resumo
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 inhibitingA. baumannii growth with a zone of inhibition of 15 mm in the agar well diffusion method and MIC and MBC of 32 mu g/mL and 64 mu g/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 mu g/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.
palavras-chave
ANTIFUNGAL ACTIVITY; BIOSYNTHESIS; BIOFILMS
categoria
Science & Technology - Other Topics
autores
Gautam, D; Dolma, KG; Khandelwal, B; Gupta, M; Singh, M; Mahboob, T; Teotia, A; Thota, P; Bhattacharya, J; Goyal, R; Oliveira, SMR; Pereira, MD; Wiart, C; Wilairatana, P; Eawsakul, K; Rahmatullah, M; Saravanabhavan, SS; Nissapatorn, V
nossos autores
Maria de Lourdes Gomes Pereira
Professor Associado com Agregação
Sónia M. R. Oliveira
Investigador JúniorProjectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
This work has been supported by the following: 1. Ph.D. Scholarship for Outstanding International Students, Scholarship no. MOE571900/110/2562 and Graduate Studies Research Fund CGS-RF-2021/02. Walailak University, Nakhon Si Thammarat, Thailand. 2. TMA Pai University Research Seed Grant-Major (2018-19), Reference no. 176/SMU/Reg/TMAPURF/30/2019. Sikkim Manipal University, Sikkim, India. 3. Project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MCTES(PIDDAC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.