Green synthesis of silver nanoparticles using Citrus limon peels and evaluation of their antibacterial and cytotoxic properties

Biosynthesis, characterization, and anticoagulant properties of copper nanoparticles from red seaweed of Acanthophora sp

INTRODUCTION

In the last few decades, nanoparticles have found extensive use in a variety of biological applications. Traditional medicine widely uses Acanthophora sp., a marine macroalgae, to cure and prevent diabetes, skin disorders, and blood clotting.

OBJECTIVE

The present study aims to investigate whether green-synthesized copper nanoparticles (CuNPs) might work as an anticoagulant.

METHODOLOGY

The CuNPs were made using an environmentally friendly method that uses Acanthophora extract. We used UV-vis spectroscopy to assess the surface plasmon resonance of the material, scanning electron microscopy (SEM) to analyze its form, and energy dispersive X-ray (EDX) spectroscopy to identify the material's constituent elements. Furthermore, Fourier-transform infrared (FT-IR) determined the functional groups of the CuNPs.

RESULTS

The biosynthesis of CuNPs was confirmed by UV-vis spectroscopy, which showed a surface plasmon resonance peak at 570 nm. The FT-IR analysis showed that certain functional groups are involved in the formation of CuNPs. These groups include OH stretching, C=O stretching, C-H bonding, C-N bonding, and Cu vibration. SEM analysis demonstrated the morphology of CuNPs synthesized, with a size of 0.5 μm, while EDS analysis confirmed their purity. The anticoagulant activity of prothrombin time (PT) and activated partial thromboplastin time (aPTT) assays showed that the clotting time got longer depending on the concentration. The CuNPs synthesized from Acanthophora had strong anticoagulant effects at 100 μg/mL, further suggesting that they might be useful as a natural blood thinner.

CONCLUSION

The interesting thing we observed is that the green-synthesized CuNPs made from Acanthophora extract could be used in anticoagulation therapy.

Green synthesis of metal nanoparticles and study their anti-pathogenic properties against pathogens effect on plants and animals

According to an estimate, 30% to 40%, of global fruit are wasted, leading to post harvest losses and contributing to economic losses ranging from $10 to $100 billion worldwide. Among, all fruits the discarded portion of oranges is around 20%. A novel and value addition approach to utilize the orange peels is in nanoscience. In the present study, a synthesis approach was conducted to prepare the metallic nanoparticles (copper and silver); by utilizing food waste (Citrus plant peels) as bioactive reductants. In addition, the Citrus sinensis extracts showed the reducing activity against metallic salts copper chloride and silver nitrate to form Cu-NPs (copper nanoparticles) and Ag-NPs (Silver nanoparticles). The in vitro potential of both types of prepared nanoparticles was examined against plant pathogenic bacteria Erwinia carotovora (Pectobacterium carotovorum) and pathogens effect on human health Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Moreover, the in vivo antagonistic potential of both types of prepared nanoparticles was examined by their interaction with against plant (potato slices). Furthermore, additional antipathogenic (antiviral and antifungal) properties were also examined. The statistical analysis was done to explain the level of significance and antipathogenic effectiveness among synthesized Ag-NPs and Cu-NPs. The surface morphology, elemental description and size of particles were analyzed by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy and zeta sizer (in addition polydispersity index and zeta potential). The justification for the preparation of particles was done by UV-Vis Spectroscopy (excitation peaks at 339 nm for copper and 415 nm for silver) and crystalline nature was observed by X-ray diffraction. Hence, the prepared particles are quite effective against soft rot pathogens in plants and can also be used effectively in some other multifunctional applications such as bioactive sport wear, surgical gowns, bioactive bandages and wrist or knee compression bandages, etc.

Antibacterial and antioxidant activity of gold and silver nanoparticles in dextran-polyacrylamide copolymers

Search for new antimicrobial agents is of great significance due to the issue of antimicrobial resistance, which nowadays has become more important than many diseases. The aim of this study was to evaluate the toxicity and biological effects of a dextran-graft-polyacrylamide (D-PAA) polymer-nanocarrier with/without silver or gold nanoparticles (AgNPs/D-PAA and AuNPs/D-PAA, respectively) to analyze their potential to replace or supplement conventional antibiotic therapy. The toxicity of nanocomplexes against eukaryotic cells was assessed on primary dermal fibroblasts using scratch, micronucleus and proliferation assays. DPPH (2,2-diphenyl-1-picrylhydrazylradical) assay was used to evaluate the antioxidant capacity of D-PAA, AgNPs/D-PAA and AuNPs/D-PAA. DNA cleavage, antimicrobial and biofilm inhibition effects of nanocomplexes were investigated. Nanocomplexes were found to be of moderate toxicity against fibroblasts with no genotoxicity observed. AgNPs/D-PAA reduced motility and proliferation at lower concentrations compared with the other studied nanomaterials. AgNPs/D-PAA and AuNPs/D-PAA showed radical scavenging capacities in a dose-dependent manner. The antimicrobial activity of AgNPs/D-PAA against various bacteria was found to be much higher compared to D-PAA and AuNPs/D-PAA, especially against E. hirae, E. faecalis and S. aureus, respectively. D-PAA, AgNPs/D-PAA and AuNPs/D-PAA showed DNA-cleaving and biofilm inhibitory activity, while AgNPs/D-PAA displayed the highest anti-biofilm activity. AgNPs/D-PAA and AuNPs/D-PAA were characterized by good antimicrobial activity. According to the findings of the study, AgNPs/D-PAA and AuNPs/D-PAA can be evaluated as alternatives for the preparation of new antimicrobial agents, the fight against biofilms, sterilization and disinfection processes. Our findings confirm the versatility of nanosystems based on dextran-polyacrylamide polymers and indicate that AgNPs/D-PAA and AuNPs/D-PAA can be evaluated as alternatives for the preparation of novel antimicrobial agents.

Green synthesis of silver nanoparticles using Phlebopus portentosus polysaccharide and their antioxidant, antidiabetic, anticancer, and antimicrobial activities

Silver nanoparticles (AgNPs) by green synthesis from fungi polysaccharides are attracting increasing attention owing to their distinctive features and special applications in numerous fields. In this study, a cost-effective and environmentally friendly biosynthesizing AgNPs method with no toxic chemicals involved from the fruiting body polysaccharide of Phlebopus portentosus (PPP) was established and optimized by single factor experiment and response surface methodology. The optimum synthesis conditions of polysaccharide-AgNPs (PPP-AgNPs) were identified to be the reaction time of 140 min, reaction temperature of 94 °C, and the PPP: AgNO3 ratio of 1:11.5. Formation of PPP-AgNPs was indicated by visual detection of colour change from yellowish to yellowish brown. PPP-AgNPs were characterized by different methods and further evaluated for biological activities. That the Ultraviolet-visible (UV-Vis.) spectroscopy displayed a sharp absorption peak at 420 nm confirmed the formation of AgNPs. Fourier transform infrared (FTIR) analysis detected the presence of various functional groups. The lattice indices of (111), (200), (220), and (331), which indicated a faced-centered-cubic of the Ag crystal structure of PPP-AgNPs, was confirmed by X-ray diffraction (XRD) and the particles were found to be spherical through high resolution transmission electron microscopy (HRTEM). Energy dispersive X-ray spectroscopy (EDS) determined the presence of silver in PPP-AgNPs. The percentage relative composition of elements was determined as silver (Ag) 82.5 % and oxygen (O) 17.5 % for PPP-AgNPs, and did not exhibit any nitrogen peaks. The specific surface area of PPP-AgNPs was calculated to be 0.5750 m2/g with an average pore size of 24.33 nm by BET analysis. The zeta potential was -4.32 mV, which confirmed the stability and an average particle size of 64.5 nm was calculated through dynamic light scattering (DLS). PPP-AgNPs exhibited significant free radical scavenging activity against DPPH with an IC50 value of 0.1082 mg/mL. The MIC values of PPP-AgNPs for E. coli, S. aureus, C. albicans, C. glabrata, and C. parapsilosis are 0.05 mg/mL. The IC50 value of the inhibition of PPP-AgNPs against α-glucosidase was 11.1 μg/mL, while the IC50 values of PPP-AgNPs against HepG2 and MDA-MB-231 cell lines were calculated to be 14.36 ± 0.43 μg/mL and 40.05 ± 2.71 μg/mL, respectively. According to the evaluation, it can be concluded that these green-synthesized and eco-friendly PPP-AgNPs are helpful to improve therapeutics because of significant antioxidant, antimicrobial, antidiabetic, and anticancer properties to provide new possibilities for clinic applications.

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.

Biogenic nanoparticles from waste fruit peels: Synthesis, applications, challenges and future perspectives

Nanotechnology is a continually growing field with a wide range of applications from food science to biotechnology and nanobiotechnology. As the current world is grappling with non-biodegradable waste, considered more challenging and expensive to dispose of than biodegradable waste, new technologies are needed today more than ever. Modern technologies, especially nanotechnology, can transform biodegradable waste into products for human use. Researchers are exploring sustainable pathways for nanotechnology by utilizing biodegradable waste as a source for preparing nanomaterials. Over the past ten years, the biogenic production of metallic nanoparticles (NPs) has become a promising alternative technique to traditional NPs synthesis due to its simplicity, eco-friendliness, and biocompatibility in nature. Fruit and vegetable waste (after industrial processing) contain various bioactives (such as flavonoids, phenols, tannins, steroids, triterpenoids, glycosides, anthocyanins, carotenoids, ellagitannins, vitamin C, and essential oils) serving as reducing and capping agents for NP synthesis and they possess antibacterial, antioxidant, and anti-inflammatory properties. This review addresses various sources of biogenic NPs including their synthesis using fruit/vegetable waste, types of biogenic NPs, extraction processes and extracted biomaterials, the pharmacological functionality of NPs, industrial aspects, and future perspectives. In this manner, this review will cover the most recent research on the biogenic synthesis of NPs from fruit/vegetable peels to transform them into therapeutic nanomedicines.

Citrus By-Products as a Valuable Source of Biologically Active Compounds with Promising Pharmaceutical, Biological and Biomedical Potential

Citrus fruits processing results in the generation of huge amounts of citrus by-products, mainly peels, pulp, membranes, and seeds. Although they represent a major concern from both economical and environmental aspects, it is very important to emphasize that these by-products contain a rich source of value-added bioactive compounds with a wide spectrum of applications in the food, cosmetic, and pharmaceutical industries. The primary aim of this review is to highlight the great potential of isolated phytochemicals and extracts of individual citrus by-products with bioactive properties (e.g., antitumor, antimicrobial, antiviral, antidiabetic, antioxidant, and other beneficial activities with health-promoting abilities) and their potential in pharmaceutical, biomedical, and biological applications. This review on citrus by-products contains the following parts: structural and chemical characteristics; the utilization of citrus by-products; bioactivities of the present waxes and carotenoids, essential oils, pectins, and phenolic compounds; and citrus by-product formulations with enhanced biocactivities. A summary of the recent developments in applying citrus by-products for the treatment of different diseases and the protection of human health is also provided, emphasizing innovative methods for bioaccessibility enhancements (e.g., extract/component encapsulation, synthesis of biomass-derived nanoparticles, nanocarriers, or biofilm preparation). Based on the representative phytochemical groups, an evaluation of the recent studies of the past six years (from 2018 to 2023) reporting specific biological and health-promoting activities of citrus-based by-products is also provided. Finally, this review discusses advanced and modern approaches in pharmaceutical/biological formulations and drug delivery (e.g., carbon precursors for the preparation of nanoparticles with promising antimicrobial activity, the production of fluorescent nanoparticles with potential application as antitumor agents, and in cellular imaging). The recent studies implementing nanotechnology in food science and biotechnology could bring about new insights into providing innovative solutions for new pharmaceutical and medical discoveries.

One-pot biogenic synthesis of C. limon/TiO2 with dual applications as an advance photocatalyst and antimicrobial agent

The present study portrays a facile, cost effective and environmental benign way for preparation of TiO₂ nanoparticles utilizing C. limon extract which possesses phytochemicals as reducing and stabilizing agents. Structural characterization by XRD reveals that C. limon/TiO₂ NPs exhibits anatase-type tetragonal crystallinity. An average crystallite-size is calculated using Debye Scherrer's method (3.79 nm), Williamson-Hall plot (3.60 nm), and Modified Debye Scherrer plot (3.68 nm) which are very much intercorrelated. The absorption peak at 274 nm (UV-Visible spectrum) corresponds to the bandgap (E_g) value of3.8 eV. The existence of different phytochemicals containing organic groups like N-H, C=O, O-H, has been elucidated from FTIR along with Ti-O bond stretching at wavenumber 780 cm^-1. Micro-structural investigations of TiO₂ NPs using FESEM and TEM display different geometrical configurations involving spherical, pentagons, hexagons, heptagons and capsule like structures. BET and BJH analysis show mesoporous characteristics of synthesized nanoparticles with specific surface-area (97.6 m² g^-1), pore-volume (0.018322 cm³ g^-1), and mean pore-diameter (∼7.5 nm) values. In adsorption studies, the influence of reaction parameters i.e., catalyst dosage and contact-time for removal of Reactive Green dye is explored along with Langmuir and Freundlich models. The highest adsorption capability is ∼219 mg g^-1 for green dye. TiO₂ displays an excellent photocatalytic efficiency of ∼96% towards the degradation of reactive green dye within 180 min and excellent reusable performance. C. limon/TiO₂ is found to have an outstanding performance with quantum yield value of 4.68 × 10^-5 molecules photon^-1 for Reactive Green dye degradation. Additionally, synthesized nanoparticles have exhibited antimicrobial activity against Gram-positive Staphylococcus aureus (S. aureus) and gram-negative Pseudomonas aeruginosa (P. aeruginosa) bacteria.

Green Synthesized Silver Nanoparticles: A Novel Approach for the Enhanced Growth and Yield of Tomato against Early Blight Disease

Tomato plants are among the most widely cultivated and economically important crops worldwide. Farmers' major challenge when growing tomatoes is early blight disease caused by Alternaria solani, which results in significant yield losses. Silver nanoparticles (AgNPs) have gained popularity recently due to their potential antifungal activity. The present study investigated the potential of green synthesized silver nanoparticles (AgNPs) for enhancing the growth and yield of tomato plants and their resistance against early blight disease. AgNPs were synthesized using leaf extract of the neem tree. Tomato plants treated with AgNPs showed a significant increase in plant height (30%), number of leaves, fresh weight (45%), and dry weight (40%) compared to the control plants. Moreover, the AgNP-treated plants exhibited a significant reduction in disease severity index (DSI) (73%) and disease incidence (DI) (69%) compared to the control plants. Tomato plants treated with 5 and 10 ppm AgNPs reached their maximum levels of photosynthetic pigments and increased the accumulation of certain secondary metabolites compared to the control group. AgNP treatment improved stress tolerance in tomato plants as indicated by higher activities of antioxidant enzymes such as PO (60%), PPO (65%), PAL (65.5%), SOD (65.3%), CAT (53.8%), and APX (73%). These results suggest that using green synthesized AgNPs is a promising approach for enhancing the growth and yield of tomato plants and protecting them against early blight disease. Overall, the findings demonstrate the potential of nanotechnology-based solutions for sustainable agriculture and food security.

Citrus limon phytocompounds decorated nanoparticles control poultry pathogens

Antibiotic resistance poses a significant threat to the global health, food security, and environment. In poultry and livestock, antibiotics are beneficial since they improve poultry performance and are economically effective. Therefore, it is crucial to search for alternatives that can be environmentally safe and successful in treating these infections. In this study, we employed molecular docking to evaluate lemon peel phytochemical's protein binding capability against various poultry pathogens. The nanoparticles (LP AgNPs) obtained from the lemon peel were characterized and tested for their antibacterial activity against more poultry pathogens. LP AgNPs were characterized by using UV-Visible absorption spectra, which revealed an absorption peak at a wavelength of 420-440 nm. The FT-IR analysis demonstrated that flavonoids and phenolic acids acted as capping, reducing, and stabilizing agents during the biosynthesis of AgNPs. EDAX showed a strong peak was observed at 3 keV which revealed the absorption of metallic silver nanoparticles. The mean diameter was from 2 to 20 nm through HRTEM. Zeta potential of the LP AgNps at - 17.2 mV showed the high stability of the green synthesized AgNps. Maximum inhibitory concentrations of LP AgNps against the isolated poultry pathogens were 50 μg/ml concentration. The toxicity tests were performed in the Vigna radiata seedlings and Artemia nauplii, which showed less toxic effects and eco-friendly nature of the LP AgNps. LP AgNps have the potential to treat antibiotic resistant poultry pathogens, thereby paving the way for the development of value-added novel products incorporated with nanoparticles for treating various infection caused by antibiotic-resistant poultry pathogens.

Biomedical and catalytic applications of agri-based biosynthesized silver nanoparticles

Nanotechnology has been recognized as the emerging field for the synthesis, designing, and manipulation of particle structure at the nanoscale. Its rapid development is also expected to revolutionize industries such as applied physics, mechanics, chemistry, and electronics engineering with suitably tailoring various nanomaterials. Inorganic nanoparticles such as silver nanoparticles (Ag-NPs) have garnered more interest with their diverse applications. In correspondence to green chemistry, researchers prioritize green synthetic techniques over conventional ones due to their eco-friendly and sustainable potential. Green-synthesized NPs have proven more beneficial than those synthesized by conventional methods because of capping by secondary metabolites. The present study reviews the various means being used by the researchers for the green synthesis of Ag-NPs. The morphological characteristics of these NPs as obtained from numerous characterization techniques have been explored. The potential applications of bio-synthesized Ag-NPs viz. Antimicrobial, antioxidant, catalytic, and water remediation along with the plausible mechanisms have been discussed. In addition, toxicity analysis and biomedical applications of these NPs have also been reviewed to provide a detailed overview. The study signifies that biosynthesized Ag-NPs can be efficiently used for various applications in the biomedical and industrial sectors as an environment-friendly and efficient tool.

Ultrasound-assisted rapid biological synthesis and characterization of silver nanoparticles using pomelo peel waste

Synthesis of silver nanoparticles by green route is an emerging technique drawing more attention recently because of several advantages over the conventional chemical ways. The overall objective of the research was focused on the green synthesis of silver nanoparticles using pomelo peel waste via a rapid and eco-friendly ultrasonic-assisted technique and their characterization. Different factors affecting the synthesis, like methodology for the preparation of extract and various treatment conditions for the synthesis, were also studied. The developed nanoparticles were characterized for their optical, molecular, microstructural, and physical properties by UV-visible spectroscopy, dynamic light scattering (DLS), zeta-potential measurements, scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). The green synthesized nanoparticles were found almost spherical when treated at room and high temperatures and cubical when treated with ultrasonication. As obtained from the XRD studies, the size of crystallitenanoparticles was 35 to 40 nm in diameter. The EDX, FT-IR, and zeta potential analysis corroborated the role of phenolic compounds in capping and reduction of the metal ion. The capping ability of the polyphenolic component in the extract was used to achieve size stability. The nanoparticles also showed antibacterial activity against gram-negative and gram-positive bacteria, owing to the inherent antibacterial capability of silver nanoparticles.

Antimicrobial Effects of Nanostructured Rare-Earth-Based Orthovanadates

The search for novel antimicrobial agents is of huge importance. Nanomaterials can come to the rescue in this case. The aim of this study was to assess the cytotoxicity and antimicrobial effects of rare-earth-based orthovanadate nanoparticles. The cytotoxicity against host cells and antimicrobial activity of LaVO₄:Eu³⁺ and GdVO₄:Eu³⁺ nanoparticles were analyzed. Effects of nanomaterials on fibroblasts were assessed by MTT, neutral red uptake and scratch assays. The antimicrobial effects were evaluated by the micro-dilution method estimating the minimum inhibitory concentration (MIC) of nanoparticles against various strains of microorganisms, DNA cleavage and biofilm inhibition. GdVO₄:Eu³⁺ nanoparticles were found to be less toxic against eukaryotic cells compared with LaVO₄:Eu³⁺. Both nanoparticles exhibited antimicrobial activity and the highest MIC values were 64 mg/L for E. hirae, E. faecalis and S. aureus shown by GdVO₄:Eu³⁺ nanoparticles. Nanoparticles demonstrated good DNA cleavage activity and induction of double-strand breaks in supercoiled plasmid DNA even at the lowest concentrations used. Both nanoparticles showed the biofilm inhibition activity against S. aureus at 500 mg/L and reduced the microbial cell viability. Taken the results of host toxicity and antimicrobial activity studies, it can be assumed that GdVO₄:Eu³⁺ nanoparticles are more promising antibacterial agents compared with LaVO₄:Eu³⁺ nanoparticles.

A Review on Plants and Microorganisms Mediated Synthesis of Silver Nanoparticles, Role of Plants Metabolites and Applications

Silver nanoparticles are one of the most extensively studied nanomaterials due to their high stability and low chemical reactivity in comparison to other metals. They are commonly synthesized using toxic chemical reducing agents which reduce metal ions into uncharged nanoparticles. However, in the last few decades, several efforts were made to develop green synthesis methods to avoid the use of hazardous materials. The natural biomolecules found in plants such as proteins/enzymes, amino acids, polysaccharides, alkaloids, alcoholic compounds, and vitamins are responsible for the formation of silver nanoparticles. The green synthesis of silver nanoparticles is an eco-friendly approach, which should be further explored for the potential of different plants to synthesize nanoparticles. In the present review we describe the green synthesis of nanoparticles using plants, bacteria, and fungi and the role of plant metabolites in the synthesis process. Moreover, the present review also describes some applications of silver nanoparticles in different aspects such as antimicrobial, biomedicine, mosquito control, environment and wastewater treatment, agricultural, food safety, and food packaging.

Alkhattaf F, Albasher G, A. Aldehaish H. Antifungal, Antibacterial, and Cytotoxic Activities of Silver Nanoparticles Synthesized from Aqueous Extracts of Mace-Arils of Myristica fragrans

In the present study, mace-mediated silver nanoparticles (mace-AgNPs) were synthesized, characterized, and evaluated against an array of pathogenic microorganisms. Mace, the arils of Myristica fragrans, are a rich source of several bioactive compounds, including polyphenols and aromatic compounds. During nano synthesis, the bioactive compounds in mace aqueous extracts serve as excellent bio reductants, stabilizers, and capping agents. The UV-VIS spectroscopy of the synthesized NPs showed an intense and broad SPR absorption peak at 456 nm. Dynamic light scattering (DLS) analysis showed the size with a Z average of 50 nm, while transmission electron microscopy (TEM) studies depicted the round shape and small size of the NPs, which ranged between 5-28 nm. The peaks related to important functional groups, such as phenols, alcohols, carbonyl groups, amides, alkanes and alkenes, were obtained on a Fourier-transform infrared spectroscopy (FTIR) spectrum. The peak at 3 keV on the energy dispersive X-ray spectrum (EDX) validated the presence of silver (Ag). Mace-silver nanoparticles exhibited potent antifungal and antibacterial activity against several pathogenic microorganisms. Additionally, the synthesized mace-AgNPs displayed an excellent cytotoxic effect against the human cervical cancer cell line. The mace-AgNPs demonstrated robust antibacterial, antifungal, and cytotoxic activity, indicating that the mace-AgNPs might be used in the agrochemical industry, pharmaceutical industry, and biomedical applications. However, future studies to understand its mode of action are needed.

The Second Life of Citrus Fruit Waste: A Valuable Source of Bioactive Compounds

Citrus fruits (CF) are among the most widely cultivated fruit crops throughout the world and their production is constantly increasing along with consumers' demand. Therefore, huge amounts of waste are annually generated through CF processing, causing high costs for their disposal, as well as environmental and human health damage, if inappropriately performed. According to the most recent indications of an economic, environmental and pharmaceutical nature, CF processing residues must be transformed from a waste to be disposed to a valuable resource to be reused. Based on a circular economy model, CF residues (i.e., seeds, exhausted peel, pressed pulp, secondary juice and leaves) have increasingly been re-evaluated to also obtain, but not limited to, valuable compounds to be employed in the food, packaging, cosmetic and pharmaceutical industries. However, the use of CF by-products is still limited because of their underestimated nutritional and economic value, hence more awareness and knowledge are needed to overcome traditional approaches for their disposal. This review summarizes recent evidence on the pharmacological potential of CF waste to support the switch towards a more environmentally sustainable society.

Innovative Delivery Systems Loaded with Plant Bioactive Ingredients: Formulation Approaches and Applications

Plants constitute a rich source of diverse classes of valuable phytochemicals (e.g., phenolic acids, flavonoids, carotenoids, alkaloids) with proven biological activity (e.g., antioxidant, anti-inflammatory, antimicrobial, etc.). However, factors such as low stability, poor solubility and bioavailability limit their food, cosmetics and pharmaceutical applications. In this regard, a wide range of delivery systems have been developed to increase the stability of plant-derived bioactive compounds upon processing, storage or under gastrointestinal digestion conditions, to enhance their solubility, to mask undesirable flavors as well as to efficiently deliver them to the target tissues where they can exert their biological activity and promote human health. In the present review, the latest advances regarding the design of innovative delivery systems for pure plant bioactive compounds, extracts or essential oils, in order to overcome the above-mentioned challenges, are presented. Moreover, a broad spectrum of applications along with future trends are critically discussed.

Silver Nanoparticle-Coated Ethyl Cellulose Inhibits Tumor Necrosis Factor-α of Breast Cancer Cells

Introduction

Cancer is one of the leading causes of death worldwide. In many cases, cancer is related to the elevated expression of a significant cytokine known as tumor necrosis factor-α (TNF-α). Breast cancer in particular is linked to increased proliferation of tumor cells, high incidence of malignancies, more metastases, and generally poor prognosis for the patient. The research sought to assess the effect of silver nanoparticles reduced with ethyl cellulose polymer (AgNPs-EC) on TNF-α expression in MCF-7 human breast cancer cells.

Methods

The AgNPs-EC were produced using the green synthesis reduction method, and their formation was proofed via UV–VIS spectroscopy. Furthermore, AgNPs-EC were characterized for their size, charge, morphology, Ag ion release, and stability. The MCF-7 cells were treated with AgNPs-EC. Then, the expression of TNF-α genes was determined through PCR in real time, and protein expression was studied using ELISA.

Results

The AgNPs-EC were spherical with an average size of 150±5.1 nm and a zeta-potential of −41.4±0.98 mV. AgNPs-EC had an inhibitory effect on cytokine mRNA and protein expression levels, which suggests that they could be used safely in the fight against cancer. AgNPs-EC cytotoxicity was also found to be non-toxic to MCF-7.

Conclusion

Our data determined AgNPs-EC as a novel inhibitor of TNF-α production. These results are promising for developing novel therapeutic approaches for the future treatment of cancer with safe materials.

Characterization and Evaluation of Multiple Biological Activities of Silver Nanoparticles Fabricated from Dragon Tongue Bean Outer Peel Extract

BACKGROUND

The dragon tongue beans are a legume belonging to the Fabaceae family, are rich in protein, starch, fiber, and other micronutrients that have numerous health-promoting benefits. Its peel commonly the waste parts also contains lots of bioactive compounds.

MATERIALS AND METHODS

In the current research, dragon tongue bean peels (DtbP) extract is tested for the existence of phytochemicals. Ag nanoparticles are biosynthesized using DtbP extract. The generated DtbP silver nanoparticle characterization was accomplished using UV-Vis spectral analysis, FTIR spectral analysis, SEM analysis, EDX analysis, XRD analysis, zeta potential, and DLS study. Furthermore, comparative assessment on multi-biological activities of the biosynthesized Ag nanoparticles was accomplished by employing cytotoxicity (inhibition against HepG2 cancer cells), antidiabetic (α-glucosidase inhibition assay), and antioxidant (free-radical scavenging) analysis.

RESULTS

The characterization result of the DtbP-AgNPs demonstrated that the AgNPs synthesized within 24 h. The AgNPs are nearly spherical. The biological effect assay of AgNPs displayed that DtbP-AgNPs is having significant cytotoxicity, antidiabetic, and moderate antioxidant effect. This study results as a whole report the biosynthesis of DtbP-AgNPs utilizing the legume dragon tongue bean waste peel and assessment of their multiple biological activities. The synthesized DtbP-AgNPs could serve as a potential candidate in the pharmaceutical industries in the formulation of drugs for the treatment of several medical ailments concerning cancer, diabetes, etc.