Antimicrobial, antioxidant, and cytotoxic properties of biosynthesized copper oxide nanoparticles (CuO-NPs) using Athrixia phylicoides DC

Amani Gabriel Kaningini; Thobo Motlhalamme; Garland Kgosi More; Keletso Cecilia Mohale; Malik Maaza

doi:10.1016/j.heliyon.2023.e15265

Antimicrobial, antioxidant, and cytotoxic properties of biosynthesized copper oxide nanoparticles (CuO-NPs) using Athrixia phylicoides DC

Heliyon. 2023 Apr 12;9(4):e15265. doi: 10.1016/j.heliyon.2023.e15265. eCollection 2023 Apr.

Authors

Amani Gabriel Kaningini^{1

2

3}, Thobo Motlhalamme^{1

2

3}, Garland Kgosi More⁴, Keletso Cecilia Mohale³, Malik Maaza^{1

2}

Affiliations

¹ UNESCO-UNISA Africa Chair in Nanoscience and Nanotechnology College of Graduates Studies, University of South Africa, Muckleneuk Ridge, Pretoria, 392, South Africa.
² Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape, South Africa.
³ Department of Agriculture and Animal Health, College of Agriculture and Environmental Sciences, University of South Africa, Private Bag X06, Florida, Johannesburg, 1710, South Africa.
⁴ Department of Life and Consumer Sciences, College of Agriculture and Environmental Sciences, University of South Africa, Private Bag X06, Florida 1710, South Africa.

Abstract

Nanoparticles produced from various metal elements including copper have been used in the treatment of infectious diseases in response to antibiotic failure due to microbial resistance. Copper is recommended for use in the production of nanoparticles largely because of its accessibility and affordability. This study aimed to synthesise copper oxide nanoparticles (CuO-NPs) using leaf extracts of Athrixia phylicoides and assess their antibacterial, antioxidant and cytotoxicity properties. The characterization of the obtained NPs was done through X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Energy-dispersive spectroscopy (EDS). Our results showed that the NPs had a highly crystalline, quasi-spherical shape with an average diameter of 42 nm. Also, gram-positive bacteria Bacillus cereus and Staphylococcus aureus were the most susceptible to CuO-NPs with MIC values of 0.62 mg/mL and 0.16 mg/mL, respectively, as shown by the broth microdilution method. In addition, CuO-NPs demonstrated strong radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibitory activity with an IC₅₀ value of 10.68 ± 0.03 μg/mL. However, the cytotoxicity activity determined by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) (MTT) assay revealed that the CuO-NPs were not toxic to human embryonic kidney cells (HEK 293 cells) at an LC₅₀ value of 66.08 ± 0.55 μg/mL. The synthesised CuO-NPs showed high antibacterial, and antioxidant potency and less toxicity. Therefore, they could be a feasible alternative source of therapeutic agents in treating bacterial and oxidative stress-induced diseases.

Keywords: Antibacterial; Copper-oxide; Cytotoxicity; Green nanotechnology; Nanoparticles.