Catharanthus roseus-assisted bio-fabricated zinc oxide nanoparticles for promising antibacterial potential against Klebsiella pneumoniae.

This study emphasized on the synthesis of zinc oxide nanoparticles (ZnO NPs) in an environmentally friendly manner from the extract of Catharanthus roseus leaves and its antibacterial assessment against the pneumonia-causing pathogen Klebsiella pneumoniae. This simple and convenient phytosynthesis approach is found to be beneficial over conventional methods, wherein plants serve as excellent reducing, capping, and stabilizing agents that enables the formation of ZnO NPs without the use of harmful chemicals. The formation of ZnO NPs was confirmed through several characterization techniques such as UV-visible spectroscopy, XRD, FT-IR, SEM, HR-TEM, and EDX. XRD analysis revealed high polycrystallinity with crystallite size of approximately 13 nm. SEM and HR-TEM revealed the hexagonal structure of ZnO NPs with the particle size range of 20-50 nm. The EDX shows the elemental purity without any impurity. Furthermore, the antibacterial efficacy by the technique of disc diffusion exhibited clear inhibition zones in ZnO NPs-treated discs. In addition, 125 µg/mL of ZnO NP concentration showed minimum inhibition by the microbroth dilution method. The potent inhibitory activity was further validated with trypan blue dye exclusion and fluorescence microscopy. Finally, SEM examination confirmed the efficient antibacterial potential of ZnO NPs through disruption of the intact morphology of Klebsiella pneumoniae.

Green Synthesis of Cerium Oxide Nanoparticles, Characterization, and Their Neuroprotective Effect on Hydrogen Peroxide-Induced Oxidative Injury in Human Neuroblastoma (SH-SY5Y) Cell Line.

Cerium oxide nanoparticles (CeO2NPs) have a broad scale of applications in the biomedical field due to their excellent physicochemical and catalytic properties. The present study aims to synthesize the CeO2NPs from Centella asiatica (C. asiatica) leaf extract, which has been used in Indian traditional medicine for its neuroprotective properties. The CeO2NPs were characterized by ultraviolet-visible, X-ray diffraction, Fourier transform infrared, Raman spectroscopy, scanning electron microscopy- energy dispersive X-ray spectroscopy, and high-resolution transmission electron microscopy. The antioxidant property was evaluated by 2,2-di (4-tert-octyl phenyl)-1-picrylhydrazyl and OH radical assays. The neuroprotective potential was assessed against the oxidative stress (OS) induced by H2O2 in the human neuroblastoma (SH-SY5Y) cell line. CeO2NPs exhibited significant DPPH and OH radical scavenging activity. Our results revealed that CeO2NPs significantly increased H2O2-induced cell viability, decreased lactate dehydrogenase, protein carbonyls, reactive oxygen species generation, apoptosis, and upregulated antioxidant enzyme activity. Our findings suggest that the CeO2NPs protect the SH-SY5Y cells from OS and apoptosis, which could potentially counter OS-related neurodegenerative disorders.

Fabrication and in vitro Evaluation of 4-HIA Encapsulated PLGA Nanoparticles on PC12 Cells.

PURPOSE: 4-Hydroxyisophthalic acid (4-HIA) is a bioactive compound present in the roots of Decalepis hamiltonii, which has attracted considerable attention in attenuating oxidative stress-related neurodegenerative diseases. However, its efficacy is limited because of its low solubility and bioavailability. Therefore, the present study aimed to encapsulate 4-HIA using biocompatible copolymer polylactide-co-glycolide (PLGA) and evaluate its antioxidant and neuroprotective potential. METHODS: The nanoparticles (NPs) were fabricated by solid/oil/water (s/o/w) emulsion technique and characterized using XRD, SEM, HR-TEM, and FTIR spectroscopy. Antioxidant assays such as 1,1 diphenyl-2-picrylhydrazyl (DPPH), superoxide, and hydroxyl radical scavenging ability were performed to assess the antioxidant potential of the fabricated NPs. RESULTS: The bioactive component, 4-HIA, was efficiently encapsulated by the PLGA polymer and was found to be spherical and smooth with a size <10nm. 4-HIA showed better scavenging capability in DPPH and superoxide assays as compared to 4-HIA encapsulated PLGA and butylated hydroxytoluene (BHT). In contrast, 4-HIA encapsulated PLGA NPs exhibited a significant hydroxyl radical scavenging activity than 4-HIA and BHT alone. Further, the encapsulated NPs efficiently curtailed hydrogen peroxide (H2O2)-induced cytotoxicity in PC12 cells. CONCLUSION: Our findings indicate that 4-HIA encapsulated PLGA NPs might be a therapeutic intervention towards the effective management of oxidative stress as it has exhibited efficient neuroprotective potential against H2O2-induced oxidative stress in PC12 cells.