Antibacterial and phytotoxicological properties assessment of Momordica charantia extract-based ZnO nanoparticles

BACKGROUND

Utilizing the fruit extract of bitter melon (Momordica charantia), zinc nanoparticles (ZnO-NPs) were synthesized through a green approach, a novel endeavor in current literature. The primary objective was to evaluate the phytotoxic and growth-promoting effects of these ZnO-NPs on wheat, chosen as a test plant. Structural characterization using X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy revealed the hexagonal wurtzite crystal structure of ZnO-NPs and identified spherical M. charantia-produced (MC)-ZnO-NPs ranging in size from 48 to 150 nm.

RESULTS

At a concentration of 2000 mg L-1 , both MC- and raw-ZnO-NPs augmented wheat germination percentages. Furthermore, raw-ZnO-NPs at 4000 mg L-1 demonstrated the highest chlorophyll content. Despite the plant's increased accumulation of MC-ZnO-NPs, no statistically significant toxic effects were observed. The antibacterial efficacy of ZnO-NPs was assessed against Gram-positive and Gram-negative microorganisms. MC-ZnO-NPs exhibited a 67.9% inhibition zone against Escherichia coli at 0.04 mg L-1 , while raw-ZnO-NPs exhibited 75.6% inhibition at the same concentration.

CONCLUSION

The study suggests that ZnO-NPs synthesized from M. charantia exhibit both growth-promoting effects on wheat without significant phytotoxicity and potent antibacterial properties, particularly against Escherichia coli. However, further investigations are warranted to comprehensively understand the interactions between ZnO-NPs and plants. Future research should focus on M. charantia, exploring its enhanced effects on plant growth, development and antibacterial attributes. These findings hold promise for potential agricultural applications, emphasizing the need for detailed phytotoxicological assessments of ZnO-NPs. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Green nanotechnology advances: green manufacturing of zinc nanoparticles, characterization, and foliar application on wheat and antibacterial characteristics using Mentha spicata (mint) and Ocimum basilicum (basil) leaf extracts

Due to their distinctive characteristics and widespread application across all scientific disciplines, nanoparticles have attracted a lot of attention in the current millennium. Green synthesis of ZnO-NPs is gaining a lot of interest at the moment due to a number of its advantages over traditional methods, including being quicker, less expensive, and more environmentally friendly. In the current study, two distinct plant extracts are used to quickly, cheaply, and environmentally friendly synthesize zinc oxide nanoparticles (ZnO-NPs). Mint (Mentha spicata) and basil (Ocimum basilicum) were the plants employed in this study as stabilizing agents to synthesize ZnO-NPs with a green chemistry approach. The innovative aspect of the study is the use of mint and basil extracts in the conversion of zinc chloride to zinc oxide and then determining the effect of these two types of nanoparticles produced by green synthesis on the growth parameters of the plant when they reach the plants by foliar spraying and their uptake by plants and evaluating the antibacterial properties of these nanoparticles. The physical properties of the produced nanoparticles were investigated using XRD, SEM, and FTIR. Moreover, Escherichia coli and Staphylococcus aureus were used to demonstrate the antibacterial properties of ZnO-NPs against both gram-positive and gram-negative bacteria, respectively. Synthesized ZnO-NPs were also given as foliar treatment in order to determine Zn⁺² uptake by plants and potential toxic effects on the growth of wheat. The shape of ZnO-NPs was triangular, as revealed by SEM analysis. In the X-ray diffraction study, strong and clearly discernible sharp peaks were seen, with an average size of 24.5 nm for M-ZnO-NPs and 26.7 nm for B-ZnO-NPs determined using Scherrer's formula. The phytoconstituents of the plant extract served as capping/stabilizing agents during the synthesis of ZnO-NPs, as demonstrated by Fourier transform-infrared spectroscopy. The produced nanoparticles were applied to the green parts of wheat plants by spraying, and the development of the plants and the change of zinc uptake were investigated. At the same time, the effect of these three types of nanoparticles on the germination of wheat seeds in the soil medium containing these nanoparticles was investigated. According to experimental results, M-ZnO-NPs (produced from mint) and B-ZnO-NPs (produced from basil) improved the germination percentage of wheat at 400 mg/L concentration (100%), while raw ZnO-NPs showed 90% germination at the same concentration. When the Zn⁺² uptake of the plant by the leaves depending on the Zn⁺² concentration in the environment after spraying was examined, it was determined that the Zn⁺² uptake of the plants increased due to the increase in the applied Zn⁺² concentration. The highest Zn⁺² uptake of the plant was determined as 50, 25, and 50 mg/L for M-ZnO-NP, B-ZnO-NPs, and raw ZnO-NPs, respectively. Therefore, it has been determined that plant growth varies depending on the type and concentration of ZnO-NPs, and therefore, if foliar nanoparticle applications are made to wheat, the threshold concentrations, sizes, and types of ZnO-NPs should be carefully evaluated. In addition, antibacterial properties results showed that S. aureus was more sensitive to all three types of ZnO-NPs than E. coli.

Effects of ZnO Nanoparticles and Ethylenediamine-N,N'-Disuccinic Acid on Seed Germination of Four Different Plants

The release of nanoparticles and biodegradable chelating agents into the environment may cause toxicological and ecotoxicological effects. The aim of this study is to determine the ecotoxic effects of zinc oxide (ZnO) nanoparticles and ethylenediamine disuccinic acid (EDDS) on most cultured four plants. The durum wheat, bread wheat, barley, and rye are exposed to 5 mL 10 mg L-1 ZnO nanoparticles and 10 mg L-1 EDDS in the seed germination stage. Results show that these different plant species have different responses to ZnO nanoparticles and EDDS. The germination percentage of bread wheat and rye decreases in the application of ZnO nanoparticles while the germination of durum wheat and barley increases as much as in radicle elongation and seedling vigor. While ZnO treatment causes a decrease in bread wheat and rye germinated rat in the range of 33-14.3%, respectively, there is no change in germination rate of these plants at EDDS treatment. In addition, EDDS treatment positively affects barley germination rate. In conclusion, it is clear that ZnO nanoparticles have more toxic effects on bread wheat and rye than EDDS, while barley is positively affected by ZnO nanoparticles and EDDS.