Antimicrobial activity of the biologically synthesized zinc oxide nanoparticles against important rice pathogens

Interaction of plants and metal nanoparticles: Exploring its molecular mechanisms for sustainable agriculture and crop improvement

Metal nanoparticles offer promising prospects in agriculture, enhancing plant growth and ensuring food security. Silver, gold, copper, and zinc nanoparticles possess unique properties making them attractive for plant applications. Understanding molecular interactions between metal nanoparticles and plants is crucial for unlocking their potential to boost crop productivity and sustainability. This review explores metal nanoparticles in agriculture, emphasizing the need to understand these interactions. By elucidating mechanisms, it highlights the potential for enhancing crop productivity, stress tolerance, and nutrient-use efficiency, contributing to sustainable agriculture and food security. Quantifying benefits and risks reveal significant advantages. Metal nanoparticles enhance crop productivity by 20% on average and reduce disease incidence by up to 50% when used as antimicrobial agents. They also reduce nutrient leaching by 30% and enhance soil carbon sequestration by 15%, but concerns about toxicity, adverse effects on non-target organisms, and nanoparticle accumulation in the food chain must be addressed. Metal nanoparticles influence cellular processes including sensing, signaling, transcription, translation, and post-translational modifications. They act as signaling molecules, activate stress-responsive genes, enhance defense mechanisms, and improve nutrient uptake. The review explores their catalytic role in nutrient management, disease control, precision agriculture, nano-fertilizers, and nano-remediation. A bibliometric analysis offers insights into the current research landscape, highlighting trends, gaps, and future directions. In conclusion, metal nanoparticles hold potential for revolutionizing agriculture, enhancing productivity, mitigating environmental stressors, and promoting sustainability. Addressing risks and gaps is crucial for their safe integration into agricultural practices.

Biosynthesis of Zinc Oxide-Zerumbone (ZnO-Zer) Nanoflakes Towards Evaluating Its Antibacterial and Reactive Oxygen Species (ROS)-Dependent Cytotoxic Activity

Being the second most prevalent metal oxide, zinc oxide (ZnO) nanomaterials have been widely studied and found to exhibit promising applications in various domains of biomedicine and agriculture. Considering the enhanced bioactivities displayed by secondary metabolite (SM) derived ZnO nanomaterials, present study was undertaken to evaluate the efficacy of ZnO nanoflake (NF) derived from Zerumbone (Zer), a sesquiterpenoid from Zingiber zerumbet rhizome with diverse pharmacological properties. ZnO NF prepared by homogeneous precipitation method using ZnSO4.7H2O (0.1 M) and NaOH (0.2 M) as precursors with and without the addition of Zer (0.38 mM) were characterized by powder UV-visible spectroscopy, X-ray diffraction (XRD), FT-IR spectroscopy and Field emission scanning electron microscope (FESEM) analysis. Optical and physical properties of ZnO-Zer NF were found to match with the typical ZnO nanomaterial properties. XRD analysis revealed reduction in size (15 nm) of the green synthesized ZnO-Zer NF compared to ZnO NF (21 nm). ZnO-Zer NF displayed linear correlation between concentration and antimicrobial activity to Salmonella typhi, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Determination of cytotoxic potential of the synthesized ZnO-Zer NF in cervical cancer cells (HeLa) showed higher cytotoxicity of ZnO-Zer NF (39.32 ± 3.01%) compared to Zer alone (27.02 ± 1.22%). Present study revealing improvement in bioactivity of Zer following conjugation with ZnO NF signifies potential of NF formation in improving therapeutic application of Zer that otherwise displays low solubility limiting its bioavailability.

Therapeutic Potential of Green-Engineered ZnO Nanoparticles on Rotenone-Exposed D. melanogaster (Oregon R+): Unveiling Ameliorated Biochemical, Cellular, and Behavioral Parameters

Nanotechnology holds significant ameliorative potential against neurodegenerative diseases, as it can protect the therapeutic substance and allow for its sustained release. In this study, the reducing and capping agents of Urtica dioica (UD), Matricaria chamomilla (MC), and Murraya koenigii (MK) extracts were used to synthesize bio-mediated zinc oxide nanoparticles (ZnO-NPs) against bacteria (Staphylococcus aureus and Escherichia coli) and against rotenone-induced toxicities in D. melanogaster for the first time. Their optical and structural properties were analyzed via FT-IR, DLS, XRD, EDS, SEM, UV-Vis, and zeta potential. The antioxidant and antimicrobial properties of the fabricated ZnO-NPs were evaluated employing cell-free models (DPPH and ABTS) and the well diffusion method, respectively. Rotenone (500 µM) was administered to Drosophila third instar larvae and freshly emerged flies for 24-120 h, either alone or in combination with plant extracts (UD, MC, an MK) and their biogenic ZnO-NPs. A comparative study on the protective effects of synthesized NPs was undertaken against rotenone-induced neurotoxic, cytotoxic, and behavioral alterations using an acetylcholinesterase inhibition assay, dye exclusion test, and locomotor parameters. The findings revealed that among the plant-derived ZnO-NPs, MK-ZnO NPs exhibit strong antimicrobial and antioxidant activities, followed by UD-ZnO NPs and MC-ZnO NPs. In this regard, ethno-nano medicinal therapeutic uses mimic similar effects in D. melanogaster by suppressing oxidative stress by restoring biochemical parameters (AchE and proteotoxicity activity) and lower cellular toxicity. These findings suggest that green-engineered ZnO-NPs have the potential to significantly enhance outcomes, with the promise of effective therapies for neurodegeneration, and could be used as a great alternative for clinical development.