Brassica oleracea L. (Acephala Group) based zinc oxide nanoparticles and their efficacy as antibacterial agent

Abstract

Zinc oxide nanoparticles were synthesized from the leaf extract of Brassica oleracea L. Acephala group (collard green) followed by their characterization using Scanning Electron Microscope (SEM), and Energy Dispersive X-ray (EDX). The antibacterial properties of zinc nanoparticles were tested against Gram-negative bacteria, Pseudomonas aeruginosa (ATCC ® 9027™), Escherichia coli (ATCC ® 8739™), Klebsiella pneumoniae (ATCC® BAA-1705™) and Gram-positive bacteria, Staphylococcus aureus (ATCC ® 6538™) and Listeria monocytogenes (ATCC ® 13932™), at four different concentrations (50.00 µg/ml, 100.00 µg/ml, 500.00 µg/ml and 1 mg/ml) of zinc oxide nanoparticles suspension. Results revealed that the synthesized nanoparticles exhibit strong antibacterial effects against Pseudomonas aeruginosa, Listeria monocytogenes, Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli at 500.00 µg/ml-1 mg/ml concentrations. An increase in efficacy of nanoparticles with the decrease of their size was also evident. This is a first ever report on Brassica oleracea, L. based nanoparticles which demonstrates that 500.00 µg-1 mg/ml conc. of zinc oxide nanoparticles have antibacterial activity against both Gram -ve and Gram +ve bacteria and have the potential to be considered as an antibacterial agent in future.

Study of the morphological characteristics of nanoparticles synthesized by biogenic method

“…Although Mkhize, S. et al obtained a smaller size, the nanostructures were agglomerated [10]. The reference [45] mention the influence of the precursor salt, especially with the use of ZnSO4 on the size and shape. Despite this, the most variable factor in the synthesis is the influence of the extract, since it is subject to the phytoconstituent chemical properties in the extracts.…”

Plant-Origin Components: New Players to Combat Antibiotic Resistance in Klebsiella pneumoniae

“…Other AgNPs from the leaf extract of Alternanthera sessilis have shown potential biomedical application against MDR-Kpn strains [147]. Zinc oxide (ZnSO 4 ) NPs produced with Brassica oleracea extract showed insufficient antibacterial activity against MDR-Kpn strains but demonstrated antibacterial and antifungal potential against other pathogens [148]. Zirconium oxide (ZrO 2 ) NPs are proposed to be functional in the production of medical devices, such as tissue scaffolds, microscale valves, and bone prostheses, suggesting that they possess favourable antibacterial potential.…”

Antimicrobial properties in nanoparticles synthesized by biogenic route

“…Por el otro lado, las investigaciones señalaron como efecto común la aglomeración, recalcando las NPs ZnO [44], [45], [50], lo cual se deba al tamaño de la nanoestructura. La referencia [38] al experimentar con distintas proporcionalidades, concluyo que con una relación 1:1 las nanopartículas obtenidas son menores a 50 nanómetros (nm), y sus aglomerados reducen significativamente (0,50-01,00 µm). Recalcando, la complejidad de la síntesis biogénica, en sus factores influyentes (extracto, precursor, pH, etc.)…”

“…En cuanto a los resultados de ZnO, la literatura demostró reducciones significativas a concentraciones mayores, logrando de 10-22 mm contra E. coli, [38], [39], [46], 11+-0.56 mm E. aerogenes [41], 10-13 mm S. aureus [42], [45], [46] 8-17 mm contra B. subtilis [41]- [43]. Causándolo, el aumento de compuestos bioactivos efectivos contra los microbios, esto concuerda con los resultados de [50] atribuyéndolo a la alta presencia de flavonoides, taninos y alcaloides del extracto.…”