Silver nanoparticles (AgNPs) biosynthesized using pod extract of Cola nitida enhances antioxidant activity and phytochemical composition of Amaranthus caudatus Linn

Green synthesized AgNPs of the Anchusa arvensis aqueous extract resulting in impressive protein kinase, antioxidant, antibacterial, and antifungal activities

This study focused on analyzing the pharmacological activities of AgNPs synthesized from an aqueous plant extract of Anchusa arvensis. The effectiveness of AgNPs was evaluated for protein kinase inhibition, antioxidant, antibacterial, and antifungal activities. The AgNPs and plant were used to regulate the protein kinase activity using the liquid TSB and ISP4 medium protein kinase inhibition study demonstrated that nanoparticles exhibited a larger zone of inhibition (9.1 ± 0.8) compared to the plant extract (8.1 ± 0.6). The antioxidant activity was assessed using DPPH reagent, and the results indicated that AgNPs displayed potent free radical scavenging properties. In terms of antibacterial activity, AgNPs showed higher efficacy against Enterobacter aerogens (20.1 ± 0.9), Bordetella bronchiseptaca (19.1 ± 0.9), and Salmonella typhimurium (17.2 ± 0.8) at 4 mg/mL. The antifungal activity of AgNPs was prominent against Aspergillus fumagatus (14.1 ± 0.9), Mucor species (19.2 ± 0.8), and Fusarium solani (11.2 ± 0.8) at 20 mg/mL. These findings suggest that AgNPs possess multiple beneficial properties, including bactericidal/fungicidal effects, protein kinase inhibition, and potential free radical scavenging abilities. Therefore, AgNPs have potential applications in various fields, such as biomedicine and industry, due to their ability to counteract the harmful effects of free radicals.

Potential biological application of silver nanoparticles synthesized from Citrus paradisi leaves

Developing sustainable and eco-friendly methods for nanoparticle (NP) production in an era of environmental consciousness is crucial. This study introduces a novel approach to synthesizing silver (Ag) NPs using Citrus paradisi leaves extract (CPLE) as a green precursor at optimum conditions of the AgNO3 (2 mM) with CPLE in 1:3 ratio, at pH 14 and 80 °C temperature for reaction time of 4 h. The CP@AgNPs were formed and stabilized by Naringen, a major Citrus paradisi component. CP@AgNPs were thoroughly characterized through ultraviolet-visible (UV-vis) and Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, and field emission scanning electron microscopy (FE-SEM) imaging techniques. CP@AgNPs demonstrated SPR peak at 450 nm, face cubic crystal structure, the average size of 8 nm, rod-shaped particle adsorbed on quasi-spherical shaped agglomerated NPs, significantly impacting both environmental and biomedical fields. In the catalytic degradation experiment, an application for environment pollutant reducer, CP@AgNPs, achieved an impressive 85% degradation efficiency of the methyl orange (MO) dye, showcasing their potential as a sustainable solution for wastewater treatment. Additionally, CP@AgNPs exhibited potent anti-biofilm properties, with half maximal inhibitory concentration (IC50) values of 0.13 and 0.12 mg/ml against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively, indicating their promise in addressing biofilm-related issues in healthcare and industrial settings. CP@AgNPs also displayed exceptional antioxidant potential with IC50 values of 2.02, 0.07, and 0.035 mg/ml for CPLE, CP@AgNPs, and ascorbic acid, respectively, in scavenging DPPH radical, suggesting their utility in biomedical applications for mitigating oxidative stress. Notably, the bio-activity results of CP@AgNPs surpassed those of CP leaf extract, highlighting the enhanced properties achieved through this green synthesis approach. This study provides a sustainable and environmental remediation to biomedical science.

Current Advances in Nanotechnology-Mediated Delivery of Herbal and Plant-Derived Medicines

Phytomedicine has been used by humans since ancient times to treat a variety of diseases. However, herbal medicines face significant challenges, including poor water and lipid solubility and instability, which lead to low bioavailability and insufficient therapeutic efficacy. Recently, it has been shown that nanotechnology-based drug delivery systems are appropriate to overcome the above-mentioned limitations. The present review study first discusses herbal medicines and the challenges involved in the formulation of these drugs. The different types of nano-based drug delivery systems used in herbal delivery and their potential to improve therapeutic efficacy are summarized, and common techniques for preparing nanocarriers used in herbal drug delivery are also discussed. Finally, a list of nanophyto medicines that have entered clinical trials since 2010, as well as those that the FDA has approved, is presented.

Nanoparticles as novel elicitors in plant tissue culture applications: Current status and future outlook

Plant tissue culture is the primary, fundamental, and applied aspect of plant biology. It is an indispensable and valuable technique for investigating morphogenesis, embryogenesis, clonal propagation, crop improvements, generation of pathogen-free plants, gene transfer and expression, and the production of secondary metabolites. The extensive use of various nanoparticles (NPs) in fields such as cosmetics, energy, medicine, pharmaceuticals, electronics, agriculture, and biotechnology have demonstrated positive impacts in microbial decontamination, callus differentiation, organogenesis, somatic variations, biotransformation, cryopreservation, and enhanced synthesis of bioactive compounds. This review summarizes the current state of knowledge with regard to the use of nanoparticles in plant tissue culture, with a particular focus on the beneficial outcomes. The positive (beneficial) and negative (toxic) effects of engineered NPs in tissue culture medium, delivery of transgenes, NPs toxicity concerns, safety issues, and potential hazards arising from utilization of nanomaterials in agriculture through plant tissue culture are discussed in detail, along with the future prospects for these applications. In addition, the potential use of novel nanomaterials such as graphene, graphite, dendrimers, quantum dots, and carbon nanotubes as well as unique metal or metalloid NPs are proposed. Further, the potential mechanisms underlying NPs elicitation of tissue culture response in different applications are critically evaluated. The potential of these approaches in plant nanobiotechnology is only now becoming understood and it is clear that the role of these strategies in sustainably increasing crop production to combat global food security and safety in a changing climate will be significant.

Dandelion flower-fabricated Ag nanoparticles versus synthetic ones with characterization and determination of photocatalytic, antioxidant, antibacterial, and α-glucosidase inhibitory activities

In the present work, Silver nanoparticles (AgNPs) were fabricated through the dandelion flower hydroalcoholic extract, and their properties were characterized by FTIR, XRD, UV visible, SEM, and EDX. The results demonstrated that the average diameter of the green fabricated AgNPs is 45-55 nm (G-AgNPs). The antioxidant, antimicrobial, antidiabetic, and photocatalytic properties of G-AgNPs were compared with two commercially available different diameter sizes (20 and 80-100 nm) of AgNPs (C-AgNPs1- and C-AgNPs2, respectively). The sample's capacity for antioxidants was evaluated by DPPH free radical scavenging method. The consequences showed that G-AgNPs have higher radical scavenging activity (47.8%) than C-AgNPs2 (39.49%) and C-AgNPs1 (33.91%). To investigate the photocatalytic property, methylene blue dye was used. The results displayed that G-AgNPs is an effective photo-catalyst compared to C-AgNPs2 and C-AgNPs1, which respectively have an inhibition potential of 75.22, 51.94, and 56.65%. Also, the antimicrobial capacity of nanoparticles was assayed against, the gram-negative Escherichia coli and gram-positive Staphylococcus aureus bacteria. The results indicated that G-AgNPs could effectively inhibit the growth of both bacteria, compared to C-AgNPs1 and C-AgNPs2. Finally, G-AgNPs exhibited a considerable α-glucosidase enzyme inhibitory effect (88.37%) in comparison with C-AgNPs1 (61.7%) and C-AgNPs2 (50.5%).

A critical review on the biosynthesis, properties, applications and future outlook of green MnO2 nanoparticles

MnO2 nanoparticles have played a vital role in biomedical, catalysis, electrochemical and energy storage fields, but requiring toxic chemicals in the fabrication intercepts their applications. There is an increasing demand for biosynthesis of MnO2 nanoparticles using green sources such as plant species in accordance with the purposes of environmental mitigation and production cost reduction. Here, we review recent advancements on the use of natural compounds such as polyphenols, reducing sugars, quercetins, etc. Extracted directly from low-cost and available plants for biogenic synthesis of MnO2 nanoparticles. Role of these phytochemicals and formation mechanism of bio-medicated MnO2 nanoparticles are shed light on. MnO2 nanoparticles own small particle size, high crystallinity, diverse morphology, high surface area and stability. Thanks to higher biocompatibility, bio-mediated synthesized MnO2 nanoparticles exhibited better antibacterial, antifungal, and anticancer activity than chemically synthesized ones. In terms of wastewater treatment and energy storage, they also served as efficient adsorbents and catalyst. Moreover, several aspects of limitation and future outlook of bio-mediated MnO2 nanoparticles in the fields are analyzed. It is expected that the present work not only expands systematic understandings of synthesis methods, properties and applications MnO2 nanoparticles but also pave the way for the nanotechnology revolution in combination with green chemistry and sustainable development.

Delivery of Immunomodulators: Challenges and Novel Approaches

&nbsp;Immunomodulators can be either synthetic in origin or naturally obtained. Natural plant-based compounds can influence the immune system by either affecting antibody secretion to control the infection or affecting the functions of immune cells, thus contributing to maintaining immune homeostasis. Phytochemicals in plants, such as polysaccharides, lactones, flavonoids, alkaloids, diterpenoids and glycosides, have been reported to possess immunomodulating properties. However, there are many challenges limiting the clinical use of natural immunomodulators. In this chapter, we have discussed in detail standardization, formulation development, route of administration and regulatory concerns of natural immunomodulators. In order to overcome these challenges and ensure that natural immunomodulators reach the target site at therapeutic concentrations, different polymer and lipid-based nanocarrier delivery systems have been developed. These nanocarriers by virtue of their size, can easily penetrate and reach the target site and deliver the drugs. Many nanocarriers like liposomes, niosomes, nanoparticles, microemulsions, phytosomes and other vesicular systems designed for natural immunomodulators are discussed in this chapter.<br>

Alnus nitida and urea-doped Alnus nitida-based silver nanoparticles synthesis, characterization, their effects on the biomass and elicitation of secondary metabolites in wheat seeds under in vitro conditions

Nano-fertilizers are superior to conventional fertilizers, but their effectiveness has not yet been adequately explored in the field of agriculture. In this study, silver nanoparticles using leaves extract of an Alnus nitida plant were synthesized and further doped with urea to enhance the plant biomass and metabolic contents. The synthesized Alnus nitida silver nanoparticles (A.N-AgNPs) and urea-doped silver nanoparticles (U-AgNPs) were characterized using Scanning Electron Microscopy, Transmission Electron Microscopy, Powder X-ray Diffraction, and Energy Dispersive X-ray. The wheat seeds were grown in media under controlled conditions in the plant growth chamber. The effectiveness of nanoparticles was studied using different A.N-AgNPs and U-AgNPs concentrations (0.75 μg/ml, 1.5 μg/ml, 3 μg/ml, 6 μg/ml, and 15 μg/ml). They were compared with a control group that received no dose of nanoparticles. The plant biomass, yield parameters, and wheat quality were analyzed. The effect of silver nanoparticles and U-AgNPs were examined in developing wheat seeds and their potency in combating biotic stresses such as nematodes, herbivores, fungi, insects, weeds and bacteria; abiotic stresses such as salinity, ultraviolet radiation, heavy metals, temperature, drought, floods etc. In the seedlings, six possible phytochemicals at a spray dose of 6 μg/ml of U-AgNPs were identified such as dihydroxybenzoic acids, vanillic acid, apigenin glucosidase, p-coumaric acid, sinapic acid, and ferulic acid whereas in other treatments the number of phenolic compounds was lesser in number as well as in concentrations. Moreover, various parameters of the wheat plants, including their dry weight and fresh weight, were assessed and compared with control group. The findings of the study indicated that A.N-AgNPs and U-AgNPs act as metabolite elicitors that induced secondary metabolite production (total phenolic, flavonoid, and chlorophyll contents). In addition, U-AgNPs provided a nitrogen source and were considered a smart nitrogen fertilizer that enhanced the plant biomass, yields, and metabolite production.

A Review of Sustainable Use of Biogenic Nanoscale Agro-Materials to Enhance Stress Tolerance and Nutritional Value of Plants

Climate change is more likely to have a detrimental effect on the world's productive assets. Several undesirable conditions and practices, including extreme temperature, drought, and uncontrolled use of agrochemicals, result in stresses that strain agriculture. In addition, nutritional inadequacies in food crops are wreaking havoc on human health, especially in rural regions of less developed countries. This could be because plants are unable to absorb the nutrients in conventional fertilizers, or these fertilizers have an inappropriate or unbalanced nutrient composition. Chemical fertilizers have been used for centuries and have considerably increased crop yields. However, they also disrupt soil quality and structure, eventually impacting the entire ecosystem. To address the situation, it is necessary to develop advanced materials that can release nutrients to targeted points in the plant-soil environment or appropriate receptors on the leaf in the case of foliar applications. Recently, nanotechnology-based interventions have been strongly encouraged to meet the world's growing food demand and to promote food security in an environmentally friendly manner. Biological approaches for the synthesis of nanoscale agro-materials have become a promising area of research, with a wide range of product types such as nanopesticides, nanoinsecticides, nanoherbicides, nanobactericides/fungicides, bio-conjugated nanocomplexes, and nanoemulsions emerging therefrom. These materials are more sustainable and target-oriented than conventional agrochemicals. In this paper, we reviewed the literature on major abiotic and biotic stresses that are detrimental to plant growth and productivity. We comprehensively discussed the different forms of nanoscale agro-materials and provided an overview of biological approaches in nano-enabled strategies that can efficiently alleviate plant biotic and abiotic stresses while potentially enhancing the nutritional values of plants.

Environmentally benign silver bio-nanomaterials as potent antioxidant, antibacterial, and antidiabetic agents: Green synthesis using Salacia oblonga root extract

Introduction: The use of plant extracts in the green synthesis of metallic nanoparticles is one of the simplest, most practical, economical, and ecologically friendly methods for avoiding the use of toxic chemicals. Method: Silver nanoparticles (AgNPs) were synthesized, employing a high-efficiency, non- toxic, cost-effective, green, and simple technique that included the use of Salacia oblonga root extract (SOR) as a capping agent compared to synthetic nanoparticles. The use of S. oblonga can be seen in traditional medicines for treating diabetes, obesity, rheumatism, gonorrhea, asthma, and hyperglycemia. The objectives of the current study were to green synthesize S. oblonga root extract silver nanoparticles (SOR-AgNPs), characterize them, and study their antioxidant, antibacterial, and antidiabetic activities. Result: The shape of SOR-AgNPs was spherical, at less than 99.8 nm in size, and exhibited a crystalline peak at XRD. The green synthesized SOR-AgNPs showed significant antioxidant properties like DPPH (80.64 μg/mL), reducing power capacity (81.09 ± SEM μg/mL), nitric oxide (96.58 μg/mL), and hydroxyl (58.38 μg/mL) radical scavenging activities. The MIC of SOR-AgNPs was lower in gram-positive bacteria. The SOR-AgNPs have displayed efficient inhibitory activity against α-amylase, with an EC50 of 58.38 μg/mL. Analysis of capping protein around the SOR-AgNPs showed a molecular weight of 30 kDa. Discussion: These SOR-AgNPs could be used as antibacterial and antidiabetic drugs in the future as it is cheap, non-toxic, and environmentally friendly. Bio-fabricated AgNPs had a significant impact on bacterial strains and could be used as a starting point for future antibacterial drug development.

Valorisation of fruit peel bioactive into green synthesized silver nanoparticles to modify cellulose wrapper for shelf-life extension of packaged bread

Fruit peels are rich source of bioactive compounds such as polyphenols, flavonoids, and antioxidants but are often discarded as waste due to limited pharmaceutical and nutraceutical applications. This study aimed to valorise pomegranate and citrus fruit peel into green synthesised silver nanoparticles (AgNPs) in order to modify cellulose-based wrapping material for prospective food packaging applications and propose an alternate and sustainable approach to replace polyethene based food packaging material. Four different concentrations of AgNO₃ (0.5 mM, 1 mM, 2 mM, and 3 mM) were used for green synthesis of AgNPs from fruit peel bioactive, which were characterised followed by phytochemical analysis. Ultraviolet-Visible spectroscopy showed surface plasmon resonance at 420 nm, XRD analysis showed 2θ peak at 27.8°, 32.16°, 38.5°, 44.31°, 46.09°, 54.76°, 57.47°, 64.61° and 77.50° corresponding to (210), (122), (111), (200), (231), (142), (241), (220) and (311) plane of face centred cubic crystal structure of AgNPs. Fourier-transform infrared spectroscopy analysis of AgNPs green synthesised from pomegranate and kinnow peel extract showed a major peak at 3277, 1640 and 1250-1020 1/cm while a small peak at 2786 1/cm was observed in case of pomegranate peel extract which was negligible in AgNPs synthesized from kinnow peel extract. Particle sizes of AgNPs showed no statistically significant variance with p > 0.10 and thus, 2 mM was chosen for further experimentation and modification of cellulose based packaging material as it showed smallest average particle size. Zeta potential was observed to be nearly neutral with a partial negative strength due to presence of various phenolic compounds such as presence of gallic acid which was confirmed by ultrahigh performance liquid chromatography-photodiode array(UHPLC-PDA) detector. Thermal stability analysis of green synthesised AgNPs qualified the sterilisation conditions up to 100 °C. AgNPs green synthesized from both the peel extracts had higher polyphenolic content, antioxidant and radical scavenging activity as compared to peel extracts without treatment (p < 0.05). The cellulose based food grade packaging material was enrobed by green synthesised AgNPs. The characterisation of modified cellulose wrappers showed no significant difference in thickness of modified cellulose wrappers as compared with untreated cellulose wrapper (p > 0.42) while weight and grammage increased significantly in modified cellulose wrapper (p < 0.05). The colour values on CIE scale (L*, a* and b*) showed statistically significant increase in yellow and green colour (p < 0.05) for modified cellulose wrappers as compared to control wrapper. The oxygen permeability coefficient, water vapour permeability coefficient, water absorption capacity and water behaviour characteristics (water content, swelling degree and solubility) showed significant decrease (p < 0.05) for modified cellulose wrapper as compared to control wrapper. A uniform distribution and density of green synthesised AgNPs across cellulose wrapper matrix was observed through scanning electron microscopy (SEM) images with no significant aggregation, confirming successful enrobing and stable immobilisation of nanoparticles from cellulose matrix. A seven-day storage study of bread wrapped in modified and control cellulose wrappers showed delayed occurrence of microbial, yeast and mould count in bread packaged in modified cellulose wrappers and thus, resulting in shelf life extension of bread. The results are encouraging for the potential applications of modified cellulose wrappers to replace polyethene based food packaging.

Biogenic Selenium Nanoparticles in Biomedical Sciences: Properties, Current Trends, Novel Opportunities and Emerging Challenges in Theranostic Nanomedicine

Selenium is an important dietary supplement and an essential trace element incorporated into selenoproteins with growth-modulating properties and cytotoxic mechanisms of action. However, different compounds of selenium usually possess a narrow nutritional or therapeutic window with a low degree of absorption and delicate safety margins, depending on the dose and the chemical form in which they are provided to the organism. Hence, selenium nanoparticles (SeNPs) are emerging as a novel therapeutic and diagnostic platform with decreased toxicity and the capacity to enhance the biological properties of Se-based compounds. Consistent with the exciting possibilities offered by nanotechnology in the diagnosis, treatment, and prevention of diseases, SeNPs are useful tools in current biomedical research with exceptional benefits as potential therapeutics, with enhanced bioavailability, improved targeting, and effectiveness against oxidative stress and inflammation-mediated disorders. In view of the need for developing eco-friendly, inexpensive, simple, and high-throughput biomedical agents that can also ally with theranostic purposes and exhibit negligible side effects, biogenic SeNPs are receiving special attention. The present manuscript aims to be a reference in its kind by providing the readership with a thorough and comprehensive review that emphasizes the current, yet expanding, possibilities offered by biogenic SeNPs in the biomedical field and the promise they hold among selenium-derived products to, eventually, elicit future developments. First, the present review recalls the physiological importance of selenium as an oligo-element and introduces the unique biological, physicochemical, optoelectronic, and catalytic properties of Se nanomaterials. Then, it addresses the significance of nanosizing on pharmacological activity (pharmacokinetics and pharmacodynamics) and cellular interactions of SeNPs. Importantly, it discusses in detail the role of biosynthesized SeNPs as innovative theranostic agents for personalized nanomedicine-based therapies. Finally, this review explores the role of biogenic SeNPs in the ongoing context of the SARS-CoV-2 pandemic and presents key prospects in translational nanomedicine.

New aspects of lipopeptide-incorporated nanoparticle synthesis and recent advancements in biomedical and environmental sciences: a review

The toxicity of metal nanoparticles has introduced promising research in the current scenario since an enormous number of people have been potentially facing this problem in the world. The extensive attention on green nanoparticle synthesis has been focussed on as a vital step in bio-nanotechnology to improve biocompatibility, biodegradability, eco-friendliness, and huge potential utilization in various environmental and clinical assessments. Inherent influence on the study of green nanoparticles plays a key role to synthesize the controlled and surface-influenced molecule by altering the physical, chemical, and biological assets with the provision of various precursors, templating/co-templating agents, and supporting solvents. However, in this article, the dominant characteristics of several kinds of lipopeptide biosurfactants are discussed to execute a critical study of factors affecting synthesis procedure and applications. The recent approaches of metal, metal oxide, and composite nanomaterial synthesis have been deliberated as well as the elucidation of the reaction mechanism. Furthermore, this approach shows remarkable boosts in the production of nanoparticles with the very less employed harsh and hazardous processes as compared to chemical or physical method-based nanoparticle synthesis. This study also shows that the advances in strain selection for green nanoparticle production could be a worthwhile and strong economical approach in futuristic medical science research.

Potential of enhancing anti-obesogenic agriceuticals by applying sustainable fertilizers during plant cultivation

Overweight and obesity are two of the world's biggest health problems. They are associated with excessive fat accumulation resulting from an imbalance between energy consumed and energy expended. Conventional therapies for obesity commonly include synthetic drugs and surgical procedures that can lead to serious side effects. Therefore, developing effective, safe, and readily available new treatments to prevent and treat obesity is highly relevant. Many plant extracts have shown anti-obesogenic potential. These plant extracts are composed of different agriceuticals such as fibers, phenolic acids, flavonoids, anthocyanins, alkaloids, lignans, and proteins that can manage obesity by suppressing appetite, inhibiting digestive enzymes, reducing adipogenesis and lipogenesis, promoting lipolysis and thermogenesis, modulating gut microbiota and suppressing obesity-induced inflammation. These anti-obesogenic agriceuticals can be enhanced in plants during their cultivation by applying sustainable fertilization strategies, improving their capacity to fight the obesity pandemic. Biofertilization and nanofertilization are considered efficient, eco-friendly, and cost-effective strategies to enhance plant growth and development and increase the content of nutrients and bioactive compounds, representing an alternative to overproducing the anti-obesogenic agriceuticals of interest. However, further research is required to study the impact of anti-obesogenic plant species grown using these agricultural practices. This review presents the current scenario of overweight and obesity; recent research work describing different plant species with significant effects against obesity; and several reports exhibiting the potential of the biofertilization and nanofertilization practices to enhance the concentrations of bioactive molecules of anti-obesogenic plant species.

Nanoparticles, a Double-Edged Sword with Oxidant as Well as Antioxidant Properties—A Review

The usage of nanoparticles became inevitable in medicine and other fields when it was found that they could be administered to hosts to act as oxidants or antioxidants. These oxidative nanoparticles act as pro-oxidants and induce oxidative stress-mediated toxicity through the generation of free radicals. Some nanoparticles can act as antioxidants to scavenge these free radicals and help in maintaining normal metabolism. The oxidant and antioxidant properties of nanoparticles rely on various factors including size, shape, chemical composition, etc. These properties also help them to be taken up by cells and lead to further interaction with cell organelles/biological macromolecules, leading to either the prevention of oxidative damage, the creation of mitochondrial dysfunction, damage to genetic material, or cytotoxic effects. It is important to know the properties that make these nanoparticles act as oxidants/antioxidants and the mechanisms behind them. In this review, the roles and mechanisms of nanoparticles as oxidants and antioxidants are explained.

Mitigation of lead toxicity in Vigna radiata genotypes by silver nanoparticles

Heavy metal (HM) contamination of the soil through anthropogenic activities influences the living systems and drastically impacts food chain. This study examined the application of silver nanoparticles (AgNPs) in two genotypes (G1 and G2) of Mung bean (Vigna radiata) for ameliorating the Pb toxicity. Different doses of Pb (0, 25, 50 μM) were differentially tackled by AgNPs with the aim of ameliorating the plant attributes. Both genotypes displayed statistically significant quantitative and qualitative modulations for Pb tolerance. In G2, the most prominent increase in plant height (43.79%), fresh biomass (49.56%) and total chlorophyll (20%) was observed at L2 (AgNPs 10 mg/L) in comparison with the control. Overall, photosynthetic rate was increased by 26% in G2 at L6 (AgNPs 25 mg/L + Pb 25 μM). In addition, the results presented 78.5% increase in water use efficiency of G2 while G1 experienced a maximum internal CO₂ concentration (209.8%) at L8 (Pb 50 μM). AgNPs triggered balanced uptake of minerals and improved growth of Vigna genotypes. 50 μM Pb was most hazardous and caused maximum reduction in growth of Vigna plants along with a significant suppression in photosynthetic activity, increase in MDA (199.7%) in G1 and H₂O₂ (292.8%) in G2. In comparison to control, maximum superoxide dismutase (376%), peroxidase (659.8%) and catalase (9.3%) activity was observed in G2 at L11. The application of AgNPs substantially enhanced plant growth and helped them in surviving well in absence as well as presence of Pb. G2 genotype exhibited substantial tolerance capability and revealed less impairment in the studied attributes than G1 and treatment of AgNPs i.e. 25 mg/L was the best level that yielded best results in both genotypes. The results demonstrate that AgNPs mediate response(s) of plants under Pb stress and particularly contributed to HM tolerance of plants and thus showing great promise for use in phytoremediation.

Pseudomonas indica-Mediated Silver Nanoparticles: Antifungal and Antioxidant Biogenic Tool for Suppressing Mucormycosis Fungi

Mucormycosis is considered one of the most dangerous invasive fungal diseases. In this study, a facile, green and eco-friendly method was used to biosynthesize silver nanoparticles (AgNPs) using Pseudomonas indica S. Azhar, to combat fungi causing mucormycosis. The biosynthesis of AgNPs was validated by a progressive shift in the color of P. indica filtrate from colorless to brown, as well as the identification of a distinctive absorption peak at 420 nm using UV-vis spectroscopy. Fourier-transform infrared spectroscopy (FTIR) results indicated the existence of bioactive chemicals that are responsible for AgNP production. AgNPs with particle sizes ranging from 2.4 to 53.5 nm were discovered using transmission electron microscopy (TEM). Pattern peaks corresponding to the 111, 200, 220, 311, and 222 planes, which corresponded to face-centered cubic forms of metallic silver, were also discovered using X-ray diffraction (XRD). Moreover, antifungal activity measurements of biosynthesized AgNPs against Rhizopus Microsporus, Mucor racemosus, and Syncephalastrum racemosum were carried out. Results of antifungal activity analysis revealed that the biosynthesized AgNPs exhibited outstanding antifungal activity against all tested fungi at a concentration of 400 µg/mL, where minimum inhibitory concentrations (MIC) were 50, 50, and 100 µg/mL toward R. microsporus, S. racemosum, and M. racemosus respectively. In addition, the biosynthesized AgNPs revealed antioxidant activity, where IC₅₀ was 31 µg/mL when compared to ascorbic acid (0.79 µg/mL). Furthermore, the biosynthesized AgNPs showed no cytotoxicity on the Vero normal cell line. In conclusion, the biosynthesized AgNPs in this study can be used as effective antifungals with safe use, particularly for fungi causing mucormycosis.

Plants-derived bioactives: Novel utilization as antimicrobial, antioxidant and phytoreducing agents for the biosynthesis of metallic nanoparticles

Medicinal and aromatic higher plants are sustainable resources for natural product compounds, including essential oils, phenolics, flavonoids, alkaloids, glycosides, and saponins. Extractives and essential oils as well as their bioactive compounds have many uses due to their antimicrobial, anticancer, and antioxidant properties as well as application in food preservation. These natural compounds have been reported in many works, for instance biofungicide with phenolic and flavonoid compounds being effective against mold that causes discoloration of wood. Additionally, the natural extracts from higher plants can be used to mediate the synthesis of nanoparticle materials. Therefore, in this review, we aim to promote and declare the use of natural products as environmentally eco-friendly bio-agents against certain pathogenic microbes and make recommendations to overcome the extensive uses of conventional pesticides and other preservatives.

Evaluation of the effects of nanoparticles on the therapeutic function of platelet: a review

OBJECTIVES

Nanotechnology and nanoparticles are used in different applications in disease monitoring and therapy in contact with blood. Nanoparticles showed different effects on blood components and reduced or improved the function of therapeutic platelet during the storage time. This review study was performed to evaluate the impacts of various sizes and charges of nanoparticles on platelet function and storage time. The present review contains the literature between 2010 and 2020. The data have been used from different sites such as PubMed, Wiley, ScienceDirect and online electronic journals.

KEY FINDINGS

From the literature survey, it has been demonstrated that among various properties, size and charge of nanoparticles were critical on the function of therapeutic platelet during the storage and inhibition of their aggregation. Overall, this study described that nanoparticles with smaller size and negative charge were more effective in increasing the survival time, inhibition of aggregation and improving the function of therapeutic platelet.

SUMMARY

Based on the current review, it can be confirmed that nanoparticles such as dendrimer, Au, Ag and iron oxide nanoparticles with smaller size and negative charge have significant advantages for improving the efficacy of platelets during the storage chain and inhibition of their aggregation.

Responses of Moringa oleifera to alteration in soil properties induced by calcium nanoparticles (CaNPs) on mineral absorption, physiological indices and photosynthetic indicators

Background

The application of nanofertilisers in agriculture has been widely utilised due to their distinct characteristics and negative impacts of conventional chemical fertilisers. This study thus examined the influence of calcium nanoparticles (CaNPs) on soil composition vis-à-vis performance parameters in Moringa oleifera L exposed to water, 100 mg Ca(NO3)2kg−1 soil and 100, 75 and 50 mg CaNPs kg−1 soil. Soil morphology was determined with a scanning electron microscope coupled with energy dispersive x-ray (SEM-EDX) and elemental composition in both soils and M. oleifera roots determined with inductively coupled plasma-optical emission spectrometer (ICP-OES).

Results

The CaNP-amended soils were more crystalline, more fertile and had reduced salinity. An increase in immobilisation percentage of heavy metals, improvement in physiological parameters (percentage germination, vigour indices, relative water contents, lengths of roots and shoots) and photosynthetic efficiency in M. oleifera were recorded.

Conclusion

This study has demonstrated that CaNPs could improve soil composition for better plant performance and can act as nanofertilisers mobilising essential nutrients.

Graphical abstract

The avenue of fruit wastes to worth for synthesis of silver and gold nanoparticles and their antimicrobial application against foodborne pathogens: A review

The emerging fruit wastes valorization tactic is a strategy for minimizing the dependence on toxic solvents and chemicals commonly used in the preparation of nanoparticles (NPs). Furthermore, the NPs have exhibited promising antimicrobial applications against foodborne pathogens. Hence, a timely review of this topic is in demand to provide a clear insight into the subject. In this article, the synthesis of silver and gold NPs from fruit wastes and their antimicrobial application against foodborne pathogens are reviewed. The extraction method, mechanism of NPs formation and influences of various experimental parameters on the shape and size of the NPs are described. In the second part of the article, antimicrobial activities against foodborne pathogens regarding the nature, optimum composition, surface structure, synergism and morphology of the NPs are reviewed. Furthermore, challenges and future trends related to the synthesis and antimicrobial application of fruit wastes-mediated NPs are discussed.

Nano-Elicitation as an Effective and Emerging Strategy for In Vitro Production of Industrially Important Flavonoids

Flavonoids represent a popular class of industrially important bioactive compounds. They possess valuable health-benefiting and disease preventing properties, and therefore they are an important component of the pharmaceutical, nutraceutical, cosmetical and medicinal industries. Moreover, flavonoids possess significant antiallergic, antihepatotoxic, anti-inflammatory, antioxidant, antitumor, antiviral, and antibacterial as well as cardio-protective activities. Due to these properties, there is a rise in global demand for flavonoids, forming a significant part of the world market. However, obtaining flavonoids directly from plants has some limitations, such as low quantity, poor extraction, over-exploitation, time consuming process and loss of flora. Henceforth, there is a shift towards the in vitro production of flavonoids using the plant tissue culture technique to achieve better yields in less time. In order to achieve the productivity of flavonoids at an industrially competitive level, elicitation is a useful tool. The elicitation of in vitro cultures induces stressful conditions to plants, activates the plant defense system and enhances the accumulation of secondary metabolites in higher quantities. In this regard, nanoparticles (NPs) have emerged as novel and effective elicitors for enhancing the in vitro production of industrially important flavonoids. Different classes of NPs, including metallic NPs (silver and copper), metallic oxide NPs (copper oxide, iron oxide, zinc oxide, silicon dioxide) and carbon nanotubes, are widely reported as nano-elicitors of flavonoids discussed herein. Lastly, the mechanisms of NPs as well as knowledge gaps in the area of the nano-elicitation of flavonoids have been highlighted in this review.

Multifunctional titanium dioxide nanoparticles biofabricated via phytosynthetic route using extracts of Cola nitida: antimicrobial, dye degradation, antioxidant and anticoagulant activities

First study of phytosynthesis of TiO₂ NPs using the leaf (KL), pod (KP), seed (KS) and seed shell (KSS) extracts of kola nut tree (Cola nitida) is herein reported. The TiO₂ NPs were characterized and evaluated for their antimicrobial, dye degradation, antioxidant and anticoagulant activities. The nearly spherical-shaped particles had λmax of 272.5–275.0 nm with size range of 25.00–191.41 nm. FTIR analysis displayed prominent peaks at 3446.79, 1639.49 and 1382.96 cm⁻¹, indicating the involvement of phenolic compounds and proteins in the phytosynthesis of TiO₂ NPs. Both SAED and XRD showed bioformation of crystalline anatase TiO₂ NPs which inhibited multidrug-drug resistant bacteria and toxigenic fungi. The catalytic activities of the particles were profound, with degradation of malachite green by 83.48–86.28 % without exposure to UV-irradiation, scavenging of DPPH and H₂O₂by 51.19–60.08 %, and 78.45–99.23 % respectively. The particles as well prevented the coagulation of human blood. In addition to the antimicrobial and dye-degrading activities, we report for the first time the H₂O₂ scavenging and anticoagulant activities of TiO₂ NPs, showing that the particles can be useful for catalytic and biomedical applications.

A Brief Overview on Antioxidant Activity Determination of Silver Nanoparticles

Our objective in this review article is to find out relevant information about methods of determination of antioxidant activity of silver nanoparticles. There are many studies dealing with mentioned problem and herein we summarize the knowledge about methods evaluating the antioxidant activity of silver nanoparticles reported so far. Many authors declare better antioxidant activity of silver nanoparticles compared to the extract used for synthesis of them. In this review, we focused on methods of antioxidant activity determination in detail to find out novel and perspective techniques to solve the general problems associated with the determination of antioxidant activity of silver nanoparticles.

The effects on oxidative aging, physical and flow properties of Agbabu natural bitumen modified with silver nanoparticles

The quest for improvement in service life and performance of road pavement via reduction of oxidative aging failure of bitumen, led us to the investigation of novel application of Silver nanoparticles (AgNPs) as potential anti-oxidative material for Agbabu natural bitumen (ANB). The raw ANB was purified to form the base and the base modified in a stainless reactor using AgNPs via melt blend technique at temperature of 120 °C under stirring at 1200rpm. The proportions of AgNPs used for the modification were 1.5, 3.0 and 4.5 wt% and long-term aging was thermally simulated on the base and modified base samples at 60 °C. The aged samples were then subjected to Fourier Transform Infrared (FTIR) Spectroscopic Analysis to study the changes in the size of the peaks of the oxidation-related compounds. Physical and flow parameters (PFPs) of the base and modified base samples were characterized using softening point temperature, kinematic viscosity, penetration index, flash and fire points, penetration, kinematic viscosity and Oscillatory disc Rheometer (ODR) test. FTIR analysis showed that the AgNPs incorporation into ANB at 1797 cm⁻¹, 1217 cm⁻¹, 1300 cm⁻¹ and 1097 cm⁻¹ in the spectrum of the base sample. The sulphoxide peaks at 1031 cm⁻¹ was completely obliterated. There was progressive reduction in the area of the carbonyl peak at 1693 cm⁻¹ implying progressive lowering of the carbonyl index value with increasing in the amount of AgNPs used in the modification. These changes are attributable to the anti-oxidative potential of the AgNPs. The mechanism of the anti-oxidative effect of AgNPs is proposed to be due to scavenging of the free radical produced in the oxidation process. The values of softening point temperature, kinematic viscosity, penetration index, and flash and fire points increased while that of penetration and specific gravity reduced as the quantity of AgNPs in the base increased. The ODR test showed that, the modified samples compared to base sample at lower and higher road pavement temperatures are less prone to fatigue cracking and rutting, respectively. Thus, this study provides preliminary information about the novelty of AgNPs as potential antioxidant for improving the durability/performance of bitumen in pavements.

Green nano-phytoremediation and solubility improving agents for the remediation of chlorfenapyr contaminated soil and water

Chlorfenapyr is a novel class of insecticide-miticide used for crop protection. It poses substantial risks to the reproductive ability of birds as well as environmental stability. This study was focused on the remediation of chlorfenapyr-polluted soil and water through the combined application of green nanotechnology, solubility improving agents and phytoremediation. An analysis using electron microscopy showed that the green synthesis resulted in circular ficus iron nanoparticles (F-Fe⁰) with diameters of 2.46 nm-11.49 nm, while the ipomoea-silver (Ip-Ag⁰) and brassica-silver nanoparticles (Br-Ag⁰) were circular, cubical, hexagonal, triangular and rod -like in shape with sizes ranging from 6.27 to 21.23 nm in IP-Ag⁰ and from 6.05 to 15.02 nm in Br-Ag⁰. After 24 h of treatment with F-Fe⁰, Ip-Ag⁰ and Br-Ag⁰ supported on activated charcoal (Ach), the chlorfenapyr in the aqueous solution was reduced to 86%, 79.70%, and 79.70%, respectively, compared to the 6.16% in aqueous solution. Moreover, after 24 h of treatment with Plantago major plus F-Fe⁰Ach, P. major plus Ip-Ag⁰Ach, and P. major plus Br-Ag⁰Ach, the chlorfenapyr in the aqueous solution was reduced to 93.7%, 91.30%, and 92.92%, respectively, as compared to the 69.27% in P. major. After four days of exposure, the percentage of chlorfenapyr degradation in the soil (i.e. control) only reached 12.40%,while the degradation rates were enhanced by 71.22%, 57.32% and 73.10%, respectively, in the presence of P. major plus nanoparticles (F-Fe0, Ip-Ag0 and Br-Ag0). The integration of green nanotechnology, solubility-improving agents, and phytoremediation by Plantago major has played a major role in the remediation of soil and water contaminated with chlorfenapyr.

Novel Drug Delivery Systems for Loading of Natural Plant Extracts and Their Biomedical Applications

Many types of research have distinctly addressed the efficacy of natural plant metabolites used for human consumption both in cell culture and preclinical animal model systems. However, these in vitro and in vivo effects have not been able to be translated for clinical use because of several factors such as inefficient systemic delivery and bioavailability of promising agents that significantly contribute to this disconnection. Over the past decades, extraordinary advances have been made successfully on the development of novel drug delivery systems for encapsulation of plant active metabolites including organic, inorganic and hybrid nanoparticles. The advanced formulas are confirmed to have extraordinary benefits over conventional and previously used systems in the manner of solubility, bioavailability, toxicity, pharmacological activity, stability, distribution, sustained delivery, and both physical and chemical degradation. The current review highlights the development of novel nanocarrier for plant active compounds, their method of preparation, type of active ingredients, and their biomedical applications.

Carnosic Acid Content Increased by Silver Nanoparticle Treatment in Rosemary (Rosmarinus officinalis L.)

Biosynthesis of carnosic acid (CA), one of the most industrially valuable medicinal compounds present in rosemary (Rosmarinus officinalis L.) leaves, is affected by various plant stressors. In this study, effects of silver nanoparticle (AgNP) treatment on the secondary metabolism and CA production of rosemary plants were investigated. AgNP of 0, 25, 50, 100, and 200 ppm were utilized on hydroponically grown plants using foliar spray. Efficient absorbance and translocation of AgNPs to the plant roots were confirmed by XRF (X-ray fluorescence) analysis. The fluctuations of important antioxidant compounds such as CA content, phenolics, flavonoids, and acid ascorbic were analyzed and their correlations evaluated. Results revealed that application of 200 ppm AgNPs for 12 days increased CA level more than 11%, as compared to the control plants. Furthermore, significant positive correlations were observed between total flavonoids and CA content under AgNP treatment, suggesting that AgNP acted as an elicitor and triggered the enhancement of CA accumulation effectively. These data suggest that concentration-dependent AgNP may be used to boost antioxidant activity and phytochemical contents of other medicinal plants.

Advances in nanomaterials as novel elicitors of pharmacologically active plant specialized metabolites: current status and future outlooks

During the last few decades major advances have shed light on nanotechnology. Nanomaterials have been widely used in various fields such as medicine, energy, cosmetics, electronics, biotechnology and pharmaceuticals. Owing to their unique physicochemical characteristics and nanoscale structures, nanoparticles (NPs) have the capacity to enter into plant cells and interact with intracellular organelles and various metabolites. The effects of NPs on plant growth, development, physiology and biochemistry have been reported, but their impact on plant specialized metabolism (aka as secondary metabolism) still remains obscure. In reaction to environmental stress and elicitors, a common response in plants results in the production or activation of different types of specialized metabolites (e.g., alkaloids, terpenoids, phenolics and flavonoids). These plant specialized metabolites (SMs) are important for plant adaptation to an adverse environment, but also a huge number of them are biologically active and used in various commercially-valued products (pharmacy, cosmetic, agriculture, food/feed). Due to their wide array of applications, SMs have attracted much attention to explore and develop new strategies to enhance their production in plants. In this context, NPs emerged as a novel class of effective elicitors to enhance the production of various plant SMs. In recent years, many reports have been published regarding the elicitation of SMs by different types of NPs. However, in order to achieve an enhanced and sustainable production of these SMs, in-depth studies are required to figure out the most suitable NP in terms of type, size and/or effective concentration, along with a more complete understanding about their uptake, translocation, internalization and elicitation mechanisms. Herein, we are presenting a comprehensive and critical account of the plant SMs elicitation capacities of the three main classes of nanomaterials (i.e., metallic NPs (MNPs), metal oxide NPs (MONPs) and carbon related nanomaterials). Their different proposed uptake, translocation and internalization pathways as well as elicitation mechanism along with their possible deleterious effect on plant SMs and/or phytotoxic effects are summarized. We also identified and critically discussed the current research gaps existing in this field and requiring future investigation to further improve the use of these nanomaterials for an efficient production of plant SMs.

Antioxidant and phytochemical activities of Amaranthus caudatus L. harvested from different soils at various growth stages

This study aimed at profiling the biological activities of Amaranthus caudatus cultivated on different soils in a glasshouse experiment. Five soil types namely; sandy clay loam, silty clay loam, clayey loam, loam and control (unfractionated soil) were experimentally formulated from primary particles of clay, sand and silt following the United State Department of Agriculture's (USDA) soil triangle technique. After harvesting at pre-flowering (61 days after planting), flowering (71 days after planting) and post-flowering (91 days after planting) stages, crude extracts were obtained with water and ethanol. Total flavonoids, phenolic and proanthocyanidin contents of the extracts, as well as their biological activities, were determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2 diphenyl-1-picrylhydrazyl ethanol (DPPH), nitric oxide and phosphomolybdate assays. It was observed that biological activity of A. caudatus varied with soil types, stages of maturity and solvents of extraction. The highest phytochemical yield was recorded in ethanolic extracts of clayey loam harvested prior to flowering and the same trend was replicated in the antioxidant properties of the plant. For optimal biological activity, it is recommended that clayey loam soil should be used for cultivation of A. caudatus and harvest should be made near flowering to capture high phytochemical yield from the species.

Zero-valent silver nanoparticles attenuate Cd and Pb toxicities on Moringa oleifera via immobilization and induction of phytochemicals

Potentials of zero-valent extract of cocoa pod mediated silver nanoparticles (AgNPs) for heavy metals (cadmium and lead) immobilization, attenuation of induced toxicities and influence on phytochemical contents in Moringa oleifera were investigated. M. oleifera seeds were planted in soil spiked and watered with water (control), 0.2 mg AgNPs, 0.5 mg CdCl₂, 0.5 mg PbCl₂, 0.2 mg AgNPs + 0.5 mg CdCl₂, 0.2 mg AgNPs + 0.5 mg PbCl₂, 0.2 mg AgNPs + 0.75 mg CdCl₂ and 0.2 mg AgNPs + 0.75 mg PbCl₂ per g soil designated as groups A, B, C, D, E, F, G and H respectively. Significant (p < 0.05) repression in shoot and root lengths, percentage germination, number of leaves, vigour and growth tolerance indices, relative water contents with attendant inhibition of photosynthetic pigments, total carotenoid contents, total flavonoid contents and total phenolic contents were obtained for M. oleifera planted on Cd and Pb spiked soil. There were marked decrease in ferric reducing, hydrogen peroxide scavenging and free radical scavenging activities with resultant significant increase in lipid peroxidation (MDA) levels for M. oleifera grown on Cd and Pb treated soil compared to control with Pb having more deleterious effects. Conversely, AgNPs significantly enhanced both physiological and biochemical parameters in M. oleifera over control and considerably attenuated suppressions of these parameters in M. oleifera induced by Cd and Pb. Results in this study have shown AgNPs as excellent immobilizing agents and outstanding modulators of heavy metal induced toxicities.

Phytomodulatory effects of silver nanoparticles on Corchorus olitorius: Its antiphytopathogenic and hepatoprotective potentials

This study has reported the effects of biogenic silver nanoparticles (AgNPs) using cocoa pod extract on physiological tolerance indices, antioxidant activity and hepatoprotective potentials of Corchorus olitorius as well as its efficiency for controlling soil phytopathogens. C. olitorius seeds were grown in soil prepared with water (control), 0.05, 0.1, 0.15 and 0.2 mg AgNPs/g soil. C. olitorus grown with AgNPs had significantly (p < 0.05) higher free radical scavenging ability, ferric reducing ability, percentage germination, vigour indices, longer roots and shoots as well as lower moisture content over control. C. olitorius grown with AgNPs attenuated hydrogen peroxide (H₂O₂)-mediated reduction in catalase concentrations and H₂O₂-induced malondialdehyde elevations in liver. Efficiency of AgNPs to reduce soil phytopathogens (fungi and nematodes) revealed significant (p < 0.05) reduction in the incidences of soil and shoot Meloidogyne spp., Aspergillus terreus, A. niger, Fusarium spp. and Cladosporium spp. with increase in concentrations of AgNPs. More efficiently, there was complete extermination of A. niger and Fusarium spp. in the leaves of C. olitorius grown with AgNPs. Results in this study have shown the positive influence of AgNPs on C. olitorius by strengthening its resistance against fungi, and nematodes, improvement of its shelf-life, modulation of antioxidant activities and promotion of liver-detoxifying potentials.

Assessment of the effects of metal oxide nanoparticles on the growth, physiology and metabolic responses in in vitro grown eggplant (Solanum melongena)

Nanoparticles (NPs) are widely used in various domestic products and their usage is constantly increasing which in turn can raise several environmental health issues. Like other abiotic stresses, nanomaterials also affect the growth of crop plants. Solanum melongena is a common vegetable crop grown in the tropics and subtropics regions with medicinal properties. In this study, S. melongena was analyzed for its response to three commercially important metallic nanoparticles, namely NiO, CuO, and ZnO, at four different concentrations (100, 250, 500 and 1000 mg/L). The growth of the eggplant seedlings was suppressed by all the NPs in a concentration-dependent manner and among them, NiO was shown to be more toxic as it suppressed the root and shoot growth effectively. Total chlorophyll contents were decreased in the NP-treated plants compared to control plants. Significant changes were found in the secondary metabolites such as anthocyanins, total phenolic and total flavonoid contents in the NP-treated plants. A dose-dependent increase in the reactive oxygen species (ROS) generation was noticed in the NP-treated plants which are evidenced by the 4-nitro blue tetrazolium chloride (NBT) and 3,3'-diamiobenzidine (DAB) histochemical staining. The DNA damage imposed by the NP in the seedlings of eggplants may be due to the elevated ROS and MDA (malondialdehyde) production. NiO NP was found to be more toxic comparable to CuO and ZnO NPs in the present study. Apart from the toxic effects, nanoparticles also showed profound effects on the production of important secondary metabolites such as phenolics and flavonoid compounds.

Characterization, antimicrobial, antioxidant, and anticoagulant activities of silver nanoparticles synthesized from Petiveria alliacea L. leaf extract

Phytosynthesis of silver nanoparticles (AgNPs) using leaf extract of Petiveria alliacea (PA) was the focus of this research work. The PA-AgNPs were characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) study. Studies were made on the AgNPs for antibacterial, antifungal, anticoagulant, free-radical scavenging, and hydrogen peroxide scavenging activities. The crystalline PA-AgNPs were monodispersed, with a size range of 16.70-33.74 nm and maximum absorption at 410 nm. FTIR analysis displayed prominent peaks at 3430.6, 1711.8, and 1165.9/cm, which showed the existence of phenolic compounds and proteins in the synthesis of AgNPs. PA-AgNPs was active against Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus, with 100% inhibition. The PA-AgNPs also displayed good antifungal properties, as the concentrations of 100 and 150 µg/mL had 100% inhibition toward Aspergillus fumigatus and Aspergillus flavus. However, there was 66.67% inhibition of Aspergillus niger. It scavenged both DPPH and H₂O₂ by 70.69 and 89.02%, respectively. PA-AgNPs also prevented the coagulation of human blood. This study, being the first of its kind to use the leaf extract of PA for the synthesis of AgNPs has shown that PA-AgNPs can find biomedical applications.