successful (NMR). Zerconium oxide nanoparticles were found reusable up to five consecutive cycles of transesterification. The fuel-related properties of methyl ester have been determined and are in line with the requirements of the international standards ASTM D-6571 and EN 14214. In the course of our ongoing research, we made use of membrane technology, which led to the production of biodiesel from the seed oil of Saussurea heteromalla that was better for the environment, more cost effective, and produced in greater quantities.

Green nanoparticles as multifunctional nanomedicines: Insights into anti-inflammatory effects, growth signaling and apoptosis mechanism in cancer

Recently, green nanotechnology got great attention due to their reliable, sustainable, and eco-friendly synthesis protocols. The green nanoparticles (GNPs) are preferred over chemically synthesized nanoparticles owing to less destructive effects associated with the synthesis procedures as well as therapeutic involvement. In this review, we have discussed the applications of GNPs in inflammation-mediated disorders, with special emphasis on cancer, initiated due to oxidative stress and inflammatory cascade. Real-time mechanism based studies on GNPs have suggested their anticancer effects through inducing apoptosis, inhibiting angiogenesis, tissue invasion metastasis, reduced replicative capabilities in addition to target specific different signaling molecules and cascades involved in the development or progression of cancer. Moreover, the association of GNPs with the inhibition or induction of autophagy for the management of cancer has also been discussed. A large number of studies showed the GNPs have multifunctional biomedical properties of theranostic prominence. Therefore, the development of GNPs with naturally established systems could upsurge their definite applications as biomedicines including target specific destruction of the cancerous cells.

Iron oxide nanoparticles ameliorated the cadmium and salinity stresses in wheat plants, facilitating photosynthetic pigments and restricting cadmium uptake

Cadmium and salinity are the major threats to environmental resources and agricultural practice worldwide. The present work aims green synthesis, characterization, and application of iron oxide nanoparticles for co-alleviation of Cd and salt stresses in wheat plants. The iron oxide NPs were synthesized from a native bacterial strain, Pantoea ananatis strain RNT4, yielding a spherical FeO-NPs with a size ranging from 19 to 40 nm evidenced by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. Results showed that application of 100 mg kg^-1 of the bioengineered FeO-NPs in an original saline soil stimulated wheat plant growth, gaining 36.7% of additional length as compared with the control scenarios, via alleviating the detrimental effects of abiotic stresses and thereby reprogramming the morpho-physiological state of wheat plants. In addition, the presence of FeO-NPs in soil significantly increased the nutrient concentrations of N, P and K⁺, while reducing the Na⁺ and Cl^- components in the wheat grain. Interestingly, application of the FeO-NPs in Cd-polluted soils eventually reduced wheat plant uptake of Cd by 72.5%, probably due to the adsorption of Cd onto the large surface of NPs and thereby, constraining Cd bioavailability to the plants. It provides the first evidence that a FeO-NPs-based treatment could be a candidate agricultural strategy for mitigating the Cd and salt stresses in Cd-polluted saline soils for safe agriculture practice.

Biogenic copper nanoparticles synthesized by using a copper-resistant strain Shigella flexneri SNT22 reduced the translocation of cadmium from soil to wheat plants

The mechanistic role of green copper nanoparticles (CuNPs) in cadmium (Cd) toxicity alleviation in plants is poorly understood. Here, the CuNPs, synthesized by using a bacterium Shigella flexneri SNT22, were confirmed through UV-vis spectroscopy with a characteristic peak at 334.50 nm. Moreover, FT-IR, XRD, SEM, and TEM techniques revealed that the spherical shaped crystals of CuNPs with a size range of 17.24 nm to 38.03 nm were stabilized by coating proteins. Diff ;erent levels of CuNPs (e.g., 25, 50, and 100 mg kg^-1 of soil) were examined in pots having Cd-mixed soil to evaluate their effect on wheat plants in a growth chamber under optimal environmental conditions. Treatment of soil with 100 mg kg^-1 of CuNPs increased plant length by 44.4 %, shoot dry weight by 28.26 %, nitrogen contents by 41.60 %, and phosphorus contents by 58.79 %, whereas decreased the acropetal Cd translocation by 49.62 %. An increase in the N, P, K⁺, Ca²⁺, K⁺/Na⁺, and Ca²⁺/Na⁺ contents and decrease in the Na⁺ concentration in wheat plants treated with CuNPs was also recorded. Overall, the results are valuable to establish a green CuNPs-based approach for sustainable wheat growth in metal-contaminated soils.

Comparative in situ ROS mediated killing of bacteria with bulk analogue, Eucalyptus leaf extract (ELE)-capped and bare surface copper oxide nanoparticles

This study demonstrates a simple one-pot green method for biosynthesis of terpenoids encapsulated copper oxide nanoparticles (CuONPs) using aqueous leaf extract of Eucalyptus globulus (ELE), as reducing, dispersing, and stabilizing agent. Indeed, the greater attachment and internalization of ELE-CuONPs in Gram-positive and -negative biofilm producing clinical bacterial isolates validated the hypothesis that terpenoids encapsulated CuONPs are more stable and effective antibacterial and antibiofilm agent vis-à-vis commercially available nano and micro sized analogues. Gas chromatography-mass spectroscopy (GC-MS) analysis of pristine ELE identified 17 types of terpenoids based on their mass-to-charge (m/z) ratios. Amongst them four bioactive terpenoids viz. terpineols, 2,6-octadienal-3,7-dimethyl, benzamidophenyl-4-benzoate and β-eudesmol were found associated with the CuONPs as ELE-cap, and most likely involved in the nucleation and stabilization of ELE-CuONPs. Further, the Fourier transformed infrared (FTIR) analysis of ELE-CuONPs also implicated other functional biomolecules like proteins, sugars, alkenes, etc. with ELE terpenoids corona. Flow cytometric (FCM) data exhibited significantly enhanced intracellular uptake propensity of terpenoids encapsulated ELE-CuONPs and accumulation of intracellular reactive oxygen species (ROS), which ensued killing of planktonic cells of extended spectrum β-lactamases (ESβL) producing Escherichia coli-336 (E. coli-336), Pseudomonas aeruginosa-621 (P. aeruginosa-621) and methicillin-resistant Staphylococcus aureus-1 (MRSA-1) clinical isolates compared to the bare surface commercial nano-CuO and bulk sized CuO. The study for the first-time demonstrated the (i) differential bio-nano interface activities due to ELE surface and varied cell wall composition of test bacterial isolates, (ii) antibacterial effect and biofilm inhibition due to disruption of proteins involved in adhesion and biofilm formation triggered by CuONPs induced intracellular oxidative stress, and (iii) indigenous terpenoids-capped bio-inspired CuONPs are more stable and effective antibacterial and antibiofilm agent as compared with commercially available nano-CuO and bulk-CuO.

New insights on the green synthesis of metallic nanoparticles using plant and waste biomaterials: current knowledge, their agricultural and environmental applications

Nanotechnology is a rapidly growing scientific field and has attracted a great interest over the last few years because of its abundant applications. Green nanotechnology is a multidisciplinary field that has emerged as a rapidly developing research area, serving as an important technique that emphasize on making the procedure which are clean, non-hazardous, and especially environmentally friendly, in contrast with chemical and physical methods currently employed for nanosynthesis. The biogenic routes could be termed green as these do not involve the use of highly toxic chemicals or elevated energy inputs during the synthesis. Differences in the bio-reducing agents employed for nanosynthesis can lead to the production of nanoparticles (NPs) having distinct shapes, sizes, and bioactivity. The exquitiveness of the green fabricated NPs have capacitated their potential applications in various sectors such as biomedicine, pharmacology, food science, agriculture, and environmental engineering. The present review summarizes current knowledge on various biogenic synthesis methods, relying on plants, waste biomass, and biopolymers and their reducing and stabilizing agents to fabricate nanomaterials. The main emphasis has been given on the current status and future challenges related to the wide-scale fabrication of nanoparticles for environmental remediation, pathogenicity, and agricultural applications.