Antibacterial Activity of Biosynthesized Selenium Nanoparticles Using Extracts of Calendula officinalis against Potentially Clinical Bacterial Strains.

José A Hernández-Díaz,Jenny Arratia-Quijada,Adalberto Zamudio-Ojeda,Julio C López-Velázquez,Janet M León-Morales,Gilberto Velázquez-Juárez,Soledad García-Morales,Jorge Jo Garza-García

doi:10.3390/molecules26195929

Abstract

The use of selenium nanoparticles (SeNPs) in the biomedical area has been increasing as an alternative to the growing bacterial resistance to antibiotics. In this research, SeNPs were synthesized by green synthesis using ascorbic acid (AsAc) as a reducing agent and methanolic extract of Calendula officinalis L. flowers as a stabilizer. Characterization of SeNPs was performed by UV-vis spectrophotometry, infrared spectrophotometry (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) techniques. SeNPs of 40–60 nm and spherical morphologies were obtained. The antibacterial activity of marigold extracts and fractions was evaluated by disk diffusion methodology. The evaluation of SeNPs at different incubation times was performed through the colony-forming unit (CFU) count, in both cases against Serratia marcescens, Enterobacter cloacae, and Alcaligenes faecalis bacteria. Partial antibacterial activity was observed with methanolic extracts of marigold leaves and flowers and total inhibition with SeNPs from 2 h for S. marcescens, 1 h for E. cloacae, and 30 min for A. faecalis. In addition, SeNPs were found to exhibit antioxidant activity. The results indicate that SeNPs present a potentiated effect of both antimicrobial and antioxidant activity compared to the individual use of marigold extracts or sodium selenite (Na2SeO3). Their application emerges as an alternative for the control of clinical pathogens.

Highlights

Two methanolic extracts of leaves/stems and flowers were evaluated for their antibacterial activity against three Gram-negative bacteria
Comparable results were presented by Efstratiou et al [9], which demonstrated the antibacterial potential of methanolic extracts of marigold flowers at this same concentration against a large number of bacteria, such as Bacillus subtilis, Escherichia coli, and Staphylococcus aureus
The antibacterial activity of the extract, ascorbic acid (AsAc), and Na2 SeO3 was enhanced by producing the SeNPs, which significantly inhibited the growth of S. marcescens, E. cloacae, and A. faecalis bacterial strains

Summary

Introduction

Nanotechnology is an emerging area of science that deals with the study and manipulation of matter at the molecular and atomic levels [1]. With the emergence of nanotechnology, a new industrial revolution was generated that impacted the world, especially in the biomedical area, where the physicochemical and biological properties of nanoparticles (NPs) have been widely used and exploited [2]. It gave rise to nanomedicine, considered a new discipline of medicine, whose main areas of application include diagnostics, imaging, and smart drug delivery systems to increase therapeutic efficiency by selective delivery to specific targets [3], as well as the generation of diverse nanomaterials against pathogenic microorganisms such as fungi and bacteria [4]. One of the fundamental characteristics of NPs is that they have a larger surface area, a property different from those of ionic or metallic elements on a macroscopic scale [5]. Se is a fundamental trace element for human health, which has structural and enzymatic functions necessary for the proper functioning of the immune system, counteracting the incidence of viruses such as HIV and maintaining sperm motility [6]

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Results

Conclusion