Green synthesis of silver nanoparticles using Ocimum sanctum Linn. and its antibacterial activity against multidrug resistant Acinetobacter baumannii

Deepan Gautam, Karma Gurmey Dolma*, Bidita Khandelwal, Madhu Gupta, Meghna Singh, Tooba Mahboob, Anil Teotia, Prasad Thota, Jaydeep Bhattacharya, Ramesh Goyal, Sonia M.R. Oliveira, Maria de Lourdes Pereira, Christophe Wiart, Polrat Wilairatana, Komgrit Eawsakul, Mohammed Rahmatullah, Shanmuga Sundar Saravanabhavan, Veeranoot Nissapatorn*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

The biosynthesis of nanoparticles using the green route is an effective strategy in nanotechnology that provides a cost-effective and environmentally friendly alternative to physical and chemical methods. This study aims to prepare an aqueous extract of Ocimum sanctum (O. sanctum)-based silver nanoparticles (AgNPs) through the green route and test their antibacterial activity. The biosynthesized silver nanoparticles were characterised by colour change, UV spectrometric analysis, FTIR, and particle shape and size morphology by SEM and TEM images. The nanoparticles are almost spherical to oval or rod-shaped with smooth surfaces and have a mean particle size in the range of 55 nm with a zeta potential of −2.7 mV. The antibacterial activities of AgNPs evaluated against clinically isolated multidrug-resistant Acinetobacter baumannii (A. baumannii) showed that the AgNPs from O. sanctum are effective in inhibiting A. baumannii growth with a zone of inhibition of 15 mm in the agar well diffusion method and MIC and MBC of 32 µg/mL and 64 µg/mL, respectively. The SEM images of A. baumannii treated with AgNPs revealed damage and rupture in bacterial cells. The time-killing assay by spectrophotometry revealed the time- and dose-dependent killing action of AgNPs against A. baumannii, and the assay at various concentrations and time intervals indicated a statistically significant result in comparison with the positive control colistin at 2 µg/mL (P < 0.05). The cytotoxicity test using the MTT assay protocol showed that prepared nanoparticles of O. sanctum are less toxic against human cell A549. This study opens up a ray of hope to explore the further research in this area and to improve the antimicrobial activities against multidrug resistant bacteria.

Original languageEnglish
Article numbere15590
JournalPeerJ
Volume11
DOIs
Publication statusPublished - 2023
Externally publishedYes

Keywords

  • Antibacterial activity
  • Biosynthesis
  • Green nanotechnology
  • Ocimum sanctum
  • Silver nanoparticles

Fingerprint

Dive into the research topics of 'Green synthesis of silver nanoparticles using Ocimum sanctum Linn. and its antibacterial activity against multidrug resistant Acinetobacter baumannii'. Together they form a unique fingerprint.

Cite this