RESUMO
Current study was aimed to determine the antibacterial, antioxidant and cytotoxic potential of Titanium dioxide nanoparticles (TiO2NPs) and Zinc oxide nanoparticles (ZnONPs). Nanoparticles were characterized by UV-Vis spectrophotometry, particle size analyzer (PSA), fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The Minimum inhibitory concentration (MIC) was determined by standard agar dilution method. Antibacterial potential of nanoparticles was analyzed by standard disc diffusion method against bacterial strains including Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumonia. Different concentrations of NPs (0.2, 0.4, 0.6, 0.8, 1.0, 1.2 and 1.4 mg/mL) were incorporated to evaluate the antimicrobial activity. Antioxidant activity and cytotoxicity of these NPs was analyzed by DPPH method and brine shrimp cytotoxicity assay, respectively. The MIC of TiO2NPs against E. coli, P. aeruginosa and K. pneumoniae was 0.04, 0.08 and 0.07 mg/mL respectively while the MIC of ZnONPs against the above strains was 0.01, 0.015 and 0.01 mg/mL. The maximum zone of inhibition was observed for K. pneumoniae i.e., 20mm and 25mm against TiO2 and ZnO NPs respectively, at 1.4 mg/mL concentration of NPs. The susceptibility of NPs against bacterial strains was evaluated in the following order: K. pneumoniae > P. aeruginosa > E. coli. The antioxidant activity of nanoparticles increased by increasing the concentration of NPs while cytotoxic analysis exhibited non-toxic effect of ZnO NPs while TiO2 had toxic effects on 1.2 and 1.4 mg/mL concentrations. Results revealed that ZnO NPs have more antibacterial and negligible cytotoxic potential in contrast to TiO2 NPs.
RESUMO
Nanotechnology is a rapidly developing field of research that studies materials having dimensions of less than 100 nanometers. It is applicable in many areas of life sciences and medicine including skin care and personal hygiene, as these materials are the essential components of various cosmetics and sunscreens. The aim of the present study was to synthesize Zinc oxide (ZnO) and Titanium dioxide (TiO2) nanoparticles (NPs) by using Calotropis procera (C. procera) leaf extract. Green synthesized NPs were characterized by UV spectroscopy, Fourier transform infrared (FTIR), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM) to investigate their structure, size, and physical properties. The antibacterial and synergistic effects of ZnO and TiO2 NPs along with antibiotics were also observed against bacterial isolates. The antioxidant activity of synthesized NPs was analyzed by their α-diphenyl-ß-picrylhydrazyl (DPPH) radical scavenging activity. In vivo toxic effects of the synthesized NPs were evaluated in albino mice at different doses (100, 200, and 300 mg/kg body weight) of ZnO and TiO2 NPs administered orally for 7, 14, and 21 days. The antibacterial results showed that the zone of inhibition (ZOI) was increased in a concentration-dependent manner. Among the bacterial strains, Staphylococcus aureus showed the highest ZOI, i.e., 17 and 14 mm against ZnO and TiO2 NPs, respectively, while Escherichia coli showed the lowest ZOI, i.e., 12 and 10 mm, respectively. Therefore, ZnO NPs are potent antibacterial agents compared to TiO2 NPs. Both NPs showed synergistic effects with antibiotics (ciprofloxacin and imipenem). Moreover, the DPPH activity showed that ZnO and TiO2 NPs have significantly (p > 0.05) higher antioxidant activity, i.e., 53% and 58.7%, respectively, which indicated that TiO2 has good antioxidant potential compared to ZnO NPs. However, the histological changes after exposure to different doses of ZnO and TiO2 NPs showed toxicity-related changes in the structure of the kidney compared to the control group. The current study provided valuable information about the antibacterial, antioxidant, and toxicity impacts of green synthesized ZnO and TiO2 NPs, which can be influential in the further study of their eco-toxicological effects.
