Antimicrobial and Cytotoxicity Effects of Synthesized Silver Nanoparticles from Punica granatum Peel Extract

Advances in silver nanoparticles: a comprehensive review on their potential as antimicrobial agents and their mechanisms of action elucidated by proteomics

Nanoparticles play a crucial role in the field of nanotechnology, offering different properties due to their surface area attributed to their small size. Among them, silver nanoparticles (AgNPs) have attracted significant attention due to their antimicrobial properties, with applications that date back from ancient medicinal practices to contemporary commercial products containing ions or silver nanoparticles. AgNPs possess broad-spectrum biocidal potential against bacteria, fungi, viruses, and Mycobacterium, in addition to exhibiting synergistic effects when combined with certain antibiotics. The mechanisms underlying its antimicrobial action include the generation of oxygen-reactive species, damage to DNA, rupture of bacterial cell membranes and inhibition of protein synthesis. Recent studies have highlighted the effectiveness of AgNPs against various clinically relevant bacterial strains through their potential to combat antibiotic-resistant pathogens. This review investigates the proteomic mechanisms by which AgNPs exert their antimicrobial effects, with a special focus on their activity against planktonic bacteria and in biofilms. Furthermore, it discusses the biomedical applications of AgNPs and their potential non-preparation of antibiotic formulations, also addressing the issue of resistance to antibiotics.

Pomegranate peel: Bioactivities as antimicrobial and cytotoxic agents

This is a comparative study to evaluate the effectiveness of six pomegranate peel extracts (PPEs) as antibacterial and antiproliferative agents. The Six PPEs were prepared using four solvent systems and each filtrate was concentrated to a gummy material to be used in the evaluation. The well-diffusion method was used to evaluate their antimicrobial activity against bacteria typically associated with food spoilage: Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus aureus, and three Bacillus species. The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTT) was used to evaluate the cytotoxicity against colorectal carcinoma cells (HCT116), prostate adenocarcinoma (PC3), ovarian cancer cells (SKOV-3), and fibroblasts (MRC-5). The antioxidant evaluation was done using the 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH) assay. The pH of the water-containing extracts was acidic and almost the same over 6 weeks. The six PPEs inhibited the bacterial growth in a comparable level to standard antibiotics. The effectiveness of each extract was dependent on the bacterial strain, and the Listeria showed a remarkable inhibition when exposed to the aqueous extract prepared at room temperature (RT). The aqueous (RT) and methanol PPEs had a significant antioxidant scavenging capability and a remarkable cytotoxic activity against the PC3 with half maximal inhibitory concentration (IC50) of 0.1 μg/mL. The boiled aqueous extract exhibited antiproliferative activity against HCT116 with an IC50 of 21.45 μg/mL. The effect on SKOV-3 and fibroblasts was insignificant. With the exception of butanol, the antioxidant screening shows an inverse correlation between the polarity of the extraction solvent and the IC50 exhibited by the PPEs. The variation in the effectiveness of PPEs is suggested to be due to variable soluble bioactive compounds that may interact differently with different cells, though water-containing extracts are promising antibacterial agents. The findings clearly show that pomegranate peel possessed the potential to be an eco-friendly novel source for natural compounds that can be implemented in the food industry as a natural antimicrobial and natural food additive to prevent foodborne illnesses.

Evaluation of biological potential of UV-spectrophotometric, SEM, FTIR, and EDS observed Punica granatum and Plectranthus rugosus extract-coated silver nanoparticles: A comparative study

Recent developments in the green synthesis of metallic nanoparticles (NPs) using phytoconstituents have attracted the attention of the global scientific community. The present study was designed to synthesize silver NPs (AgNPs) using Punica granatum and Plectranthus rugosus plant extracts. The fabricated AgNPs were characterized using UV-visible spectrophotometry (UV-Vis), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDS). The shift in the color of the silver nitrate (AgNO3 ) solution after the addition of P. granatum and P. rugosus extracts indicated the synthesis of AgNPs. The effect of AgNO3 concentrations and pH on the synthesis of AgNPs was also evaluated. The findings of this study suggest that AgNO3 concentration of 1 mM, reaction time of 1 h, and pH of 7 at room temperature were the best suited conditions for the synthesis of AgNPs. According to the FTIR analysis, amidic and carbonyl compounds were primarily responsible for the encapsulation of AgNPs. SEM investigations have shown irregularly shaped geometry with sizes of 35 nm (P. granatum) and 33 nm (P. rugosus) with low agglomeration. The prepared AgNPs exhibited good potential for 2,2-diphenyl-1-picrylhydrazyl radical scavenging, with values of 70% (P. granatum) and 68% (P. rugosus). Hence, we conclude that the leaves of P. granatum and P. rugosus are excellent material for designing of different plant-extracted-conjugated AgNPs for biomedical applications. RESEARCH HIGHLIGHTS: Preparation of the AgNPs using novel plants extracts. P. granatum and P. rugosus extract as reducing, capping, stabilizing, and optimizing agents. Thorough comparative characterization using UV-Vis spectrophotometer, FTIR, SEM, and EDS which is a first of its kind. Comparative antioxidant activity.

Therapeutic Potential of Punica granatum and Isolated Compounds: Evidence-Based Advances to Treat Bacterial Infections

Punica granatum Linn has been known for its nutritional and medicinal value since ancient times and is used in the treatment of various pathologies owing to its antibacterial properties. This review reports the results of the most recent studies on the antibacterial effects of P. granatum and its isolated compounds on bacteria of clinical interest. A search in the PubMed, Scopus, Science Direct, and Science Citation Index Expanded (Web of Science) databases was performed, which included articles that evaluated the antibacterial activity of P. granatum extracts and excluded articles that analyzed other microorganisms or nonpathogenic bacteria, as well as theses, dissertations, duplicate articles, and those not fully available. The literature suggests that P. granatum extracts can act on bacteria, such as methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. In addition, fruit peel was the most commonly used pharmacogen and methanol, ethanol, and water were the most common solvents for the extraction of bioactive compounds. The antibacterial potential of the methanolic extract of pomegranate peel could be attributed to the presence of active compounds, such as 5-hydroxymethylfurfural, punicic acid, gallic acid, and punicalagin. Thus, there is evidence that these plant extracts, having high polyphenol content, can disrupt the bacterial plasma membrane and inhibit the action of proteins related to antimicrobial resistance. P. granatum shows antibacterial activity against Gram-positive and Gram-negative bacteria, with great potential against multidrug-resistant strains. Further research is needed to clarify the mechanism of action related to this biological activity and investigate the isolated substances that may be responsible for the antibacterial effects.

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.

Application of Conductive Hydrogels on Spinal Cord Injury Repair: A Review

Spinal cord injury (SCI) causes severe motor or sensory damage that leads to long-term disabilities due to disruption of electrical conduction in neuronal pathways. Despite current clinical therapies being used to limit the propagation of cell or tissue damage, the need for neuroregenerative therapies remains. Conductive hydrogels have been considered a promising neuroregenerative therapy due to their ability to provide a pro-regenerative microenvironment and flexible structure, which conforms to a complex SCI lesion. Furthermore, their conductivity can be utilized for noninvasive electrical signaling in dictating neuronal cell behavior. However, the ability of hydrogels to guide directional axon growth to reach the distal end for complete nerve reconnection remains a critical challenge. In this Review, we highlight recent advances in conductive hydrogels, including the incorporation of conductive materials, fabrication techniques, and cross-linking interactions. We also discuss important characteristics for designing conductive hydrogels for directional growth and regenerative therapy. We propose insights into electrical conductivity properties in a hydrogel that could be implemented as guidance for directional cell growth for SCI applications. Specifically, we highlight the practical implications of recent findings in the field, including the potential for conductive hydrogels to be used in clinical applications. We conclude that conductive hydrogels are a promising neuroregenerative therapy for SCI and that further research is needed to optimize their design and application.

Antimicrobial and Antiproliferative Activity of Green Synthesized Silver Nanoparticles Using Bee Bread Extracts

Bee bread (BB) is a fermented mixture of bee pollen, is rich in proteins, amino acids, fatty acids, polyphenols, flavonoids, as well as other bioactive compounds, and is considered functional food for humans. In this study, we explored an innovative green synthesis of colloidal silver nanoparticles, using BB extracts as reducing and stabilizing agents. A preliminary chemical characterization of the BB extracts was conducted. The plasmonic response of the as-synthesized silver nanoparticles (BB-AgNPs) was evaluated by UV-Vis spectroscopy, while their hydrodynamic diameter and zeta potential were investigated by dynamic light spectroscopy (DLS). Transmission electron microscopy (TEM) analysis pointed out polydisperse NPs with quasi-spherical shapes. The newly synthesized nanoparticles showed good antioxidant activity against the tested free radicals, DPPH, ABTS^•+, and FRAP, the best results being obtained in the case of ABTS^•+. BB-AgNPs exhibited good antibacterial activity on the tested Gram-positive and Gram-negative bacterial strains: herein S. aureus, B. cereus, E. faecalis, E. coli, P. aeruginosa, S. enteritidis, and on yeast C. albicans, respectively. The inhibition diameters varied between 7.67 ± 0.59 and 22.21 ± 1.06 mm, while the values obtained for minimum inhibitory concentration varied between 0.39 and 6.25 µg/mL. In vitro antiproliferative activity was tested on colon adenocarcinoma, ATCC HTB-37 cell line, and the results have shown that the green synthetized BB-AgNPs induced a substantial decrease in tumor cell viability in a dose-dependent manner with an IC50 ranging from 24.58 to 67.91 µg/mL. Consequently, more investigation is required to comprehend the processes of the cytotoxicity of AgNPs and develop strategies to mitigate their potentially harmful effects while harnessing their antimicrobial properties.

In vitro investigation of silver nanoparticles synthesized using Gracilaria veruccosa - A seaweed against multidrug resistant Staphylococcusaureus

In recent years, the biosynthesis of silver (Ag) nanoparticles has attracted a great deal of interest for applications in biomedicine and bioremediation. In the present study, Gracilaria veruccosa extract was used to synthesize Ag nanoparticles for investigating their antibacterial and antibiofilm potentials. The color shift from olive green to brown indicated the synthesis of AgNPs by plasma resonance at 411 nm. Physical and chemical characterization revealed that AgNPs of 20-25 nm sizes were synthesized. Detecting functional groups, such as carboxylic acids and alkenes, suggested that the bioactive molecules in the G. veruccosa extract assisted the synthesis of AgNPs. X-ray diffraction verified the s purity and crystallinity of the AgNPs with an average diameter of 25 nm, while DLS analysis showed a negative surface charge of -22.5 mV. Moreover, AgNPs were tested in vitro for antibacterial and antibiofilm efficacies against S. aureus. The minimum inhibitory concentration (MIC) of AgNPs against S. aureus was 3.8 μg/mL. Light and fluorescence microscopy proved the potential of AgNPs to disrupt the mature biofilm of S. aureus. Therefore, the present report has deciphered the potential of G. veruccosafor the synthesis of AgNPs and targeted the pathogenic bacteria S. aureus.

Biosynthesis and characterization of polysaccharide-capped silver nanoparticles from Acalypha indica L. and evaluation of their biological activities

Biosynthesized silver nanoparticles (AgNPs) are gaining popularity due to their distinctive biological applications. In this research work, an eco-friendly method of synthesizing AgNPs from the leaf polysaccharide (PS) of Acalypha indica L. ( A. indica) was carried out. Synthesis of polysaccharide-AgNPs (PS-AgNPs) was indicated by visual detection of colour change from pale yellow to light brown. The PS-AgNPs were characterized with different techniques and further evaluated for biological activities. The Ultra violet-visible (UV-Vis.) spectroscopy expressed a sharp absorption peak at 415 nm confirmed the synthesis. Atomic force microscopy (AFM) analysis revealed the size range of particles from 14 nm to 85 nm. Fourier transform infrared (FTIR) analysis detected the presence of various functional groups. The cubic crystalline structure of PS-AgNPs was confirmed by X-ray diffraction (XRD) and the particles were found to be oval to polymorphic shaped through transmission electron microscopy (TEM) with sizes from 7.25 nm to 92.51 nm. Energy dispersive X-ray (EDX) determined the presence of silver in PS-AgNPs. The zeta potential was -28.0 mV, which confirmed the stability and an average particle size of 62.2 nm was calculated through dynamic light scattering (DLS). Lastly, the thermo gravimetric analysis (TGA) showed the PS-AgNPs were resistant to high temperature. The PS-AgNPs exhibited significant free radical scavenging activity with an IC₅₀ value of 112.91 μg/ml. They were highly capable of inhibiting the growth of different bacterial and plant fungal pathogens and also active to reduce the cell viability of prostate cancer (PC-3) cell line. The IC₅₀ value was 101.43 μg/ml. The flow cytometric apoptosis analysis revealed the percentage of viable, apoptotic and necrotic cells of PC-3 cell line. According to this evaluation, it can be concluded that these biosynthesized and environmentally friendly PS-AgNPs are helpful to improve therapeutics because of significant antibacterial, antifungal, antioxidant, and cytotoxic properties to open up new possibilities for euthenics.

UPLC‒ESI‒MS/MS profiling of active polyphenolics in Morinda coreia leaf extract and in vitro antioxidant and antibacterial activity

In this study, aqueous and methanol extracts of Morinda coreia (MC) leaves were tested for antioxidant and antibacterial activity under in vitro conditions. Phytochemical analysis using UPLC-ESI-MS revealed the presence of phenolics, flavonoids, alkaloids, glycosides, amino acids, proteins, saponins, and tannins. Under in vitro conditions, antioxidant test using DPPH, ABTS, and reducing power demonstrated that the plant leaves play a crucial role in antioxidant activity compared to the commercial antioxidant butylated hydroxytoluene (BHT). The ABTS and DPPH free radical scavenging activities showed that the IC₅₀ values of the M. coreia methanol extract were 26.35 μg/mL and 200.23 μg/mL, respectively. The methanol extract of M. coreia contained higher levels of total phenols and flavonoids and higher free radical scavenging capacity than the aqueous extract. FTIR analysis of the methanol extract showed a substantial number of phenols in the functional groups of M. coreia leaves. The well diffusion assay using the methanolic extract of M. coreia (200 μg/mL) leaves showed antibacterial activity against Pseudomonas aeruginosa (19 ± 0.85 mm), Proteus sp. (20 ± 0.97 mm), Streptococcus sp. (21 ± 1.29 mm), and Enterobacter sp. (17 ± 0.2 mm). Thus, the present study revealed that the antibacterial and antioxidant activity of M. coreia leaf extract was due to the presence of 18 unknown and 15 primary known polyphenols.

The Therapeutic Alliance between Pomegranate and Health Emphasizing on Anticancer Properties

Pomegranate is a fruit bearing-plant that is well known for its medicinal properties. Pomegranate is a good source of phenolic acids, tannins, and flavonoids. Pomegranate juice and by-products have attracted the scientific interest due to their potential health benefits. Currently, the medical community has showed great interest in exploiting pomegranate potential as a protective agent against several human diseases including cancer. This is demonstrated by the fact that there are more than 800 reports in the literature reporting pomegranate's anticancer properties. This review is an update on the research outcomes of pomegranate's potential against different types of human diseases, emphasizing on cancer. In addition, perspectives of potential applications of pomegranate, as a natural additive aiming to improve the quality of animal products, are discussed.

Eco-friendly Green Synthesis of Silver Nanoparticles from Leaf Extract of Solanum khasianum: Optical Properties and Biological Applications

The green synthesis of silver nanoparticles (AgNPs) was considered to be efficacious over other approaches due to their eco-friendliness, cost-effectiveness, and high stability. The biosynthesis of AgNPs was achieved by the reduction of silver nitrate using the aqueous leaf extract of Solanum khasianum. The biosynthesized AgNPs were examined by a color change and UV-Vis spectroscopy with an absorption spectrum at 440 nm. The biomolecules existing in S. khasianum leaf extract accountable for bioreduction and capping of AgNPs were analyzed by FTIR analysis and confirmed the presence of alcohols, phenols, alkanes, carboxylic acid, nitro compounds, and amines. The crystalline nature of Sk-AgNPs with face-centered cubic lattice was confirmed by X-ray diffraction (XRD) spectrum. The average crystallite size of Sk-AgNPs was computed as 15.96 nm. The lattice constant, unit cell volume, and spacing values of Sk-AgNPs were parallel to the values indexed in the Joint Committee on Powder Diffraction Standard of silver (JCPDS-04-0783). Scanning electron microscope (SEM) imaging witnessed the spherical structure of synthesized AgNPs. Energy dispersive X-ray (EDX) spectrum acknowledged the AgNPs fabrication with strong signals of silver atoms at 3 keV energy. The biofabricated Sk-AgNPs showed a photoluminescence (PL) emission spectrum of 445 nm with an excitation at 330 nm. Sk-AgNPs showed considerable DPPH radical scavenging activity (87.98%) than BHT (86.14%) and also exhibited significant antidiabetic activity compared to acarbose. Sk-AgNPs revealed antibacterial potentiality against B. sphaericus, E. coli, S. aureus, and P. fluorescens. Moreover, Sk-AgNPs showed dose-dependent cytotoxicity against MCF-7 cell line. This method of green synthesis would support the eco-friendly fabrication of AgNPs from S. khasianum leaf extract with considerable therapeutic activities.

Nano-delivery systems for encapsulation of phenolic compounds from pomegranate peel

Pomegranate fruit is getting more attention due to its positive health effects, and pomegranate peel (PP) is its main byproduct. PP has the potential to be converted from environmentally polluting waste to wealth due to its rich phenolic compounds such as ellagitannins, proanthocyanidins, and flavonoids with antioxidant, antimicrobial, and health effects. These phenolics are susceptible to environmental conditions such as heat, light, and pH as well as in vivo conditions of gastrointestinal secretions. Some phenolics of PP, e.g., ellagitannins could interfere with food ingredients and thus reduce their beneficial effects. Also, ellagitannins could form complexes with salivary glycoproteins, then a feeling of astringency taste. In this article, nano-delivery systems such as nanoparticles, nanoemulsions, and vesicular nanocarriers, designed and fabricated for PP bioactive compounds in recent years have been reviewed. Among them, lipid-based nano carriers i.e., solid lipid nanoparticles, nanostructured lipid carriers, and vesicular nanocarriers have low toxicity, large-scale production feasibility, easy synthesis, and high biocompatibility. So, it seems that the extraction and purification of bioactives from pomegranate wastes and nanoencapsulating them with cost effective and generally recognized as safe (GRAS) materials can be a bright prospect in enhancing the quality, safety, shelf life and health benefits of pomegranate products.

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

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

Antimicrobial Activity of Silver and Gold Nanoparticles Prepared by Photoreduction Process with Leaves and Fruit Extracts of Plinia cauliflora and Punica granatum

The increased number of resistant microbes generates a search for new antibiotic methods. Metallic nanoparticles have emerged as a new platform against several microorganisms. The nanoparticles can damage the bacteria membrane and DNA by oxidative stress. The photoreduction process is a clean and low-cost method for obtaining silver and gold nanoparticles. This work describes two original insights: (1) the use of extracts of leaves and fruits from a Brazilian plant Plinia cauliflora, compared with a well know plant Punica granatum, and (2) the use of phytochemicals as stabilizing agents in the photoreduction process. The prepared nanoparticles were characterized by UV-vis, FTIR, transmission electron microscopy, and Zeta potential. The antimicrobial activity of nanoparticles was obtained with Gram-negative and Gram-positive bacteria, particularly the pathogens Staphylococcus aureus ATCC 25923; Bacillus subtilis ATCC 6633; clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecalis; Escherichia coli ATCC 25922; Escherichia coli O44:H18 EAEC042 (clinical isolate); Klebsiella pneumoniae ATCC 700603, Salmonella Thiphymurium ATCC 10231; Pseudomonas aeruginosa ATCC 27853; and Candida albicans ATCC 10231. Excellent synthesis results were obtained. The AgNPs exhibited antimicrobial activities against Gram-negative and Gram-positive bacteria and yeast (80–100%), better than AuNPs (0–87.92%), and may have the potential to be used as antimicrobial agents.

Optimization, Characterization, and Anticancer Potential of Silver Nanoparticles Biosynthesized Using Olea europaea

Green synthesis has attracted significant attention as an eco-friendly, low-cost, energy-efficient, and non-toxic method for preparing silver nanoparticles (AgNPs) for cancer therapy. This study optimized the green synthesis of AgNPs using Olea europaea extracts and evaluated their anticancer potential. The biosynthesized AgNPs were characterized using various methods, showing stable AgNPs with a desirable morphology and high yield, improving the properties of AgNPs for various medicinal applications. The biosynthesized AgNPs were predominantly spherical, with small sizes ranging from 13 to 21 nm and highly stable at −23 and −24 mV. The findings of this study suggest that green-synthesized AgNPs using Olea europaea and sunlight possess significant anticancer activity against cancer cells in vitro. Further investigation of green synthesis would help to form high-quality AgNPs that have promising potential in treating disease and fighting undesirable pathogens.

Natural Antioxidant, Antibacterial, and Antiproliferative Activities of Ethanolic Extracts from Punica granatum L. Tree Barks Mediated by Extracellular Signal-Regulated Kinase

The nonedible parts of the pomegranate plant, such as tree barks and fruit peels, have pharmacological properties that are useful in traditional medicine. To increase their value, this study aimed to compare the antioxidative and antibacterial effects of ethanolic extracts from pomegranate barks (PBE) and peels (PPE). The antiproliferative effects on HeLa and HepG2 cells through the extracellular signal-regulated kinase pathway were also evaluated. The results indicated that the total amounts of phenolics and flavonoids of PBE and PPE were 574.64 and 242.60 mg equivalent gallic acid/g sample and 52.98 and 23.08 mg equivalent quercetin/g sample, respectively. Gas chromatography−mass spectrometry revealed that 5-hdroxymethylfurfural was the major component of both PBE (23.76%) and PPE (33.19%). The 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical scavenging capacities of PBE and PPE, in terms of the IC50 value, were 4.1 and 9.6 µg/mL, respectively. PBE had a greater potent antibacterial effect against Escherichia coli, Staphylococcus aureus, Salmonella Enteritidis, and S. Typhimurium. PBE and PPE (1000 µg/mL) had exhibited no cytotoxic effects on LLC-MK2. PBE and PPE (250 and 1000 µg/mL, respectively) treatments were safe for BHK-21. Both extracts significantly inhibited HepG2 and HeLa cell proliferations at 10 and 50 µg/mL, respectively (p < 0.001). The results indicated that PBE and PPE have remarkable efficiencies as free radical scavengers and antibacterial agents, with PBE exhibiting greater efficiency. The inhibitory effects on HepG2 might be through the modulation of the ERK1/2 expression. PBE and PPE have the potential for use as optional supplementary antioxidative, antibacterial, and anticancer agents.

Central Composite Design (CCD) for the Optimisation of Ethosomal Gel Formulation of Punica granatum Extract: In Vitro and In Vivo Evaluations

This research manuscript’s objective was to develop the Punica granatum extract ethosome gel. The use of nanotechnology can improve transdermal drug delivery permeation of its major bioactive compound β-sitosterol. The optimised and developed formulations were further studied in vitro and in vivo. The assessment of the anti-inflammatory activity of the gel was performed in Albino rats. Methanolic extract was prepared and developed into an ethosome suspension and an ethosome gel. To optimise the formulation’s response in terms of particle size (nm) and entrapment efficiency (%), the central composite design (CCD) was used in 2² levels. The effects of factors such as lecithin (%) and ethanol (mL) in nine formulations were observed. Characterisation of ethosome gel was performed and the results showed the particle size (516.4 nm) and mean zeta potential (−45.4 mV). Evaluations of the gel formulation were performed. The results were good in terms of pH (7.1), viscosity (32,158 cps), spreadability (31.55 g cm/s), and no grittiness. In an in vitro study, the percentages of β-sitosterol release of ethosome gel (91.83%), suspension (82.74%), and extracts (68.15%) at 279 nm were recorded. The effects of the formulated gel on formalin-induced oedema in Albino rats showed good results in terms of anti-inflammatory activity. The comparative anti-inflammatory activity of Punica granatum extract and gel showed that the gel action was good for their topical application.

Investigation of Cytotoxicity of Biosynthesized Colloidal Nanosilver against Local Leishmania tropica: In Vitro Study

Leishmaniasis is one of the biggest health problems in the world. Traditional therapeutic methods still depend on a small range of products, mostly chemically. However, the treatment with these drugs is expensive and can cause serious adverse effects, and they have inconsistent effectiveness due to the resistance of parasites to these drugs. The treatment of leishmanial disease has always been a challenge for researchers. The development of nanoscale metals such as silver has attracted significant attention in the field of medicine. The unique characteristic features of silver nanoparticles (AgNPs) make them effective antileishmanial agents. In recent years, green nanotechnology has provided the development of green nanoparticle-based treatment methods for Leishmaniasis. Although there are many studies based on green nanoparticles against Leishmania parasites, this is the first study on the antileishmanial effect of biosynthesized AgNPs using an aqueous extract of Eucalyptus camaldulensis leaves (AEECL) as a reducing agent of silver ions. Different parameters such as AgNO3 concentration, AEECL concentration, and reaction time were studied to investigate the optimum factors for the preparation of stable and small-sized silver nanoparticles. The spherical shape of colloidal nanosilver (CN-Ag) was confirmed by atomic force microscope (AFM) and scanning electron microscope (SEM) images with sizes of 27 and 12 nm, respectively. A high density of nanoparticles with a small size of 10 nm has been confirmed from dynamic light scattering (DLS) analysis. The zeta potential value of 23 mV indicated that colloidal silver nanoparticles were stable. The nano-tracker analysis (NTA) showed the Brownian motion of silver nanoparticles with a hydrodynamic diameter of 31 nm. The antioxidant property of CN-Ag was determined using the stable radical 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay. In this study, a significant cytotoxic effect of biosynthesized CN-Ag has been shown against Leishmania tropica parasites at low concentrations (1.25, 2.5, and 3.75 µg/mL). These results could be used as a future alternative drug or could be a supportive treatment for Leishmaniasis.

Nanoencapsulation of Eggplant (Solanum melongena L.) Peel Extract in Electrospun Gelatin Nanofiber: Preparation, Characterization, and In Vitro Release

This study describes the preparation and characterization of eggplant peel extract-loaded electrospun gelatin nanofiber and study of its in vitro release. Results obtained by scanning electron microscopy (SEM) and transmission electronic microscopy (TEM) micrograph revealed that eggplant peel extract-loaded electrospun gelatin nanofiber is in nanometric range with an average diameter 606.7 ± 184.5 and 643.6 ± 186.7 nm for 20 and 33.3 mg mL⁻¹ of extract addition, respectively. Moreover, the incorporation of extract improved morphology by being smooth, homogeneous, and without account formation compared to nanofibers without extract (control). Fourier transform-infrared (FT-IR) spectra indicated that interaction exists between electrospun gelatin nanofiber and eggplant peel extract by hydrogen bond interactions, mainly. Electrospun gelatin nanofibers showed encapsulation efficiency greater than 90% of extract and a maximum release of 95 and 80% for the medium at pH 1.5 and 7.5, respectively. Therefore, the electrospinning technique is a good alternative for the conservation of bioactive compounds present in the eggplant peel through electrospun gelatin nanofiber.

Synergistic Antifungal Efficiency of Biogenic Silver Nanoparticles with Itraconazole against Multidrug-Resistant Candidal Strains

Fungal infections caused by multidrug-resistant strains are considered one of the leading causes of morbidity and mortality worldwide. Moreover, antifungal medications used in conventional antifungal treatment revealed poor therapeutic effectiveness and possible side effects such as hepatotoxicity, nephrotoxicity, and myelotoxicity. Therefore, the current study was developed to determine the antifungal effectiveness of green synthesized silver nanoparticles (AgNPs) and their synergistic efficiency with antifungal drugs against multidrug-resistant candidal strains. The AgNPs were greenly synthesized using the aqueous peel extract of Punica granatum. In addition, AgNPs were characterized using ultraviolet-visible spectrophotometry (UV/Vis), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), and zeta potential analysis. In this regard, UV-vis analysis indicated SPR of AgNPs at 396 nm, while the particle size distribution revealed that the average particle size was 18.567 ± 1.46 nm. The surface charge of AgNPs was found to be −15.6 mV, indicating their stability in aqueous solutions. The biofabricated AgNPs indicated antifungal activity against Candida tropicalis, C. albicans, and C. glabrata strains showing inhibitory zone diameters of 23.78 ± 0.63, 21.38 ± 0.58, and 16.53 ± 0.21 mm, respectively while their minimum inhibitory concentration (MIC) was found to be 2.5 µg/mL against C. tropicalis strain. AgNPs and itraconazole revealed the highest synergistic activity against the multidrug-resistant strain, C. glabrata, recording a synergism percentage of 74.32%. In conclusion, the biogenic AgNPs in combination with itraconazole drug exhibited potential synergistic activity against different candidal strains indicating their potential usage in the bioformulation of highly effective antifungal agents.

A Critical Review of the Antimicrobial and Antibiofilm Activities of Green-Synthesized Plant-Based Metallic Nanoparticles

Metallic nanoparticles (MNPs) produced by green synthesis using plant extracts have attracted huge interest in the scientific community due to their excellent antibacterial, antifungal and antibiofilm activities. To evaluate these pharmacological properties, several methods or protocols have been successfully developed and implemented. Although these protocols were mostly inspired by the guidelines from national and international regulatory bodies, they suffer from a glaring absence of standardization of the experimental conditions. This situation leads to a lack of reproducibility and comparability of data from different study settings. To minimize these problems, guidelines for the antimicrobial and antibiofilm evaluation of MNPs should be developed by specialists in the field. Being aware of the immensity of the workload and the efforts required to achieve this, we set out to undertake a meticulous literature review of different experimental protocols and laboratory conditions used for the antimicrobial and antibiofilm evaluation of MNPs that could be used as a basis for future guidelines. This review also brings together all the discrepancies resulting from the different experimental designs and emphasizes their impact on the biological activities as well as their interpretation. Finally, the paper proposes a general overview that requires extensive experimental investigations to set the stage for the future development of effective antimicrobial MNPs using green synthesis.

First Report of the Biosynthesis and Characterization of Silver Nanoparticles Using Scabiosa atropurpurea subsp. maritima Fruit Extracts and Their Antioxidant, Antimicrobial and Cytotoxic Properties

Candida and dermatophyte infections are difficult to treat due to increasing antifungal drugs resistance such as fluconazole, as well as the emergence of multi-resistance in clinical bacteria. Here, we first synthesized silver nanoparticles using aqueous fruit extracts from Scabiosa atropurpurea subsp. maritima (L.). The characterization of the AgNPs by means of UV, XRD, FTIR, and TEM showed that the AgNPs had a uniform spherical shape with average sizes of 40–50 nm. The biosynthesized AgNPs showed high antioxidant activity when investigated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The AgNPs displayed strong antibacterial potential expressed by the maximum zone inhibition and the lowest MIC and MBC values. The AgNPs revealed a significant antifungal effect against the growth and biofilm of Candida species. In fact, the AgNPs were efficient against Trichophyton rubrum, Trichophyton interdigitale, and Microsporum canis. The antifungal mechanisms of action of the AgNPs seem to be due to the disruption of membrane integrity and a reduction in virulence factors (biofilm and hyphae formation and a reduction in germination). Finally, the silver nanoparticles also showed important cytotoxic activity against the human multiple myeloma U266 cell line and the human breast cancer cell line MDA-MB-231. Therefore, we describe new silver nanoparticles with promising biomedical application in the development of novel antimicrobial and anticancer agents.

Activity of Silver Nanoparticles against Staphylococcus spp

Staphylococcus epidermidis is a bacterium that is part of the human microbiota. It is most abundant on the skin, in the respiratory system and in the human digestive tract. Also, Staphylococcus aureus contributes to human infections and has a high mortality rate. Both of these bacterial species produce biofilm, a pathogenic factor increasing their resistance to antibiotics. For this reason, we are looking for new substances that can neutralize bacterial cells. One of the best-known substances with such effects are silver nanoparticles. They exhibited antibacterial and antibiofilm formation activity that depended on their size, shape and the concentration used. In this review, we presented the data related to the use of silver nanoparticles in counteracting bacterial growth and biofilm formation published in scientific papers between 2017 and 2021. Based on the review of experimental results, the properties of nanoparticles prompt the expansion of research on their activity.

Combating Bacterial Biofilm Formation in Urinary Catheter by Green Silver Nanoparticle

Urinary catheters are commonly associated with urinary tract infections. This study aims to inhibit bacterial colonisation and biofilm of urinary tract catheters. Silicon catheter pieces were varnished with green silver nanoparticles (AgNPs) using Pistacia lentiscus mastic to prevent bacterial colonisation. Pomegranate rind extract was used to synthesize AgNPs. AgNPs were characterized by UV-Vis spectroscopy, X-ray crystallography, and transmission electron microscopy (TEM). Results obtained revealed that the size of most AgNPs ranged between 15–25 nm and they took crystallised metal and oxidised forms. The amounts of released silver ions from 1 cm pieces of catheters coated with AgNPs were estimated for five days and ranged between 10.82 and 4.8 µg. AgNPs coated catheters significantly inhibited the colonisation of catheters by antibiotic-resistant clinical Gram-positive (Staphylococcus epidermidis and Staphylococcus aureus) and Gram-negative (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa) bacteria. AgNPs-varnish was more active against Gram-negative bacteria than Gram-positive bacteria. The significant inhibitory effect of coated catheters lasted for 72 h for both Gram-positive and Gram-negative bacteria. Varnishing catheters with AgNPs may help to prevent bacterial colonisation and infections.

Preparation and characterization of low-cost nano-particle material using pomegranate peels for brilliant green removal

A low-cost nano-particle material was successfully prepared using waste pomegranate peels. Batch adsorption experiments were carried out to investigate the effect of different operating conditions on the removal of brilliant green (BG) dye from an aqueous solution. SEM images of pomegranate peels nano-particles (PPNP) declared roughness of the surfaces and TEM images indicated a spheroid shape with an average particle size of 37 nm. The specific surface area of the PPNP was 354.46 m²/g and the particle size had a mean diameter of 613.4 nm. The active nano-particle suspension showed a net negative charge (-29 mV) at natural pH. The XRD pattern of PPNP displayed an average crystallite size of 13.50 nm and EDS analysis shows that the PPNP consists of 83% carbon. The experimental work showed that the removal of BG had optimum removal efficiency at 20 min, 0.3 g adsorbent mass, 25 °C, and pH 8. The kinetic data can be described well with the pseudo-second-order model and the isotherm data was found to fit the Dubinin model. The thermodynamic study proved that BG adsorption on PPNP was physisorption (ΔG = -5.949 kJ/mol) and spontaneous at low temperature (ΔH = -17.193 kJ/mol, ΔS = -0.0382 kJ/mol. k)This study used an agriculture waste (pomegranate peels) to prepare an environmentally friendly and low-cost adsorbent within the nano-scale by thermal activation. The nano-particles prepared were shown to be a promising adsorbent, demonstrating high surface area and well-developed porosity. The prepared adsorbent will have a great impact on wastewater treatment technology and possible applications at a large scale.

Antibacterial Activity of Green Synthesised Silver Nanoparticles on Saccharomyces cerevisiae

Green synthesis of nanoparticles is a widely researched and popular direction in the development of nanotechnology. It is a simple, cheap and effective method for obtaining nanoparticles with interesting biological properties. In light of the development of antibiotic resistance to important clinical strains of bacteria, this method was used in the present study to obtain silver nanoparticles with antibacterial activity. The aim of this study was to synthesise silver nanoparticles with antibacterial action by yeast in a process known as “green synthesis”. We are also considering the prospect of using silver nanoparticles as an antibacterial substance for drug development. The production of nanoparticles was confirmed by UV spectroscopy. Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 test strains and Staphylococcus aureus 1536 and Klebsiella pneumoniae 520 clinical isolates were used to study the antibacterial effect. The effect of synthesised nanoparticles on the metabolic activity of bacterial cells and their ability to adhere, as well as the minimum inhibitory concentrations (MICs) of synthesised nanoparticles for each of the strains, were determined. Following UV spectroscopy, the nanoparticles obtained were found to have a pronounced peak in optical absorption at 400 nm, corresponding to the plasmon resonance of silver nanoparticles, and demonstrated a high antibacterial effect against all the strains studied.

Fruit peel bioactives, valorisation into nanoparticles and potential applications: A review

Nanotechnology is a rapidly growing field with profound applications in different domains, particularly in food science and technology. Nanoparticles (NPs) synthesis, an integral part of nanotechnology-based applications, is broadly classified into chemical, physical and biosynthesis methods. Chemically sensitive and energy-intensive procedures employed for NPs synthesis are some of the limits of traditional chemical approaches. Recent research has focused on developing easy, nontoxic, cost-effective, and environment-friendly NPs synthesis during the last decade. Biosynthesis approaches have been developed to achieve this goal as it is a viable alternative to existing chemical techniques for the synthesis of metallic nanomaterials. Fruit peels contain abundant bioactive compounds including phenols, flavonoids, tannins, triterpenoids, steroids, glycosides, carotenoids, anthocyanins, ellagitannins, vitamin C, and essential oils with substantial health benefits, anti-bacterial and antioxidant properties, generally discarded as byproduct or waste by the fruit processing industry. NPs synthesized using bioactive compounds from fruit peel has futuristic applications for an unrealized market potential for nutraceutical and pharmaceutical delivery. Numerous studies have been conducted for the biosynthesis of metallic NPs such as silver (AgNPs), gold (AuNPs), zinc oxide, iron, copper, palladium and titanium using fruit peel extract, and their synthesis mechanism have been reported in the present review. Additionally, NPs synthesis methods and applications of fruit peel NPs have been discussed.

Green Synthesis and Potential Antibacterial Applications of Bioactive Silver Nanoparticles: A Review

Green synthesis of silver nanoparticles (AgNPs) using biological resources is the most facile, economical, rapid, and environmentally friendly method that mitigates the drawbacks of chemical and physical methods. Various biological resources such as plants and their different parts, bacteria, fungi, algae, etc. could be utilized for the green synthesis of bioactive AgNPs. In recent years, several green approaches for non-toxic, rapid, and facile synthesis of AgNPs using biological resources have been reported. Plant extract contains various biomolecules, including flavonoids, terpenoids, alkaloids, phenolic compounds, and vitamins that act as reducing and capping agents during the biosynthesis process. Similarly, microorganisms produce different primary and secondary metabolites that play a crucial role as reducing and capping agents during synthesis. Biosynthesized AgNPs have gained significant attention from the researchers because of their potential applications in different fields of biomedical science. The widest application of AgNPs is their bactericidal activity. Due to the emergence of multidrug-resistant microorganisms, researchers are exploring the therapeutic abilities of AgNPs as potential antibacterial agents. Already, various reports have suggested that biosynthesized AgNPs have exhibited significant antibacterial action against numerous human pathogens. Because of their small size and large surface area, AgNPs have the ability to easily penetrate bacterial cell walls, damage cell membranes, produce reactive oxygen species, and interfere with DNA replication as well as protein synthesis, and result in cell death. This paper provides an overview of the green, facile, and rapid synthesis of AgNPs using biological resources and antibacterial use of biosynthesized AgNPs, highlighting their antibacterial mechanisms.

Green Fabrication of Silver Nanoparticles using Euphorbia serpens Kunth Aqueous Extract, Their Characterization, and Investigation of Its In Vitro Antioxidative, Antimicrobial, Insecticidal, and Cytotoxic Activities

The silver nanoparticles (AgNPs) were synthesized via green synthesis approach using Euporbia serpens Kunth aqueous extract. The synthesized AgNPs were characterized by UV-visible spectroscopy and Furrier Transformer Infra-Red spectroscopy to justify the reduction and stabilization of AgNPs from its precursors. AgNPs characteristic absorption peak was observed at 420 nm in the UV-visible spectrum. The SEM and TEM analysis demonstrated the spherical shape of the synthesized nanoparticles with particle sizes ranging from 30 nm to 80 nm. FTIR transmission bands at 2920 cm-1, 1639 cm-1, 1410 cm-1, 3290 cm-1, and 1085 cm-1 were attributed to C-H, C=O, C-C, N-H, and C-N functional groups, respectively. XRD peaks could be attributed to (111), (200), (220), and (311) crystalline plane of the faced-centered cube (FCC) crystalline structure of the metallic silver nanoparticles. The AgNPs showed good antibacterial activity against all the tested bacteria at each concentration. The particles were found to be more active against Escherichia coli (E. coli) with $20\pm 06\text{mm}$ and Salmonella typhi (S. typhi) with $18\pm 0.5\text{mm}$ zone of inhibition in reference to standard antibiotic amoxicillin with $23\pm 0.3\text{mm}$ and $20\pm 0.4\text{mm}$ zone of inhibition, respectively. Moderate antifungal activities were observed against Candida albicans (C. albicans) and Alternaria alternata (A. alternata) with zone of inhibitions 16.5 mm and 15 mm, respectively, compared to the standard with 23 mm of inhibition. Insignificant antifungal inhibition of 7.5 mm was observed against Fusarium gramium (F. gramium). All the tested concentrations of AgNPs showed comparable % RSA with the standard reference ascorbic acid in the range sixty percent to seventy five percent. The percent motility at 3 hours postincubation showed quick response and most Tetramorium caespitum were found deceased or paralyzed. Similarly, the percent mortality showed a linear response at concentration and time. It was observed that 1 μg/mL to 2 μg/mL concentration of AgNPs displayed a significant cytotoxic activity against Artemia salina with LD50 of 5.37 and 5.82, respectively.

Green Synthesis of Silver Nanoparticles by the Cyanobacteria Synechocystis sp.: Characterization, Antimicrobial and Diabetic Wound-Healing Actions

Green nanotechnology is now accepted as an environmentally friendly and cost-effective advance with various biomedical applications. The cyanobacterium Synechocystis sp. is a unicellular spherical cyanobacterium with photo- and hetero-trophic capabilities. This study investigates the ability of this cyanobacterial species to produce silver nanoparticles (AgNPs) and the wound-healing properties of the produced nanoparticles in diabetic animals.

METHODS

UV-visible and FT-IR spectroscopy and and electron microscopy techniques investigated AgNPs' producibility by Synechocystis sp. when supplemented with silver ion source. The produced AgNPs were evaluated for their antimicrobial, anti-oxidative, anti-inflammatory, and diabetic wound healing along with their angiogenesis potential.

RESULTS

The cyanobacterium biosynthesized spherical AgNPs with a diameter range of 10 to 35 nm. The produced AgNPs exhibited wound-healing properties verified with increased contraction percentage, tensile strength and hydroxyproline level in incision diabetic wounded animals. AgNPs treatment decreased epithelialization period, amplified the wound closure percentage, and elevated collagen, hydroxyproline and hexosamine contents, which improved angiogenesis factors' contents (HIF-1α, TGF-β1 and VEGF) in excision wound models. AgNPs intensified catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities, and glutathione (GSH) and nitric oxide content and reduced malondialdehyde (MDA) level. IL-1β, IL-6, TNF-α, and NF-κB (the inflammatory mediators) were decreased with AgNPs' topical application.

CONCLUSION

Biosynthesized AgNPs via Synechocystis sp. exhibited antimicrobial, anti-oxidative, anti-inflammatory, and angiogenesis promoting effects in diabetic wounded animals.

Ongoing and potential novel trends of pomegranate fruit peel; a comprehensive review of its health benefits and future perspectives as nutraceutical

Pomegranate is an ancient shrub, globally distributed nowadays. It has been used in the middle east as a medicinal food and traditional medicine for thousands of years. Pomegranate peel (PP) constitutes about 50% of the total fruit, however, it has been previously regarded as a waste. Recent research points to PP as a rich source of phenolics (e.g., ellagitannins, flavonoids, and anthocyanins), polysaccharides, in addition to its biotransformed metabolites viz. urolithins making it a valuable waste with promising pharmacological actions. Compared to the pulp and the juice, PP exhibited stronger antioxidant and antimicrobial activities. Besides, it inhibited inflammation in several conditions, including colitis, arthritis, hepatitis, contact dermatitis, and lung inflammation. Moreover, it displayed anti-osteoporosis, anti-hyperglycemic, antidiabetic, antihypertensive, vasculoprotective, hepatoprotective, neuroprotective, and immunomodulatory effects. Additionally, it was effective as a prebiotic and in obesity control, besides it promoted wound healing. Furthermore, PP demonstrated anticancer effects against different cancer types, for example, colon, liver, thyroid, uterine, breast, bladder, prostate, leukemia, and osteosarcoma. Despite PP safety, it may interfere with the metabolism of other drugs because it inhibits cytochromes (CYP) changing their bioavailability, effectiveness, and toxicity. PP biowaste valorization not only avoids against its environmental and economic burden but can also provide a promising platform to produce novel or improved nutraceuticals. This study provides a comprehensive overview of PP biological activities with the reported action mechanisms related to its phytochemicals and further biotransformed metabolites inside the body. Future research prospects to unravel the merits of such waste and optimize its use are discussed. PRACTICAL APPLICATION: Pomegranate is widely distributed throughout the world. Although its peel was previously considered a waste, recent research regards it as a rich source of bioactive compounds with promising biological activities. Its recycling not only overcomes the bio-waste problems, but also provides a source of valuable compounds with several health benefits. In recent years, PP has been demonstrated to exhibit excellent pharmacological bioactivities, for example, antioxidant, anti-inflammatory, antimicrobial, antiosteoporosis, antihyperlipidemic, and anticancer activities. Its health-promoting power is mostly attributed to the phenolic and polysaccharide content, in addition to its amazing biotransformed metabolites. The underlying action mechanisms of such pharmacological activities are discussed and related to its chemical content. This review presents the latest research progress on the role of PP in the prevention and treatment of various chronic diseases, and its protective health effects for future research to be used in nutraceuticals.

The catalytic and ROS-scavenging activities of green synthesized, antiferromagneticα-Fe2O3nanoparticle with a prismatic octahedron morphology from pomegranate rind extract

Phenolic compounds (like 4-nitrophenol) and dyes (like methyl orange) are common by-products discharged by many industries as wastes; they are toxic and may induce discomfort and irritation in humans when ingested. Most of these compounds can be made less toxic through catalytic degradation. Metal oxide nanoparticles are found to have high catalytic activity and can degrade toxic phenolic compounds and dyes. In the current study, pomegranate rind extract was used for the green synthesis of iron oxide nanoparticles that exhibited an octahedron morphology revealed by scanning electron microscopy analysis. Energy dispersive x-ray analysis showed 47.96% content of Fe (by weight); high resolution-transmission electron microscopy analysis confirmed that the nanoparticles had a particle size of 22.54 ± 4.13 nm. The particles were further characterized by x-ray diffraction, fourier transform-infrared spectroscopy, vibrating sample magnetometer, and thermogravimetric analysis. The nanoparticle proved to be efficient in reducing 4-nitrophenol and methyl orange. It was also found to be non-toxic towards murine macrophages, RAW 264.7 with good ROS-scavenging potential compared to control.

Exploring the Antibacterial and Antibiofilm Efficacy of Silver Nanoparticles Biosynthesized Using Punica granatum Leaves

The current research work illustrates an economical and rapid approach towards the biogenic synthesis of silver nanoparticles using aqueous Punica granatum leaves extract (PGL-AgNPs). The optimization of major parameters involved in the biosynthesis process was done using Box-Behnken Design (BBD). The effects of different independent variables (parameters), namely concentration of AgNO3, temperature and ratio of extract to AgNO3, on response viz. particle size and polydispersity index were analyzed. As a result of experiment designing, 17 reactions were generated, which were further validated experimentally. The statistical and mathematical approaches were employed on these reactions in order to interpret the relationship between the factors and responses. The biosynthesized nanoparticles were initially characterized by UV-vis spectrophotometry followed by physicochemical analysis for determination of particle size, polydispersity index and zeta potential via dynamic light scattering (DLS), SEM and EDX studies. Moreover, the determination of the functional group present in the leaves extract and PGL-AgNPs was done by FTIR. Antibacterial and antibiofilm efficacies of PGL-AgNPs against Gram-positive and Gram-negative bacteria were further determined. The physicochemical studies suggested that PGL-AgNPs were round in shape and of ~37.5 nm in size with uniform distribution. Our studies suggested that PGL-AgNPs exhibit potent antibacterial and antibiofilm properties.

Green Silver Nanoparticles Embedded in Cellulosic Network for Fresh Food Packaging

The demand for increasing the shelf life of fresh food as well as the need for protecting the food against foodborne infections warrant the demand for increasing the shelf life of fresh food. The incorporation of nanoparticles into the packaging material can enhance the preservation of perishable foods. Silver nanoparticles (AgNPs), in particular, have antibacterial, anti-mold, anti-yeast, and anti-viral activities can be embedded into the biodegradable packaging materials for this purpose. This study focuses on antimicrobial packaging materials for food by mixing the extracts of different plants with silver nitrate and depositing this mixture as a layer on the blotting papers, which are thick sheets of paper made of cellulose. Because the blotting papers are highly absorbent and porous, silver nitrate solution along with the plant extracts can be easily applied and allowed for in situ synthesis of AgNPs. Subsequently, these papers were analyzed and characterized using scanning electron microscopy, transmission electron microscopy, atomic absorption spectroscopy, and energy dispersive X-ray analysis. The coated paper exhibited good antibacterial activity against Escherichia coli and Staphylococcus aureus. Furthermore, the coated paper when used as a packaging material for tomatoes and coriander leaf, the shelf life was extended to about 30 days and 15 days respectively. The prepared cost-effective silver packing material can be used in food packaging for various perishable foods.

Pomegranate peel induced biogenic synthesis of silver nanoparticles and their multifaceted potential against intracellular pathogen and cancer

In the field of nano-biotechnology, silver nanoparticles (AgNPs) share a status of high repute owing to their remarkable medicinal values. Biological synthesis of environment-friendly AgNPs using plant extracts has emerged as the beneficial alternative approach to chemical synthesis. In the current study, we have synthesized biogenic silver nanoparticles (PG-AgNPs) using the peel extract of Punica granatum as a reducing and stabilizing agent. The as-synthesized PG-AgNPs were characterized and evaluated for their antibacterial and anticancer potential. UV-Visible spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS) confirmed the formation of biogenic PG-AgNPs. The antibacterial potential was assessed against the biofilm of Listeria monocytogenes. The PG-AgNPs were efficacious against sessile bacteria and their biofilm as well. The as-synthesized nanoparticles at sub-MIC values showed dose-dependent inhibition of biofilm formation. Corroborating results were observed under crystal violet assay, Congo red staining, Confocal microscopy and SEM analysis. The anticancer ability of the nanoparticles was evaluated against MDA-MB-231 metastatic breast cancer cells. As evident from the MTT results, PG-AgNPs significantly reduced the cell viability in a dose-dependent manner. Exposure of MDA-MB-231 cells led to the accumulation of reactive oxygen species (ROS). Morphological changes and DNA fragmentation showed the strong positive effect of PG-AgNPs on the induction of apoptosis. Collectively, the as-synthesized PG-AgNPs evolved with synergistically emerged attributes that were effective against L. monocytogenes and also inhibited its biofilm formation; moreover, the system displayed lower cytotoxic manifestation towards mammalian cells. In addition, the PG-AgNPs embodies intriguing anticancer potential against metastatic breast cancer cells.

Biological Nanofactories: Using Living Forms for Metal Nanoparticle Synthesis

Metal nanoparticles are nanosized entities with dimensions of 1-100 nm that are increasingly in demand due to applications in diverse fields like electronics, sensing, environmental remediation, oil recovery and drug delivery. Metal nanoparticles possess large surface energy and properties different from bulk materials due to their small size, large surface area with free dangling bonds and higher reactivity. High cost and pernicious effects associated with the chemical and physical methods of nanoparticle synthesis are gradually paving the way for biological methods due to their eco-friendly nature. Considering the vast potentiality of microbes and plants as sources, biological synthesis can serve as a green technique for the synthesis of nanoparticles as an alternative to conventional methods. A number of reviews are available on green synthesis of nanoparticles but few have focused on covering the entire biological agents in this process. Therefore present paper describes the use of various living organisms like bacteria, fungi, algae, bryophytes and tracheophytes in the biological synthesis of metal nanoparticles, the mechanisms involved and the advantages associated therein.

Green Synthesis of Silver Nanoparticles Using the Flower Extract of Abelmoschus esculentus for Cytotoxicity and Antimicrobial Studies

BACKGROUND

Abelmoschus esculentus (L.) Moench, an economically important malvaceous vegetable crop popularly known as okra, is used in various culinary preparations and is rich in vitamins, minerals, and nutrients. The biological properties of okra flowers in relation to nanoparticle synthesis have not yet been reported.

MATERIALS AND METHODS

In the current study, silver nanoparticles (AgNPs) were synthesized using extracts of the flowers of A. esculentus. The characteristics of the AgNPs were studied using a UV-vis spectrometer, Fourier transmission infrared spectrophotometer (FTIR), X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray spectrometer (EDX). Antibacterial activity screening was performed using the agar well diffusion method, and cytotoxicity and cell viability studies were conducted using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

RESULTS

The synthesized AgNPs were spherical and ranged in size from 5.52 to 31.96 nm, with an average size of 16.19 nm, as determined by UV-vis spectroscopy, FTIR, XRD, TEM and EDX. A. esculentus flower extract-mediated silver nanoparticles (AME-AgNPs) exhibited excellent activities in vitro studies, particularly in vitro cytotoxic and antiproliferative studies against cancer cell lines, such as the TERT-4 and A-549 cell lines. The antibacterial effects on the Gram-positive pathogens Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes and the Gram-negative pathogens Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella typhimurium and Shigella sonnei were tested. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values varied with the bacterial strain. The IC50 values of the synthesized NPs for the tested cell lines were close to that of a standard drug.

CONCLUSION

Compared to other NPs the NPs synthesized in this study were smaller in size and exhibited a higher level of antibacterial activity, cytotoxicity and apoptosis at minimal concentrations, and this is the first study on okra flower-induced anticancer and antimicrobial activities.

Trends in targeted delivery of nanomaterials in colon cancer diagnosis and treatment

Colon cancer is an adenocarcinoma, which subsequently develops into malignant tumors, if not treated properly. The current colon cancer therapy mainly revolves around chemotherapy, radiotherapy and surgery, but the search continues for more effective interventions. With the advancement of nanoparticles (NPs), it is now possible to diagnose and treat colon cancers with different types, shapes, and sizes of NPs. Nanoformulations such as quantum dots, iron oxide, polymeric NPs, dendrimers, polypeptides, gold NPs, silver NPs, platinum NPs, and cerium oxide have been either extensively used alone or in combination with other nanomaterials or drugs in colon cancer diagnosis, and treatments. These nanoformulations possess high biocompatibility and bioavailability, which makes them the most suitable candidates for cancer treatment. The size and shape of NPs are critical to achieving an effective drug delivery in cancer treatment and diagnosis. Most NPs currently are under different testing phases (in vitro, preclinical, and clinical), whereas some of them have been approved for therapeutic applications. We have comprehensively reviewed the recent advances in the applications of NPs-based formulations in colon cancer diagnosis and treatment.

Synthesis of silver nanoparticles using gum Arabic: Evaluation of its inhibitory action on Streptococcus mutans causing dental caries and endocarditis

BACKGROUND

Streptococcus mutans are an oral pathogen that causes dental caries, endocarditis, and systemic dysfunctions, an alternative antibacterial solution from silver nanoparticles (AgNPs) are investigated.

METHODS

AgNPs were synthesized using the ethnobotanical product gum Arabic. It influenced the nanoparticles with medicinal value through their role as capping, stabilizing, or surface-attached components. The biophysical characteristics of the synthesized AgNPs were studied using UV-vis spectrum, XRD, EDAX, SEM, and TEM tools. The AgNPs were spherical with the average size less than 10 nm. By using the well diffusion and microdilution techniques, the impact of synthesized AgNPs was tested against S. mutans isolates.

RESULTS

The smaller the size, the greater the antibacterial and antiviral potential the particles exhibit. The biophysical characteristics of AgNPs the presence of phenols, alcohols, amides, sulfoxide, flavanoids, terpenoids and steroids. The AgNPs exhibited a good antibacterial action against the oral pathogen S. mutans. The synthesized NPs at a dose level of 200 μg/mL exhibited an inhibition zone with 18.30 ± 0.5 nm diameter. The synthesised nanoparticles inhibited the genes responsible for biofilm formation of S. mutans over host tooth and gums (gtfB, gtfc, gtfD) and virulent protective factors (comDE, brpA and smu 360) and survival promoter genes (gyrA and spaP, gbpB).

CONCLUSION

The potent antibiotic action over S. mutans seen with the synthesized NPs, paves the way for the development of novel dental care products. Also, the small-sized NPs promote its applicability in COVID-19 pandemic containment.

Transformation of Biowaste for Medical Applications: Incorporation of Biologically Derived Silver Nanoparticles as Antimicrobial Coating

Nanobiotechnology has undoubtedly influenced major breakthroughs in medical sciences. Application of nanosized materials has made it possible for researchers to investigate a broad spectrum of treatments for diseases with minimally invasive procedures. Silver nanoparticles (AgNPs) have been a subject of investigation for numerous applications in agriculture, water treatment, biosensors, textiles, and the food industry as well as in the medical field, mainly due to their antimicrobial properties and nanoparticle nature. In general, AgNPs are known for their superior physical, chemical, and biological properties. The properties of AgNPs differ based on their methods of synthesis and to date, the biological method has been preferred because it is rapid, nontoxic, and can produce well-defined size and morphology under optimized conditions. Nevertheless, the common issue concerning biological or biobased production is its sustainability. Researchers have employed various strategies in addressing this shortcoming, such as recently testing agricultural biowastes such as fruit peels for the synthesis of AgNPs. The use of biowastes is definitely cost-effective and eco-friendly; moreover, it has been reported that the reduction process is simple and rapid with reasonably high yield. This review aims to address the developments in using fruit- and vegetable-based biowastes for biologically producing AgNPs to be applied as antimicrobial coatings in biomedical applications.

Antimicrobial and anticancer properties of Carica papaya leaves derived di-methyl flubendazole mediated silver nanoparticles

BACKGROUND

In this study, a biologically active molecule, di-methyl flubendazole isolated from the extract of Carica papaya leaves confirmed by using GC-MS, ¹H NMR, and ¹³C NMR analysis was applied to synthesize silver nanoparticles (AgNPs). The AgNPs with plant sources an alternative therapeutic agent for synthetic compound used in cancer chemotherapy.

METHODS

The AgNPs were characterized using UV, FT-IR, XRD, FESEM with EDX and TEM. The antibacterial effects of AgNPs were determined with agar well diffusion method. The MTT assay used to evaluate the inhibitory effect cell lines. The acridine orange and ethidium bromide and DAPI have used cell morphological effects.

RESULTS

The AgNPs were mono-crystalline and their size ranged from 7 to 22 nm. AgNPs showed good antibacterial activity against both Gram-positive and Gram-negative bacteria. Studies on the antiproliferative potential of bioinspired AgNPs in cancer cell lines revealed that the antiproliferative effect was much stronger in HepG2 than in MCF-7 and A549 cell lines. Similarly, AgNPs exerted less cytotoxic activity in Vero cells (normal cells). AgNPs-treated cells showed necrosis, apoptotic morphology evidenced by cell shrinkage, membrane blebbing, cell decay, and necrosis. HepG2 cells treated with biosynthesized AgNPs exhibited a G0/G1 phase (52-53.37%) blockage. Compared to the control, AgNP-treated HepG2 cells showed elevated ®-actin levels; however, Bcl-2 was significantly down regulated in AgNP-treated cells, indicating the involvement of Bcl-2 in apoptosis.

CONCLUSION

Overall, the fact that di-methyl flubendazole-based silver nanoparticles showed a novel and cost-effective natural antitumor and antibacterial agent.