Green synthesis of gold nanoparticles using chlorogenic acid and their enhanced performance for inflammation

Greener healing: sustainable nanotechnology for advanced wound care

Wound healing involves a carefully regulated sequence of events, encompassing pro-inflammatory and anti-inflammatory stages, tissue regeneration, and remodeling. However, in individuals with diabetes, this process gets disrupted due to dysregulation caused by elevated glucose levels and pro-inflammatory cytokines in the bloodstream. Consequently, the pro-inflammatory stage is prolonged, while the anti-inflammatory phase is delayed, leading to impaired tissue regeneration and remodeling with extended healing time. Furthermore, the increased glucose levels in open wounds create an environment conducive to microbial growth and tissue sepsis, which can escalate to the point of limb amputation. Managing diabetic wounds requires meticulous care and monitoring due to the lack of widely available preventative and therapeutic measures. Existing clinical interventions have limitations, such as slow recovery rates, high costs, and inefficient drug delivery methods. Therefore, exploring alternative avenues to develop effective wound-healing treatments is essential. Nature offers a vast array of resources in the form of secondary metabolites, notably polyphenols, known for their antimicrobial, anti-inflammatory, antioxidant, glucose-regulating, and cell growth-promoting properties. Additionally, nanoparticles synthesized through environmentally friendly methods hold promise for wound healing applications in diabetic and non-diabetic conditions. This review provides a comprehensive discussion and summary of the potential wound-healing abilities of specific natural polyphenols and their nanoparticles. It explores the mechanisms of action underlying their efficacy and presents effective formulations for promoting wound-healing activity.

Green Synthesis of Gold Nanoparticles Using Liquiritin and Other Phenolics from Glycyrrhiza glabra and Their Anti-Inflammatory Activity

Phenolic compounds are the main phytochemical constituents of many higher plants. They play an important role in synthesizing metal nanoparticles using green technology due to their ability to reduce metal salts and stabilize them through physical interaction/conjugation to the metal surface. Six pure phenolic compounds were isolated from licorice (Glycyrrhiza glabra) and employed in synthesizing gold nanoparticles (AuNPs). The isolated compounds were identified as liquiritin (1), isoliquiritin (2), neoisoliquiritin (3), isoliquiritin apioside (4), liquiritin apioside (5), and glabridin (6). The synthesized AuNPs were characterized using UV, zeta sizer, HRTEM, and IR and tested for their stability in different biological media. The phenolic isolates and their corresponding synthesized NP conjugates were tested for their potential in vitro cytotoxicity. The anti-inflammatory effects were investigated in both normal and inflammation-induced settings, where inflammatory biomarkers were stimulated using lipopolysaccharides (LPSs) in the RAW 264.7 macrophage cell line. LPS, functioning as a mitogen, promotes cell growth by reducing apoptosis, potentially contributing to observed outcomes. Results indicated that all six pure phenolic isolates inhibited cell proliferation. The AuNP conjugates of all the phenolic isolates, except liquiritin apioside (5), inhibited cell viability. LPS initiates inflammatory markers by binding to cell receptors and setting off a cascade of events leading to inflammation. All the pure phenolic isolates, except isoliquiritin, neoisoliquiritin, and isoliquiritin apioside inhibited the inflammatory activity of RAW cells in vitro.

Direct Polyphenol Attachment on the Surfaces of Magnetite Nanoparticles, Using Vitis vinifera, Vaccinium corymbosum, or Punica granatum

This study presents an alternative approach to directly synthesizing magnetite nanoparticles (MNPs) in the presence of Vitis vinifera, Vaccinium corymbosum, and Punica granatum derived from natural sources (grapes, blueberries, and pomegranates, respectively). A modified co-precipitation method that combines phytochemical techniques was developed to produce semispherical MNPs that range in size from 7.7 to 8.8 nm and are coated with a ~1.5 nm thick layer of polyphenols. The observed structure, composition, and surface properties of the MNPs@polyphenols demonstrated the dual functionality of the phenolic groups as both reducing agents and capping molecules that are bonding with Fe ions on the surfaces of the MNPs via -OH groups. Magnetic force microscopy images revealed the uniaxial orientation of single magnetic domains (SMDs) associated with the inverse spinel structure of the magnetite (Fe3O4). The samples' inductive heating (H0 = 28.9 kA/m, f = 764 kHz), measured via the specific loss power (SLP) of the samples, yielded values of up to 187.2 W/g and showed the influence of the average particle size. A cell viability assessment was conducted via the MTT and NRu tests to estimate the metabolic and lysosomal activities of the MNPs@polyphenols in K562 (chronic myelogenous leukemia, ATCC) cells.

Nanoassemblies from the aqueous extract of roasted coffee beans modulate the behavioral and molecular effects of smoking withdrawal-induced anxiety in female rats

Antioxidant-rich plant extracts have demonstrated tremendous value as inflammatory modulators and as nanomaterial precursors. Chronic cigarette smoking alters neurotransmitter systems, particularly the glutamatergic system, and produces neuroinflammation. This study aimed to investigate the behavioral and molecular correlates of cigarette smoking withdrawal-induced anxiety-like behavior in rats, and whether these effects could be mitigated by the administration of antioxidant nanoassemblies prepared by spontaneous oxidation of dark-roasted Arabica coffee bean aqueous extracts. Four experimental groups of female Sprague-Dawley rats were randomly assigned to: (i) a control group that was only exposed to room air, (ii) a COF group that was administered 20 mg/kg of the coffee nanoassemblies by oral gavage, (iii) a SMOK group that was exposed to cigarette smoke and was given an oral gavage of distilled water, (iv) and a SMOK + COF group that was exposed to cigarette smoke and administered 20 mg/kg of the coffee nanoassemblies. Animals were exposed to cigarette smoke for 2 h per day, five days per week, with a 2-day withdrawal period each week. At the end of the 4th week, rats began receiving either distilled water or the coffee nanoassemblies before being exposed to cigarette smoke for 21 additional days. Weekly behavioral tests revealed that cigarette smoking withdrawal exacerbated anxiety, while the administration of the coffee nanoassemblies reduced this effect. The effect of cigarette smoking on astroglial glutamate transporters and nuclear factor kappa B (NF-κB) expression in brain subregions was also measured. Smoking reduced the relative mRNA and protein levels of the glutamate transporter 1 (GLT-1) and the cystine/glutamate antiporter (xCT), and increased the levels of NF-κB, but these effects were attenuated by the coffee nanoassemblies. Thus, administration of the antioxidant nanoassemblies decreased the negative effects of cigarette smoke, which included neuroinflammation, changes in glutamate transporters' expression, and a rise in anxiety-like behavior.

Chlorogenic Acid Restores Ovarian Functions in Mice with Letrozole-Induced Polycystic Ovarian Syndrome Via Modulation of Adiponectin Receptor

Around the world, polycystic ovary syndrome (PCOS) is a complex endocrine-metabolic condition that typically affects 6–20% of females. Our study’s major goal was to examine how chlorogenic acid (CGA) affected mice with endocrine and metabolic problems brought on by letrozole-induced PCOS. Group I served as the control for 81 days; Group II was given Letrozole (LETZ) orally at a dose of 6 mg/kg bw for 21 days to induce PCOS; Group III was given LETZ (6 mg/kg) for 21 days, followed by treatment with CGA (50 mg/kg bw daily) for 60 days. The study indicated that LETZ-treated mice displayed symptoms of PCOS, such as dyslipidemia, hyperinsulinemia, elevated testosterone, increases in inflammatory markers and malonaldehyde, and a decline in antioxidants (Ar, lhr, fshr, and esr2) in the ovaries. These alterations were affected when the mice were given CGA and were associated with reduced levels of adiponectin. Adiponectin showed interactions with hub genes, namely MLX interacting protein like (MLXIPL), peroxisome proliferator-activated receptor gamma Coactivator 1- alpha (PPARGC1), peroxisome proliferator-activated receptor gamma (Pparg), and adiponectin receptor 1 (Adipor1). Lastly, the gene ontology of adiponectin revealed that adiponectin was highly involved in biological processes. The findings from our research suggest that adiponectin has direct impacts on metabolic and endocrine facets of PCOS.

Advances in Production of Hydroxycinnamoyl-Quinic Acids: From Natural Sources to Biotechnology

Hydroxycinnamoyl-quinic acids (HCQAs) are polyphenol esters formed of hydroxycinnamic acids and (-)-quinic acid. They are naturally synthesized by plants and some micro-organisms. The ester of caffeic acid and quinic acid, the chlorogenic acid, is an intermediate of lignin biosynthesis. HCQAs are biologically active dietary compounds exhibiting several important therapeutic properties, including antioxidant, antimicrobial, anti-inflammatory, neuroprotective, and other activities. They can also be used in the synthesis of nanoparticles or drugs. However, extraction of these compounds from biomass is a complex process and their synthesis requires costly precursors, limiting the industrial production and availability of a wider variety of HCQAs. The recently emerged production through the bioconversion is still in an early stage of development. In this paper, we discuss existing and potential future strategies for production of HCQAs.

Retrospective analysis of the key molecules involved in the green synthesis of nanoparticles

Emerging nanotechnology leads to success in synthesizing and applying nanoparticles (NPs) using the green-chemistry approach. NPs synthesized using naturally derived materials are a potential alternative to chemical and physical methods because they are simple, cost-effective, eco-friendly, and lower the possibility of hazardous residues being released into the environment. Furthermore, NPs synthesized using the green synthesis approach are stable and biocompatible. However, because natural extracts contain a diverse spectrum of bioactive components, it is difficult to pinpoint the specific component involved in NP formation. Furthermore, the bioactive component contained in the extract changes based on a number of environmental factors; therefore, several studies began with the synthesis of NPs using a pure compound isolated from diverse natural sources. Hence, the present review paper makes an effort to retrospectively analyze the key compounds of the extracts which are responsible for the synthesis of the NPs. The analysis was carried out based on the physicochemical characteristics and biological activities of NPs synthesized from either the extract or the pure compounds. These pure-compound-based NPs were studied for their antimicrobial, antibiofilm, anti-inflammatory, anticancer, and antioxidant properties. In addition, the present review also describes progress in the study of pure compound-based numerous biological activities and the underlying mechanisms of action.

Green route synthesis of alpinia calcarata functionalized gold nanoparticles for nonlinear optical applications

Gold nanoparticles are synthesized from alpinia calcarata extract. The synthesized nanoparticles are considered for their structural, morphological and nonlinear optical properties. Powder X-ray diffraction analysis revealed the structural purity of the prepared samples. FTIR confirmed the presence of biomolecules involved in the reduction and stabilization process. UV–visible spectroscopic studies confirmed the Surface Plasmon Resonance of the prepared nanoparticle. HRTEM exposed the spherical shape morphology of the prepared gold nanoparticles. Zeta potential analysis inferred the stabilization of gold nanoparticles. The synthesised gold nanoparticles are found to be poly-dispersed with an average size of 15 nm. The studies suggest that the glucose and its complex in the alpinia calcarata extract are responsible for the reduction nanoparticles, whereas proteins act as capping agents around the nanoparticles. The Z-scan studies discovered the nonlinear optical behaviour and thus measured its parameters.

Validation of the traditional medicinal use of a Mexican endemic orchid (Prosthechea karwinskii) through UPLC-ESI-qTOF-MS/MS characterization of its bioactive compounds

Ethnopharmacological relevance

The orchid Prosthechea karwinskii is a medicinal orchid in Oaxaca, Mexico, used to treat diabetes, cough, wounds, and burns, prevent miscarriage and assist in labor. Each part of the plant (leaves, pseudobulbs, or flowers) is used by healers for certain treatment conditions, indicating that each part has different biocompounds with specific pharmacological activity.

Aim of the study

To characterize the biocompounds in extracts from leaves, pseudobulbs, and flowers of P. karwinskii and evaluate their ROS inhibition capacity to associate it with medicinal uses.

Materials and methods

The compounds present in extracts from leaves, pseudobulbs, and flowers of P. karwinskii were identified by UPLC-ESI-qTOF-MS/MS. The chemical differentiation of each extract was tested by principal component analysis (PCA) using compound intensity values. For each extract, total phenol and flavonoid contents were quantified. Their antioxidant capacity was evaluated ex vivo by inhibition of ROS with DCFH-DA and in vitro with DPPH radical.

Results

Based on the PCA, it was observed that some compounds were completely separated from others according to the correlation that they presented. The compounds common to all three plant parts were quinic, malic, succinic, azelaic, and pinellic acids. Among the compounds identified, two were exclusive to leaves, four to pseudobulbs, and ten to flowers. Some of the identified compounds have well-known antioxidant activity. The leaves had the highest content of total phenols and flavonoids, and the highest in vitro and ex vivo antioxidant capacity. A strong correlation was observed between phenol and flavonoid contents, and antioxidant capacity ex vivo and in vitro.

Conclusions

It was found that the bioactive compounds and antioxidant capacity of each part of the plant were associated with its traditional medicinal use. A pharmacological potential was also found in P. karwinskii for further biological studies because of the type of compounds it contained.

•

Compounds common and specific to each plant part were identified by UPLC-ESI-qTOF-MS/MS.

•

The biological activities reported for the identified compounds validate the traditional medicinal use of P. karwinskii.

•

Embelin (inflammation) is exclusive to leaves, phloridzin (diabetes) to pseudobulbs, and abscisic acid (in labor) to flowers.

•

In the literature, the antioxidant compounds are rutin, kaempferol-3-O-rutinoside, embelin, guanosine, and azelaic acid.

•

Pearson's correlation coefficients indicate that a higher content of phenols and flavonoids has a higher antioxidant capacity.

Sustained release of chlorogenic acid-loaded nanomicelles alleviates bone loss in mouse periodontitis

Abstract Periodontitis is a prevalent chronic inflammatory disease that destroys the periodontal supporting tissues, impinges on oral health, and is correlative with an increased risk of systemic disease. Currently, the...

Phytotoxic effects of biosynthesized ZnO nanoparticles using Betonica officinalis extract

The unique properties of nanoparticles create broad opportunities as regards their application in almost all disciplines of science and technology. There are many reports about the negative influence of nanoproducts on the environment and humans. Therefore, it is of vital importance to explore the impact of metal nanoparticles on plants. This is why this work is concerned with the phytotoxic activity of ZnO nanoparticles synthesized biologically from Betonica officinalis extract against the seed of Lepidium sativum, Linum flavum, Zea mays and Salvia hispanica-Chia. The obtained ZnO nanoparticles were characterized by UV-Vis, Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM) and Atomic Force Microscopy (AFM). Those methods made it possible to assess the structure and size of the obtained ZnO nanoparticles, which was 5 nm. The obtained ZnO nanoparticles exhibited significant toxic properties throughout the range of the tested concentrations. ZnO nanoparticles were the most toxic to Lepidium sativum, for which the IC50 value was 0.0000112 [mg/ml]. The solution of Zn(NO3)2 was toxic as well, as it inhibited the growth of the tested sample throughout the range of the tested concentrations.

Effect on Human Vascular Endothelial Cells of Au Nanoparticles Synthesized from Vitex mollis

A green method for synthesizing gold nanoparticles is proposed using hydroethanolic extract of Vitex mollis fruit (Vm extract) as a reducer and stabilizer. The formation of gold nanoparticles synthesized with Vm extract (AuVmNPs) was monitored by measuring the ultraviolet-visible spectra. The morphology and crystalline phase were determined using scanning electron microscopy, X-ray diffraction, and high-resolution transmission electron microscopy. Synthesized nanoparticles were generally spherical, and the size distribution obtained by transmission electron microscopy shows two populations with mean sizes of 12.5 and 22.5 nm. Cell viability assay using MTT and cellular apoptosis studies using annexin V on human umbilical vein endothelial cells (HUVECs) and the human mammary epithelial cell line (MCF10A) indicate that AuVmNPs have low toxicity. Cell migration tests indicate that AuVmNPs significantly inhibit HUVEC cell migration in a dose-dependent manner. The evaluation of the localization of AuVmNPs in HUVECs using confocal laser scanning microscopy indicates that nanoparticles penetrate cells and are found in the cytosol without preferential distribution and without entering the nucleus. The inhibitory effect on cellular migration and low toxicity suggest AuVmNPs as appropriate candidates in future studies of antiangiogenic activity.

Astaxanthin and its gold nanoparticles mitigate cadmium toxicity in rice by inhibiting cadmium translocation and uptake

Cadmium (Cd) is one of the main heavy metal in rice, Cd uptake by cereal crops from soil leads to toxicity in plants and pose serious health risks due to human body's accumulation through the food chain. Astaxanthin, a natural and anti-oxidative oxycarotenoid, is widely distributed in various microorganisms and seafood. In this study, we demonstrated that astaxanthin in the form of gold nanoparticles (Ast-AuNPs) can efficiently alleviate Cd toxicity to a greater extent in hydroponically grown rice plants than single astaxanthin. When supplemented with 100 μg/mL Ast-AuNPs in medium, the Cd level of rice was significantly reduced by 26.2% (in roots) and 85.9% (in leaves), respectively. We also found Ast-AuNPs supplement restores chlorophyll biosynthesis and mitigate Cd-induced oxidative stresses: the contents of superoxide anion (O₂^-), hydrogen peroxide (H₂O₂), and malondialdehyde (MDA) were significantly reduced while the activity of the antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) was significantly elevated. Further study showed that the supplement of Ast-AuNPs inhibited Cd-induced gene expression of the metal transporter genes (OsHMA2, OsHMA3, OsIRT1, OsIRT2, OsNramp1, and OsNramp5) in rice roots. Moreover, Ast-AuNPs regulated the metabolism of free amino acids and increased the level of non-enzymatic antioxidants such as glutathione and ascorbic acid. Therefore, this study demonstrates that Ast-AuNPs could mitigate the Cd toxicity in rice seedlings by suppressing Cd uptake, scavenging of ROS, and enhancing the activity of antioxidants, and also expands the application of functional gold nanoparticles in the alleviation of heavy metal pollution in plants.

Green synthesis of gold nanoparticles for immune response regulation: Mechanisms, applications, and perspectives

Immune responses are involved in the pathogenesis of many diseases, including cancer, autoimmune diseases, and chronic inflammation. These responses are attributed to immune cells that produce cytokines, mediate cytotoxicity, and synthesize antibodies. Gold nanoparticles (GNPs) are novel agents that intervene with immune responses because of their unique physical-chemical properties. In particular, GNPs enhance anti-tumour activity during immunotherapy and eliminate excessive inflammation in autoimmune diseases. However, GNPs synthesized by conventional methods are toxic to living organisms. Green biosynthesis provides a safe and eco-friendly method to obtain GNPs from microbes or plant extracts. In this review, we describe several patterns for green GNP biosynthesis. The applications of GNPs to target immune cells and modulate the immune response are summarized. In particular, we elaborate on how GNPs regulate innate immunity and adaptive immunity, including inflammatory signaling and immune cell differentiation. Finally, perspectives and challenges in utilizing green biosynthesized GNPs for novel therapeutic approaches are discussed.

Biosynthetic gold nanoparticles of Hibiscus syriacus L. callus potentiates anti-inflammation efficacy via an autophagy-dependent mechanism

Biological applications of gold nanoparticles (AuNps) have potentially explored an efficient agent attributed to their biocompatibility and high efficiency in drug delivery. Our study applied an extract of Hibiscus syriacus L. callus (HCE) with a pioneer implementation on the induction of mass production. Bioactive compounds present in HCE were identified by Gas chromatography-mass spectrometry (GC-MS) and Liquid chromatography MS (LC-MS), wherein, the Denatonium was exclusively identifiable in HCE. Next, AuNps were synthesized and optimized using HCE (HCE-AuNps), and the comparison was conducted to evaluate the anti-inflammatory effect in lipopolysaccharide (LPS)-stimulated macrophages. As per result, HCE-AuNps was reported to show a prominent reduction of pro-inflammatory cytokines and renovate the mitochondrial function through restoring the mitochondrial membrane potential changes, decreasing reactive oxygen species (ROS) accumulation, and recovering ATP contents, respectively. Furthermore, the immunoblotting of LC3b/a accumulation, and p62 rapid degradation revealed that HCE-AuNps could induce the autophagy as an intracellular response to reinforce alleviation of pro-inflammatory cytokines and mitochondria dysfunction. Besides, 740 Y-P (PI3K agonist) was used to verify that inhibiting autophagy could partially reverse HCE-AuNps suppressed mitochondrial dysfunction, and thus exacerbated inflammation, supporting a causal role for autophagy in the anti-inflammatory effect of HCE-AuNps. Taken together, we strongly anticipate that HCE-AuNps would act as a potential autophagy inducer for LPS-triggered macrophage's inflammation, providing a novel insight for biosynthetic nanoparticles in the treatment of mitochondria dysfunction and inflammation related diseases.

Phaseolin Attenuates Lipopolysaccharide-Induced Inflammation in RAW 264.7 Cells and Zebrafish

Kushen (Radix Sophorae flavescentis) is used to treat ulcerative colitis, tumors, and pruritus. Recently, phaseolin, formononetin, matrine, luteolin, and quercetin, through a network pharmacology approach, were tentatively identified as five bioactive constituents responsible for the anti-inflammatory effects of S. flavescentis. However, the role of phaseolin (one of the primary components of S. flavescentis) in the direct regulation of inflammation and inflammatory processes is not well known. In this study, the beneficial role of phaseolin against inflammation was explored in lipopolysaccharide (LPS)-induced inflammation models of RAW 264.7 macrophages and zebrafish larvae. Phaseolin inhibited LPS-mediated production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), without affecting cell viability. In addition, phaseolin suppressed pro-inflammatory mediators such as cyclooxygenase 2 (COX-2), interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and interleukin-6 (IL-6) in a dose-dependent manner. Furthermore, phaseolin reduced matrix metalloproteinase (MMP) activity as well as macrophage adhesion in vitro and the recruitment of leukocytes in vivo by downregulating Ninjurin 1 (Ninj1), an adhesion molecule. Finally, phaseolin inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB). In view of the above, our results suggest that phaseolin could be a potential therapeutic candidate for the management of inflammation.

Neuroprotective Effect of Chlorogenic Acid on Mitochondrial Dysfunction-Mediated Apoptotic Death of DA Neurons in a Parkinsonian Mouse Model

Mitochondrial dysfunction and oxidative stress characterize major factors involved in the activation of complex processes corresponding to apoptosis-mediated neuronal senescence of dopaminergic neurons (DA) in Parkinson's disease (PD). Here, we evaluated the molecular mechanisms participating in the treatment of a 1-methyl-4-phenyl-1,2,3,6-tetrahydopyridine- (MPTP-) intoxicated PD mouse model in response to chlorogenic acid (CGA). The results indicate that CGA treatment significantly improved the motor coordination of the MPTP-intoxicated mice. CGA also alleviated the fall in activity of mitochondrial complexes I, IV, and V in accordance with ameliorating the level of superoxide dismutase and mitochondrial glutathione in the midbrain of MPTP-induced mice. CGA inhibited the activation of proapoptotic proteins including Bax and caspase-3, while elevating the expression of antiapoptotic protein like Bcl-2 consequently preventing the MPTP-mediated apoptotic cascade. The study also revealed the improved phosphorylation state of Akt, ERK1/2, and GSK3β which was downregulated as an effect of MPTP toxicity. Our findings signify that CGA may possess pharmacological properties and contribute to neuroprotection against MPTP induced toxicity in a PD mouse model associated with phosphorylation of GSK3β via activating Akt/ERK signalling in the mitochondrial intrinsic apoptotic pathway. Thus, CGA treatment may arise as a potential therapeutic candidate for mitochondrial-mediated apoptotic senescence of DA neurons in PD.

Advances in the application of gold nanoparticles in bone tissue engineering

The materials used in bone tissue engineering (BTE) have been advancing with each passing day. With the continuous development of nanomedicine, gold nanoparticles (GNPs), which are easy to be synthesized and functionalized, have attracted increasing attention. Recent years have witnessed this amazing material, i.e., GNPs characterized with large surface area to volume ratio, biocompatibility, medical imaging property, hypotoxicity, translocation into the cells, high reactivity, and other properties, perform distinct functions in BTE. However, the low stability of GNPs in the biotic environment makes them in the requirements of modification or recombination before being used. After being combined with the advantages of other materials, the structures of GNPs have exhibited great potential in stem cells, scaffolds, delivery systems, medical imaging, and other aspects. This review will focus on the advances in the application of GNPs after modification or recombination with other materials to BTE.

Synthesis of antibacterial gold nanoparticles with different particle sizes using chlorogenic acid

This study proposes a strategy for the rapid and simple synthesis of gold nanoparticles (CGA-AuNPs) with different particle sizes using trisodium citrate (TSC) as the first reducing agent and chlorogenic acid (CGA) as the second reducing agent. And the antibacterial activity of CGA-AuNPs with different particle sizes in vitro was checked by measuring the growth curves of Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923). The CGA-AuNPs obtained by the analysis of transmission electron microscope (TEM) images and ultraviolet-visible (UV-Vis) spectra were mainly spherical, and the average diameters were 18.94 ± 1.81, 30.42 ± 6.32, 37.86 ± 3.80 and 48.72 ± 6.47 nm, respectively. High-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) showed that these nanoparticles were polycrystalline gold structures. Both CGA-AuNPs and CGA have excellent antibacterial activity, and CGA-AuNPs with small particle size has a stronger antibacterial effect than the larger one. UV-Vis absorption spectrum data revealed that the synthesized CGA-AuNPs without adding other stabilizing agent were well maintained even after 26 days. This work provides a special idea to regulate the size of CGA-AuNPs with CGA by chemical synthesis, and the potent antibacterial activity of these CGA-AuNPs may be applied in the field of antibacterial in the future.

Antidiabetic Activity of Gold Nanoparticles Synthesized Using Wedelolactone in RIN-5F Cell Line

We synthesized the gold nanoparticles (AuNPs) using wedelolactone (WDL) and characterized them using UV-visible spectroscopy, fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopic (SEM), transmission electron microscopic (TEM), energy dispersive X-ray diffraction, and atomic force microscopic (AFM) studies. The electronic spectrum exhibited an absorption peak at 535 nm. The FT-IR results proved that WDL was stabilized on the surface of AuNPs by acting as a capping or reducing agent. The crystalline structure was affirmed by XRD pattern and the spherical shape of WDL-AuNPs was evidenced by SEM, TEM, and AFM. The synthesized WDL-AuNPS were evaluated for anti-diabetic activity in pancreatic RIN-5F cell lines. In vitro results showed that WDL-AuNPs did not only improve the insulin secretion affected by di-(2-ethylhexyl) phthalate (DEHP), but also the cell viability in RIN5F cells. WDL-AuNPs treatment modulates the pro-apoptotic proteins and anti-apoptotic proteins expression to prevent the cells undergoing apoptosis in DEHP-exposed RIN-5F cells. The exposure of DEHP causes an increase in ROS production and lipid peroxidation levels. The free radical scavenging and antioxidant properties of WDL-AuNPs increase the deleterious effect caused by DEHP. On the other side, WDL-AuNPs increase mRNA expressions of insulin-signaling proteins in RIN-5F cells. This study concludes that WDL-AuNPs can be successfully used to regulate the expression of Bcl-2 family proteins, reduce lipid peroxidation, and to improve the secretion of antioxidants and insulin through the GLUT2 pathway in RIN-5F cell lines.

NF-κB-Mediated Neuroinflammation in Parkinson's Disease and Potential Therapeutic Effect of Polyphenols

Different animal and human studies from last two decades in the case of Parkinson's disease (PD) have concentrated on oxidative stress due to increased inflammation and cytokine-dependent neurotoxicity leading to induction of dopaminergic (DA) degeneration pathway in the nigrostriatal region. Chronic inflammation, the principle hallmark of PD, forms the basis of neurodegeneration. Aging in association with activation of glia due to neuronal injury, perhaps because of immune alterations and genetic predispositions, leads to deregulation of inflammatory pathways premising the onset of PD. A family of inducible transcription factors, nuclear factor-κB (NF-κB), is found to show expression in various cells and tissues, such as microglia, neurons, and astrocytes which play an important role in activation and regulation of inflammatory intermediates during inflammation. Both canonical and non-canonical NF-κB pathways are involved in the regulation of the stimulated cells. During the prodromal/asymptomatic stage of age-associated neurodegenerative diseases (i.e., PD and AD), chronic neuroinflammation may act silently as the driver of neuronal dysfunction. Though research has provided an insight over age-related neurodegeneration in PD, elaborative role of NF-κB in neuroinflammation is yet to be completely understood and thus requires more investigation. Polyphenols, a group of naturally occurring compound in medicinal plants, have gained attention because of their anti-oxidative and anti-neuroinflammatory properties in neurodegenerative diseases. In this aspect, this review highlights the role of NF-κB and the possible therapeutic roles of polyphenols in NF-κB-mediated neuroinflammation in PD.

Metal nanoparticles synthesis through natural phenolic acids

For being applied in medicine as therapeutic agents, nanostructures need to be biocompatible and eco-friendly. Plant-derived phenolic acids have been utilised for green synthesis of metallic or metallic oxide nanoparticles (NPs). The phenolic acids play role as both reducing agents and stabilisers in the process of NPs synthesis. Many experiments have been dedicated to develop efficient green synthesis techniques for producing metal NPs. Using phenolic acids represents a reproducible, simple, profitable, and cost-effective strategy to synthesise metal NPs. As a phytochemical for metal NPs synthesis, phenolic acids are antioxidants that represent many health benefits. However, limited studies have been dedicated to the synthesis and characterisation of NPs produced by phenolic acids. Thus, this review focused on phenolic acids mediated nanomaterial synthesis and its biomedical applications. It should be noted the mechanism of metal ion bioreduction, phenolic acids surface adsorption, characterisation, and toxicity of metal NPs made with different phenolic acids have been discussed in this review.

Structural Optimization of Caffeoyl Salicylate Scaffold as NO Production Inhibitors

Chlorogenic acid (CGA) has been considered as one of important active components in a number of medicinal herbs. Recently our group demonstrated that caffeoyl salicylate scaffold derived from CGA can be employed for the development of novel anti-inflammatory agents. The most active compound D104 can be a very promising starting point for the further structural optimization. A series of novel caffeoyl salicylate analogs were designed, synthesized, and evaluated by preliminary biological evaluation. The obtained results showed that the two compounds B12 and B13 can not only inhibit production of nitric oxide (NO) in RAW264.7 cells induced by lipopolysaccharides (LPS) effectively, but also have high safety in in vitro cytotoxic test, which could be comparable with D104. Molecular docking study on the peroxisome proliferator-activated receptor γ (PPARγ) protein revealed that compounds B12 and B13 can follow the same binding mode with D104, and the carboxyl group of caffeoyl salicylate scaffold might play a key role in the interaction with protein target, which implied the carboxyl group should be retained in the further optimization.

Multifunctionality of gold nanoparticles: Plausible and convincing properties

In a couple of decades, nanotechnology has become a trending area in science due to it covers all subject that combines diverse range of fields including but not limited to chemistry, physics and medicine. Various metal and metal oxide nanomaterials have been developed for wide range applications. However, the application of gold nanostructures and nanoparticles has been received more attention in various biomedical applications. The unique property of gold nanoparticles (AuNPs) is surface plasmon resonance (SPR) that determine the size, shape and stability. The wide surface area of AuNPs eases the proteins, peptides, oligonucleotides, and many other compounds to tether and enhance the biological activity of AuNPs. AuNPs have multifunctionality including antimicrobial, anticancer, drug and gene delivery, sensing applications and imaging. This state-of-the-art review is focused on the role of unique properties of AuNPs in multifunctionality and its various applications.

Synthesis of arbutin-gold nanoparticle complexes and their enhanced performance for whitening

Arbutin, a natural polyphenol, possesses numerous biological activities including whitening, anti-oxidant, anti-cancer, anti-inflammatory activities, as well as strong reducing power, making it an ideal bioactive ingredient for preparing gold nanoparticles (GNPs). Previously, we developed a novel green, mild synthetic method for GNPs using glycosides such as arbutin as reducing agents and stabilizers. Herein, we optimized the synthetic method for glycoside-GNPs using arbutin, methyl β-D-glucoside, and phenyl β-D-glucoside and validated their whitening efficacy in vitro and in vivo. The resulting glycoside-GNPs were predominantly mono-dispersed and spherical (10.30-17.13 nm diameter). Compared with arbutin itself, arbutin-GNP complexes (GNP-A1 and GNP-P2) displayed enhanced whitening capabilities. Furthermore, GNP-P2 exhibited enhanced anti-inflammatory activity and lacked the toxicity associated with arbutin. Bioactive glycoside-GNP complexes may open new directions for cosmeceuticals, and GNP-P2 may serve as a useful whitening ingredient in future cosmeceutical applications.

Functionalized Nanomaterial Assembling and Biosynthesis Using the Extremophile Deinococcus radiodurans for Multifunctional Applications

The development of functionalized nanomaterial biosynthesis processes is important to expand many cutting-edge nanomaterial application areas. However, unclear synthesis mechanisms and low synthesis efficiency under various chemical stresses have limited the use of these biomaterials. Deinococcus radiodurans is an extreme bacterium well known for its exceptional resistance to radiation oxidants and electrophilic agents. This extremophile, which possesses a spontaneous self-assembled surface-layer (S-layer), has been an optimal model organism to study microbial nanomaterial biotemplates and biosynthesis under various stresses. This review summarizes the S-layers from D. radiodurans as an excellent biotemplate for various pre-synthesized nanomaterials and multiple applications, and highlights recent progresses about the biosynthesis of functionalized gold nanoparticles (AuNPs), silver nanoparticles (AgNPs), as well as gold and silver bimetallic nanoparticles using D. radiodurans. Their formation mechanisms, properties, and applications are discussed and summarized to provide significant insights into the design or modification of functionalized nanomaterials via natural materials. Grand challenges and future directions to realize the multifunctional applications of these nanomaterials are highlighted for a better understanding of their biosynthesis mechanisms and functionalized modifications.

Green synthesis of gold nanoparticles using Euphrasia officinalisleaf extract to inhibit lipopolysaccharide-induced inflammation through NF-κB and JAK/STAT pathways in RAW 264.7 macrophages

Background

Gold nanoparticles (AuNPs) have potential applications in the treatment and diagnosis process, which are attributed to their biocompatibility and high efficiency of drug delivery. In the current study, we utilized an extract of Euphrasia officinalis, a traditional folk medicine, to synthesize gold nanoparticles (EO-AuNPs), and investigated their anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages.

Materials and methods

The AuNPs were synthesized from an ethanol extract of E. officinalis leaves and characterized using several analytical techniques. Anti-inflammatory activities of EO-AuNPs were detected by a model of LPS-induced upregulation of inflammatory mediators and cytokines including nitric oxide (NO), inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), IL-1β, and IL-6 in RAW 264.7 cells. The activation of nuclear factor (NF)-κB and Janus kinase/signal transducer and activators of transcription (JAK/STAT) signaling pathways was investigated by Western blot.

Results

The results confirmed the successful synthesis of AuNPs by E. officinalis. Transmission electron microscopy images showed obvious uptake of EO-AuNPs and internalization into intracellular membrane–bound compartments, resembling endosomes and lysosomes by RAW 264.7 cells. Cell viability assays showed that EO-AuNPs exhibited little cytotoxicity in RAW 264.7 cells at 100 µg/mL concentration after 24 hours. EO-AuNPs significantly suppressed the LPS-induced release of NO, TNF-α, IL-1β, and IL-6 as well as the expression of the iNOS gene and protein in RAW 264.7 cells. Further experiments demonstrated that pretreatment with EO-AuNPs significantly reduced the phosphorylation and degradation of inhibitor kappa B-alpha and inhibited the nuclear translocation of NF-κB p65. In addition, EO-AuNPs suppressed LPS-stimulated inflammation by blocking the activation of JAK/STAT pathway.

Conclusion

The synthesized EO-AuNPs showed anti-inflammatory activity in LPS-induced RAW 264.7 cells, suggesting they may be potential candidates for treating inflammatory-mediated diseases.

Gold Nanoparticles Biosynthesized and Functionalized Using a Hydroxylated Tetraterpenoid Trigger Gene Expression Changes and Apoptosis in Cancer Cells

Understanding the synthetic mechanisms and cell-nanoparticle interactions of biosynthesized and functionalized gold nanoparticles (AuNPs) using natural products is of great importance for developing their applications in nanomedicine. In this study, we detailed the biotransformation mechanism of Au(III) into AuNPs using a hydroxylated tetraterpenoid deinoxanthin (DX) from the extremophile Deinococcus radiodurans. During the process, Au(III) was rapidly reduced to Au(I) and subsequently reduced to Au(0) by deprotonation of the hydroxyl head groups of the tetraterpenoid. The oxidized form, deprotonated 2-ketodeinoxanthin (DX3), served as a surface-capping agent to stabilize the AuNPs. The functionalized DX-AuNPs demonstrated stronger inhibitory activity against cancer cells compared with sodium citrate-AuNPs and were nontoxic to normal cells. DX-AuNPs accumulated in the cytoplasm, organelles, and nuclei, and induced reactive oxygen species generation, DNA damage, and apoptosis within MCF-7 cancer cells. In the cells treated with DX-AuNPs, 374 genes, including RRAGC gene, were upregulated; 135 genes, including the genes encoding FOXM1 and NR4A1, were downregulated. These genes are mostly involved in metabolism, cell growth, DNA damage, oxidative stress, autophagy, and apoptosis. The anticancer activity of the DX-AuNPs was attributed to the alteration of gene expression and induction of apoptosis. Our results provide significant insight into the synthesis mechanism of AuNPs functionalized with natural tetraterpenoids, which possess enhanced anticancer potential.

Effect of Chlorogenic Acid Supplementation in MPTP-Intoxicated Mouse

Oxidative stress and neuroinflammation play a key role in dopaminergic (DA) neuronal degeneration, which results in the hindrance of normal ongoing biological processes in the case of Parkinson's disease. As shown in several studies, on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration, different behavioral parameters have suggested motor impairment and damage of antioxidant defence. Thus, some specific biological molecules found in medicinal plants can be used to inhibit the DA neuronal degeneration through their antioxidant and anti-inflammatory activities. With this objective, we studied chlorogenic acid (CGA), a naturally occurring polyphenolic compound, for its antioxidant and anti-inflammatory properties in MPTP-intoxicated mice. We observed significant reoccurrence of motor coordination and antioxidant defence on CGA supplementation, which has been in contrast with MPTP-injected mice. Moreover, in the case of CGA-treated mice, the enhanced expression of tyrosine hydroxylase (TH) within the nigrostriatal region has supported its beneficial effect. The activation of glial cells and oxidative stress levels were also estimated using inducible nitric oxide synthase (iNOS) and glial fibrillary acidic protein (GFAP) immunoreactivity within substantia nigra (SN) and striatum of MPTP-injected mice. Administration of CGA has prevented the neuroinflammation in SN by regulating the nuclear factor-κB expression in the MPTP-induced group. The significant release of certain pro-inflammatory mediators such as tumor necrosis factor-α and interleukin (IL)-1β has also been inhibited by CGA with the enhanced expression of anti-inflammatory cytokine IL-10. Moreover, reduced GFAP staining within the nigrostriatal region has supported the fact that CGA has significantly helped in the attenuation of astrocyte activation. Hence, our study has shown that CGA supplementation shows its therapeutic ability by reducing the oxidative stress and neuroinflammation in MPTP-intoxicated mice.

Secondary Metabolites in the Green Synthesis of Metallic Nanoparticles

The ability of organisms and organic compounds to reduce metal ions and stabilize them into nanoparticles (NPs) forms the basis of green synthesis. To date, synthesis of NPs from various metal ions using a diverse array of plant extracts has been reported. However, a clear understanding of the mechanism of green synthesis of NPs is lacking. Although most studies have neglected to analyze the green-synthesized NPs (GNPs) for the presence of compounds derived from the extract, several studies have demonstrated the conjugation of sugars, secondary metabolites, and proteins in these biogenic NPs. Despite several reports on the bioactivities (antimicrobial, antioxidant, cytotoxic, catalytic, etc.) of GNPs, only a handful of studies have compared these activities with their chemically synthesized counterparts. These comparisons have demonstrated that GNPs possess better bioactivities than NPs synthesized by other methods, which might be attributed to the presence of plant-derived compounds in these NPs. The ability of NPs to bind with organic compounds to form a stable complex has huge potential in the harvesting of precious molecules and for drug discovery, if harnessed meticulously. A thorough understanding of the mechanisms of green synthesis and high-throughput screening of stabilizing/capping agents on the physico-chemical properties of GNPs is warranted to realize the full potential of green nanotechnology.

The aqueous extract from Artemisia capillaris inhibits acute gastric mucosal injury by inhibition of ROS and NF-kB

Artemisia capillaris, also called "InJin" in Korean, has been used as traditional oriental medicine in Korea because of its various pharmacological activities. These include hepatoprotective, analgesic, and antipyretic activities. The present study was designed to validate the beneficial effects of the aqueous extract of A. capillaris (AEAC) against acute gastric mucosal injury and investigate the underlying molecular mechanisms. The pharmacological efficacy of AEAC was evaluated using the gastric ulcer index and histological examination. AEAC decreased gastric mucosal lesions mediated by HCl/ethanol in vivo in a dose-dependent manner. Interestingly, the mucosal damage was almost prevented by pretreatment with 200 or 400?mg/kg AEAC. However, AEAC did not have acid-neutralizing activity in vitro and did not prevent histamine secretion in HMC-1 mast cells. In the gastric mucosa, AEAC also significantly inhibited lipid peroxide formation through superoxide dismutase (SOD) activation. Moreover, AEAC strongly reduced the generation of pro-inflammatory cytokines, such as interleukin-6 (IL-6) and interleukin-1? (IL-1?), through nuclear factor kappa B (NF-?B) downregulation. Taken together, our findings suggest that AEAC inhibits inflammation and maintains oxidant/antioxidant homeostasis, resulting in a gastro-protective effect against HCl/ethanol-induced gastric damage. Therefore, AEAC might be a promising drug or useful neutraceutical for treatment of gastritis and gastric ulcer.

A self-assembly nanodrug delivery system based on amphiphilic low generations of PAMAM dendrimers-ursolic acid conjugate modified by lactobionic acid for HCC targeting therapy

Ursolic acid (UA), a natural triterpene acid, is a promising anti-cancer drug due to its inhibitory effect on tumor growth and metastasis. However, clinical translation of UA is limited by its poor water solubility and low bioavailability. To overcome these problems, herein an amphiphilic self-assembly nanodrug composed of UA, lactobionic acid (LA) and low-polyamidoamine (low-PAMAM) dendrimers is developed. This near-spherical nanodrug with a uniform size (~180 nm) demonstrated to have an enhanced cytotoxicity against liver cancer SMMC7721 cells, and could attenuate the migration and adhesion of SMMC7721 cells at non-toxic concentrations by suppressing metastasis-related protein MMP-9 expression. Furthermore, in vivo study indicates that the nanodrug exhibited prolonged circulation time in blood as well as increased AUC, MRT and Cmax, and could effectively inhibit the tumor growth in H22 mice model. Overall, the UA-based nanodrug delivery system reported in the present work represents a novel strategy for targeted tumor therapy.

Synthesis of gold nanomaterials and their cancer-related biomedical applications: an update

Recently, the advances in the synthesis of new types of nanomaterials have created several opportunities in drug delivery and targeted therapy applications. Among the various nanostructures, gold nanostructures with controllable physical and chemical properties have received attention for various biomedical uses, including sensing of biomolecules, in vitro and in vivo bioimaging (as advanced contrast agents for photothermal and bioimaging techniques), photothermolysis of cancer cells, and targeted drug delivery. The attractive properties of gold nanomaterials, particularly, anti-angiogenic properties, are highly useful in a variety of cancers studies. In addition, they can bind many proteins and drugs and can be actively targeted to cancer cells over-expressing cell surface receptors and they are biocompatible in nature with a high atomic number, which directs to greater absorption of kilovoltage X-rays and provides greater contrast than standard agents. In this review, we have summarized the synthesis, structure and functionalization of gold nanostructures, and their biomedical applications with special reference to cancer studies.

Kalopanacis Cortex extract-capped gold nanoparticles activate NRF2 signaling and ameliorate damage in human neuronal SH-SY5Y cells exposed to oxygen-glucose deprivation and reoxygenation

Recently, environment-friendly synthesis of gold nanoparticles (GNPs) has been extensively explored by biologists and chemists. However, significant research is still required to determine whether “eco-friendly” GNPs are beneficial to human health and to elucidate the molecular mechanisms of their effects on human cells. We used human neuronal SH-SY5Y cells to show that treatment with Kalopanacis Cortex extract-capped GNPs (KC-GNs), prepared via an eco-friendly, fast, one-pot synthetic route, protected neuronal cells against oxygen–glucose deprivation/reoxygenation (OGD/R)-induced damage. To prepare GNPs, Kalopanacis Cortex was used without any chemical reducing and stabilizing agents. Ultraviolet–visible spectroscopy showed maximum absorbance at 526 nm owing to KC-GN surface plasmon resonance. Hydrodynamic size (54.02±2.19 nm) and zeta potential (−20.3±0.04 mV) were determined by dynamic light scattering. The average diameter (41.07±3.05 nm) was determined by high-resolution transmission electron microscopy. Energy-dispersive X-ray diffraction spectroscopy and X-ray diffraction confirmed the presence of assembled GNPs. Fourier transform infrared analysis suggested that functional groups such as O–H, C–C, and C–N participated in KC-GN formation. Cell viability assays indicated that KC-GNs restored the viability of OGD/R-treated SH-SY5Y cells. Flow cytometry demonstrated that KC-GNs inhibited the OGD/R-induced reactive oxygen species production and mitochondrial membrane potential disruption. KC-GNs also inhibited the apoptosis of OGD/R-exposed cells. Western blot analysis indicated that the OGD/R-induced cellular apoptosis and simultaneous increases in the expression of cleaved caspase-3, p53, p21, and B-cell lymphoma 2-associated X protein were reversed by KC-GNs. The KC-GN-mediated protection against OGD/R-induced neurotoxicity was diminished by NRF2 and heme oxygenase-1 gene knockdowns. Collectively, these results suggested that KC-GNs exerted strong neuroprotective effects on human neuronal cells, which might be attributed to the attenuation of OGD/R-induced neuronal cell injury through the NRF2 signaling pathway.

Facile Synthesis of Gold Nanoparticles with Alginate and Its Catalytic Activity for Reduction of 4-Nitrophenol and H₂O₂ Detection

Gold nanoparticles (AuNPs) were synthesized using a facile solvothermal method with alginate sodium as both reductant and stabilizer. Formation of AuNPs was confirmed by UV-vis spectroscopic analysis. The synthesized AuNPs showed a localized surface plasmon resonance at approximately 520-560 nm. The AuNPs were characterized using transmission electron microscopy, X-ray diffraction and dynamic light scattering. Transmission electron microscopy revealed that the AuNPs were mostly nanometer-sized spherical particles. Powder X-ray diffraction analysis proved the formation of face-centered cubic structure of Au. Catalytic reduction of 4-nitrophenol was monitored via spectrophotometry using AuNPs as catalyst, and further a non-enzymatic sensor was fabricated. The results demonstrated that AuNPs presented excellent catalytic activity and provided a sensitive response to H₂O₂ detection.

Recent advances in green nanoparticulate systems for drug delivery: efficient delivery and safety concern

Nanotechnology manipulates therapeutic agents at the nanoscale for the development of nanomedicines. However, there are current concerns over nanomedicines, mainly related to the possible toxicity of nanomaterials used for health medications. Due to their small size, they can enter the human body more readily than larger sized particles. Green chemistry encompasses the green synthesis of drug-loaded nanoparticles by reducing the use of hazardous materials in the synthesis process, thus reducing the adverse health impacts of pharmaceutics. This would greatly expand their potential in biomedical treatments. This review highlights the potential risks of nanomedicine formulations to health, delivery routes of green nanomedicines, recent advances in the development of green nanoscale systems for biomedical applications and future perspectives for the green development of nanomedicines.