Estimation of toxic effects of chemically and biologically synthesized silver nanoparticles on human gut microflora containing Bacillus subtilis

Tyagi, Pankaj; Tyagi, Shruti; Verma, Charul; Rajpal, Aanchal

doi:10.5897/jtehs2013.0271

Cited by 25 publications

(11 citation statements)

References 29 publications

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“…These color changes and sharp peaks confirm the biosynthesis of colloidal AgNP formation in the solution (Figures 1(a) and 1(b)). In some previous reports, a plasmon peak ranging 400-500 nm in AgNP formation [36] and some reports evident the absorption peak at 350-450 nm for the silver nanoparticles [27]. All in all, some factors such as size and shape of nanoparticles present in the reaction solution may be affecting the SPR absorbance.…”

Section: Resultsmentioning

confidence: 90%

Ascorbic Acid and Polyphenols Mediated Green Synthesis of Silver Nanoparticles from Tagetes erecta L. Aqueous Leaf Extract and Studied Their Antioxidant Properties

Tyagi

Gola

et al. 2021

Journal of Nanomaterials

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Silver nanoparticle synthesis of the leaf extract Tagetes erecta L. enriched with ascorbic acid and polyphenols has been investigated. The color of the golden yellow extract has changed to pinkish-brown due to the reduction of Ag+ to the colloidal solution of AgNPs and a sharp absorption peak at 420 nm under the UV-Vis spectrophotometer. In addition, the Fourier Transfer Infrared Spectroscopy (FTIR) estimation was completed in order to recognize and identify the biomolecules present in the extract acting as a reducing and capping agent for the AgNPs. The X-ray diffraction (XRD) peaks at (111), (201), (220), and (311) confirm the presence of monoclinic crystals in the solution. The morphology and size of the particles were provided by transmission electron microscopy (TEM) images of AgNPs. At a scale of 100 nm, synthesized AgNPs were predominantly spherical with a size range of 7-35 nm. In comparison to 7.39 mg/100 g in AgNPs, aqueous leaf extract was 55.14 mg/100 g higher in ascorbic acid. The phenolic and flavonoid content of extract was 52.54 ± 2.15 mg (GAE/100 g) and 15.43 ± 0.34 mg (QE/mL), and the colloidal AgNP solution was 21.45 ± 1.15 mg (GAE/100 g) and 8.05 ± 2.42 mg (QE/mL), respectively. Phenolic and flavonoid contents play a major role as a reducing agent and reduce the precursor AgNO3 into AgNPs. The DPPH scavenging assay also assessed the antioxidant properties of extract and its derived AgNPs. As compared antioxidant value to aqueous leaf extract (mg/mL), higher percentage inhibition (PI) was found in AgNPs and free-radical scavenging activity of extract and AgNPs were directly linked to their concentrations. Results of this research have discovered a higher potential for free-radical scavenging AgNPs and will help to develop new and more potent antioxidants for the treatment of different diseases caused by oxidative stress; the higher antioxidant properties bearing AgNPs might be used.

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Section: Resultsmentioning

confidence: 90%

Ascorbic Acid and Polyphenols Mediated Green Synthesis of Silver Nanoparticles from Tagetes erecta L. Aqueous Leaf Extract and Studied Their Antioxidant Properties

Tyagi

Gola

et al. 2021

Journal of Nanomaterials

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“…Moreover, in other studied topical application of AgNPs on damaged skin for wound healing purposes in preclinical mouse models were shown produce no toxic effects 38,39 . Furthermore, Tyagi et al, (2013) have reported that AgNPs are biocompatible and friendlier to the human body microflora even after their ingestion 40 . Therefore, our findings together with these previous observations generate enthusiasm for potential future human applications of AgNPs as chemopreventive agents.…”

Section: Discussionmentioning

confidence: 99%

Silver nanoparticles protect human keratinocytes against UVB radiation-induced DNA damage and apoptosis: potential for prevention of skin carcinogenesis

Arora¹,

Tyagi²,

Bhardwaj³

et al. 2015

Nanomedicine: Nanotechnology, Biology and Medicine

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Ultraviolet (UV)-B radiation from the sun is an established etiological cause of skin cancer, which afflicts more than a million lives each year in the United States alone. Here, we tested the chemopreventive efficacy of silver-nanoparticles (AgNPs) against UVB-irradiation-induced DNA damage and apoptosis in human immortalized keratinocytes (HaCaT). AgNPs were synthesized by reduction-chemistry and characterized for their physicochemical properties. AgNPs were well tolerated by HaCaT cells and their pretreatment protected them from UVB-irradiation-induced apoptosis along with significant reduction in cyclobutane-pyrimidine-dimer formation. Moreover, AgNPs pre-treatment led to G1-phase cell-cycle arrest in UVB-irradiated HaCaT cells. AgNPs were efficiently internalized in UVB-irradiated cells and localized into cytoplasmic and nuclear compartments. Furthermore, we observed an altered expression of various genes involved in cell-cycle, apoptosis and nucleotide-excision repair in HaCaT cells treated with AgNPs prior to UVB-irradiation. Together, these findings provide support for potential utility of AgNPs as novel chemopreventive agents against UVB-irradiation-induced skin carcinogenesis.

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“…Because of its nano-size, NPs can translocate from the entry ports into the circulatory and lymphatic systems, and ultimately to body tissues and organs. Some nanoparticles produce irreversible damage to cells by oxidative stress and/or organelle injury and the extent of which depends on the size and composition of the NPs [216][217][218]. The toxicity of metallic nanoparticles can be due to various reasons, such as dose, size, surface area of nanoparticles, concentration, particle chemistry and crystalline structure, aspect ratio and surface coating and functionalization [217].…”

Section: Environmental Issuesmentioning

confidence: 99%

Biological synthesis of metallic nanoparticles: plants, animals and microbial aspects

Das

Pachapur

Lonappan

et al. 2017

Nanotechnol. Environ. Eng.

373

138

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The green synthesis (GS) of different metallic nanoparticles (MNPs) has re-evaluated plants, animals and microorganisms for their natural potential to reduce metallic ions into neutral atoms at no expense of toxic and hazardous chemicals. Contrary to chemically synthesized MNPs, GS offers advantages of enhanced biocompatibility and thus has better scope for biomedical applications. Plant, animals and microorganisms belonging to lower and higher taxonomic groups have been experimented for GS of MNPs, such as gold (Au), silver (Ag), copper oxide (CuO), zinc oxide (ZnO), iron (Fe 2 O 3 ), palladium (Pd), platinum (Pt), nickel oxide (NiO) and magnesium oxide (MgO). Among the different plant groups used for GS, angiosperms and algae have been explored the most with great success. GS with animal-derived biomaterials, such as chitin, silk (sericin, fibroin and spider silk) or cell extract of invertebrates have also been reported. Gram positive and gram negative bacteria, different fungal species and virus particles have also shown their abilities in the reduction of metal ions. However, not a thumb rule, most of the reducing agents sourced from living world also act as capping agents and render MNPs less toxic or more biocompatible. The most unexplored area so far in GS is the mechanism studies for different natural reducing agents expect for few of them, such as tea and neem plants. This review encompasses the recent advances in the GS of MNPs using plants, animals and microorganisms and analyzes the key points and further discusses the pros and cons of GS in respect of chemical synthesis.

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Estimation of toxic effects of chemically and biologically synthesized silver nanoparticles on human gut microflora containing Bacillus subtilis

Cited by 25 publications

References 29 publications

Ascorbic Acid and Polyphenols Mediated Green Synthesis of Silver Nanoparticles from Tagetes erecta L. Aqueous Leaf Extract and Studied Their Antioxidant Properties

Ascorbic Acid and Polyphenols Mediated Green Synthesis of Silver Nanoparticles from Tagetes erecta L. Aqueous Leaf Extract and Studied Their Antioxidant Properties

Silver nanoparticles protect human keratinocytes against UVB radiation-induced DNA damage and apoptosis: potential for prevention of skin carcinogenesis

Biological synthesis of metallic nanoparticles: plants, animals and microbial aspects

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