Phytogenic silver, gold, and bimetallic nanoparticles as novel antitubercular agents

TitlePhytogenic silver, gold, and bimetallic nanoparticles as novel antitubercular agents
Publication TypeJournal Article
Year of Publication2016
AuthorsSingh, R, Nawale, L, Arkile, MA, Wadhwani, S, Shedbalkar, U, Chopade, S, Sarkar, D, Chopade, BAnanda
JournalInternational Journal of Nanomedicine
Volume11
Pagination1889—1897
Date PublishedMAY
ISSN1178-2013
KeywordsAntimycobacterial agent, Cytotoxicity, drug resistance, Mycobacteria, Nanoparticles, tuberculosis
Abstract

Purpose: Multi- and extensively drug-resistant tuberculosis (TB) is a global threat to human health. It requires immediate action to seek new antitubercular compounds and devise alternate strategies. Nanomaterials, in the present scenario, have opened new avenues in medicine, diagnosis, and therapeutics. In view of this, the current study aims to determine the efficacy of phytogenic metal nanoparticles to inhibit mycobacteria. Methods: Silver (AgNPs), gold (AuNPs), and gold-silver bimetallic (Au-AgNPs) nanoparticles synthesized from medicinal plants, such as Barleria prionitis, Plumbago zeylanica, and Syzygium cumini, were tested against Mycobacterium tuberculosis and M. bovis BCG. In vitro and ex vivo macrophage infection model assays were designed to determine minimum inhibitory concentration (MIC) and half maximal inhibitory concentration of nanoparticles. Microscopic analyses were carried out to demonstrate intracellular uptake of nanoparticles in macrophages. Besides this, biocompatibility, specificity, and selectivity of nanoparticles were also established with respect to human cell lines. Results: Au-AgNPs exhibited highest antitubercular activity, with MIC of <2.56 mu g/mL, followed by AgNPs. AuNPs did not show such activity at concentrations of up to 100 mu g/mL. In vitro and ex vivo macrophage infection model assays revealed the inhibition of both active and dormant stage mycobacteria on exposure to Au-AgNPs. These nanoparticles were capable of entering macrophage cells and exhibited up to 45% cytotoxicity at 30 mu g/mL (ten times MIC concentration) after 48 hours. Among these, Au-AgNPs synthesized from S. cumini were found to be more specific toward mycobacteria, with their selectivity index in the range of 94-108. Conclusion: This is the first study to report the antimycobacterial activity of AuNPs, AgNPs, and Au-AgNPs synthesized from medicinal plants. Among these, Au-AgNPs from S. cumini showed profound efficiency, specificity, and selectivity to kill mycobacteria. These should be investigated further to develop novel TB nanoantibiotics.

DOI10.2147/IJN.S102488
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

4.32

Divison category: 
Organic Chemistry