Synthesis of silver nanoparticles using Dioscorea bulbifera tuber extract and evaluation of its synergistic potential in combination with antimicrobial agents

Abstract

Background Development of an environmentally benign process for the synthesis of silver nanomaterials is an important aspect of current nanotechnology research. Among the 600 species of the genus Dioscorea, Dioscorea bulbifera has profound therapeutic applications due to its unique phytochemistry. In this paper, we report on the rapid synthesis of silver nanoparticles by reduction of aqueous Ag + ions using D. bulbifera tuber extract. Methods and results Phytochemical analysis revealed that D. bulbifera tuber extract is rich in flavonoid, phenolics, reducing sugars, starch, diosgenin, ascorbic acid, and citric acid. The biosynthesis process was quite fast, and silver nanoparticles were formed within 5 hours. Ultraviolet-visible absorption spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy dispersive spectroscopy, and x-ray diffraction confirmed reduction of the Ag + ions. Varied morphology of the bioreduced silver nanoparticles included spheres, triangles, and hexagons. Optimization studies revealed that the maximum rate of synthesis could be achieved with 0.7 mM AgNO 3 solution at 50°C in 5 hours. The resulting silver nanoparticles were found to possess potent antibacterial activity against both Gram-negative and Gram-positive bacteria. Beta-lactam (piperacillin) and macrolide (eryth-romycin) antibiotics showed a 3.6-fold and 3-fold increase, respectively, in combination with silver nanoparticles selectively against multidrug-resistant Acinetobacter baumannii. Notable synergy was seen between silver nanoparticles and chloramphenicol or vancomycin against Pseudomonas aeruginosa , and was supported by a 4.9-fold and 4.2-fold increase in zone diameter, respectively. Similarly, we found a maximum 11.8-fold increase in zone diameter of streptomycin when combined with silver nanoparticles against E. coli , providing strong evidence for the synergistic action of a combination of antibiotics and silver nanoparticles. Conclusion This is the first report on the synthesis of silver nanoparticles using D. bulbifera tuber extract followed by an estimation of its synergistic potential for enhancement of the antibacterial activity of broad spectrum antimicrobial agents.

Chelating effect of silver nitrate by chitosan on its toxicity and growth performance in broiler chickens

“…Briefly, chitosan stock solution (1%, w/v) was prepared under magnetic stirring by dissolving 10.875 gm of chitosan in 1000 mL of distilled water at ambient temperature overnight. Ag + ions were reduced to Ag 0 by addition of 435 mL of AgNO3 solution to 1087.5 mL of chitosan solution under magnetic stirrer for 2 h. The homogeneous solution obtainned was kept in a sealed transparent bottle at ambient temperature and the creation of the complex between chitosan and AgNO3 or the bioreduction of Ag + to Ag 0 was effective when the color of the solution changes from transparent to yellowish-brown, as reported by Ghosh et al (2012). This solution was then mixed to a premix and incorporated in the feed.…”

Antimicrobial activity of biogenic silver nanoparticles, and silver chloride nanoparticles: an overview and comments

“…The same pattern were also published for Ag°nanoparticles synthesized from Phanerochaete chrysosporium (MTCC 787/ATCC 24725) culture (Vigneshwaran et al 2006), Schizophyllum radiatum HE 863742.1 (Metuku et al 2014), or from Aspergillus fumigatus (Bhainsa and D'Souza, 2006) following the Joint Plant sources such as Annona squamosa leaf broth (Arjunan et al 2012) produced only Ag o nanoparticles, the same was observed in the case of biogenic synthesis of Ag°nanoparticles from aqueous extract of Gloriosa superba Linn. (Glory Lily) (Ashokkumar et al 2013), Dioscorea bulbifera (Ghosh et al 2012), Sinapis arvensis seeds (Khatami et al 2015), gum tragacanth exudate of the bark from Astragalus gummifer (Fabaceae family) (Kora and Arunachalam, 2012), Gum ghatti from Anogeissus latifolia , Medicago sativa seed exudates (Lukman et al 2011), from Cinnamomum zeylanicum bark extract (Sathishkumar et al 2009), from extract of Lawsonia inermis (Henna) (Gupta et al 2014), and from latex of Jatropha curcas (Bar et al 2009). …”

Kajian Teoritis Kemampuan Capping Katekin, Kateku Tanat Dan Quarsetin Terhadap Nanopartikel Perak Dengan Menggunakan Metoda DFT-B

“…Berbagai macam ekstrak tumbuhan terbukti mampu menghasilkan nanopartikel perak dengan dengan ukuran partikel yang halus, seperti : ekstrak Citrullus colocynthis [3] , Camellia sinensis [4] , Dioscorea bulbifera [5] , Rumex hymenosepalus [6] dan Withania somnifera [7] . Kemampuan ekstrak tumbuhan yang dapat bertindak sebagai reduktor sekaligus capping agent pada proses sintesis nanopartikel, tidak terlepas dari kandungan senyawa metabolit sekunder, seperti fenolik, tanin dan saponin yang ada didalam ekstrak tumbuhan tersebut [8] .…”