Josua Markus

Intracellular synthesis of gold nanoparticles with antioxidant activity by probiotic Lactobacillus kimchicus DCY51T isolated from Korean kimchi

A straightforward synthesis of gold nanoparticles (AuNps) is achieved by novel probiotic Lactobacillus kimchicus DCY51T isolated from Korean kimchi via an intracellular membrane-bound mechanism. The bioreduction of HAuCl4 into AuNps was verified by ultraviolet-visible spectrophotometry at ∼540nm. AuNps were spherical with varying sizes of 5-30nm. AuNps maintained an average crystallite size of 13nm and demonstrated long-term stability in physiological buffer and biological media. Furthermore, the protective capping layer consisted of amino acid residues and surface-bound proteins rendered them non-toxic to murine macrophage (RAW264.7) and human colorectal adenocarcinoma (HT29) cell lines. Finally, biosynthesized AuNps served as superior free radical scavengers against 2,2-diphenyl-1-picrylhydrazyl (DPPH) in contrast to their corresponding gold salt. In short, this green synthesis is cost-effective and advantageous for the development of a new class of probiotics mediated and non-toxic carriers in targeted drug delivery systems, cancer diagnostic, photothermal therapy, biosensing, and medical imaging.

Cardamom fruits as a green resource for facile synthesis of gold and silver nanoparticles and their biological applications

Abstract Gold (FA-AuNps) and silver (FA-AgNps) nanoparticles were synthesized at room temperature by aqueous extract of dried fruits of Amomum villosum, also known as Fructus Amomi (cardamom), in order to confer antioxidant, catalytic, antimicrobial activities and treatment effect against breast cancer cells. Fruit extracts served as both reducing agents and stabilizers in lieu of chemical agents. Ultra-violet visible (UV-Vis) spectroscopy, field emission transmission electron microscopy (FE-TEM), energy-dispersive X-ray (EDX) spectroscopy, elemental mapping, X-ray powder diffraction (XRD), selected area electron diffraction (SAED), dynamic light scattering (DLS) and Fourier transform infrared (FTIR) spectroscopy were employed to characterize the biosynthesized nanoparticles. Both FA-AuNps and FA-AgNps exhibited free radical scavenging activity against 2,2-diphenyl-1-picrylhydrzyl (DPPH). Additionally, biosynthesized nanoparticles successfully reduced methylene blue, a well-known redox indicator. FA-AgNps showed zones of inhibition against pathogenic Staphylococcus aureus and Escherichia coli. Finally, the biological activities and cytotoxicity of nanoparticles were subsequently investigated in vitro. FA-AuNps demonstrated a potential cytotoxic agent against breast cancer cells as evaluated by MTT assay. The study highlights a rapid synthesis of FA-AuNps and FA-AgNps by dried Fructus Amomi aqueous extract and evaluates their potential biological applications on medical platforms. Graphical Abstract

Green synthesis of multifunctional silver and gold nanoparticles from the oriental herbal adaptogen: Siberian ginseng.

Pharmacologically active stem of the oriental herbal adaptogen, Siberian ginseng, was employed for the ecofriendly synthesis of Siberian ginseng silver nanoparticles (Sg-AgNPs) and Siberian ginseng gold nanoparticles (Sg-AuNPs). First, for metabolic characterization of the sample, liquid chromatography-tandem mass spectrometry analysis (indicated the presence of eleutherosides A and E), total phenol content, and total reducing sugar were analyzed. Second, the water extract of the sample mediated the biological synthesis of both Sg-AgNPs and Sg-AuNPs that were crystalline face-centered cubical structures with a Z-average hydrodynamic diameter of 126 and 189 nm, respectively. Moreover, Fourier transform infrared analysis indicated that proteins and aromatic hydrocarbons play a key role in the formation and stabilization of Sg-AgNPs, whereas phenolic compounds accounted for the synthesis and stability of Sg-AuNPs. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) assay determined that Sg-AgNPs conferred strong cytotoxicity against MCF7 (human breast cancer cell line) and was only slightly toxic to HaCaT (human keratinocyte cell line) at 10 µg⋅mL−1. However, Sg-AuNPs did not display cytotoxic effects against both of the cell lines. The disc diffusion assay indicated a dose-dependent increase in the zone of inhibition of Staphylococcus aureus (ATCC 6538), Bacillus anthracis (NCTC 10340), Vibrio parahaemolyticus (ATCC 33844), and Escherichia coli (BL21) treated with Sg-AgNPs, whereas Sg-AuNPs did not show inhibitory activity. In addition, the 2,2-diphenyl-1-picrylhydrazyl assay demonstrated that both Sg-AgNPs and Sg-AuNPs possess strong antioxidant activity. To the best of our knowledge, this is the first report unraveling the potential of Eleutherococcus senticosus for silver and gold nanoparticle synthesis along with its biological applications, which in turn would promote widespread usage of the endemic Siberian ginseng.

Biological synthesis of gold and silver chloride nanoparticles by Glycyrrhiza uralensis and in vitro applications

Abstract The current study highlights the rapid biosynthesis of gold nanoparticles (Gu–AuNps) and silver chloride nanoparticles (Gu–AgClNps) by aqueous root extract of Glycyrrhiza uralensis, a medicinal plant. G. uralensis has been reported for anticancer and hepatoprotective effects. The reduction of chloroauric acid and silver nitrate by the Glycyrrhiza root extract prompted the formation of Gu–AuNps and Gu–AgClNps within 4 and 40u2009min at 80u2009°C, respectively. The complete reaction did not require supplemental reducing and stabilizing agents, which demonstrated green synthesis. Field emission transmission electron microscopy (FE-TEM) revealed the spherical shape of Gu–AuNps and Gu–AgClNps. X-ray diffraction (XRD) showed face-centred cubic structure of Gu–AuNps and Gu–AgClNps with average crystallite size 12.25u2009nm and 8.01u2009nm, respectively. The biosynthesized Gu–AgClNps served as competent antimicrobial agent against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella enterica. Additionally, Gu–AuNps and Gu–AgClNps were analyzed for their catalytic ability to reduce methylene blue as model test pollutant. Likewise, both nanoparticles possessed free radical scavenging activity against 2,2-diphenyl-1-picrylhydrzyl (DPPH). Moreover, in vitro cytotoxicity in murine macrophage (RAW264.7) and human breast cancer (MCF7) cells were evaluated. Thus, the study proposes a green synthesis of Gu–AuNps and Gu–AgClNps by G. uralensis extract and in vitro biological applications.

Ginseng-berry-mediated gold and silver nanoparticle synthesis and evaluation of their in vitro antioxidant, antimicrobial, and cytotoxicity effects on human dermal fibroblast and murine melanoma skin cell lines

There has been a growing interest in the design of environmentally affable and biocompatible nanoparticles among scientists to find novel and safe biomaterials. Panax ginseng Meyer berries have unique phytochemical profile and exhibit beneficial pharmacological activities such as antihyperglycemic, antiobesity, antiaging, and antioxidant properties. A comprehensive study of the biologically active compounds in ginseng berry extract (GBE) and the ability of ginseng berry (GB) as novel material for the biosynthesis of gold nanoparticles (GBAuNPs) and silver nanoparticles (GBAgNPs) was conducted. In addition, the effects of GBAuNPs and GBAgNPs on skin cell lines for further potential biological applications are highlighted. GBAuNPs and GBAgNPs were synthesized using aqueous GBE as a reducing and capping agent. The synthesized nanoparticles were characterized for their size, morphology, and crystallinity. The nanoparticles were evaluated for antioxidant, anti-tyrosinase, antibacterial, and cytotoxicity activities and for morphological changes in human dermal fibroblast and murine melanoma skin cell lines. The phytochemicals contained in GBE effectively reduced and capped gold and silver ions to form GBAuNPs and GBAgNPs. The optimal synthesis conditions (ie, temperature and v/v % of GBE) and kinetics were investigated. Polysaccharides and phenolic compounds present in GBE were suggested to be responsible for stabilization and functionalization of nanoparticles. GBAuNPs and GBAgNPs showed increased scavenging activity against 2,2-diphenyl-1-picrylhydrazyl free radicals compared to GBE. GBAuNPs and GBAgNPs effectively inhibited mushroom tyrosinase, while GBAgNPs showed antibacterial activity against Escherichia coli and Staphylococcus aureus. In addition, GBAuNPs were nontoxic to human dermal fibroblast and murine melanoma cell lines, and GBAgNPs showed cytotoxic effect on murine melanoma cell lines. The current results evidently suggest that GBAgNPs can act as potential agents for antioxidant, anti-tyrosinase, and antibacterial activities. In addition, GBAuNPs can be further developed into mediators in drug delivery and as antioxidant, anti-tyrosinase, and protective skin agents in cosmetic products. Consequently, the study showed the advantages of using nanotechnology and green chemistry to enhance the natural properties of GBs.

Biosynthesis, Characterization, and Bioactivities Evaluation of Silver and Gold Nanoparticles Mediated by the Roots of Chinese Herbal Angelica pubescens Maxim

A facile synthesis and biological applications of silver (DH-AgNps) and gold nanoparticles (DH-AuNps) mediated by the aqueous extract of Angelicae Pubescentis Radix (Du Huo) are explored. Du Huo is a medicinal root belonging to Angelica pubescens Maxim which possesses anti-inflammatory, analgesic, and antioxidant properties. The absorption spectra of nanoparticles in varying root extract and metal ion concentration, pH, reaction temperatures, and time were recorded by ultraviolet–visible (UV-Vis) spectroscopy. The presence of DH-AgNps and DH-AuNps was confirmed from the surface plasmon resonance intensified at ~414 and ~540xa0nm, respectively. Field emission transmission electron micrograph (FE-TEM) analysis revealed the formation of quasi-spherical DH-AgNps and spherical icosahedral DH-AuNps. These novel DH-AgNps and DH-AuNps maintained an average crystallite size of 12.48 and 7.44xa0nm, respectively. The biosynthesized DH-AgNps and DH-AuNps exhibited antioxidant activity against 2,2-diphenyl-1-picrylhydrzyl (DPPH) radicals and the former exhibited antimicrobial activity against clinical pathogens including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enterica. The expected presence of flavonoids, sesquiterpenes, and phenols on the nanoparticle surface were conjectured to grant protection against aggregation and free radical scavenging activity. DH-AgNps and DH-AuNps were further investigated for their cytotoxic properties in RAW264.7 macrophages for their potential application as drug carriers to sites of inflammation. In conclusion, this green synthesis is favorable for the advancement of plant mediated nano-carriers in drug delivery systems, cancer diagnostic, and medical imaging.Graphical abstractSchematic diagram of biosynthesis of DH-AgNps and DH-AuNps and evaluation of their bioactivities.

Biosynthesized gold and silver nanoparticles by aqueous fruit extract of Chaenomeles sinensis and screening of their biomedical activities

Abstract The design of mild and non-toxic synthesis of metallic nanoparticles is a topical subject in the nanotechnology field. The objective of this present study is to screen the bioactivity of biosynthesized nanoparticles by aqueous fruit extract of Chaenomeles sinensis. The reducing and stabilizing ability of C. sinensis to fabricate gold (Cs-AuNps) and silver (Cs-AgNps) nanoparticles was confirmed by UV–visible (UV–Vis) spectroscopy at 562u2009nm and 477u2009nm, respectively. The field-emission transmission electron microscopy (FE-TEM) and X-ray diffraction analysis (XRD) verify the nano-scale morphology and crystallinity of Cs-AuNps (20–40u2009nm) and Cs-AgNps (5–20u2009nm). Furthermore, we evaluated the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity, antimicrobial activity against Staphylococcus aureus and Escherichia coli and cytotoxicity against breast cancer cells. The results showed that Cs-AuNps (IC50: 725.93u2009μg/mL) displayed superior inhibitory activities on DPPH than Cs-AuNps. The biosynthesized Cs-AuNps successfully inhibited the growth of pathogenic bacteria S. aureus (ATCC 6538) and E. coli (BL21). The cytotoxic effect of Cs-AuNps and Cs-AgNps was evaluated in murine macrophage (RAW264.7) and human breast cancer cell lines (MCF7) by MTT assay. Thus, the present study explores the biomedical applications of gold and silver nanoparticles synthesized by C. sinensis.

Rare ginsenoside Ia synthesized from F1 by cloning and overexpression of the UDP-glycosyltransferase gene from Bacillus subtilis: synthesis, characterization, and in vitro melanogenesis inhibition activity in BL6B16 cells

Background Ginsenoside F1 has been described to possess skin-whitening effects on humans. We aimed to synthesize a new ginsenoside derivative from F1 and investigate its cytotoxicity and melanogenesis inhibitory activity in B16BL6 cells using recombinant glycosyltransferase enzyme. Glycosylation has the advantage of synthesizing rare chemical compounds from common compounds with great ease. Methods UDP-glycosyltransferase (BSGT1) gene from Bacillus subtilis was selected for cloning. The recombinant glycosyltransferase enzyme was purified, characterized, and utilized to enzymatically transform F1 into its derivative. The new product was characterized by NMR techniques and evaluated by MTT, melanin count, and tyrosinase inhibition assay. Results The new derivative was identified as (20S)-3β,6α,12β,20-tetrahydroxydammar-24-ene-20-O-β-D-glucopyranosyl-3-O-β-D-glucopyranoside (ginsenoside Ia), which possesses an additional glucose linked into the C-3 position of substrate F1. Ia had been previously reported; however, no in vitro biological activity was further examined. This study focused on the mass production of arduous ginsenoside Ia from accessible F1 and its inhibitory effect of melanogenesis in B16BL6 cells. Ia showed greater inhibition of melanin and tyrosinase at 100 μmol/L than F1 and arbutin. These results suggested that Ia decreased cellular melanin synthesis in B16BL6 cells through downregulation of tyrosinase activity. Conclusion To our knowledge, this is the first study to report on the mass production of rare ginsenoside Ia from F1 using recombinant UDP-glycosyltransferase isolated from B. subtillis and its superior melanogenesis inhibitory activity in B16BL6 cells as compared to its precursor. In brief, ginsenoside Ia can be applied for further study in cosmetics.

Green synthesis of gold and silver nanoparticles using aqueous extract of Cibotium barometz root

Abstract Green synthesis of gold (CB-AuNps) and silver (CB-AgNps) nanoparticles using Cibotium barometz root extract was highlighted. CB-AuNps were synthesized almost instantly and CB-AgNps were formed after 25u2009min in a heated aqueous extract. The formation of CB-AuNps and CB-AgNps was detected at 548 and 412u2009nm; they were spherical with crystallite sizes of 6u2009nm and 23u2009nm, respectively. CB-AgNps were further investigated for their antimicrobial activity against Escherichia, Staphylococcus aureus, Salmonella enterica, and Pseudomonas aeruginosa. Furthermore, scavenging activity against 1,1-diphenyl-2-picrylhydrzyl (DPPH) free radicals was demonstrated. Lastly, the cytotoxic properties of CB-AuNps and CB-AgNps were explored in murine macrophages (RAW264.7) cells and MCF-7 breast cancer cells. This study demonstrated the prospective biomedical applications of CB-AuNps and CB-AgNps as antioxidant, antimicrobial agents, and drug-delivery agents.

Coalescence of functional gold and monodisperse silver nanoparticles mediated by black Panax ginseng Meyer root extract

A rapid biological synthesis of multifunctional gold nanoparticle (AuNp) and monodisperse silver nanoparticle (AgNp) was achieved by an aqueous extract of black Panax ginseng Meyer root. The physicochemical transformation into black ginseng (BG) greatly enhanced the pharmacological activities of white ginseng and its minor ginsenoside content. The optimal temperature conditions and kinetics of bioreduction were investigated. Formation of BG-AuNps and BG-AgNps was verified by ultraviolet–visible spectrophotometry at 548 and 412 nm, respectively. The biosynthesized BG-AgNps were spherical and monodisperse with narrow distribution, while BG-AuNps were icosahedral-shaped and moderately polydisperse. Synthesized nanoparticles exhibited long-term stability in buffers of pH 7.0–8.0 and biological media (5% bovine serum albumin) at an ambient temperature and at 37°C. BG-AgNps showed effective antibacterial activity against Escherichia coli and Staphylococcus aureus. BG-AuNps and BG-AgNps demonstrated increased scavenging activity against 2,2-diphenyl-1-picrylhydrazyl free radicals. In addition, BG-AuNps and BG-AgNps were nontoxic to HaCaT and MCF-7 cells; the latter showed no cytotoxicity at concentrations lower than 10 µg/mL. At higher concentrations, BG-AgNps exhibited apparent apoptotic activity in MCF-7 breast cancer cell line through reactive oxygen species generation and nuclear fragmentation.