Biosynthesis, characterization, and anticancer effect of plant-mediated silver nanoparticles using Coptis chinensis

Synthesis and characterization of Fe3O4@SiO2@PDA@Ag core-shell nanoparticles and biological application on human lung cancer cell line and antibacterial strains

Novel magnetic and metallic nanoparticles garner much attention of researchers due to their biological, chemical and catalytic properties in many chemical reactions. In this study, we have successfully prepared a core-shell Fe3O4@SiO2@PDA nanocomposite wrapped with Ag using a simple synthesis method, characterised and tested on small cell lung cancer and antibacterial strains. Incorporating Ag in Fe3O4@SiO2@PDA provides promising advantages in biomedical applications. The magnetic Fe3O4 nanoparticles were coated with SiO2 to obtain negatively charged surface which is then coated with polydopamine (PDA). Then silver nanoparticles were assembled on Fe3O4@SiO2@PDA surface, which results in the formation core-shell nanocomposite. The synthesised nanocomposite were characterized using SEM-EDAX, dynamic light scattering, XRD, FT-IR and TEM. In this work, we report the anticancer activity of silver nanoparticles against H1299 lung cancer cell line using MTT assay. The cytotoxicity data revealed that the IC50 of Fe3O4@SiO2@PDA@Ag against H1299 lung cancer nanocomposites cells was 21.52 µg/mL. Furthermore, the biological data of nanocomposites against Gram-negative 'Pseudomonas aeruginosa' and Gram-positive 'Staphylococcus aureus' were carried out. The range of minimum inhibitory concentration was found to be 115 µg/mL where gentamicin was used as a standard drug. The synthesized AgNPs proves its supremacy as an efficient biomedical agent and AgNPs may act as potential beneficial molecule in lung cancer chemoprevention and antibacterial strains.

Biosynthesized metallic nanoparticles: A new era in cancer therapy

Cancer remains a global health crisis, claiming countless lives throughout the years. Traditional cancer treatments like chemotherapy and radiation often bring about severe side effects, underscoring the pressing need for innovative, more efficient, and less toxic therapies. Nanotechnology has emerged as a promising technology capable of producing environmentally friendly anticancer nanoparticles. Among various nanoparticle types, metal-based nanoparticles stand out due to their exceptional performance and ease of use in methods of imaging. The widespread accessibility of biological precursors for synthesis based on plants of metal nanoparticles has made large-scale, eco-friendly production feasible. This evaluation provides a summary of the green strategy for synthesizing metal-based nanoparticles and explores their applications. Moreover, this review delves into the potential of phyto-based metal nanoparticles in combating cancer, shedding light on their probable mechanisms of action. These insights are invaluable for enhancing both biomedical and environmental applications. The study also touches on the numerous potential applications of nanotechnology in the field of medicine. Consequently, this research offers a concise and well-structured summary of nanotechnology, which should prove beneficial to researchers, engineers, and scientists embarking on future research endeavors.

Green synthesis of silver nanoparticle prepared with Ocimum species and assessment of anticancer potential

Silver nanoparticles (AgNPs) have gained much attention due to their unique physical, and chemical properties. Integration of phytochemicals in nanoformulation might have higher applicability in healthcare. Current work demonstrates the synthesis of green AgNPs with O. gratissimum (gr-AgNPs) O. tenuiflorum (te-AgNPs) and O. americanum (am-AgNPs) followed by an evaluation of their antimicrobial and anticancer properties. SEM analysis revealed spherical-shaped particles with average particle sizes of 69.0 ± 5 nm for te-AgNPs, 46.9 ± 9 nm for gr-AgNPs, and 58.5 ± 18.7 nm for am-AgNPs with a polydispersity index below 0.4. The synthesized am-AgNPs effectively inhibited Klebsiella pneumonia, Escherichia coli, Staphylococcus aureus, Aspergillus niger, and Candida albicans with 23 ± 1.58 mm, 20 ± 1.68 mm, 22 ± 1.80 mm, 26 ± 1.85 mm, and 22 ± 1.40 nm of zone of inhibition respectively. Synthesized AgNPs also induced apoptotic cell death in MCF-7 in concentration-dependent manner. IC50 values for am-AgNPs, te-AgNPs, and gr-AgNPs were 14.78 ± 0.89 µg, 18.04 ± 0.63 and 15.41 ± 0.37 µg respectively which suggested that am-AgNPs were the most effective against cancer. At higher dose size (20 µg) AgNPs were equally effective to commercial standard Doxorubicin (DOX). In comparison to te-AgNPs and gr-AgNPs, am-AgNPs have higher in vitro anticancer and antimicrobial effects. The work reported Ocimum americanum for its anticancer properties with chemical profile (GCMS) and compared it with earlier reported species. The activity against microbial pathogens and selected cancer cells clearly depicted that these species have distinct variations in activity. The results have also emphasized on higher potential of biogenic silver nanoparticles in healthcare but before formulation of commercial products, detailed analysis is required with human and animal models.

Phyco-synthesis of silver nanoparticles by environmentally safe approach and their applications

In recent years, there has been an increasing interest in the green synthesis of metallic nanoparticles, mostly because of the evident limitations associated with chemical and physical methods. Green synthesis, commonly referred to as "biogenic synthesis," is seen as an alternative approach to produce AgNPs (silver nanoparticles). The current work focuses on the use of Asterarcys sp. (microalga) for biological reduction of AgNO3 to produce AgNPs. The optimal parameters for the reduction of AgNPs were determined as molarity of 3 mM for AgNO3 and an incubation duration of 24 h at pH 9, using a 20:80 ratio of algal extract to AgNO3. The biosynthesized Ast-AgNPs were characterised using ultraviolet-visible spectroscopy (UV-Vis), zeta potential, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED) patterns. The nanoparticles exhibited their highest absorption in the UV-visible spectra at 425 nm. The X-ray diffraction (XRD) investigation indicated the presence of characteristic peaks at certain angles: 38.30° (1 1 1), 44.40° (2 0 0), 64.64° (2 2 0), and 77.59° (3 1 1) according to the JCPDS file No. 04-0783. Based on SEM and TEM, the Ast-AgNPs had an average size of 35 nm and 52 nm, respectively. The zeta potential was determined to be - 20.8 mV, indicating their stability. The highest antibacterial effectiveness is shown against Staphylococcus aureus, with a zone of inhibition of 25.66 ± 1.52 mm at 250 μL/mL conc. of Ast-AgNPs. Likewise, Ast-AgNPs significantly suppressed the growth of Fusarium sp. and Curvularia sp. by 78.22% and 85.05%, respectively, at 150 μL/mL conc. of Ast-AgNPs. In addition, the Ast-AgNPs exhibited significant photocatalytic activity in degrading methylene blue (MB), achieving an 88.59% degradation in 120 min, revealing multiple downstream applications of Ast-AgNPs.

Silver and gold nanoparticles: Eco-friendly synthesis, antibiofilm, antiviral, and anticancer bioactivities

For the first time in this study, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were green synthesized by the cost-effective and eco-friendly procedure using Cotton seed meal and Fodder yeast extracts. The biosynthesized NPs were characterized by UV-Vis spectroscopy, dynamic light scattering analysis (DLS), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and fourier-transform infrared (FTIR) spectroscopy. Furthermore, the biosynthesized NPs were tested in vitro against biofilm formation by some pathogenic negative bacteria (Escherichia coli, Proteus mirabilis, Klebsiella sp., Salmonella sp., and Pseudomonas aeruginosa) and negative bacteria (staphylococcus aureus) as well as against human denovirus serotype 5 (HAdV-5) and anticancer activity using HepG2 hepatocarcinoma cells. UV-Vis absorption spectra of reaction mixture of AgNPs and AuNPs exhibited maximum absorbance at 440 nm and 540 nm, respectively. This finding was confirmed by DLS measurements that the highest intensity of the AgNPs and AuNPs were 84 nm and 73.9 nm, respectively. FTIR measurements identified some functional groups detected in Cotton seed meal and Fodder yeast extracts that could be responsible for reduction of silver and gold ions to metallic silver and gold. The morphologies and particle size of AgNPs and AuNPs were confirmed by the TEM and SAED pattern analysis. Biosynthesized AgNPs and AuNPs showed good inhibitory effects against biofilms produced by Escherichia coli, Proteus mirabilis, Klebsiella sp., Salmonella sp., Pseudomonas aeruginosa, and Staphylococcus aureus. In addition, they showed anticancer activities against hepatocellular carcinoma (HepG-2) and antiviral activity against human adenovirus serotype 5 infection in vitro. Finally, the results of this study is expected to be extremely helpful to nano-biotechnology, pharmaceutical, and food packing applications through developing antimicrobial and/or an anticancer drugs from ecofriendly and inexpensive nanoparticles with multi-potentiality.

Identification of the therapeutic effect and molecular mechanism of Coptis chinensis Franch. and Magnolia officinalis var. biloba on chronic gastritis

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine (TCM) theory believes that clearing heat and promoting dampness is the main treatment method for chronic gastritis. Coptis chinensis Franch. has the effects of clearing heat, detoxifying, and anti-inflammatory; Magnolia officinalis var. biloba can be used to treat abdominal pain, cough, and asthma. Coptis chinensis Franch. and Magnolia officinalis var. biloba can regulate the balance of intestinal microbiota and inhibit inflammatory reactions.

AIM

This study will verify the therapeutic effect of Coptis chinensis Franch. and Magnolia officinalis var. biloba on chronic gastritis, and explore its mechanism through transcriptome sequencing.

METHODS

Firstly, a rat chronic gastritis model was established, and the anal temperature and body weight changes of the rats before and after modeling were observed. Next, H&E staining, TUNEL assay and ELISA assay were performed on rat gastric mucosal tissues. Subsequently, the key fractions of Coptis chinensis Franch. and Magnolia officinalis var. biloba were obtained by high performance liquid chromatography (HPLC), and a GES-1 cell inflammation model was constructed to select the optimal monomer. Finally, the mechanism of action of Coptis chinensis Franch. and Magnolia officinalis var. biloba was explored through RNA seq.

RESULTS

Compared with the control group, the rats in the administered group were in better condition, with higher anal temperature, reduced inflammatory response in gastric mucosal tissue and reduced apoptosis. The optimal fraction Coptisine was subsequently determined by HPLC and GES-1 cell model. RNA-seq analysis revealed that DEG was significantly enriched in ribosomes, NF-κB signaling pathway, etc. The key genes TPT1 and RPL37 were subsequently obtained.

CONCLUSIONS

This study verified the therapeutic effects of Coptis chinensis Franch. and Magnolia officinalis var. biloba on chronic gastritis by in vivo and in vitro experiments in rats, identified Coptisine as the optimal component, and obtained two potential target genes.

The Antibacterial Effectiveness of Citrullus lanatus-Mediated Stannous Nanoparticles on Streptococcus mutans

Introduction Dental caries is a prevalent oral health issue caused by the colonization of Streptococcus mutans in the oral cavity. Citrullus lanatus, commonly known as watermelon, is rich in bioactive compounds that possess antibacterial potential. In this study, we aimed to synthesize stannous chloride (SnCl2) nanoparticles (NPs) mediated by Citrullus lanatus extract and investigate their antibacterial effectiveness against Streptococcus mutans. Materials and method Stannous nanoparticles (SnNPs) synthesized by the green method were achieved by using the watermelon extract. Dilute stannous chloride solution was obtained by adding 0.45 g of stannous (Sn) chloride (Cl) powder to 60 mL of water, which was subjected to an orbital shaker with the watermelon extract. The nanoparticles obtained were subjected to characterization using antimicrobial testing, Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray (EDAX) analysis, and scanning electron microscopy (SEM). Agar well diffusion method was used against specific strains of S. aureus, S. mutans, and Escherichia coli. Results The novel nanoparticles demonstrated promising antibacterial activity against S. mutans providing 10 mm of inhibitory action. Conclusion Due to its abundance of naturally occurring bioactive chemicals and improved efficacy against S. mutans, watermelon extract can be utilized to create stannous nanoparticles as opposed to the use of toxic chemicals. They can also be employed as oral administration systems.

Biogenic Silver Nanoparticles for Targeted Cancer Therapy and Enhancing Photodynamic Therapy

Different conventional therapeutic procedures are utilized globally to manage cancer cases, yet the mortality rate in patients with cancer remains considerably high. Developments in the field of nanotechnology have included novel therapeutic strategies to deal with cancer. Biogenic (green) metallic silver nanoparticles (AgNPs) obtained using plant-mediated protocols are attractive to researchers exploring cancer treatment. Biogenic AgNPs present advantages, since they are cost-effective, easy to obtain, energy efficient, and less toxic compared to chemically and physically obtained AgNPs. Also, they present excellent anticancer abilities thanks to their unique sizes, shapes, and optical properties. This review provides recent advancements in exploring biogenic AgNPs as a drug or agent for cancer treatment. Thus, great attention was paid to the anticancer efficacy of biogenic AgNPs, their anticancer mechanisms, their efficacy in cancer photodynamic therapy (PDT), their efficacy in targeted cancer therapy, and their toxicity.

Antifungal Activity of Juglans-regia-Mediated Silver Nanoparticles (AgNPs) against Aspergillus-ochraceus-Induced Toxicity in In Vitro and In Vivo Settings

Aflatoxins produced by some species of Aspergillus are considered secondary toxic fungal by-products in feeds and food. Over the past few decades, many experts have focused on preventing the production of aflatoxins by Aspergillus ochraceus and also reducing its toxicity. Applications of various nanomaterials in preventing the production of these toxic aflatoxins have received a lot of attention recently. The purpose of this study was to ascertain the protective impact of Juglans-regia-mediated silver nanoparticles (AgNPs) against Aspergillus-ochraceus-induced toxicity by exhibiting strong antifungal activity in in vitro (wheat seeds) and in vivo (Albino rats) settings. For the synthesis of AgNPs, the leaf extract of J. regia enriched with high phenolic (72.68 ± 2.13 mg GAE/g DW) and flavonoid (18.89 ± 0.31 mg QE/g DW) contents was used. Synthesized AgNPs were characterized by various techniques, including TEM, EDX, FT-IR, and XRD, which revealed that the particles were spherical in shape with no agglomeration and fine particle size in the range of 16-20 nm. In vitro antifungal activity of AgNPs was tested on wheat grains by inhibiting the production of toxic aflatoxins by A. ochraceus. According to the results obtained from High-Performance Liquid Chromatography (HPLC) and Thin-Layer Chromatography (TLC) analyses, there was a correlation between the concentration of AgNPs and a decrease in the production of aflatoxin G1, B1, and G2. For in vivo antifungal activity, Albino rats were administrated with different doses of AgNPs in five groups. The results indicated that the feed concentration of 50 µg/kg feed of AgNPs was more effective in improving the disturbed levels of different functional parameters of the liver (alanine transaminase (ALT): 54.0 ± 3.79 U/L and aspartate transaminase (AST): 206 ± 8.69 U/L) and kidney (creatinine 0.49 ± 0.020 U/L and BUN 35.7 ± 1.45 U/L), as well as the lipid profile (LDL 22.3 ± 1.45 U/L and HDL 26.3 ± 2.33 U/L). Furthermore, the histopathological analysis of various organs also revealed that the production of aflatoxins was successfully inhibited by AgNPs. It was concluded that the harmful effects of aflatoxins produced by A. ochraceus can be successfully neutralized by using J. regia-mediated AgNPs.

The Role of Silver Nanoparticles in the Diagnosis and Treatment of Cancer: Are There Any Perspectives for the Future?

Cancer is a fatal disease with a complex pathophysiology. Lack of specificity and cytotoxicity, as well as the multidrug resistance of traditional cancer chemotherapy, are the most common limitations that often cause treatment failure. Thus, in recent years, significant efforts have concentrated on the development of a modernistic field called nano-oncology, which provides the possibility of using nanoparticles (NPs) with the aim to detect, target, and treat cancer diseases. In comparison with conventional anticancer strategies, NPs provide a targeted approach, preventing undesirable side effects. What is more, nanoparticle-based drug delivery systems have shown good pharmacokinetics and precise targeting, as well as reduced multidrug resistance. It has been documented that, in cancer cells, NPs promote reactive oxygen species (ROS) production, induce cell cycle arrest and apoptosis, activate ER (endoplasmic reticulum) stress, modulate various signaling pathways, etc. Furthermore, their ability to inhibit tumor growth in vivo has also been documented. In this paper, we have reviewed the role of silver NPs (AgNPs) in cancer nanomedicine, discussing numerous mechanisms by which they render anticancer properties under both in vitro and in vivo conditions, as well as their potential in the diagnosis of cancer.

Ultrasound-Assisted Enzymatic Extraction and Bioactivity Analysis of Polypeptides from Cordyceps militaris

Cordyceps militaris is rich in protein, polysaccharide, cordycepin, and other active components, with anticancer and antioxidation functions. In order to improve the economic value of C. militaris, the protein was extracted from its fruiting body by alkali-soluble acid precipitation process, and the extraction technology was optimized by orthogonal test. The polypeptide was obtained by digesting those proteins with a complex enzyme. And the antimicrobial and anticancer activities of those polypeptides were evaluated by measuring inhibitory zone and cytotoxicity. The results showed that the optimal extraction conditions of protein were as follows: pH of 8.5, material-to-water ratio of 1 : 28, extraction time of 3.5 h, extraction three times, and the highest protein yield was 45.06%. The optimum enzymatic hydrolysis process of C. militaris polypeptide solution was as follows: the ratio of alkaline protease to papain was 4 : 3, the optimum temperature was 55°C, pH was 7.2, the enzyme dosage was 7000 U/mL, the enzymolysis time was 3.5 h, and the highest yield of peptide was 16.73%. Under those conditions, the polypeptides prepared from C. militaris (<3000 Da) showed good antibacterial activity against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus, with inhibitory zones of (12.08 ± 0.22), (6.67 ± 0.12), and (10.32 ± 0.23) mm, respectively. The results showed that the SAO-S (IC50 = 0.49 mg/L) and T24 (IC50 = 0.23 mg/L) were significantly inhibited by C. militaris polypeptide. Results from this study suggest that polypeptides can be utilized as a new approach for bioactive compounds production from C. militaris.

Synthesis of Green Engineered Silver Nanoparticles through Urtica dioica: An Inhibition of Microbes and Alleviation of Cellular and Organismal Toxicity in Drosophila melanogaster

Plant fractions have a diversity of biomolecules that can be used to make complicated reactions for the bioactive fabrication of metal nanoparticles (NPs), in addition to being beneficial as antioxidant medications or dietary supplements. The current study shows that Urtica dioica (UD) and biologically synthesized silver nanoparticles (AgNPs) of UD have antibacterial and antioxidant properties against bacteria (Escherichia coli and Pseudomonas putida) and Drosophila melanogaster (Oregon R+). According to their ability to scavenge free radicals, DPPH, ABTS, TFC, and TPC initially estimated the antioxidant potential of UD and UD AgNPs. The fabricated AgNPs were analyzed (UV−Vis, FTIR, EDS, and SEM) to determine the functional groups (alcohol, carboxylic acids, phenol, proteins, and aldehydes) and to observe the shape (agglomerated crystalline and rod-shaped structure). The disc diffusion method was used to test the antimicrobial properties of synthesized Ag-NPs against E. coli and P. putida. For 24 to 120 h, newly enclosed flies and third instar larvae of Drosophila were treated with UD and UD AgNPs. After exposure, tests for biochemical effects (acetylcholinesterase inhibition and protein estimation assays), cytotoxicity (dye exclusion), and behavioral effects (jumping and climbing assays) were conducted. The results showed that nanoparticles were found to have potent antimicrobial activity against all microbial strains tested at various concentrations. In this regard, ethno-medicinal characteristics exhibit a similar impact in D. melanogaster, showing (p < 0.05) significantly decreased cellular toxicity (trypan blue dye), enhanced biochemical markers (AChE efficacy and proteotoxicity), and improved behavioral patterns in the organism treated with UD AgNPs, especially in comparison to UD extract. The results of this study may help in the utilization of specific plants as reliable sources of natural antioxidants that may have been beneficial in the synthesis of metallic NPs, which aids in the production of nanomedicine and other therapeutic applications.

Novel Antibacterial, Cytotoxic and Catalytic Activities of Silver Nanoparticles Synthesized from Acidophilic Actinobacterial SL19 with Evidence for Protein as Coating Biomolecule

Silver nanoparticles (AgNPs) have potential applications in medicine, photocatalysis, agriculture, and cosmetic fields due to their unique physicochemical properties and strong antimicrobial activity. Here, AgNPs were synthesized using actinobacterial SL19 strain, isolated from acidic forest soil in Poland, and confirmed by UV-vis and FTIR spectroscopy, TEM, and zeta potential analysis. The AgNPs were polydispersed, stable, spherical, and small, with an average size of 23 nm. The FTIR study revealed the presence of bonds characteristic of proteins that cover nanoparticles. These proteins were then studied by using liquid chromatography with tandem mass spectrometry (LC-MS/ MS) and identified with the highest similarity to hypothetical protein and porin with molecular masses equal to 41 and 38 kDa, respectively. Our AgNPs exhibited remarkable antibacterial activity against Escherichia coli and Pseudomonas aeruginosa. The combined, synergistic action of these synthesized AgNPs with commercial antibiotics (ampicillin, kanamycin, streptomycin, and tetracycline) enabled dose reductions in both components and increased their antimicrobial efficacy, especially in the case of streptomycin and tetracycline. Furthermore, the in vitro activity of the AgNPs on human cancer cell lines (MCF-7, A375, A549, and HepG2) showed cancer-specific sensitivity, while the genotoxic activity was evaluated by Ames assay, which revealed a lack of mutagenicity on the part of nanoparticles in Salmonella Typhimurium TA98 strain. We also studied the impact of the AgNPs on the catalytic and photocatalytic degradation of methyl orange (MO). The decomposition of MO was observed by a decrease in intensity of absorbance within time. The results of our study proved the easy, fast, and efficient synthesis of AgNPs using acidophilic actinomycete SL19 strain and demonstrated the remarkable potential of these AgNPs as anticancer and antibacterial agents. However, the properties and activity of such particles can vary by biosynthesized batch.

Comparing the Anticancer Activities of Green-Synthesized Ginsenoside and Transformed Ginsenoside Nanoconjugates (Ag, Au, and Pt)

Aim: To assess the anticancer activity of nanoparticles synthesized via a green method using American ginseng (AG). Methods: Stem-leaf saponins from AG (SAG) and heat-transformed stem-leaf saponins from AG (TSAG) were used to synthesize different SAG nanoparticles (SAG-NPs) and TSAG nanoparticles (TSAG-NPs). The NPs were characterized, and their anticancer activity was assessed in vitro. Results: The NPs, which differed in size (16.69 nm∼253.8 nm), were spherical or polyhedral with a low PDI and good stability. The TSAG-NPs inhibited cancer cells by inhibiting proliferation, promoting cancer cell apoptosis and directly leading cancer cells to necrosis. The small cell lung cancer cell line (SCLC) NCI-H446 was the most sensitive to the TSAG-AgNPs, with an IC50 value of 20.71±2.38 μg/mL, and the TSAG-AgNPs inhibited invasiveness and reduced the risk of metastasis. Conclusion: TSAG-AgNPs, selected from many SAG-NPs and TSAG-NPs, are sensitive to SCLC and provide a new approach to the currently limited treatment.

Nanostructured Antibiotics and Their Emerging Medicinal Applications: An Overview of Nanoantibiotics

Bacterial strains resistant to antimicrobial treatments, such as antibiotics, have emerged as serious clinical problems, necessitating the development of novel bactericidal materials. Nanostructures with particle sizes ranging from 1 to 100 nanometers have appeared recently as novel antibacterial agents, which are also known as “nanoantibiotics”. Nanomaterials have been shown to exert greater antibacterial effects on Gram-positive and Gram-negative bacteria across several studies. Antibacterial nanofilms for medical implants and restorative matters to prevent bacterial harm and antibacterial vaccinations to control bacterial infections are examples of nanoparticle applications in the biomedical sectors. The development of unique nanostructures, such as nanocrystals and nanostructured materials, is an exciting step in alternative efforts to manage microorganisms because these materials provide disrupted antibacterial effects, including better biocompatibility, as opposed to minor molecular antimicrobial systems, which have short-term functions and are poisonous. Although the mechanism of action of nanoparticles (NPs) is unknown, scientific suggestions include the oxidative-reductive phenomenon, reactive ionic metals, and reactive oxygen species (ROS). Many synchronized gene transformations in the same bacterial cell are essential for antibacterial resistance to emerge; thus, bacterial cells find it difficult to build resistance to nanoparticles. Therefore, nanomaterials are considered as advanced solution tools for the fields of medical science and allied health science. The current review emphasizes the importance of nanoparticles and various nanosized materials as antimicrobial agents based on their size, nature, etc.

L-Cysteine as a reducing/capping/gel-forming agent for the preparation of silver nanoparticle composites with anticancer properties

The present article reports the in situ preparation of silver nanoparticles (AgNPs) homogeneously distributed in the gel matrix formed using only L-cysteine (CYS) as a bio-reducing agent. The physicochemical methods of analysis confirmed the formation of a gel-network from aggregates consisting of spherical/elliptical cystine-stabilized AgNPs (core) and cysteine/Ag⁺ complexes (shell) regardless of the used silver salt - AgNO₃, AgNO₂ or AgOOCCH₃. CYS/AgNO₃ and CYS/AgOOCCH₃ aqueous solution systems needed the addition of electrolytes (Cl^- and SO₄^2-) for the gelation process, but the gel-formation in CYS/AgNO₂ occurred in one stage without any additional components. The AgNP sizes were about 1-5 nm in diameter for CYS/AgNO₃, 5-10 nm for CYS/AgOOCCH₃ and 20-40 nm for CYS/AgNO₂ systems. The zeta-potential values varied from +60 mV for CYS/AgNO₃ to +25 mV for the CYS/AgNO₂ system. The MTT-test showed that the obtained composites suppressed the MCF-7 breast cancer cells and the CYS/AgNO₃ system possessed the highest activity. Flow cytofluorimetry confirmed that the cell death occurred by apoptosis and this effect was the strongest for the CYS/AgNO₃ system. All systems were non-toxic to fibroblast cells. The novel simplest "green chemistry" approach, combining the knowledge of organic, inorganic, physical and supramolecular chemistry could open possibilities for the creation of the newest soft gel materials used in various fields of our life.

Anticancer and antimicrobial activity of biosynthesized Red Sea marine algal silver nanoparticles

Biosynthesis of silver nanoparticles (AgNPs) is emerging as a simple and eco-friendly alternative to conventional chemical synthesis methods. The role of AgNPs is expanding as antimicrobial and anticancer agents, sensors, nanoelectronic devices, and imaging contrast agents. In this study, biogenic AgNPs were synthesized using extracts of different marine algae species, including Ulva rigida (green alga), Cystoseira myrica (brown alga), and Gracilaria foliifera (red alga), as reducing and capping agents. The Physiochemical properties, cytotoxicity, anticancer and antimicrobial activities of the biosynthesized AgNPs were assessed. Surface plasmonic bands of the biosynthesized AgNPs capped with U. rigida, C. myrica, and G. foliifera extracts were visually observed to determine a colour change, and their peaks were observed at 424 nm, 409 nm, and 415 nm, respectively, by UV-Vis spectroscopy; transmission electron microscopy (TEM) indicated an almost spherical shape of AgNPs with nanoscale sizes of 12 nm, 17 nm, and 24 nm, respectively. Fourier transform-infrared (FTIR) spectroscopy analysis suggested that different molecules attached to AgNPs through OH, C=O, and amide groups. The major constituents of the aqueous algal extracts included, terpenoids, polyphenols, sulfonates, polysaccharides, fatty acids, chlorophylls, amide proteins, flavonoids, carotenoids, aliphatic fluoro compounds, volatile compounds, alkalines, pyruvic acid and agar groups. The cytotoxicity and anticancer activities of the biosynthesized AgNPs were assessed using Artemia salina nauplii, normal skin cell lines (HFb-4), and breast cancer cell lines (MCF-7 cell line). The lethality was found to be directly proportional to the AgNP concentration. The IC50 values of C. myrica and G. foliifera AgNPs against A. saline nauplii were 5 and 10 μg ml-1 after 4 h and 16 h, respectively, whereas U. rigida AgNPs did not exhibit cytotoxic effects. Anticancer activity of the biosynthesized AgNPs was dose dependent. The IC50 values of the biosynthesized AgNPs were 13, 13, and 43 µg ml-1 for U. rigida, C. myrica, and G. foliifera, respectively. U. rigida AgNPs particularly exhibited potent anticancer activity (92.62%) against a human breast adenocarcinoma cell line (MCF-7) with high selectivity compared the normal cells (IC50 = 13 µg/ml, SI = 3.2), followed by C. myrica AgNPs (IC50 = 13 µg/ml, SI = 3.07). Furthermore, the biosynthesized AgNPs exhibited strong antifungal activity against dermatophyte pathogenic moulds and mild antibacterial activity against the food borne pathogen bacteria. The highest antimicrobial activity was recorded for the U. rigida AgNPs, followed by those capped with C. myrica and G. foliifera extracts, respectively. AgNPs capped with the U. rigida extract exhibited the highest antimicrobial activity against Trichophyton mantigrophytes (40 mm), followed by Trichosporon cataneum (30 mm) and E. coli (19 mm), with minimal lethal concentration of 32 and 64 μg ml-1 respectively. The study finally revealed that extracts of marine algal species, particularly U. rigida extracts, could be effectively used as reducing agents for the green synthesis of AgNPs. These AgNPs are considered efficient alternative antidermatophytes for skin infections and anticancer agents against the MCF-7 cell line.

Current Advances in Coptidis Rhizoma for Gastrointestinal and Other Cancers

Cancer is a serious disease with an increasing number of reported cases and high mortality worldwide. Gastrointestinal cancer defines a group of cancers in the digestive system, e.g., liver cancer, colorectal cancer, and gastric cancer. Coptidis Rhizoma (C. Rhizoma; Huanglian, in Chinese) is a classical Chinese medicinal botanical drug for the treatment of gastrointestinal disorders and has been shown to have a wide variety of pharmacological activity, including antifungal, antivirus, anticancer, antidiabetic, hypoglycemic, and cardioprotective effects. Recent studies on C. Rhizoma present significant progress on its anticancer effects and the corresponding mechanisms as well as its clinical applications. Herein, keywords related to C. Rhizoma, cancer, gastrointestinal cancer, and omics were searched in PubMed and the Web of Science databases, and more than three hundred recent publications were reviewed and discussed. C. Rhizoma extract along with its main components, berberine, palmatine, coptisine, magnoflorine, jatrorrhizine, epiberberine, oxyepiberberine, oxyberberine, dihydroberberine, columbamine, limonin, and derivatives, are reviewed. We describe novel and classic anticancer mechanisms from various perspectives of pharmacology, pharmaceutical chemistry, and pharmaceutics. Researchers have transformed the chemical structures and drug delivery systems of these components to obtain better efficacy and bioavailability of C. Rhizoma. Furthermore, C. Rhizoma in combination with other drugs and their clinical application are also summarized. Taken together, C. Rhizoma has broad prospects as a potential adjuvant candidate against cancers, making it reasonable to conduct additional preclinical studies and clinical trials in gastrointestinal cancer in the future.

Antibacterial, Antifungal, and Antioxidant Activities of Silver Nanoparticles Biosynthesized from Bauhinia tomentosa Linn

The biogenic synthesis of silver nanoparticles (AgNPs) has a wide range of applications in the pharmaceutical industry. Here, we synthesized AgNPs using the aqueous flower extract of Bauhinia tomentosa Linn. Formation of AgNPs was observed using ultraviolet-visible light spectrophotometry at different time intervals. Maximum absorption was observed after 4 h at 420 nm due to the reduction of Ag⁺ to Ag⁰. The stabilizing activity of functional groups was identified by Fourier-transform infrared spectroscopy. Size and surface morphology were also analyzed using scanning electron microscopy. The present study revealed the AgNPs were spherical in form with a diameter of 32 nm. The face-centered cubic structure of AgNPs was indexed using X-ray powder diffraction with peaks at 2θ = 37°, 49°, 63°, and 76° (corresponding to the planes of silver 111, 200, 220, 311), respectively. Energy-dispersive X-ray spectroscopy revealed that pure reduced silver (Ag⁰) was the major constituent (59.08%). Antimicrobial analyses showed that the biosynthesized AgNPs possess increased antibacterial activity (against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative), with larger zone formation against S. aureus (9.25 mm) compared with that of E. coli (6.75 mm)) and antifungal activity (against Aspergillus flavus and Candida albican (with superior inhibition against A. flavus (zone of inhibition: 7 mm) compared with C. albicans (zone of inhibition: 5.75 mm)). Inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was found to be dose-dependent with half-maximal inhibitory concentration (IC₅₀) values of 56.77 μg/mL and 43.03 μg/mL for AgNPs and ascorbic acid (control), respectively, thus confirming that silver nanoparticles have greater antioxidant activity than ascorbic acid. Molecular docking was used to determine the mode of antimicrobial interaction of our biosynthesized B. tomentosa Linn flower-powder extract-derived AgNPs. The biogenic AgNPs preferred hydrophobic contacts to inhibit bacterial and fungal sustainability with reducing antioxidant properties, suggesting that biogenic AgNPs can serve as effective medicinal agents.

Synthesis of Silver Nanoparticles from the Polysaccharide of Farfarae Flos and Uncovering Its Anticancer Mechanism Based on the Cell Metabolomic Approach

In this study, the polysaccharide of Farfarae Flos (FFP) was utilized as a reducing agent to the green synthesis of FFP@AgNPs, and the anticancer activity was evaluated using the HT29 cells. The results showed that the FFP@AgNPs could significantly decrease proliferation ability, inhibit migration, and promote cell apoptosis of HT29 cells, which suggested that the FFP@AgNPs showed significant, strong cytotoxicity against HT29 cells. The cell metabolomic analysis coupled with the heatmap showed an obvious metabolome difference for the cells with and without FFP@AgNPs treatment, which was related to 51 differential metabolites. Four metabolic pathways were determined as the key pathways, and the representative functional metabolites and metabolic pathways were validated in vitro. Nicotinic acid (NA) was revealed as the key metabolite relating with the effect of FFP@AgNPs, and it was interesting that NA supplementation could inhibit the proliferation ability of HT29 cells in vitro, lead to mitochondrial dysfunction, reduce intracellular ATP, and damage the integrity of the cell membrane, which exhibited a similar effect as FFP@AgNPs. In conclusion, this study not only revealed the anticancer mechanism of FFP@AgNPs against the HT29 cells but also provided the important reference that NA shows a potential role in the development of a therapy for colorectal cancer.

Biomedical Applications of Chinese Herb-Synthesized Silver Nanoparticles by Phytonanotechnology

Recent advances in nanotechnology have opened up new avenues for the controlled synthesis of nanoparticles for biomedical and pharmaceutical applications. Chinese herbal medicine is a natural gift to humanity, and it has long been used as an antibacterial and anticancer agent. This study will highlight recent developments in the phytonanotechnological synthesis of Chinese herbal medicines to utilize their bioactive components in biomedical and therapeutic applications. Biologically synthesized silver nanoparticles (AgNPs) have emerged as a promising alternative to chemical and physical approaches for various biomedical applications. The comprehensive rationale of combinational or synergistic effects of Chinese herb-based AgNPs synthesis was investigated with superior physicochemical and biological properties, and their biomedical applications, including antimicrobial and anticancer activity and wound healing properties. AgNPs can damage the cell ultrastructure by triggering apoptosis, which includes the formation of reactive oxygen species (ROS), DNA disintegration, protein inactivation, and the regulation of various signaling pathways. However, the anticancer mechanism of Chinese herbal medicine-based AgNPs is more complicated due to the potential toxicity of AgNPs. Further in-depth studies are required to address Chinese herbs' various bioactive components and AgNPs as a synergistic approach to combat antimicrobial resistance, therapeutic efficiency of drug delivery, and control and prevention of newly emerged diseases.

Green Metallic Nanoparticles for Cancer Therapy: Evaluation Models and Cancer Applications

Metal-based nanoparticles are widely used to deliver bioactive molecules and drugs to improve cancer therapy. Several research works have highlighted the synthesis of gold and silver nanoparticles by green chemistry, using biological entities to minimize the use of solvents and control their physicochemical and biological properties. Recent advances in evaluating the anticancer effect of green biogenic Au and Ag nanoparticles are mainly focused on the use of conventional 2D cell culture and in vivo murine models that allow determination of the half-maximal inhibitory concentration, a critical parameter to move forward clinical trials. However, the interaction between nanoparticles and the tumor microenvironment is not yet fully understood. Therefore, it is necessary to develop more human-like evaluation models or to improve the existing ones for a better understanding of the molecular bases of cancer. This review provides recent advances in biosynthesized Au and Ag nanoparticles for seven of the most common and relevant cancers and their biological assessment. In addition, it provides a general idea of the in silico, in vitro, ex vivo, and in vivo models used for the anticancer evaluation of green biogenic metal-based nanoparticles.

Review On Documented Medicinal Plants Used For The Treatment Of Cancer

Background:

Cancer is a frightful disease and it is the second leading cause of death worldwide. Naturally derived compounds are gaining interest of research workers as they have less toxic side effects as compared to currently used treatments such as chemotherapy. Plants are the pool of chemical compounds which provides a promising future for research on cancer.

Objective:

This review paper provides updated information gathered on medicinal plants and isolated phytoconstituents used as anticancer agents and summarises the plant extracts and their isolated chemical constituents exhibiting anticancer potential on clinical trials.

Methods:

An extensive bibliographic investigation was carried out by analysing worldwide established scientific databases like SCOPUS, PUBMED, SCIELO, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar etc. In next few decades, herbal medicine may become a new epoch of medical system.

Results:

Many researches are going on medicinal plants for the treatment of cancer but it is a time to increase further experimental studies on plant extracts and their chemical constituents to find out their mechanism of action at molecular level.

Conclusion:

The article may help many researchers to start off further experimentation that might lead to the drugs for the cancer treatment.

A review: antimicrobial properties of several medicinal plants widely used in Traditional Chinese Medicine

Due to the dramatic increase in the use of antibiotics and growing health threat of bacterial resistance to many commonly used antibiotics, many studies have been directed at developing new and effective antibacterial compounds, among which many new, natural, and effective antibacterial compounds discovered from medicinal plants have drawn great interest and raised new hope for treating the challenges of antibiotic resistance. This review aimed to summarize the most important and widely used medicinal plants that were reported to have antibacterial activities. A general literature search from 2010 to 2020 was conducted using different databases, including Science Direct, Web of Science, and PubMed. According to the literature, three medicinal plants with outstanding antibacterial activities, Taraxacum officinale, Coptis Rhizome, and Scutellaria baicalensis, were screened and reviewed by prioritization. The extraction methods, antibacterial activities of different parts of plants or the plant-derived compounds, spectra of antibacterial activities, and toxicity were described, respectively. However, the antibacterial activities of the extracts or pure compounds as reported in the reviewed literature were mostly based on in vitro assays, and moreover, the deeper antibacterial mechanisms have not been elucidated clearly. Therefore, further studies are required in the fields of purification and identification of the antibacterial compounds, its mechanisms of action, and synergistic effects in combination with other antibacterial drugs, which may be helpful in the development of new antibacterial drugs.

Green synthesized plant-based silver nanoparticles: therapeutic prospective for anticancer and antiviral activity

Nanotechnology holds an emerging domain of medical science as it can be utilized virtually in all areas. Phyto-constituents are valuable and encouraging candidates for synthesizing green silver nanoparticles (AgNPs) which possess great potentials toward chronic diseases. This review gives an overview of the Green approach of AgNPs synthesis and its characterization. The present review further explores the potentials of Phyto-based AgNPs toward anticancer and antiviral activity including its probable mechanism of action. Green synthesized AgNPs prepared by numerous medicinal plants extract are critically reviewed for cancer and viral infection. Thus, this article mainly highlights green synthesized Phyto-based AgNPs with their potential applications for cancer and viral infection including mechanism of action and therapeutic future prospective in a single window.

Phyto-fabrication, purification, characterisation, optimisation, and biological competence of nano-silver

Published studies indicate that virtually any kind of botanical material can be exploited to make biocompatible, safe, and cost-effective silver nanoparticles. This hypothesis is supported by the fact that plants possess active bio-ingredients that function as powerful reducing and coating agents for Ag+. In this respect, a phytomediation method provides favourable monodisperse, crystalline, and spherical particles that can be easily purified by ultra-centrifugation. However, the characteristics of the particles depend on the reaction conditions. Optimal reaction conditions observed in different experiments were 70-95 °C and pH 5.5-8.0. Green silver nanoparticles (AgNPs) have remarkable physical, chemical, optical, and biological properties. Research findings revealed the versatility of silver particles, ranging from exploitation in topical antimicrobial ointments to in vivo prosthetic/organ implants. Advances in research on biogenic silver nanoparticles have led to the development of sophisticated optical and electronic materials with improved efficiency in a compact configuration. So far, eco-toxicity of these nanoparticles is a big challenge, and no reliable method to improve the toxicity has been reported. Therefore, there is a need for reliable models to evaluate the effect of these nanoparticles on living organisms.

Cytotoxicity against human breast carcinoma cells of silver nanoparticles biosynthesized using Capsosiphon fulvescens extract

Targeting cancer cells with small nanoparticles is a novel and promising approach to cancer therapy. Breast cancer is the most common cancer afflicting women worldwide. In the present study, silver nanoparticles (AgNPs) were synthesized using the aqueous extract of the marine alga Capsosiphon (C.) fulvescens, and the cytotoxicity and anti-cancer activities of the nanoparticles against MCF-7 breast cancer cells were analyzed. Nanoparticle formation was confirmed by solution color change and UV-Vis spectroscopy. The size and distribution of the C. fulvescens-biosynthesized silver nanoparticles (CfAgNPs) were then examined using various analytical methods; the particle size was around 20-22 nm and spherical in shape with no agglomeration. Cytotoxicity analysis revealed that the inhibitory concentration (IC₅₀) of CfAgNPs was 50 μg/ml. MCF-7 cell viability decreased with increasing concentrations of CfAgNPs. MCF-7 cells were evaluated for morphological changes before and after treatment with the CfAgNPs; cells treated with C. fulvescens aqueous algal extract (without CfAgNPs) showed irregular confluent aggregates with round polygonal cells, similar to the untreated control. Tamoxifen- (TMX) and CfAgNPs-treated cells show significant morphological changes. An apoptosis study was conducted using 4',6-diamidino-2-phenylindole (DAPI) staining, in which CfAgNP-treated MCF-7 cells generated bright blue fluorescence and shortened, disjointed chromatin was evident; control cells displayed less bright fluorescence. Flow cytometry analysis revealed that the percentage of cells in late apoptosis was high following treatment with TMX (77.2%) and CfAgNP (74.6%). A novel anti-cancer agent, developed by generating silver nanoparticles from C. fulvescens extract, showed strong cytotoxic activity against MCF-7 cells.

Physicochemical Characterization of Bioactive Compounds in Nanocarriers

The encapsulation of bioactive compounds is an emerging technique for finding new medicines since it provides protection against ambient degradation factors before reaching the target site. Nanotechnology provides new methods for encapsulating bioactive compounds and for drug carrier development. Nanocarriers satisfactorily impact the absorption, distribution, metabolism, and excretion rate when compared to conventional carriers. The nanocarrier material needs to be compatible and bind to the drug and be bio-resorbable. In this context, the physicochemical characterization of encapsulated bioactive compounds is fundamental to guarantee the quality, reproducibility, and safety of the final pharmaceutical product. In this review, we present the physicochemical techniques most used today by researchers to characterize bioactive compounds in nanocarriers and the main information provided by each technique, such as morphology, size, degree of crystallinity, long-term stability, the efficacy of drug encapsulation, and the amount released as a function of time.

Critical analysis of biophysicochemical parameters for qualitative improvement of phytogenic nanoparticles

Conventional chemical approaches for synthesizing nanoparticles (NPs) may restrict their applicability as they are not eco-friendly, energetically efficient and often involve toxic reducing/capping agents; but phytonanotechnology enabled the synthesis of safe, inexpensive, highly biocompatible NPs. In this regard, thorough understanding of green components and the modulatory effects of different reaction conditions on the physicochemical parameters of green synthesized NPs would be a prerequisite, which is not depicted elsewhere. This review critically analyzes the relevant reaction conditions from their mechanistic viewpoints in plant-based synthesis of NPs arising fundamental issues which need to be determined carefully. The size, stability and surface chemistry of phytogenic NPs may be fabricated as a function of multiple interconnected reaction parameters and the plant species used. The therapeutic potential of phytogenic NPs may depend on the plant species used; and so the meticulous understanding of physicochemical parameters and the family wise shorting of elite plant species may potentially benefit the theranostic future of plant-based NPs.

Anticancer potential of AgNPs synthesized using Acinetobacter sp. and Curcuma aromatica against HeLa cell lines: A comparative study

BACKGROUND

Biogenic nanoparticles are gaining attention due to their low toxicity and numerous biomedical applications. Present study aimed to compare the potential anticancer activity of two biogenic silver nanoparticles (bAgNPs and pAgNPs) against human cervical cancer cell lines (HeLa).

METHODS

bAgNPs were synthesized using Acinetobacter sp. whereas pAgNPs were synthesized using aqueous root extract of Curcuma aromatica. Effect of these nanoparticles on HeLa cells viability was studied using MTT assay and colony formation assay. Anticancer potential was determined using fluorescence microscopy and flow cytometry studies. Bio-compatibility studies were performed against peripheral blood mononuclear cells (PBMCs).

RESULTS

Both the nanoparticles showed 50 % viability of peripheral blood mononuclear cells (PBMCs) when used at high concentration (200 μg/mL). IC₅₀ for bAgNPs and pAgNPs against HeLa cells were 17.4 and 14 μg/mL respectively. Colony formation ability of Hela cells was reduced on treatment with both nanoparticles. Acridine orange and ethidium bromide staining demonstrated that bAgNPs were cytostatic whereas pAgNPs were apoptotic. JC-1 dye staining revealed that the mitochondrial membrane potential was affected on treatment with pAgNPs while it remained unchanged on bAgNPs treatment. Flow cytometry confirmed cell cycle arrest in HeLa cells on treatment with nanoparticles further leading to apoptosis in case of pAgNPs. About 77 and 58 % HeLa cells were found in subG1 phase on treatment with bAgNPs and pAgNPs respectively. bAgNPs showed cytostatic effect on HeLa cells arresting the cell growth in subG1 phase, whereas, pAgNPs triggered death of HeLa cells through mitochondrial membrane potential impairment and apoptosis.

CONCLUSION

Overall, bAgNPs and pAgNPs could be safe and showed potential to be used as anticancer nano-antibiotics against human cervical cancer cells.

Cytotoxic Effect of Silver Nanoparticles Synthesized by Green Methods in Cancer

Cancer is a major public health problem, but despite the several treatment approaches available, patients develop resistance in short time periods, making overcoming resistance or finding more efficient treatments an imperative challenge. Silver nanoparticles (AgNPs) have been described as an alternative option due to their physicochemical properties. The scope of this review was to systematize the available scientific information concerning these characteristics in AgNPs synthesized according to green chemistry's recommendations as well as their cytotoxicity in different cancer models. This is the first paper analyzing, correlating, and summarizing AgNPs' main parameters that modulate their cellular effect, including size, shape, capping, and surface plasmon resonance profile, dose range, and exposure time. It highlights the strong dependence of AgNPs' cytotoxic effects on their characteristics and tumor model, making evident the strong need of standardization and full characterization. AgNPs' application in oncology research is a new, open, and promising field and needs additional studies.

Synthesis, characteristics and medical applications of plant nanomaterials

The recent preparations of metal nanoparticles using plant extracts as reducing agents are summarized here. The synthesis and characterization of plant-metal nanomaterials and the progress in antibacterial and anti-inflammatory medical applications are detailed, providing a new vision for plant-based medical applications. The medical application of plant-metal nanoparticles is becoming a research hotspot. Compared with traditional preparation methods, the synthesis of plant-metal nanoparticles is less toxic and more eco-friendly, increasing application potential. Highly efficient plant-metal nanoparticles are usually smaller than 100 nm. This review describes the synthesis, characterization and bioactivities of gold- and silver-plant nanoparticles as examples and clearly explained their antibacterial and anticancer mechanisms. An analysis of actual cases shows that the synthetic method and type of plant extract affect the activities of the products.

Efficacy of Antimicrobial and Larvicidal Activities of Green Synthesized Silver Nanoparticles Using Leaf Extract of Plumbago auriculata Lam

This work reports the synthesis of silver nanoparticles (AgNPs) using aqueous extract of Plumbago auriculata, and evaluates their antibacterial and larvicidal activities. The synthesized silver nanoparticles were characterized by various spectroscopy techniques, such as FTIR, XRD, TEM, EDX, Zeta potential, and DLS. The synthesized AgNPs exhibited significant antibacterial activity against Gram-positive and Gram-negative bacteria, such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae. Furthermore, synthesized nanoparticles inhibited the fourth instars larvae of Aedes aegypti and Culex quinquefasciatus at the concentration of 45.1 and 41.1 µg/mL respectively. Results of dose-dependent studies showed that synthesized nanoparticles were also effective at low concentrations. Molecular docking studies performed with the salivary protein and odorant-binding protein of Aedes aegypti and Culex quinquefasciatus demonstrated that the naphthoquinone compound plumbagin exhibited reliable binding affinity towards the two enzymes. The findings thus reveal that the plant extract and its nanoparticles can be a better alternative to available chemicals to control mosquitos.

RP, Bahkali AH, Syed A, Shivamallu C. Phyto-Mediated Synthesis of Silver Nanoparticles Using Terminalia chebula Fruit Extract and Evaluation of Its Cytotoxic and Antimicrobial Potential

The increasing interest in developing potent non-toxic drugs in medicine is widening the opportunities for studying the usage of nanostructures in the treatment of various diseases. The present work reports a method for a facile and an eco-friendly synthesis of silver nanoparticles (AgNPs) using Terminalia chebula fruit extract (TCE). The obtained AgNPs was characterized by using different spectroscopic and microscopic techniques. The analysis of the results revealed that the as-obtained AgNPs have spherical morphology with an average diameter of 22 nm. Furthermore, the preliminary bioactivity evaluations revealed that the bio-conjugation of AgNPs, using TCE, significantly enhanced the antibacterial and anti-breast cancer potentials of the latter. The antibacterial activity of the as-prepared AgNPs showed that B. subtilis was more sensitive towards the AgNPs, followed by P. aeruginosa; while, E. coli and S. mutans showed comparatively minimal sensitivity toward the AgNPs. The IC₅₀ values of TCE, AgNPs and TCE + AgNPs treatment of MCF-7 were found to be 17.53, 14.25 and 6.484 µg/mL, respectively. Therefore, it can be ascertained that the bio-conjugation may provide a headway with regard to the therapeutic employment of T. chebula, upon mechanistically understanding the basis of observed antibacterial and anticancer activities.

Combination drug therapy for multimodal treatment of cancer by targeting mitochondrial transcriptional pathway: An in-silico approach

Cancer pathologies are deeply associated with mitochondrial dysfunction. TFAM, transcription factor A of mitochondria plays eminent role in transcription and replication of mtDNA to synthesize different mitochondrial proteins, has been reported to have elevated levels during malignancy and can be a compelling target of the disease. We hypothesize that violacein and silver nanoparticles, as a dyad drug system, can structurally bind and inhibit TFAM at the interface of TFAM-DNA complex during replication and thus can hinder majority of pathways contributing to cancer proliferation. It is evident from our molecular docking analysis of violacein and silver nanoparticles with the TFAM-DNA complex which gave resulting negative binding energy of -8.836 kcal/mol for violacein with inhibition constant (Ki value) of 1.51 μM and high binding score of 9518 for silver nanoparticle in the DNA interacting cavity of TFAM. Hence, our hypothesis of employing violacein and silver nanoparticle for cancer treatment by TFAM inhibition seems highly promising and further in-vitro and in-vivo studies are extremely demanded in this concern.

Silver nanoparticles: Synthesis, medical applications and biosafety

Silver nanoparticles (AgNPs) have been one of the most attractive nanomaterials in biomedicine due to their unique physicochemical properties. In this paper, we review the state-of-the-art advances of AgNPs in the synthesis methods, medical applications and biosafety of AgNPs. The synthesis methods of AgNPs include physical, chemical and biological routes. AgNPs are mainly used for antimicrobial and anticancer therapy, and also applied in the promotion of wound repair and bone healing, or as the vaccine adjuvant, anti-diabetic agent and biosensors. This review also summarizes the biological action mechanisms of AgNPs, which mainly involve the release of silver ions (Ag+), generation of reactive oxygen species (ROS), destruction of membrane structure. Despite these therapeutic benefits, their biological safety problems such as potential toxicity on cells, tissue, and organs should be paid enough attention. Besides, we briefly introduce a new type of Ag particles smaller than AgNPs, silver Ångstrom (Å, 1 Å = 0.1 nm) particles (AgÅPs), which exhibit better biological activity and lower toxicity compared with AgNPs. Finally, we conclude the current challenges and point out the future development direction of AgNPs.

An Assessment of the Effect of Green Synthesized Silver Nanoparticles Using Sage Leaves (Salvia officinalis L.) on Germinated Plants of Maize (Zea mays L.)

AgNPs have attracted considerable attention in many applications including industrial use, and their antibacterial properties have been widely investigated. Due to the green synthesis process employed, the nanoparticle surface can be coated with molecules with biologically important characteristics. It has been reported that increased use of nanoparticles elevates the risk of their release into the environment. However, little is known about the behaviour of AgNPs in the eco-environment. In this study, the effect of green synthesized AgNPs on germinated plants of maize was examined. The effects on germination, basic growth and physiological parameters of the plants were monitored. Moreover, the effect of AgNPs was compared with that of Ag(I) ions in the form of AgNO₃ solution. It was found that the growth inhibition of the above-ground parts of plants was about 40%, and AgNPs exhibited a significant effect on photosynthetic pigments. Significant differences in the following parameters were observed: weights of the caryopses and fresh weight (FW) of primary roots after 96 h of exposure to Ag(I) ions and AgNPs compared to the control and between Ag compounds. In addition, the coefficient of velocity of germination (CVG) between the control and the AgNPs varied and that between the Ag(I) ions and AgNPs was also different. Phytotoxicity was proved in the following sequence: control < AgNPs < Ag(I) ions.