Antibacterial and Hemolytic Activity of Green Silver Nanoparticles from Catharanthus roseus

Author(s):  
A. Raja ◽  
S. Mohamed Salique ◽  
P. Gajalakshmi ◽  
Arthur James

The objective of this research was to standardize the Green synthesis of silver nanoparticles by C.roseus and to evaluate them for their potential against Mycobacteral tuberculosis. Phytochemical study realized the presence flavonoids, saponins, alkaloids, cardiac glycosides, steroids and tannins. Colloidal silver nanoparicle was synthesized by one step green reduction at room temperature and characterized by UV and TEM. An effort made to find out the capping agent revealed that the TLC fraction with 0.7 Rf value showed the reduction of silver ions. GCMS analysis of TLC fraction showed the presence of nine different phytochemical which includes pentadecane and piperdine carboxylic acid as major constituent. The nanoparticle diameter is in the range of 38- 52 nm and stable for 30 days under room temperature. The bactericidal activity of synthesized nanoparticle was  24 ± 0.04 and 22 ± 0.62 mm respectively against M.smegmatis and M.tuberculosis. The in vitro hemolytic assessment of silver nanoparticles was found to be safe at maximum of 1-5 µg/mL and toxic between 15- 50 µg/ml. Further this data encourages that theses biologically synthesized nanoparticles were found to be less toxic and more effective against mycobacterial strains.

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
M. A. El-Sheikh

The water soluble photoinitiator (PI) 4-(trimethyl ammonium methyl) benzophenone chloride is used for the first time in the synthesis of silver nanoparticles (AgNPs). A new green synthesis method involves using PI/UV system, carboxymethyl starch (CMS), silver nitrate, and water. A mechanism of the reduction of silver ions to AgNPs by PI/UV system as well as by the newly born aldehydic groups was proposed. The synthesis process was assessed by UV-vis spectra and TEM of AgNPs colloidal solution. The highest absorbance was obtained using CMS, PI and AgNO3concentrations of 10 g/L, 1 g/L, and 1 g/L, respectively; 40°C; 60 min; pH 7; and a material : liquor ratio 1 : 20. AgNPs so-obtained were stable in aqueous solution over a period of three weeks at room temperature (~25°C) and have round shape morphology. The sizes of synthesized AgNPs were in the range of 1–21 nm and the highest counts % of these particles were for particles of 6–10 and 1–3 nm, respectively.


2016 ◽  
Vol 15 (05n06) ◽  
pp. 1660001 ◽  
Author(s):  
V. P. Manjamadha ◽  
Karuppan Muthukumar

The current work elucidates the utilization of biowaste as a valuable reducing agent for the synthesis of silver nanoparticles. In this study, the wastewater generated during the alkaline pretreatment of lignocellulosic wastes (APLW) was used as a bioreductant to reduce silver nitrate under room temperature. Synthesis of stable silver nanoparticles (AgNPs) was achieved rapidly on addition of APLW into the silver nitrate solution (1[Formula: see text]mM). The morphological characterization of AgNPs was performed using field emission scanning electron microscopy (FESEM). The micrograph clearly depicted the presence of spherical AgNPs. The presence of elemental silver along with biomoilties was determined using energy dispersive X-ray spectroscopy (EDAX) analysis. The X-ray diffraction (XRD) study proved the crystalline form of stable AgNPs. The AgNPs exhibited excellent antibacterial performance against Gram negative organism. The immediate bioreduction of silver ions using APLW was well illustrated in the present study. Thus, APLW serve as an alternative source for reducing agents instead of utilizing valuable medicinal plants for nanoparticles synthesis.


2021 ◽  
Author(s):  
Constantinos Chrysikopoulos ◽  
Anastasios A. Malandrakis ◽  
Nektarios Kavroulakis ◽  
Anthi Stefanarou

<div><span>The potential of silver nanoparticles (Ag-NPs) to control plant pathogen <em>Monilia</em><em>fructicola </em>and to deter environmental contamination by reducing fungicide doses was evaluated <em>in vitro </em>and <em>in vivo. </em> </span>F<span>ungitoxicity screening </span>of <em><span>M. fructicola </span></em><span>isolates resulted in the detection of 18 benzimidazole-resistant (BEN-R) isolates with reduced sensitivity to fungicides  thiophanate methyl (TM)  and carbendazim. All resistant isolates caried the E198A resistance mutation in their </span><em><span>β</span>-</em>tubulin gene, target site of the benzimidazole fungicides. <span>Ag-NPs could effectively control both sensitive (BEN-S) and resistant isolates while the combination of Ag-NPs with TM significantly enhanced their fungitoxic effect both <em>in vitro </em>and in apple fruit tests. The positive correlation observed between Ag-NPs and TM+Ag-NPs treatments indicates a mixture-enhanced Ag-NPs activity/availability as a possible mechanism of synergy. No correlation between Ag-NPs  and AgNO<sub>3 </sub>could  be found suggesting difference(s) in the fungitoxic mechanism of action between Nps and their bulk/ionic counterparts. Indications of the involvement of energy (ATP) metabolism in the mode of action of Ag-NPs were also evident by the synergy observed between Ag-NPs and the </span>oxidative phosphorylation<span>-uncoupler fluazinam (FM) against both BEN-R and BEN-S phenotypes. The role of silver ions release on the inhibitory action of Ag-NPs against the fungusis probably limited since the AgNPs/NaCl combination enhanced fungitoxicity, a fact that could not be justified by the expected binding of silver with chlorine ions. Concluding, Ag-NPs can be effectively used as a means of controlling both BEN-S and BEN-R <em>M. </em><em>fructicola </em>isolates </span>while <span>their combination with conventional fungicides should aid anti-resistant strategies and reduce the environmental impact of synthetic fungicides by reducing effective doses to the control the pathogen.</span></div>


2016 ◽  
Vol 96 ◽  
pp. 50-61 ◽  
Author(s):  
Jana Jiravova ◽  
Katerina Barton Tomankova ◽  
Monika Harvanova ◽  
Lukas Malina ◽  
Jakub Malohlava ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Luis M. Carrillo-López ◽  
Hilda A. Zavaleta-Mancera ◽  
Alfredo Vilchis-Nestor ◽  
R. Marcos Soto-Hernández ◽  
Jesús Arenas-Alatorre ◽  
...  

Biosynthesis of silver nanoparticles (AgNPs) was achieved using extract ofChenopodium ambrosioidesas a reducer and coating agent at room temperature (25°C). Two molar solutions of AgNO3(1 mM and 10 mM) and five extract volumes (0.5, 1, 2, 3, and 5 mL) were used to assess quantity, shape, and size of the particles. The UV-Vis spectra gave surface plasmon resonance at 434–436 nm of the NPs synthesized with AgNO310 mM and all extract volumes tested, showing a direct relationship between extract volumes and quantity of particles formed. In contrast, the concentration of silver ions was related negatively to particle size. The smallest (4.9 ± 3.4 nm) particles were obtained with 1 mL of extract in AgNO310 mM and the larger amount of particles were obtained with 2 mL and 5 mL of extract. TEM study indicated that the particles were polycrystalline and randomly oriented with a silver structure face centered cubic (fcc) and fourier transform infrared spectroscopy (FTIR) indicated that disappearance of the –OH group band after bioreduction evidences its role in reducing silver ions.


2014 ◽  
Vol 13 (01) ◽  
pp. 1450008 ◽  
Author(s):  
R. Soleyman ◽  
A. Pourjavadi ◽  
N. Masoud ◽  
A. Varamesh

In the current study, γ- Fe 2 O 3/ SiO 2/ PCA / Ag -NPs hybrid nanomaterials were successfully synthesized and characterized. At first, prepared γ- Fe 2 O 3 core nanoparticles were modified by SiO 2 layer. Then they were covered by poly citric acid (PCA) via melting esterification method as well. PCA shell acts as an effective linker, and provides vacancies for conveying drugs. Moreover, this shell as an effective capping agent directs synthesis of silver nanoparticles ( Ag -NPs) via in situ photo-reduction of silver ions by sunlight-UV irradiation. This system has several benefits as a suitable cancer therapy nanomaterial. Magnetic nanoparticles (MNPs) can guide Ag -NPs and drugs to cancer cells and then Ag -NPs can affect those cells via Ag -NPs anti-angiogenesis effect. Size and structure of the prepared magnetic hybrid nanomaterials were characterized using FTIR and UV-Vis spectra, AFM and TEM pictures and XRD data.


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