Green synthesis of zinc oxide nanoparticles, characterization, cytotoxicity and antimicrobial activity

In this research, zinc oxide nanoparticles (ZnONP) were synthesized by green synthesis technique using the extract obtained from Sideritis akmanii plant. The characterization of the obtained ZnONPs was carried out by Ultraviolet-Visible Spectrophotometer (UV-VIS), X-Ray Diffraction (XRD) Spectroscopy, Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectrometer (FT-IR) techniques. The maximum absorbance value of the ZnONP solution synthesized by the green synthesis technique was recorded as 365 nm. It was determined that the Bragg peaks obtained as a result of the XRD analysis of the nanoparticles were compatible with the JCPDS model 36-1451 and that the nanoparticles had a hexagonal structure. As a result of XRD and SEM analysis, it was determined that the highest peak at 2θ angle was 36.262, FWHM value was 0.437 and ZnONP particle size was 21.26 nm and spherical. The cytotoxic effects of Sideritis akmanii extract and synthesized ZnONPs on the A549 cell line were evaluated depending on concentration and time. The LD50 dose for ZnONP was determined as NP50 (5 mg/mL). It was determined that ZnONPs showed higher cytotoxic activity even at very low concentrations compared to Sideritis akmanii extract. The genotoxic effects of ZnONPs and the plant extract on the A549 cell line were compared for 24 and 48 hour periods. It has been shown that ZnONPs cause different genotoxic effects at different doses on the A549 cell line. It was observed that all three concentrations of the plant extract applied in the study had a reducing effect on genotoxic damage in 24-hour and 48-hour application. It was determined that the synthesized ZnONP 25 regressed the genotoxic damage compared to the control group in both 24-hour and 48-hour application. Antimicrobial activity of ZnONPs on Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 29213), Salmonella enteritidis (ATCC 13076), Klebsiella pneumoniae (ATCC 700603) and Candida albicans (ATCC 90028) microorganisms was analyzed using the disc diffusion method. Disk diffusion test results revealed that ZnONPs were effective on 5 strains of microorganisms with inhibition zone diameters ranging from 8-13.67 mm. Doses of ZnONP for 24, 48 and 72 hours were most effective in Salmonella enteritidis. The highest inhibition diameter was recorded as 13.67 mm in the Salmonella enteritidis strain, which was administered with a dose of 250 mg/mL ZnONP for 72 hours. The obtained results show that Sideritis akmanii extract and synthesized ZnONPs may be useful in the development of alternative treatment methods against various cancer types, bacterial and fungal infections.