Synthesis and antibacterial activity of solanum torvum mediated silver nanoparticle against Xxanthomonas axonopodis pv.punicae and Ralstonia solanacearum

Toxicity evaluation of silver nanoparticles synthesized from naringin flavonoid on human promyelocytic leukemic cells and human blood cells

Increasing applications of silver nanoparticles (AgNPs) in multiple products like cosmetics, medicines, drugs, paints, and other new materials have raised concern for their toxic effects on living beings and the surrounding environment. In the present study, cytotoxicity and genotoxicity of AgNPs synthesized using plant flavonoid (Naringin) as a reducing agent were investigated on human promyelocytic leukemic (HL-60) cells and human blood as an in vitro model. The LC50 of AgNPs was found to be 4.85 µM. Dose-dependent increase in cell death and caspase activity was observed in the presence of AgNPs. The comet assay showed a 60%-70% (p < .05) increase in tail DNA at 0.48 and 0.96 µM AgNPs. CBMN in PBMCs also confirmed the genotoxic potential of AgNPs-induced DNA damage. AgNPs resulted in 1.5-1.54 fold (p < .05) increase in the level of ROS in HL-60 cells after 12 h of exposure. AgNP showed toxicity in human cells through ROS generation and cellular damage through membrane dysfunction, caspase activation, apoptosis, and DNA damage.

From nature to nanotechnology: The interplay of traditional medicine, green chemistry, and biogenic metallic phytonanoparticles in modern healthcare innovation and sustainability

As we navigate the modern era, the intersection of time-honoured natural remedies and contemporary scientific approaches forms a burgeoning frontier in global healthcare. For generations, natural products have been foundational to health solutions, serving as the primary healthcare choice for 80% to 85% of the world's population. These herbal-based, nature-derived substances, significant across diverse geographies, necessitate a renewed emphasis on enhancing their quality, efficacy, and safety. In the current century, the advent of biogenic phytonanoparticles has emerged as an innovative therapeutic conduit, perfectly aligning with principles of environmental safety and scientific ingenuity. Utilizing green chemistry techniques, a spectrum of metallic nanoparticles including elements such as copper, silver, iron, zinc, and titanium oxide can be produced with attributes of non-toxicity, sustainability, and economic efficiency. Sophisticated herb-mediated processes yield an array of plant-originated nanomaterials, each demonstrating unique physical, chemical, and biological characteristics. These attributes herald new therapeutic potentials, encompassing antioxidants, anti-aging applications, and more. Modern technology further accelerates the synthesis of natural products within laboratory settings, providing an efficient alternative to conventional isolation methods. The collaboration between traditional wisdom and advanced methodologies now signals a new epoch in healthcare. Here, the augmentation of traditional medicine is realized through rigorous scientific examination. By intertwining ethical considerations, cutting-edge technology, and natural philosophy, the realms of biogenic phytonanoparticles and traditional medicine forge promising pathways for research, development, and healing. The narrative of this seamless integration marks an exciting evolution in healthcare, where the fusion of sustainability and innovation crafts a future filled with endless possibilities for human well-being. The research in the development of metallic nanoparticles is crucial for unlocking their potential in revolutionizing fields such as medicine, catalysis, and electronics, promising groundbreaking applications with enhanced efficiency and tailored functionalities in future technologies. This exploration is essential for harnessing the unique properties of metallic nanoparticles to address pressing challenges and advance innovations across diverse scientific and industrial domains.

Assignment of the antibacterial potential of Ag2O/ZnO nanocomposite against MDR bacteria Proteus mirabilis and Salmonella typhi isolated from bone marrow transplant patients

The rate of infectious diseases started to be one of the major mortality agents in the healthcare sector. Exposed to increased bacterial infection by antibiotic-resistant bacteria became one of the complications that occurred for bone marrow transplant patients. Nanotechnology may provide clinicians and patients with the key to overcoming multidrug-resistant bacteria. Therefore, this study was conducted to clarify the prevalence of MDR bacteria in bone marrow transplant recipients and the use of Ag2O/ZnO nanocomposites to treat participants of diarrhea brought on by MDR bacteria following bone marrow transplantation (BMT). Present results show that pathogenic bacteria were present in 100 of 195 stool samples from individuals who had diarrhea. Phenotypic, biochemical, and molecular analysis clarify that Proteus mirabilis and Salmonella typhi were detected in 21 and 25 samples, respectively. Successful synthesis of Ag2O/ZnO nanocomposites with a particle enables to inhibition of both pathogens. The maximum inhibitory impact was seen on Salmonella typhi. At low doses (10-5 g/l), it prevented the growth by 53.4%, while at higher concentrations (10-1 g/l), Salmonella typhi was inhibited by 95.5%. Regarding Proteus mirabilis, at (10-5 g/l) Ag2O/ZnO, it was inhabited by 78.7%, but at higher concentrations (10-1 g/l), it was inhibited the growth by 94.6%. Ag2O/ZnO nanocomposite was therefore found to be the most effective therapy for MDR-isolated bacteria and offered promise for the treatment of MDR bacterial infections that cause diarrhea.

Zebrafish as a robust preclinical platform for screening plant-derived drugs with anticonvulsant properties-a review

Traditionally, selected plant sources have been explored for medicines to treat convulsions. This continues today, especially in countries with low-income rates and poor medical systems. However, in the low-income countries, plant extracts and isolated drugs are in high demand due to their good safety profiles. Preclinical studies on animal models of seizures/epilepsy have revealed the anticonvulsant and/or antiepileptogenic properties of, at least some, herb preparations or plant metabolites. Still, there is a significant number of plants known in traditional medicine that exert anticonvulsant activity but have not been evaluated on animal models. Zebrafish is recognized as a suitable in vivo model of epilepsy research and is increasingly used as a screening platform. In this review, the results of selected preclinical studies are summarized to provide credible information for the future development of effective screening methods for plant-derived antiseizure/antiepileptic therapeutics using zebrafish models. We compared zebrafish vs. rodent data to show the translational value of the former in epilepsy research. We also surveyed caveats in methodology. Finally, we proposed a pipeline for screening new anticonvulsant plant-derived drugs in zebrafish ("from tank to bedside and back again").

Biosynthesis and Characterization of Silver Nanoparticles Produced by Parachlorella kessleri and Cyclotella spp., and the Evaluation of Their Antibacterial Activity

Green synthesis is one of the fastest and best ways for ecofriendly nanoparticle synthesis. This study aims to investigate the use of the green microalgae Parachlorella kesseleri and Cyclotella spp. for the biological synthesis of silver nanoparticles (AgNPs). This work focuses on optimizing various parameters necessary for the production and stability of AgNPs. The nanoparticle formation was confirmed by UV-Visible analysis, which revealed the surface plasmon resonance band at 420 nm. The characterization of the AgNPs was performed using UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The antimicrobial properties of these bioactive AgNPs were also tested, showing excellent antibacterial activity against six bacterial strains, Escherichia coli, multidrug-resistant Escherichia coli, Bacillus clausii, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella typhi. The biosynthesis of AgNPs from living cultures of microalgae has remarkable antibacterial properties. Other studies are underway in our laboratory to clarify the mechanism of the biosynthesis of these nanoparticles, and their action on bacteria.

The impact of silver nanoparticles on the growth of plants: The agriculture applications

Nanotechnology is the most advanced and rapidly progressing field of science and technology. It primarily deals with developing novelty in nanomaterials by understanding and controlling matter at the nanoscale level. Silver nanoparticles (AgNPs) are the most prominent nanoparticles incorporated with wide-ranging applications, owing to their distinct characteristics. Different methods have been employed for nanoparticles synthesis like chemical method, physical method, photochemical method, top-down/bottom-up approach and biological methods. The positive impacts of silver nanoparticles have been observed in various economy-based sectors, including agriculture. The scientific curiosity about AgNPs in agriculture and plant biotechnology has shown optimum efficacy over the last few years. It not only enhances seed germination and plant growth, but also improves the quantum efficiency of the photosynthetic process. AgNPs play a vital role in agriculture by having several applications that are crucial for ensuring food security and improving crop production. Moreover, they also act as nano-pesticides, providing sufficient dose to the target plants without releasing unnecessary pesticides into the environment. Nano-fertilizers slowly release nutrients to the plants, thereby preventing excessive nutrient loss. AgNPs are utilized for effective and non-toxic pest management, making them an excellent tool for combating pests safely. They combine either edible or non-biodegradable polymers for active food packaging. In addition, AgNPs also possess diverse biological properties such as antiviral, antibacterial and antifungal activities, which protect plants from hazardous microbes. The aim of this review is to comprehensively survey and summarize recent literature regarding the positive and negative impacts of AgNPs on plant growth, as well as their agricultural applications.

Green synthesis and characterization of Solanum xanthocarpum capped silver nanoparticles and its antimicrobial effect on multidrug-resistant bacterial (MDR) isolates

Plant extracts and their bioactive compounds are considered as the promising options for green synthesis of nanoparticles instead expensive and hazardous materials. Here, Solanum xanthocarpum fruit was used for synthesis of silver nanoparticles (AgNP). The synthesized AgNPs were characterized by using chromatographic and spectroscopic analytical methods. AgNPs were confirmed by UV-visible absorbance at 420-470 nm. TEM analysis showed AgNP with 22.45 nm average size. X-ray diffraction studies revealed the crystalline and face central cubic nature of AgNPs. FTIR analysis revealed functional group present over AgNPs. The aminodiphenyl acetic acid, clomipramine, and fonisopril from fruit extracts were found to be major capping agents on AgNPs as a result of analysis by HRLC-MS. All clinical isolates showed resistance for ampicilline, amoxyclav, niladixic acid, and sulphafurazole, suggesting multidrug resistance. The results showed that all isolates were sensitive to AgNPs synthesized fruit extracts. On the contrary, all isolates were resistant to whole S. xanthocarpum fruit extracts alone. The antimicrobial activity of AgNP was explored against multidrug-resistant (MDR) Gram-negative clinical isolates including Escherichia coli, Shigella spp., Aeronomonas spp. and Pseudomonas spp. MIC values ranged between 1.25 mg/ml and 2.5 mg/ml at 8 McFarland's standards. Minimum bactericidal concentration was found to be in between 2.5 mg/ml to 5 mg/ml. Nanoparticles synthesized from fruit extract of S. xanthocarpum containing aminodiphenyl acetic acid, clomipramine, and fonisopril metabolites exhibit promising antimicrobial activity against MDR Gram-negative clinical isolates.

Effect of biosynthesized selenium nanoparticles using Nepeta extract against multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii

The problems of drug resistance in bacteria have become one of the daily challenges of the clinical treatment of patients, which inevitably forces us to use agents other than common antibiotics. Among these, we can take help from different properties and applications of nanoparticles (NPs). In this work, we evaluate the antibacterial activity of biosynthesized selenium nanoparticles (SeNPs) against standard strains of multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii. The production of biosynthesized SeNPs was proved by ultraviolet-visible, Fourier transform infrared, X-ray diffractometer, Field Emission Scanning Electron Microscopy, Dynamic light scattering, and Zeta potential methods. The cytotoxicity effect of SeNPs was investigated by MTT assay. Disk diffusion agar (DDA) and minimum inhibitory concentration (MIC) tests were performed on the mentioned bacteria using different classes of standard antibiotics and SeNPs separately. The impact of SeNPs combined with the desired antibiotics for better treatment of these infections was evaluated by checkerboard assay to determine the synergism effect. After the confirmation results based on the biosynthesis of SeNPs, both standard bacterial strains were susceptible to SeNPs and had a zone of inhibition using the DDA test. Also, the results of MICs showed that biosynthesized SeNPs in lower concentrations than antibiotics cause no growth of bacteria. On the other hand, according to the checkerboard assay, SeNPs had a synergistic effect with conventional antibiotics. The antibacterial sensitivity tests demonstrated the inhibition of bacterial growth in the presence of lower concentrations of SeNPs than common antibiotics. This property can be exerted in future applications to solve the drug resistance obstacle of microorganisms in bacterial diseases.

Metallic Nanosystems in the Development of Antimicrobial Strategies with High Antimicrobial Activity and High Biocompatibility

Antimicrobial resistance is a major and growing global problem and new approaches to combat infections caused by antibiotic resistant bacterial strains are needed. In recent years, increasing attention has been paid to nanomedicine, which has great potential in the development of controlled systems for delivering drugs to specific sites and targeting specific cells, such as pathogenic microbes. There is continued interest in metallic nanoparticles and nanosystems based on metallic nanoparticles containing antimicrobial agents attached to their surface (core shell nanosystems), which offer unique properties, such as the ability to overcome microbial resistance, enhancing antimicrobial activity against both planktonic and biofilm embedded microorganisms, reducing cell toxicity and the possibility of reducing the dosage of antimicrobials. The current review presents the synergistic interactions within metallic nanoparticles by functionalizing their surface with appropriate agents, defining the core structure of metallic nanoparticles and their use in combination therapy to fight infections. Various approaches to modulate the biocompatibility of metallic nanoparticles to control their toxicity in future medical applications are also discussed, as well as their ability to induce resistance and their effects on the host microbiome.

Bacillus sp. extract used to fabricate ZnO nanoparticles for their antagonist effect against phytopathogens

In order to achieve the food demand of a growing population, agricultural productivity needs to be increased by employing safe strategies. In the present study we have evaluated ZnONPs that were synthesized from the culture supernatant of Bacillus subtilis. Bio mimetically synthesized ZnONPs showed a surface resonance peak of 355 nm corresponding to NPs formation. Further, NPs were examined for their size, shape and element confirmation by DLS, AFM, SEM, TEM and EDAX, which confirmed the synthesized NPs were nearly spherical in size with average diameter of 32 nm by TEM. Surface charge of + 34.3 mV was observed for NPs with a low poly-dispersity index of 0.21. In vitro efficacy studies against fungi Colletotrichum capsici, Sclerotium rolfsii, Alternaria solani and Fusarium oxysporum f. sp. cicero showed up to 99% mycelial growth inhibition at 0.125% ZnONPs. Further, in-vitro disk-diffusion assay showed inhibition zones of 23 ± 0.4 mm and 12.67 ± 0.24 mm for Xanthomonas axonopodis pv. punicae (Xap) and Xanthomonas oryzae pv. oryzae (Xoo) bacterial cultures. Plant toxicity study was observed that ≤ 0.14% NPs concentration was safe under greenhouse conditions. Overall, the present study emphasizes the potential effect of ZnONPs against agricultural pathogens which play an important role in agriculture production.

Bioinspired Green Synthesis of Silver Nanoparticles Using Three Plant Extracts and Their Antibacterial Activity against Rice Bacterial Leaf Blight Pathogen Xanthomonas oryzae pv. oryzae

Rice bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae (Xoo) is responsible for a significant reduction in rice production. Due to the small impact on the environment, biogenic nanomaterials are regarded as a new type of antibacterial agent. In this research, three colloids of silver nanoparticles (AgNPs) were synthesized with different biological materials such as Arctium lappa fruit, Solanum melongena leaves, and Taraxacum mongolicum leaves, and called Al-AgNPs, Sm-AgNPs and Tm-AgNPs, respectively. The appearance of brown colloids and the UV-Visible spectroscopy analysis proved the successful synthesis of the three colloids of AgNPs. Moreover, FTIR and XRD analysis revealed the formation of AgNPs structure. The SEM and TEM analysis indicated that the average diameters of the three synthesized spherical AgNPs were 20.18 nm, 21.00 nm, and 40.08 nm, respectively. The three botanical AgNPs had the strongest bacteriostatic against Xoo strain C2 at 20 μg/mL with the inhibition zone of 16.5 mm, 14.5 mm, and 12.4 mm, while bacterial numbers in a liquid broth (measured by OD₆₀₀) decreased by 72.10%, 68.19%, and 65.60%, respectively. Results showed that the three AgNPs could inhibit biofilm formation and swarming motility of Xoo. The ultrastructural observation showed that Al-AgNPs adhered to the surface of bacteria and broke the bacteria. Overall, the three synthetic AgNPs could be used to inhibit the pathogen Xoo of rice bacterial leaf blight.

Antibacterial potency of cytocompatible chitosan-decorated biogenic silver nanoparticles and molecular insights towards cell-particle interaction

In the study, leaf extract of Carica papaya was utilized for the biogenic fabrication process of chitosan functionalized silver nanoparticles (Ag-Chito NPs). HRTEM analysis revealed that the fabricated Ag-Chito NPs was spherical in shape, with an average particle size of 13.31 (±0.07) nm. FTIR, UV-Vis, DLS, and other characterizations were also performed to analyze the diverse physicochemical properties of the particles. The antibacterial potency of the synthesized Ag-Chito NPs was tested against the two clinically isolated multidrug resistant uropathogenic bacterial strains, i.e. MLD 2 (Escherichia coli) and MLD 4 (Staphylococcus aureus) through MIC, MBC, time and concentration dependent killing kinetic assay, inhibition of biofilm formation assay, fluorescence and SEM imaging. Significantly, Ag-Chito NPs showed the highest sensitivity against the MLD 2 (MIC value of 12.5 μg/mL) strain, as compared to the MLD 4 (MIC value of 15 μg/mL) strain. From the hemolysis assay, it was revealed that Ag-Chito NPs exerted no significant toxicity up to 50 μg/mL against healthy human blood cells. Additionally, in silico analysis of chitosan (functionalized on the surface of AgNPs) and bacterial cell membrane protein also evidently suggested a strong interaction between Ag-Chito NPs and bacterial cells, which might be responsible for bacterial cell death.

Recent Advances in Green Synthesis of Ag NPs for Extenuating Antimicrobial Resistance

Combating antimicrobial resistance (AMR) is an on-going global grand challenge, as recognized by several UN Sustainable Development Goals. Silver nanoparticles (Ag NPs) are well-known for their efficacy against antimicrobial resistance, and a plethora of green synthesis methodologies now exist in the literature. Herein, this review evaluates recent advances in biological approaches for Ag NPs, and their antimicrobial potential of Ag NPs with mechanisms of action are explored deeply. Moreover, short and long-term potential toxic effects of Ag NPs on animals, the environment, and human health are briefly discussed. Finally, we also provide a summary of the current state of the research and future challenges on a biologically mediated Ag-nanostructures-based effective platform for alleviating AMR.

Biocontrol Potential of Essential Oils in Organic Horticulture Systems: From Farm to Fork

In recent decades, increasing attention has been paid to food safety and organic horticulture. Thus, people are looking for natural products to manage plant diseases, pests, and weeds. Essential oils (EOs) or EO-based products are potentially promising candidates for biocontrol agents due to their safe, bioactive, biodegradable, ecologically, and economically viable properties. Born of necessity or commercial interest to satisfy market demand for natural products, this emerging technology is highly anticipated, but its application has been limited without the benefit of a thorough analysis of the scientific evidence on efficacy, scope, and mechanism of action. This review covers the uses of EOs as broad-spectrum biocontrol agents in both preharvest and postharvest systems. The known functions of EOs in suppressing fungi, bacteria, viruses, pests, and weeds are briefly summarized. Related results and possible modes of action from recent research are listed. The weaknesses of applying EOs are also discussed, such as high volatility and low stability, low water solubility, strong influence on organoleptic properties, and phytotoxic effects. Therefore, EO formulations and methods of incorporation to enhance the strengths and compensate for the shortages are outlined. This review also concludes with research directions needed to better understand and fully evaluate EOs and provides an outlook on the prospects for future applications of EOs in organic horticulture production.

Evaluating green silver nanoparticles as prospective biopesticides: An environmental standpoint

The current method of agriculture entails the usage of excessive amounts of pesticides and fertilizers. The blatant use of conventional pesticides and fertilizers over several decades has led to their bioaccumulation with adverse effects on soil biodiversity and the development of resistance by pests. With the decline in clinically useful antibiotics and increase in multi drug resistant microbes, it is imperative to develop new and effective antimicrobial therapies. Growing awareness and demand for efficacious biorational pesticides are on the rise. Silver nanoparticles are widely known antimicrobials and have been in use for several purposes for a long time. This work reviews the implications of applying silver nanoparticles in agriculture and their possible consequences. The physiological and biochemical changes in plants due to the uptake of silver nanoparticles as a consequence of its morphology, capping biomolecules and method of application are comprehensively discussed in this review article. Studies on tolerance levels or stress due to silver nanoparticles by variation in concentration/doses on diverse flora and fauna are also analyzed here. Further, phytotoxicity and genotoxicity due to the metal as well as its transformation in soil, water and sludge are taken into account. We also gauge the potential of biogenic silver nanoparticles-viable antimicrobial agents for enhanced applications in agriculture as biopesticides.

Bioinspired Nanomodification Strategies: Moving from Chemical-Based Agrosystems to Sustainable Agriculture

Agrochemicals have supported the development of the agricultural economy and national population over the past century. However, excessive applications of agrochemicals pose threats to the environment and human health. In the last decades, nanoparticles (NPs) have been a hot topic in many fields, especially in agriculture, because of their physicochemical properties. Nevertheless, the prevalent methods for fabricating NPs are uneconomical and involve toxic reagents, hindering their extensive applications in the agricultural sector. In contrast, inspired by biological exemplifications from microbes and plants, their extract and biomass can act as a reducing and capping agent to form NPs without any toxic reagents. NPs synthesized through these bioinspired routes are cost-effective, ecofriendly, and high performing. With the development of nanotechnology, biosynthetic NPs (bioNPs) have been proven to be a substitute strategy for agrochemicals and traditional NPs in heavy-metal remediation of soil, promotion of plant growth, and management of plant disease with less toxicity and higher performance. Therefore, bioinspired synthesis of NPs will be an inevitable trend for sustainable development in agricultural fields. This critical review will demonstrate the bioinspired synthesis of NPs and discuss the influence of bioNPs on agricultural soil, crop growth, and crop diseases compared to chemical NPs or agrochemicals.

Silver Nanoparticles Biosynthesis, Characterization, Antimicrobial Activities, Applications, Cytotoxicity and Safety Issues: An Updated Review

Rapid advances in nanotechnology have led to its emergence as a tool for the development of green synthesized noble metal nanoparticles, especially silver nanoparticles (AgNPs), for applications in diverse fields such as human health, the environment and industry. The importance of AgNPs is because of their unique physicochemical and antimicrobial properties, with a myriad of activities that are applicable in various fields, including the pharmaceutical industry. Countries with high biodiversity require the collection and transformation of information about biological assets into processes, associations, methods and tools that must be combined with the sustainable utilization of biological diversity. Therefore, this review paper discusses the applicable studies of the biosynthesis of AgNPs and their antimicrobial activities towards microorganisms in different areas viz. medicine and agriculture. The confirmed antiviral properties of AgNPs promote their applicability for SARS-CoV-2 treatment, based on assimilating the virus’ activities with those of similar viruses via in vivo studies. In this review, an insight into the cytotoxicity and safety issues of AgNPs, along with their future prospects, is also provided.

Plant-mediated synthesis of nanoparticles and their antimicrobial activity against phytopathogens

Nanotechnology is an emerging science with a wide array of applications involving the synthesis and manipulation of materials with dimensions in the range of 1-100 nm. Nanotechnological applications include diverse fields such as pharmaceuticals, medicine, the environment, food processing and agriculture. Regarding the latter, applications are mainly focused on plant growth and crop protection against plagues and diseases. In recent years, the biogenic reduction of elements such as Ag, Au, Cu, Cd, Al, Se, Zn, Ce, Ti and Fe with plant extracts has become one of the most accepted techniques for obtaining nanoparticles (NPs), as it is considered an ecological and cost-effective process without the use of chemical contaminants. The objective of this work was to review NPs synthesized by green chemistry using vegetable extracts, as well as their use as antimicrobial agents against phytopathogenic fungi and bacteria. Given the need for alternatives to control and integrate management of phytopathogens, this review is relevant to agriculture, although this technology is barely exploited in this field. © 2020 Society of Chemical Industry.