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Biofabrication of silver nanoparticles from aqueous leaf extract of Leucas aspera and their anticancer activity on human cervical cancer cells
... Observation of this peak-assigned to a surface Plasmon is well documented for various metal nanoparticles with sizes ranging from 2 to100 nm (Sastry et al., 1997), UV-visible spectrum analysis is used to validate the formation of AgNPs. Most people are aware that UV-Visible spectroscopy may be used to examine the size and form of nanoparticles suspended in water (Chavata et al., 2019). In order to further characterize the composition of the silver nanoparticles, Energy dispersive X-ray (EDX) analysis was used. ...
In a phenotypic analysis extended spectrum B-lactamases production, it
was discovered that 8 (20.5%) of the clinical isolates of the proteus mirabilis were
ESBLs produced by confirmatory testing whereas 39(97.5%) were ESBL
producers by screening testing. To detect the formation of biofilm, all isolates of
Proteus mirabilis were screened by microtiter plate (MTP) and modified Congo
red agar (MCRA) methods. In the MCRA method, the results were showed that
38 (95%) were black isolates of Proteus mirabilis strong producer biofilm and
2(5%) were pink isolates which non-producers biofilm. In the MTP method
observed 20(50%) non-producers, 5(12.5%) isolates of Proteus mirabilis
produced weak biofilm, 9(22.5%) isolates as moderate biofilm and 6 (15%)
isolates strong biofilm.
In addition, a molecular study using ureC showed that all isolates possess
the ureC gene with a molecular weight of 317bp. luxS gene was also detected by
PCR and the results showed that (95%) isolates possess this gene by the
appearance of the amplicon with a molecular weight of 283bp. ZapA and pm1
genes are present in all (100%) of respectively, while pet gene are not present in
all Proteus mirabilis isolates. mrpA gene was detected in Proteus mirabilis
isolates by PCR technique and the results showed that (97.5%) of the isolates
possessed the gene. Also, the results of this experiment revealed positive
amplification for all isolates (95%) mrpI gene in Proteus mirabilis isolates.
Using an extracellular technique, this bacteria's capacity to produce AgNPs
may be discovered. AgNPs formed during biosynthesis were identified by Ultra
violet spectrophotometer (UV-Vis) spectral analysis, which showed the greatest
peak with a wavelength of 449 nanometers. In Energy dispersive X-ray ( EDX)
analysis, the atomic weight percentage of silver was (63.5%) Ag weight
demonstrated that AgNPs are metallic and crystalline, Field emission scanning
electron microscope (FE-SEM) reveals the morphology of silver nanoparticles,
the particle size ranging between (40-100) nm in the scanned area, so the average
Summary
III
particle size approximately around (66nm), the typical grain size of artificial
nanoparticles ranged from 20 to 40 nm, according to Atomic force microscope
(AFM) data for silver nanoparticle diameter.
The current study has shown the great emergence of biofilm-forming and
Multidrug-Resistant in Proteus mirabilis isolates and harbours a variety of
virulence genes. Phylogenetic tree analysis was showed the significant selection
potential of 16S rRNA to identify isolated Proteus mirabilis and the close with Iraqi strain. Also, the results show that the antimicrobial synthesized by AgNPs
is the most effective growth inhibitor against Gram-positive bacteria.
... 13 Metabolites from different plant parts such as leaves, 14 stems, 15 roots, 16 fruits, 17 flowers, 18 bark, 19 and seeds 20 have shown an influential role as reducing agents in the process of NPs biosynthesis. The green synthesis of AgNPs using several plant extracts like Leucas aspera, 21 Aloe vera, 22 Azadirachta indica, 23 Catharanthus roseus, 24 Aegle marmelos, 25 Jasminum officinal, 26 Phyllanthus emblica, 27 Acalypha indica, 28 etc. have been reported in the previous studies. ...
Background: An eco-friendly approach for the synthesis of noble metal nanoparticles employing various plant extracts has become of great interest in the field of nanotechnology. In the present study, the efficacy of Grewia tiliifolia leaf extract in reducing 1 mM silver nitrate to silver nanoparticles (AgNPs) has been reported for the first time. We also investigated the anticancer, antituberculosis and antioxidant activity. Methods: Characterization of biosynthesized AgNPs using G. tiliifolia leaf extract was evaluated by different techniques. Efficacy of biosynthesized AgNPs using G. tiliifolia leaf extract was tested for cytotoxicity against A549 Lung cancer cell lines by MTT Assay and against the infectious agent Mycobacterium tuberculosis using MABA assay. Further antioxidant activity was evaluated by DPPH radical scavenging assay. Results: The biosynthesis of AgNPs was evident by a color change of the reaction mixture from dark yellow to reddish-brown. Biofabricated AgNPs were further confirmed by characteristic surface plasmon absorption peak at 409 nm by UV-vis analysis. FTIR data reveals the presence of phytochemicals involved in bioreduction and biocapping of AgNPs, XRD analysis depicted the crystallographic nature of AgNPs. Further, size, charge, and polydispersity nature were studied using DLS (40.2 nm with polydispersity index 0.361) and Zeta potential (-35.8 mV). The morphology of AgNPs was determined by TEM analysis with a size ranging from 11-34 nm. The plant-derived AgNPs exhibited a cytotoxic effect on the lung cancer cell line with an IC 50 value of 23.45 µg/ml and were also found to be effective against M. tuberculosis with a MIC of 6.25 µg/ ml in comparison to the leaf extract (MIC 50 µg/ml). Antioxidant activity observed by AgNPs was moderate with IC 50 value of 49.60 µg/ml. Conclusion: The findings indicate that the AgNPs synthesized from leaf extract of G. tiliifolia are eco-friendly, cost-effective, non-toxic and can be effective natural anticancer, antituberculosis and antioxidant agents.
... In addition, it has been reported to exhibit free radical scavenging, anticoagulant, pharmacological, acaricidal, pharmacognostical and anthelmintic activities, along with other health benefits [6][7][8][9][10]. Meanwhile, L. aspera has demonstrated evident cancer-preventive properties against prostate and cervical cancers [11,12]. The findings above have led to this investigation on the potential of L. indica as a medicinal plant through in vitro and in silico studies. ...
The investigation of traditional medicinal plants is gaining prime importance day by day due to having a wide range of bioactive phytochemicals. The presence of diverse bioactive compounds makes medicinal plants more demandable for curing several diseases, such as inflammatory diseases, diabetes, and cancer. Leucas indica is commonly found throughout Bangladesh and traditionally used for medical purposes because of its great medicinal value to the folks. The present study addresses the evaluation of in vitro qualitative phytochemical, antioxidant, and cytotoxicity activities as well as in silico anticancer activity of methanolic leaf extract. Several standard methods were used for phytochemical analysis, which showed the presence of different phytochemicals. The plant exhibited adequate antioxidant activities through DPPH and H2O2 free radical scavenging assays. Moreover, promising cytotoxicity activity was estimated through a brine shrimp lethality assay. In addition, the present work emphasizes the in silico analysis, which finds the anticancer activity of the experimental plant based on pharmacokinetic analysis, molecular docking, and MD simulation. Four phytochemicals of the plant were selected from the literature and docked against two important protein kinases (AMPK and CDK6) that have a role in cancer progression. The docking revealed an encouraging binding score with a maximum score of 9.2 kCal/mol, where all the ligand-protein complexes showed stable conditions during simulation. According to this analysis, it can be believed that the selected ligands indicate promising anticancer activity. Moreover, the comprehensive analysis of both in vitro and in silico data shows that the leaf could be a potent source of drug and could serve as an effective therapeutic in the future.
... On the contrary, the result of cell cycle analysis showed G 0 /G 1 phase arrest, which was not consistent with the results of comet assay that showed DNA fragmentation. Apoptosis and cell cycle arrest are closely associated, as apoptosis often occur where cell proliferation affected at certain cell cycle checkpoints [87]. Reports revealed that the antiproliferative effect of AgNPs arrests the cells in the G 2 /M phase [88]. ...
Green fabrications of metallic nanoparticles are rapidly developing the research era, due to their broad spectrum of applications in the field of biomedical sciences. In the present study, the green fabrication of silver nanoparticles (AgNPs) has been demonstrated by a highly stable, biocompatible, and environmental friendly aqueous leaf extract of Ocimum americanum for their antibacterial, anticancerous, and photocatalytic dye degradation efficiency. The synthesized AgNPs were confirmed by UV–Visible spectroscopy, which indicates the surface plasmon resonance λmax band at 435 nm. The FE-SEM and HR-TEM micrographs showed spherical shaped AgNPs, and EDX analysis confirmed the crystalline purity of green fabricated AgNPs. Fourier transform infrared (FT-IR) technique indicated the presence of active functional groups such as O‒H, C˭C, C‒H, C‒N involved in the reduction and surface capping agent of green fabricated AgNPs. The XRD analysis of synthesized AgNPs showed the face-centered cubic (fcc) crystalline structure. The DLS measurement showed average particle size of distribution was 48.25 nm and Zeta potential value at −20.2 mV revealed high stability of fabricated AgNPs. Further, the synthesized AgNPs has exhibited potential antibacterial activity against pathogenic Gram +ve and Gram −ve bacteria and in-vitro antioxidant activity assessed by DPPH, H2O2 and reducing power assays. The in-vitro cytotoxic effects of fabricated AgNPs against A549 lung cancer cells displayed apoptotic cell death confirmed by fluorescent staining techniques and the cellular apoptotic induction of G0/G1 cell cycle arrest confirmed with the flow cytometry analysis. On the other hand, the AgNPs exhibited efficient photocatalytic dye degradation of eosin yellow (EY) under sunlight and UV-irradiation method. The AgNPs did not lyse the hemoglobin from human red blood cells and showed its biocompatibility on human cells. Herein, the present study proves an effective, economical, and multifunctional AgNPs for improved therapeutic and catalytic applications.
Garlic (Allium sativum) exhibit well defined therapeutic properties due to presence of distinct bioactive compounds, specifically organosulphur compounds. Spectral analysis by UV–Vis and FT-IR confirmed interaction of different functional groups and free electrons with the electromagnetic waves showed presence of different bioactive compounds formulated silver nanoparticles (AgNPs) using diallyl sulphide (DAS) also done for aqueous garlic extract. Different assays performed for confirming the presence of antibacterial and anticancer properties of DAS-AgNPs and garlic extract. The minimum inhibitory concentration required to inhibit Gram negative ( Escherichia coli , V. cholera ) and Gram positive ( S. aureus, B. cereus ) were found lesser in DAS-AgNPs followed by garlic extract. Cytotoxicity effect confirmed by DAS-AgNPs and A. sativum towards HeLa cell line by MTT assay. The IC 50 values obtained for MTT assay were at 24.09 μg/ml in DAS-AgNPs and 129.22 μg/ml in garlic extract. Anticancer efficacy was found more potent in DAS-AgNPs as compared with aqueous garlic extract.
Development of eco-friendly synthetic methods has resulted in the production of biocompatible Ag NPs for applications in medical sector. To overcome the prevailing antibiotic resistance in bacteria, Ag NPs are being extensively researched over the past few years due to their broad spectrum & robust antimicrobial properties. Silver nanoparticles are also being studied widely in advanced anticancer therapy as an alternative anticancer agent to combat cancer in an effective manner. Keeping this backdrop in consideration, this review aims to provide the extensive coverage of the recent progresses in the green synthesis of Ag NPs specifically using plant derived reducing agents such phytochemicals & numerous other biopolymers. Current development in antimicrobial activity of Ag NPs against various pathogens has been deliberated at length. Recent advances in potent anticancer activity of the biogenic Ag NPs against various cancerous cell lines has also been discussed in detail. Mechanistic details of the synthesis of Ag NPs, their anticancer & antimicrobial action has also been highlighted.
Phytosynthesized nanoparticles represent a continuously increasing field of research, with numerous studies published each year. However, with the emerging interest in this area, the quality of the published works is also continuously increasing, switching from routine antioxidant or antimicrobial studies on trivial microbial lines to antibiotic-resistant strains or antitumoral studies. However, this increasing interest has not been not reflected in the studies regarding the toxicological effects of nanoparticles (NPs); this should be a subject of greatest interest, as the increasing administration of NPs in general (and phytosynthesized NPs in particular) could lead to their accumulation in the environment (soil, water and living organisms). The present review aims to present the most recent findings in the application of phytosynthesized NPs as antimicrobial and antitumoral agents, as well as the results regarding their toxicological potential.
In this study, silver nanoparticles (AgNPs) were synthesized using aqueous extract of Nepeta deflersiana plant. The prepared AgNPs (ND-AgNPs) were examined by ultraviolet-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDX). The results obtained from various characterizations revealed that average size of synthesized AgNPs was 33 nm and in face-centered-cubic structure. The anticancer potential of ND-AgNPs was investigated against human cervical cancer cells (HeLa). The cytotoxic response was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), neutral red uptake (NRU) assays, and morphological changes. Further, the influence of cytotoxic concentrations of ND-AgNPs on oxidative stress markers, reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP), cell cycle arrest and apoptosis/necrosis was studied. The cytotoxic response observed was in a concentration-dependent manner. Furthermore, the results also showed a significant increase in ROS and lipid peroxidation (LPO), along with a decrease in MMP and glutathione (GSH) levels. The cell cycle analysis and apoptosis/necrosis assay data exhibited ND-AgNPs-induced SubG1 arrest and apoptotic/necrotic cell death. The biosynthesized AgNPs-induced cell death in HeLA cells suggested the anticancer potential of ND-AgNPs. Therefore, they may be used to treat the cervical cancer cells.
The provision of nanoparticles using biogenic material as a part of green chemistry is an attractive nanotechnology. The current research aimed to test the antimicrobial and cytotoxic efficacy of silver nanoparticles synthesized by extracts of Phoenix dactylifera, Ferula asafetida, and Acacia nilotica as reductant and stabilizing agents in silver nanoparticle formation. Synthesized nanoparticles were evaluated for their antimicrobial activity against Staphylococcus aureus (Gram-positive) and Pseudomonas aeruginosa and Escherichia coli (Gram-negative) using an agar well diffusion assay. Furthermore, cytotoxic ability was investigated against LoVo cells. The potential phyto-constituents of plant extracts were identified by Fourier-transform infrared spectroscopy (FT-IR) techniques. Field emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), and zeta potential analyzed the size and morphology of the biogenic nanoparticles. The current study revealed the ability of the tested plant extract to convert silver ions to silver nanoparticles with an average size that ranged between 67.8 ± 0.3 and 155.7 ± 1.5 nm in diameter. Biogenic AgNPs showed significant antibacterial ability (10 to 32 mm diameter) and anticancer ability against a LoVo cell with IC50 ranged between 35.15–56.73 μg/mL. The innovation of the present study is that the green synthesis of NPs, which is simple and cost effective, provides stable nano-materials and can be an alternative for the large-scale synthesis of silver nanoparticles.
Ruptured and intact plasma membranes are classically considered as hallmarks of necrotic and apoptotic cell death, respectively. As such, apoptosis is usually considered a non-inflammatory process while necrosis triggers inflammation. Recent studies on necroptosis and pyroptosis, two types of programmed necrosis, revealed that plasma membrane rupture is mediated by MLKL channels during necroptosis but depends on non-selective gasdermin D (GSDMD) pores during pyroptosis. Importantly, the morphology of dying cells executed by MLKL channels can be distinguished from that executed by GSDMD pores. Interestingly, it was found recently that secondary necrosis of apoptotic cells, a previously believed non-regulated form of cell lysis that occurs after apoptosis, can be programmed and executed by plasma membrane pore formation like that of pyroptosis. In addition, pyroptosis is associated with pyroptotic bodies, which have some similarities to apoptotic bodies. Therefore, different cell death programs induce distinctive reshuffling processes of the plasma membrane. Given the fact that the nature of released intracellular contents plays a crucial role in dying/dead cell-induced immunogenicity, not only membrane rupture or integrity but also the nature of plasma membrane breakdown would determine the fate of a cell as well as its ability to elicit an immune response. In this review, we will discuss recent advances in the field of apoptosis, necroptosis and pyroptosis, with an emphasis on the mechanisms underlying plasma membrane changes observed on dying cells and their implication in cell death-elicited immunogenicity.
This report describes the synthesis of metallic silver nanoparticles (AgNPs) using extracts of four medicinal plants (Aegle marmelos (A. marmelos), Alstonia scholaris (A. scholaris), Andrographis paniculata (A. paniculata) and Centella asiatica (C. asiatica)). The bio-conjugates were characterized by UV–visible spectroscopy, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared spectrometry (FTIR), x-ray diffraction (XRD) and zeta potential. This analysis confirmed that UV–Vis spectral peaks at 375 nm, 380 nm, 420 nm and 380 nm are corresponding to A. marmelos, A. scholaris, A. paniculata and C. asiatica mediated AgNPs, respectively. SEM images revealed that all the obtained four AgNPs are predominantly spherical, fibres and rectangle in shape with an average size of 36–97 nm. SEM-EDS and XRD analysis confirmed the presence of elemental AgNPs in crystalline form for all the four nanoparticle samples. The phytochemicals of various medicinal plant extracts with different functional groups were responsible for reduction of Ag⁺ to AgNPs, which act as capping and stabilizing agent. Among four types of AgNPs tested for anticancer activity, the Ap mediated AgNPs had shown enhanced activity against HepG2 cells (27.01 µg ml⁻¹) and PC3 cells (32.15 µg ml⁻¹).
Prostate cancer is one of the most common malignancies among men worldwide. The main aim of the present work was to clarify the advantages of a nanoformulation of ayurvedic herbal plants. Specifically, we assessed the improved anticancer activity of Leucas aspera nanoparticles compared with methanolic crude extract in PC3 prostate cancer cells and normal cells. L. aspera is a plant that is used in ayurveda due to the antirheumatic, antipyretic, anti-inflammatory, antibacterial, anticancer, and cytotoxic activities. Nanoparticles of L. aspera were prepared from plant methanolic extracts. Cytotoxic effect was studied in the normal and prostate cancer cells. Size and morphology of the formulated nanoparticles was assessed using dynamic light scattering and scanning electron microscopy. In vitro cytotoxicity of L. aspera nanoparticles for PC3 cells was concentration- and time-dependent. In vitro hemolysis assay, cellular uptake studies, cell aggregation studies, and cell migration assay established the anticancerous activity of L. aspera in prostate cancer.
In continuation of the efforts for synthesizing silver nanoparticles (AgNPs) by green chemistry route, here we report a facile bottom-up ‘green’ route for the synthesis of AgNPs using aqueous leaves extract of Urtica dioica (Linn.). The synthesized AgNPs were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), Zeta-sizer and Zeta-potential, Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) spectroscopy, Transmission electron microscopy (TEM) and Selected area electron diffraction (SAED). The results obtained from various characterizations revealed that AgNPs were in the size range of 20–30 nm and crystallized in face-centered-cubic structure. The antibacterial activity against Gram-positive (Bacillus cereus, Bacillus subtilis, Staphylococcus aureus and Staphylococcus epidermidis) and Gram-negative (Escherichia coli, Klebsiella pneumoniae, Serratia marcescens and Salmonella typhimurium) bacterial pathogens was demonstrated by synthesized nanoparticles. Further, synergistic effects of AgNPs with various antibiotics were evaluated against above mentioned bacterial pathogens. The results showed that AgNPs in combination with antibiotics have better antibacterial effect as compared with AgNPs alone and hence can be used in the treatment of infectious diseases caused by bacteria. The maximum effect, with a 17.8 fold increase in inhibition zone, was observed for amoxicillin with AgNPs against S. marcescens proving the synergistic role of AgNPs. Therefore, it may be used to augment the activities of antibiotics.
Solanum nigrum, a medicinal plant, traditionally used in treating diabetes mellitus. In this study, we used the leaf extract of the plant to synthesize silver nanoparticles (AgNPs), as a proposition to treat alloxan-induced diabetic rats. The phytosynthesised AgNPs were analyzed using UV–visible and Fourier transform infra-red spectroscopy for their functional groups. Transmission electron microscopy revealed that, the synthesized particles are found to be 4–25 nm in size. Monodispersed and spherical nature of synthesized AgNPs were shown by scanning electron microscope and the presence of Ag in the AgNPs was confirmed by energy dispersive spectrum. The phytosynthesised AgNPs were evaluated for its antidiabetic activity in alloxan-induced diabetic rats. AgNPs-treated diabetic rats found to be significantly improved the dyslipidemic condition as seen in the diabetic control. Furthermore, it also reduced the blood glucose level over the period of treatment. The improvement in body weight was also found to be evidence for S. nigrum extract-mediated AgNPs as a potential antidiabetic agent against alloxan-induced diabetic rats.
Biosynthesis of silver nanoparticles was achieved by novel simple green chemistry procedure using Achyranthes aspera leaf extract as a reducing and a capping agent. The present study focuses on larvicidal activity of synthesized silver nanoparticles (AgNPs) against Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi. Range of concentrations of synthesized AgNPs (2, 4, 6, 8 and 10mg/ml) and the aqueous extract (100, 50, 25, 12.5 and 6.25mg/ml) were tested against the fourth instar larvae for 24h exposure. The maximum efficacy was observed in the synthesized AgNPs against Cx. quinquefasciatus (LC50 2.48; LC90 8.14mg/ml) and Ae. aegypti (LC50 3.68; LC90 8.92mg/ml) whereas aqueous extract found to be effective against Cx. quinquefasciatus at a higher concentration. The synthesized AgNPs from A.aspera were highly potent than aqueous extract against all the three tested vectors. The synthesized AgNPs were characterized by UV-visible spectrophotometer, SEM, TEM, FTIR and XRD. This revealed a peak at 452nm in leaf extract of A.aspera, indicating the production of AgNPs. The synthesized AgNPs were clearly distinguishable with the respective nanometers and the XRD spectrum confirmed the presence of silver ion and it was compared with the standard spectrum peaks. The FTIR spectra of AgNPs exhibited prominent peaks of organic molecules.
The use of nanotechnology in medicine and more specifically drug delivery is set to spread rapidly. Currently many substances are under investigation for drug delivery and more specifically for cancer therapy. Interestingly pharmaceutical sciences are using nanoparticles to reduce toxicity and side effects of drugs and up to recently did not realize that carrier systems themselves may impose risks to the patient. The kind of hazards that are introduced by using nanoparticles for drug delivery are beyond that posed by conventional hazards imposed by chemicals in classical delivery matrices. For nanoparticles the knowledge on particle toxicity as obtained in inhalation toxicity shows the way how to investigate the potential hazards of nanoparticles. The toxicology of particulate matter differs from toxicology of substances as the composing chemical(s) may or may not be soluble in biological matrices, thus influencing greatly the potential exposure of various internal organs. This may vary from a rather high local exposure in the lungs and a low or neglectable exposure for other organ systems after inhalation. However, absorbed species may also influence the potential toxicity of the inhaled particles. For nanoparticles the situation is different as their size opens the potential for crossing the various biological barriers within the body. From a positive viewpoint, especially the potential to cross the blood brain barrier may open new ways for drug delivery into the brain. In addition, the nanosize also allows for access into the cell and various cellular compartments including the nucleus. A multitude of substances are currently under investigation for the preparation of nanoparticles for drug delivery, varying from biological substances like albumin, gelatine and phospholipids for liposomes, and more substances of a chemical nature like various polymers and solid metal containing nanoparticles. It is obvious that the potential interaction with tissues and cells, and the potential toxicity, greatly depends on the actual composition of the nanoparticle formulation. This paper provides an overview on some of the currently used systems for drug delivery. Besides the potential beneficial use also attention is drawn to the questions how we should proceed with the safety evaluation of the nanoparticle formulations for drug delivery. For such testing the lessons learned from particle toxicity as applied in inhalation toxicology may be of use. Although for pharmaceutical use the current requirements seem to be adequate to detect most of the adverse effects of nanoparticle formulations, it can not be expected that all aspects of nanoparticle toxicology will be detected. So, probably additional more specific testing would be needed.
In this study, rapid, simple approach was applied for synthesis of silver nanoparticles using
Azadirachta indica aqueous leaf extract. The plant extract acts both as reducing agent as
well as capping agent. To identify the compounds responsible for reduction of silver ions,
the functional groups present in plant extract were investigated by FTIR. Various techniques
used to characterize synthesized nanoparticles are DLS, photoluminescence, TEM
and UVeVisible spectrophotometer. UVeVisible spectrophotometer showed absorbance
peak in range of 436e446 nm. The silver nanoparticles showed antibacterial activities
against both gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) microorganisms.
Photoluminescence studies of synthesised silver nanoparticles were also
evaluated. Results confirmed this protocol as simple, rapid, one step, eco-friendly, nontoxic
and an alternative conventional physical/chemical methods. Only 15 min were
required for the conversion of silver ions into silver nanoparticles at room temperature,
without the involvement of any hazardous chemical
Abstract In this paper, an aqueous extract of fresh leaves of Pedalium murex was used for the synthesis of silver (Ag) nanoparticles. Different biological methods are gaining recognition for the production of silver nanoparticles (AgNPs) due to their multiple applications. The use of plants in the green synthesis of nanoparticles emerges as a cost-effective and eco-friendly approach. Characterization of nanoparticles was done using different methods, which include; ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FTIR), powder X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray analysis (EDAX), fluorescence emission spectroscopy, transmission electron microscope (TEM), dynamic light scattering (DLS), zeta potential and antibacterial activity. UV-visible spectrum of the aqueous medium containing silver nanoparticles showed absorption peak at around 430 nm. Fourier transform infrared spectra had shown that the biomolecule compounds were responsible for the reduction and capping material of silver nanoparticles. XRD study showed the particles to be crystalline in nature, with a face-centered cubic (fcc) structure. The size and stability were detected using DLS and zeta potential analysis. The antibacterial activity of AgNPs against generally found bacteria was assessed to find their potential use in silver-containing antibacterial product.
The junction of nanotechnology and biomedical sciences unfasten the possibility for a wide range of biological research topics and medical uses at the molecular and cellular level. In the present study silver nanoparticles were synthesized by using Leucas aspera leaf extract support of biological process. The extract incubated with 1mM AgNO 3 solution showed gradual change in the color of the extract from greenish to reddish brown. Reduction of silver ions by the leaf extract was examined by UV-visible spectroscopic technique. Further, it was confirmed by Fourier Transformations Infrared spectroscopic (FTIR) analysis. The purity of the synthesized silver nanoparticles was examined through X-Ray Diffraction (XRD) analysis. The nanoparticles were examined for the antibacterial activities of antibiotic (Tetracycline), silver nanoparticles and the combined effect of both antibiotic and nanoparticles against the multi drug resistant human pathogens.
The aim of this study was to evaluate the antimicrobial activity of silvercolloidal nanoparticles which were synthesised by chemical reduction. Silver nanoparticles were synthesized by reduction of silver nitrate with sodium citrate. The presence of silver nanoparticles was detected by atomic absorption spectroscopy. Antifungal activity of silver nanoparticles was detected by the zone of inhibition. Silver nanoparticles exhibited a characteristic surface plasmon resonance band that is measured by UV-Vis spectroscopy, showing a typical absorbance peak for nanoparticles centred at 430 nm. The antifungal activity of silver nanoparticles was measured by the zones of inhibition by Kirby Bauer sensitivity testing which were measured after 24 h of incubation at 370C of Candida albicans growth on sabouraud dextrose agar. This study, integrates nanotechnology leading to possible advances in the formulation of new types of fungicide.
While metal nanoparticles are being increasingly used in many sectors of the economy, there is growing interest in the biological and environmental safety of their production. The main methods for nanoparticle production are chemical and physical approaches that are often costly and potentially harmful to the environment. The present review is devoted to the possibility of metal nanoparticle synthesis using plant extracts. This approach has been actively pursued in recent years as an alternative, efficient, inexpensive, and environmentally safe method for producing nanoparticles with specified properties. This review provides a detailed analysis of the various factors affecting the morphology, size, and yield of metal nanoparticles. The main focus is on the role of the natural plant biomolecules involved in the bioreduction of metal salts during the nanoparticle synthesis. Examples of effective use of exogenous biomatrices (peptides, proteins, and viral particles) to obtain nanoparticles in plant extracts are discussed.
The present work reports a simple, cost-effective, and ecofriendly method for the synthesis of silver nanoparticles (AgNPs) using Chrysanthemum indicum and its antibacterial and cytotoxic effects. The formation of AgNPs was confirmed by color change, and it was further characterized by ultraviolet–visible spectroscopy (435 nm). The phytochemical screening of C. indicum revealed the presence of flavonoids, terpenoids, and glycosides, suggesting that these compounds act as reducing and stabilizing agents. The crystalline nature of the synthesized particles was confirmed by X-ray diffraction, as they exhibited face-centered cubic symmetry. The size and morphology of the particles were characterized by transmission electron microscopy, which showed spherical shapes and sizes that ranged between 37.71–71.99 nm. Energy-dispersive X-ray spectroscopy documented the presence of silver. The antimicrobial effect of the synthesized AgNPs revealed a significant effect against the bacteria Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Additionally, cytotoxic assays showed no toxicity of AgNPs toward 3T3 mouse embryo fibroblast cells (25 μg/mL); hence, these particles were safe to use.
The BCL-2 protein family determines the commitment of cells to apoptosis, an ancient cell suicide programme that is essential for development, tissue homeostasis and immunity. Too little apoptosis can promote cancer and autoimmune diseases; too much apoptosis can augment ischaemic conditions and drive neurodegeneration. We discuss the biochemical, structural and genetic studies that have clarified how the interplay between members of the BCL-2 family on mitochondria sets the apoptotic threshold. These mechanistic insights into the functions of the BCL-2 family are illuminating the physiological control of apoptosis, the pathological consequences of its dysregulation and the promising search for novel cancer therapies that target the BCL-2 family.
In this study Cassia angustifolia (senna) is used for the environmentally friendly synthesis of silver nanoparticles. Stable silver nanoparticles having symmetric surface plasmon resonance (SPR) band centred at 420 nm were obtained within 10 min at room temperature by treating aqueous solutions of silver nitrate with C. angustifolia leaf extract. The water soluble components from the leaves, probably the sennosides, served as both reducing and capping agents in the synthesis of silver nanoparticles. The nanoparticles were characterized using UV–Vis, Fourier transform infrared (FTIR) spectroscopic techniques and transmission electron microscopy (TEM). The nanoparticles were poly-dispersed, spherical in shape with particle size in the range 9–31 nm, the average size was found to be 21.6 nm at pH 11. The zeta potential was –36.4 mV and the particles were stable for 6 months. The crystalline phase of the nanoparticles was confirmed from the selected area diffraction pattern (SAED). The rate of formation and size of silver nanoparticles were pH dependent. Functional groups responsible for capping of silver nanoparticles were identified from the FTIR spectrum. The synthesized silver nanoparticles exhibited good antibacterial potential against Escherichia coli and Staphylococcus aureus.
Over the past few decades, nanoparticles of noble metals such as silver exhibited significantly distinct physical, chemical and biological properties from their bulk counterparts. Nano-size particles of less than 100 nm in diameter are currently attracting increasing attention for the wide range of new applications in various fields of industry. Such powders can exhibit properties that differ substantially from those of bulk materials, as a result of small particle dimension, high surface area, quantum confinement and other effects. Most of the unique properties of nanoparticles require not only the particles to be of nano-sized, but also the particles be dispersed without agglomeration. Discoveries in the past decade have clearly demonstrated that the electromagnetic, optical and catalytic properties of silver nanoparticles are strongly influenced by shape, size and size distribution, which are often varied by varying the synthetic methods, reducing agents and stabilizers. Accordingly, this review presents different methods of preparation silver nanoparticles and application of these nanoparticles in different fields.
Apoptosis is an ordered and orchestrated cellular process that occurs in physiological and pathological conditions. It is also one of the most studied topics among cell biologists. An understanding of the underlying mechanism of apoptosis is important as it plays a pivotal role in the pathogenesis of many diseases. In some, the problem is due to too much apoptosis, such as in the case of degenerative diseases while in others, too little apoptosis is the culprit. Cancer is one of the scenarios where too little apoptosis occurs, resulting in malignant cells that will not die. The mechanism of apoptosis is complex and involves many pathways. Defects can occur at any point along these pathways, leading to malignant transformation of the affected cells, tumour metastasis and resistance to anticancer drugs. Despite being the cause of problem, apoptosis plays an important role in the treatment of cancer as it is a popular target of many treatment strategies. The abundance of literature suggests that targeting apoptosis in cancer is feasible. However, many troubling questions arise with the use of new drugs or treatment strategies that are designed to enhance apoptosis and critical tests must be passed before they can be used safely in human subjects.
The aim of this study was to investigate the larvicidal potential of the hexane, chloroform, ethyl acetate, acetone, methanol, and aqueous leaf extracts of Nelumbo nucifera Gaertn. (Nymphaeaceae) and synthesized silver nanoparticles using aqueous leaf extract against fourth instar larvae of Anopheles subpictus Grassi and Culex quinquefasciatus Say (Diptera: Culicidae). Nanoparticles are being used in many commercial applications. It was found that aqueous silver ions can be reduced by aqueous extract of plant parts to generate extremely stable silver nanoparticles in water. The results recorded from UV-vis spectrum, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared support the biosynthesis and characterization of silver nanoparticles. Larvae were exposed to varying concentrations of plant extracts and synthesized silver nanoparticles for 24 h. All extracts showed moderate larvicidal effects; however, the maximum efficacy was observed in crude methanol, aqueous, and synthesized silver nanoparticles against the larvae of A. subpictus (LC(50) = 8.89, 11.82, and 0.69 ppm; LC(90) = 28.65, 36.06, and 2.15 ppm) and against the larvae of C. quinquefasciatus (LC(50) = 9.51, 13.65, and 1.10 ppm; LC(90) = 28.13, 35.83, and 3.59 ppm), respectively. These results suggest that the leaf methanol, aqueous extracts of N. nucifera, and green synthesis of silver nanoparticles have the potential to be used as an ideal eco-friendly approach for the control of the A. subpictus and C. quinquefasciatus. This is the first report on the mosquito larvicidal activity of the plant extracts and synthesized nanoparticles.
Cleavage of chromosomal DNA into oligonucleosomal size fragments is an integral part of apoptosis. Elegant biochemical work identified the DNA fragmentation factor (DFF) as a major apoptotic endonuclease for DNA fragmentation in vitro. Genetic studies in mice support the importance of DFF in DNA fragmentation and possibly in apoptosis in vivo. Recent work also suggests the existence of additional endonucleases for DNA degradation. Understanding the roles of individual endonucleases in apoptosis, and how they might coordinate to degrade DNA in different tissues during normal development and homeostasis, as well as in various diseased states, will be a major research focus in the near future.
Nanomaterials are at the leading edge of the rapidly developing field of nanotechnology. Their unique size-dependent properties make these materials superior and indispensable in many areas of human activity. This brief review tries to summarise the most recent developments in the field of applied nanomaterials, in particular their application in biology and medicine, and discusses their commercialisation prospects.
An ethnobotanical survey was undertaken to collect information from traditional healers on the use of medicinal plants in Kancheepuram district of Tamil Nadu during October 2003 to April 2004. The indigenous knowledge of local traditional healers and the native plants used for medicinal purposes were collected through questionnaire and personal interviews during field trips.
The investigation revealed that, the traditional healers used 85 species of plants distributed in 76 genera belonging to 41 families to treat various diseases. The documented medicinal plants were mostly used to cure skin diseases, poison bites, stomachache and nervous disorders. In this study the most dominant family was Euphorbiaceae and leaves were most frequently used for the treatment of diseases.
This study showed that many people in the studied parts of Kancheepuram district still continue to depend on medicinal plants at least for the treatment of primary healthcare. The traditional healers are dwindling in number and there is a grave danger of traditional knowledge disappearing soon since the younger generation is not interested to carry on this tradition.
Since its introduction, the propidium iodide (PI) flow cytometric assay has been widely used for the evaluation of apoptosis in different experimental models. It is based on the principle that apoptotic cells, among other typical features, are characterized by DNA fragmentation and, consequently, loss of nuclear DNA content. Use of a fluorochrome, such as PI, that is capable of binding and labeling DNA makes it possible to obtain a rapid (the protocol can be completed in about 2 h) and precise evaluation of cellular DNA content by flow cytometric analysis, and subsequent identification of hypodiploid cells. The original protocol enhanced the capacity for a rapid, quantitative measure of cell apoptosis. For this reason, since its publication, the PI assay has been widely used, as demonstrated by the large number of citations of the original paper and/or the continuous use of the method in many laboratories.
Cancer nanotherapeutics are rapidly progressing and are being implemented to solve several limitations of conventional drug delivery systems such as nonspecific biodistribution and targeting, lack of water solubility, poor oral bioavailability, and low therapeutic indices. To improve the biodistribution of cancer drugs, nanoparticles have been designed for optimal size and surface characteristics to increase their circulation time in the bloodstream. They are also able to carry their loaded active drugs to cancer cells by selectively using the unique pathophysiology of tumors, such as their enhanced permeability and retention effect and the tumor microenvironment. In addition to this passive targeting mechanism, active targeting strategies using ligands or antibodies directed against selected tumor targets amplify the specificity of these therapeutic nanoparticles. Drug resistance, another obstacle that impedes the efficacy of both molecularly targeted and conventional chemotherapeutic agents, might also be overcome, or at least reduced, using nanoparticles. Nanoparticles have the ability to accumulate in cells without being recognized by P-glycoprotein, one of the main mediators of multidrug resistance, resulting in the increased intracellular concentration of drugs. Multifunctional and multiplex nanoparticles are now being actively investigated and are on the horizon as the next generation of nanoparticles, facilitating personalized and tailored cancer treatment.
Five plant leaf extracts (Pine, Persimmon, Ginkgo, Magnolia and Platanus) were used and compared for their extracellular synthesis of metallic silver nanoparticles. Stable silver nanoparticles were formed by treating aqueous solution of AgNO(3) with the plant leaf extracts as reducing agent of Ag(+) to Ag(0). UV-visible spectroscopy was used to monitor the quantitative formation of silver nanoparticles. Magnolia leaf broth was the best reducing agent in terms of synthesis rate and conversion to silver nanoparticles. Only 11 min was required for more than 90% conversion at the reaction temperature of 95 degrees C using Magnolia leaf broth. The synthesized silver nanoparticles were characterized with inductively coupled plasma spectrometry (ICP), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and particle analyzer. The average particle size ranged from 15 to 500 nm. The particle size could be controlled by changing the reaction temperature, leaf broth concentration and AgNO(3) concentration. This environmentally friendly method of biological silver nanoparticles production provides rates of synthesis faster or comparable to those of chemical methods and can potentially be used in various human contacting areas such as cosmetics, foods and medical applications.
This article provides a status report on the global burden of cancer worldwide using the GLOBOCAN 2018 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer, with a focus on geographic variability across 20 world regions. There will be an estimated 18.1 million new cancer cases (17.0 million excluding nonmelanoma skin cancer) and 9.6 million cancer deaths (9.5 million excluding nonmelanoma skin cancer) in 2018. In both sexes combined, lung cancer is the most commonly diagnosed cancer (11.6% of the total cases) and the leading cause of cancer death (18.4% of the total cancer deaths), closely followed by female breast cancer (11.6%), prostate cancer (7.1%), and colorectal cancer (6.1%) for incidence and colorectal cancer (9.2%), stomach cancer (8.2%), and liver cancer (8.2%) for mortality. Lung cancer is the most frequent cancer and the leading cause of cancer death among males, followed by prostate and colorectal cancer (for incidence) and liver and stomach cancer (for mortality). Among females, breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death, followed by colorectal and lung cancer (for incidence), and vice versa (for mortality); cervical cancer ranks fourth for both incidence and mortality. The most frequently diagnosed cancer and the leading cause of cancer death, however, substantially vary across countries and within each country depending on the degree of economic development and associated social and life style factors. It is noteworthy that high‐quality cancer registry data, the basis for planning and implementing evidence‐based cancer control programs, are not available in most low‐ and middle‐income countries. The Global Initiative for Cancer Registry Development is an international partnership that supports better estimation, as well as the collection and use of local data, to prioritize and evaluate national cancer control efforts. CA: A Cancer Journal for Clinicians 2018;0:1‐31. © 2018 American Cancer Society
Cervical cancer is a worldwide public health problem. In 2012, cervical cancer was the fourth most common disease in women and the seventh around the world, representing approximately 9 of every 10 deaths in less developed regions (87%). In Mexico, its relevance is also considerable; it is the neoplasia with the second highest incidence rates and the second leading cause of death among women of all ages. The most affected age groups are from 50–59 and 30–49 years old. Persistent infection with human papilloma virus (HPV) is a necessary factor for its development. There are certain risk factors that have been associated with cervical cancer, such as tobacco consumption, sexually transmitted diseases (STDs), oral contraceptive use and age at onset of sexual activity. In federal states such as Morelos or Chiapas, this disease has a greater impact on mortality partly because of social differences among the population. Although the strengthening of detection procedures, treatment and timely diagnosis have contributed to an important decrease in the mortality attributed to this cause in our country, there is still a need to keep improving the areas of prevention and promotion.
Background: Leucas aspera is a widely used ethno-medicinal plant for various diseases in India. In our recent research work, this plant showed powerful anti-cancer activity in various cancer cell lines by stimulating macrophage cells which plays a central role in the immune system. Objective: The present study was conducted to evaluate the immunomodulatory activity of ethyl acetate extract of aerial parts of Leucas aspera (EALA). Materials and Methods: In the current study, we have used neutrophil adhesion test, carbon clearance test, haemagglutinating antibody titre test, delayed-type hypersensitivity reaction test and cyclophosphamide-induced immunosuppression test. EALA 200 and 400 mg/kg oral dose were selected for the study after conducting the acute dose toxicity study. All the studies were performed in Swiss albino mice. Results: EALA showed a dose dependant increase in the neutrophil adhesion to the nylon fibres, produced a significant increase in the phagocytic index in carbon clearance test and a significant protection against cyclophosphamide-induced immunosuppression. Moreover both doses of EALA produced an increase in the circulating serum immunoglobulins in haemagglutinating antibody titre test along with an increase in the foot pad edema in delayed-type hypersensitivity reaction test. Conclusion: From the above findings it is concluded that EALA has the ability to modulate both humoral and cell-mediated immunity.
Background:
North East India is a rich source of medicinal plants and a number of plant extracts are used by tribal peoples living in this area for various disorders. L.aspera is such a plant, traditionally used as an antitumor agent.
Aim:
In the present study, aerial parts of L.aspera were investigated for antitumor activity in Dalton's lymphoma (DAL) bearing mice. The ability of plant extract in free radical scavenging, neoangiogenesis inhibition and macrophage stimulation were also checked.
Materials and methods:
Based on the preliminary in vitro cytotoxicity studies ethyl acetate fraction of L.aspera (EALA) was selected for the detailed study. DAL ascites tumor model was performed to check the antitumor activity of EALA (200 and 400mg/kg of body weight). Hematological and histopathological parameters were estimated. Antioxidant levels, neoangiogenesis and peritoneal macrophage count were also determined.
Results:
In vitro MTT and Trypan blue assay results showed the cytotoxic effect of EALA in DAL cells lines. EALA treatment resulted in significant decrease in ascites tumor volume and viable cell count. Hematological and liver antioxidant parameters were normalised by EALA treatment. It was also found that EALA treatment inhibits neovascularisation and produce macrophage stimulation in treated mice.
Conclusion:
The results showed that EALA is a promising anticancer agent and its activity is comparable to the standard drug 5-Flouro uracil (5-FU).
Albumin nanoparticles are attractive drug delivery systems as they can be prepared under soft conditions and incorporate several kinds of molecules. The aim of this study was to upscale the desolvation process for preparing bovine serum albumin (BSA) nanoparticles using a membrane contactor. At a first step, the BSA nanoparticles were prepared at small scale using a syringe pump. BSA nanoparticles of 139 nm in size, with a polydispersity index of 0.046 were obtained at the optimal conditions: pH 8.2, 100 mg.mL(-1) BSA albumin solution (2 mL), 1 mL.min(-1) flowrate of ethanol addition (8 mL). The upscaling with a membrane contactor was achieved by permeating ethanol through the pores of a Shirasu Porous Glass (SPG Technology Co., Japan) membrane and circulating the aqueous phase tangentially to the membrane surface. By increasing the pressure of the ethanol from 1 to 2.7 bars, a progressive decrease in nanoparticle size was obtained with a high nanoparticles yield (around 94-96%). In addition, the flowrate of the circulating phase did not affect the BSA nanoparticle characteristics. At the optimal conditions (pH 8.2, 100 mg.mL(-1) BSA albumin solution, pressure of ethanol 2.7 bars, flowrate of the circulating phase 30.7 mL.s(-1)), the BSA nanoparticles showed similar characteristics to those obtained with the syringe pump. Large batches of BSA nanoparticles were prepared up to 10 g BSA. The BSA nanoparticles were stable at least during 2 months at 4° C and their characteristics were reproducible. It was then concluded that the membrane contactor technique could be a suitable method for the preparation of albumin nanoparticles at large scale with properties similar to that obtained at small scale.
Context:
Whole plant of Leucas aspera (LA) Willd. (Labiatae) is traditionally used in Siddha medicine for hepatic ailments.
Objective:
LA was investigated for its hepatoprotective, antioxidant, and protective effect on microsomal drug metabolizing enzymes (MDMEs).
Materials and methods:
LA aqueous extract (200 and 400 mg/kg, p.o.) was evaluated for its hepatoprotective and antioxidant activity in d-galactosamine (D-GalN)-induced hepatotoxicity in rats. Biochemical and histopathological studies were performed to assess hepatoprotective activity. Hexobarbitone-induced sleeping time model was used to study the protective effect of LA on MDMEs.
Results:
D-GalN administration induced hepatotoxicity in rats which was manifested by increased levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total cholesterol, triglycerides, total bilirubin and oxidative stress. Pretreatment with LA extract significantly protected the liver in D-GalN administered rats. LA extract significantly elevated antioxidant enzymes like superoxide dismutase, catalase, glutathione peroxidase and decreased lipid peroxidation levels in liver. The total phenolic and flavonoid content in LA aqueous extract was found to be 28.33 ± 0.19 gallic acid equivalents mg/g of extract and 3.96 ± 0.57 rutin equivalent mg/g of extract, respectively. LA extract (200 and 400 mg/Kg) treatment with CCl₄ decreased the hexobarbitone-induced sleeping time in mice by 56.67 and 71.30%, respectively, which indicated the protective effect of LA on hepatic MDMEs. Histological studies showed that LA at 400 mg/kg attenuated the hepatocellular necrosis in D-GalN intoxicated rats.
Conclusion:
Our results contribute towards validation of the traditional use of LA in hepatic disorders.
In recent years interest in silver nanoparticles and their applications has increased mainly because of the important antimicrobial activities of these nanomaterials, allowing their use in several industrial sectors. However, together with these applications, there is increasing concerning related to the biological impacts of the use of silver nanoparticles on a large scale, and the possible risks to the environment and health. In this scenario, some recent studies have been published based on the investigation of potential inflammatory effects and diverse cellular impacts of silver nanoparticles. Another important issue related to nanoparticle toxicity in biological media is the capacity for increased damage to the genetic material, since nanoparticles are able to cross cell membranes and reach the cellular nucleus. In this regard, there is increasing interest in the analysis of potential nanoparticle genotoxicity, including the effects of different nanoparticle sizes and methods of synthesis. However, little is known about the genotoxicity of different silver nanoparticles and their effects on the DNA of organisms; thus further studies in this field are required. This mini-review aims to present and to discuss recent publications related to genotoxicity and the cytotoxicity of silver nanoparticles in order to better understand the possible applications of these nanomaterials in a safe manner. This present work concludes that biogenic silver nanoparticles are generally less cyto/genotoxic in vivo compared with chemically synthesized nanoparticles. Furthermore, human cells were found to have a greater resistance to the toxic effects of silver nanoparticles in comparison with other organisms. Copyright © 2012 John Wiley & Sons, Ltd.
In recent years, the development of efficient green chemistry methods for synthesis of metal nanoparticles has become a major focus of researchers. They have investigated in order to find an eco-friendly technique for production of well-characterized nanoparticles. One of the most considered methods is production of metal nanoparticles using organisms. Among these organisms plants seem to be the best candidates and they are suitable for large-scale biosynthesis of nanoparticles. Nanoparticles produced by plants are more stable and the rate of synthesis is faster than in the case of microorganisms. Moreover, the nanoparticles are more various in shape and size in comparison with those produced by other organisms. The advantages of using plant and plant-derived materials for biosynthesis of metal nanoparticles have interested researchers to investigate mechanisms of metal ions uptake and bioreduction by plants, and to understand the
possible mechanism of metal nanoparticle formation in plants. In this review, most of the plants used in metal nanoparticle synthesis are shown.
The application of nanotechnology in medicine, referred to as nanomedicine, is offering numerous exciting possibilities in healthcare. Herein, we discuss two important aspects of nanomedicine, drug delivery and tissue engineering, highlighting the advances we have recently experienced, the challenges we are currently facing, and what we are likely to witness in the near future.
Nanotechnology is the engineering and manufacturing of materials at the atomic and molecular scale. In its strictest definition from the National Nanotechnology Initiative, nanotechnology refers to structures roughly in the 1-100 nm size regime in at least one dimension. Despite this size restriction, nanotechnology commonly refers to structures that are up to several hundred nanometers in size and that are developed by top-down or bottom-up engineering of individual components. Herein, we focus on the application of nanotechnology to drug delivery and highlight several areas of opportunity where current and emerging nanotechnologies could enable entirely novel classes of therapeutics.
It is not uncommon to treat plant-derived foods and feeds with alkali. Such exposure to high pH is being used to recover proteins from cereals and legumes, to induce the formation of fiber-forming meat analogue vegetable protein, for preparing peeled fruits and vegetables, and for destroying microorganisms. In addition to their profound effects on functional and nutritional properties in such foods, such treatments may also cause other side reactions, including the destruction of natural polyphenolic compounds. Because plants contain a large number of structurally different antioxidant, anticarcinogenic, and antimicrobial polyphenolic compounds, it is of interest to know whether such compounds are stable to heat and to high pH. In this model study, the stability of the following natural polyphenols to pH in the range 3-11 was studied with the aid of ultraviolet spectroscopy: caffeic acid, (-)-catechin, chlorogenic acid, ferulic acid, gallic acid, (-)-epigallocatechin, rutin, and the nonphenolic compound trans-cinnamic acid. This study demonstrates that caffeic, chlorogenic, and gallic acids are not stable to high pH and that the pH- and time-dependent spectral transformations are not reversible. By contrast, chlorogenic acid is stable to acid pH, to heat, and to storage when added to apple juice. (-)-Catechin, (-)-epigallocatechin, ferulic acid, rutin, and trans-cinnamic acid resisted major pH-induced degradation. The results are rationalized in terms of relative resonance stabilization of phenoxide ions and quinone oxidation intermediates. The possible significance of these findings to food chemistry and microbiology is discussed.
The aim of this study was to compare four in vitro cytotoxicity assays and determine their ability to detect early cytotoxic events. Two hepatoma cell lines, namely HTC and HepG2 cells, were exposed to cadmium chloride (0-300 microM) for 3, 5 and 8 h. Following exposure to the toxic metal cytotoxicity was determined with the lactate dehydrogenase leakage assay (LDH), a protein assay, the neutral red assay and the methyl tetrazolium (MTT) assay. In HTC cells no toxicity was observed for any incubation period when the LDH leakage, the MTT and the protein assay were employed whereas the neutral red assay revealed early cytotoxicity starting after incubation of HTC cells with CdCl(2) for 3 h. In the case of HepG2 cells the MTT assay reveals cytotoxicity due to CdCl(2) exposure after 3 h whereas no such effect is seen with the other three assays. Following 5 h exposure of HepG2 cells to CdCl(2), toxicity is observed with the MTT assay at lower concentrations compared to the ones required for detection of toxicity with the LDH leakage and the neutral red assay. In conclusion different sensitivity was observed for each assay with the neutral red and the MTT assay being the most sensitive in detecting cytotoxic events compared to the LDH leakage and the protein assay.