In vitro and In vivo toxicity assessment of phytofabricated ZnO nanoparticles showing bacteriostatic effect and larvicidal efficacy against Culex quinquefasciatus

Zinc Oxide-Based Nanomaterials for Microbiostatic Activities: A Review

The world is fighting infectious diseases. Therefore, effective antimicrobials are required to prevent the spread of microbes and protect human health. Zinc oxide (ZnO) nano-materials are known for their antimicrobial activities. Because of their distinctive physical and chemical characteristics, they can be used in medical and environmental applications. ZnO-based composites are among the leading sources of antimicrobial research. They are effective at killing (microbicidal) and inhibiting the growth (microbiostatic) of numerous microorganisms, such as bacteria, viruses, and fungi. Although most studies have focused on the microbicidal features, there is a lack of reviews on their microbiostatic effects. This review provides a detailed overview of available reports on the microbiostatic activities of ZnO-based nano-materials against different microorganisms. Additionally, the factors that affect the efficacy of these materials, their time course, and a comparison of the available antimicrobials are highlighted in this review. The basic properties of ZnO, challenges of working with microorganisms, and working mechanisms of microbiostatic activities are also examined. This review underscores the importance of further research to better understand ZnO-based nano-materials for controlling microbial growth.

Biogenic Synthesis of Zinc Oxide Nanoparticles Mediated by the Extract of Terminalia catappa Fruit Pericarp and Its Multifaceted Applications

Zinc oxide nanoparticles (ZnO-NPs) were biosynthesized by using the pericarp aqueous extract from Terminalia catappa Linn. These NPs were characterized using various analytical techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV) spectroscopy, dynamic light scattering (DLS), and scanning electron microscopy (SEM), and XRD studies of the nanoparticles reported mean size as 12.58 nm nanocrystals with highest purity. Further SEM analysis emphasized the nanoparticles to be spherical in shape. The functional groups responsible for capping and stabilizing the NPs were identified with FTIR studies. DLS studies of the synthesized NPs reported ζ potential as -10.1 mV and exhibited stable colloidal solution. These characterized ZnO-NPs were evaluated for various biological applications such as antibacterial, antifungal, antioxidant, genotoxic, biocompatibility, and larvicidal studies. To explore its multidimensional application in the field of medicine. NPs reported a potential antimicrobial activity at a concentration of 200 μg/mL against bacterial strains in the decreasing order of Streptococcus pyogenes > Streptococcus aureus > Streptococcus typhi > Streptococcus aeruginosa and against the fungi Candida albicans. In vitro studies of RBC hemolysis with varying concentrations of NPs confirm their biocompatibility with IC50 value of 211.4 μg/mL. The synthesized NPs' DPPH free radical scavenging activity was examined to extend their antioxidant applications. The antiproliferation and genetic toxicity were studied with meristematic cells of Allium cepa reported with mitotic index (MI index) of 1.2% at the concentration of 1000 μg/mL. NPs exhibited excellent Larvicidal activity against Culex quinquefasciatus larvae with the highest mortality rate as 98% at 4 mg/L. Our findings elicit the therapeutic potentials of the synthesized zinc oxide NPs.

Green synthesized Ag nanoparticles stimulate gene expression and paclitaxel production in Corylus avellana cells

Synthesis of nanoparticles (NPs) through plant extracts has been suggested as an effective and nature-friendly method. Paclitaxel is one of the most valuable secondary metabolites with therapeutic uses, and hazelnut has been suggested as one of the sustainable resources for producing this metabolite. In the present study, we synthesized Ag NPs using the ethanolic extract of C. avellana leaves and were characterized using UV-visible, FTIR, XRD, EDX, DLS, SEM, and TEM analyses. In addition, we investigated the effect of green synthesized Ag (GS Ag) NPs (5 and 10 mg/L), para-aminobenzoic acid (PABA) (20 mg/L), and AgNO3 (10 mg/L) on cell viability, physiological characteristics, gene expression, and biosynthesis of secondary metabolites in hazelnut cell cultures. The results showed that 10 mg/L Ag NPs and AgNO3 significantly affected the cell viability, the content of ROS, peroxidation of lipids, antioxidant capacity, secondary metabolite production, and expression pattern of the genes involved in the taxanes biosynthesis pathway in the hazelnut cells. The cytotoxicity increased by increasing the GS Ag NPs concentration from 5 to 10 mg/L, which was associated with reduced membrane integrity and cell viability. Elicitation of the cells with 10 mg/L Ag NPs combined with 20 mg/L PABA (as a precursor) remarkably excited the expression of TAT and GGPPS genes and the production of secondary metabolites as well as paclitaxel. So that the highest expression of TAT and GGPPS genes (3.71 and 3.69) and the highest amount of taxol (230.21 μg g-1 FW) and baccatin (1025.8 μg g-1 FW) were observed in this treatment. KEY POINTS: • For the first time, we assessed and reported the molecular and physiological responses of C. avellana cells to GS Ag NPs, AgNO3, and PABA. • In hazel cells, GS Ag NPs stimulate several physiological and molecular responses. • In addition to increasing antioxidant activity, GS Ag NPs significantly increased the expression of genes involved in the paclitaxel biosynthesis pathway and the production of secondary metabolites.

Hemolytic Activity of Nanoparticles as a Marker of Their Hemocompatibility

The potential use of nanomaterials in medicine offers opportunities for novel therapeutic approaches to treating complex disorders. For that reason, a new branch of science, named nanotoxicology, which aims to study the dangerous effects of nanomaterials on human health and on the environment, has recently emerged. However, the toxicity and risk associated with nanomaterials are unclear or not completely understood. The development of an adequate experimental strategy for assessing the toxicity of nanomaterials may include a rapid/express method that will reliably, quickly, and cheaply make an initial assessment. One possibility is the characterization of the hemocompatibility of nanomaterials, which includes their hemolytic activity as a marker. In this review, we consider various factors affecting the hemolytic activity of nanomaterials and draw the reader's attention to the fact that the formation of a protein corona around a nanoparticle can significantly change its interaction with the red cell. This leads us to suggest that the nanomaterial hemolytic activity in the buffer does not reflect the situation in the blood plasma. As a recommendation, we propose studying the hemocompatibility of nanomaterials under more physiologically relevant conditions, in the presence of plasma proteins in the medium and under mechanical stress.

The dietary supplementation of zinc oxide and selenium nanoparticles enhance the immune response in freshwater fish Oreochromis mossambicus against aquatic pathogen Aeromonas hydrophila

BACKGROUND

Green nanoparticles are subjected as an immunostimulant against bacterial pathogens.

METHODS

Murraya koenigii berry extract-based synthesized zinc oxide nanoparticles (Mb-ZnO NPs) and selenium nanoparticles (Mb-Se NPs) were relatively analyzed for immunostimulation in serum and mucus fish Oreochromis mossambicus against Aeromonas hydrophila infections. Initial minimum inhibitory concentration (MIC) was determined for both Mb-ZnO NPs and Mb-Se NPs followed by specific growth rate (SGR), antioxidant level (Superoxide dismutase activity (SOD), Catalase activity (CA), and Glutathione peroxidase activity (GPx)), and immune parameters Myeloperoxidase activity (MPO), Respiratory burst activity (RBA), Lysozyme activity (LYZ), Alkaline phosphatase activity (ALP), Serum antiprotease activity and Natural complement activity (NAC).

RESULTS

The potential bacterial inhibition property of Mb-ZnO NPs and Mb-Se NPs exhibited the most negligible concentration of 25 and 15 μg mL^-1, respectively, against A. hydrophila. In addition, Mb-ZnO NPs and Mb-Se NPs exhibited 70-80 % and 90-95 % diminished biofilm activity at 50 μg mL^-1 that was viewed under an inverted research microscope and confocal laser scanning microscopy (CLSM). Protein leakage and nucleic acid leakage assay quantified oozed out protein and nucleic acid from A. hydrophila that confirms Mb-Se NPs exhibited vigorous antibacterial activity than Mb-ZnO NPs at tested concentrations. Oreochromis mossambicus fed with Mb-ZnO NPs and Mb-Se NPs supplemented diet at different concentrations (0.5 mg/kg, 1 mg/kg and 2 mg/kg) improved SGR along with a rise in the immune response of those fishes against A. hydrophila infection. Serum and mucus of fish fed with Mb-Se NPs supplemented diet exhibited a significant rise in antioxidant level SOD, CA and GPx at a dosage of 2 mg/kg. Likewise, lipid peroxidation assay detected significantly diminished oxidative stress in the serum and mucus of fish fed with Mb-Se NPs supplemented diet (2 mg/kg). Enhanced immune parameters in serum and mucus of fish fed with Mb-Se NPs supplemented diet determined by MPO, RBA, LYZ, ALP, Serum antiprotease activity and NAC.

CONCLUSION

Thus O. mossambicus fed with Mb-Se NPs supplemented diet was less prone to become infected by aquatic pathogen A. hydrophila established by challenge study. On the whole, Mb-Se NPs supplemented diet ensured the rise in antioxidant response that boosts the immune responses and reduces the chance of getting infected against A. hydrophila infections.

In-vivo toxicity and therapeutic efficacy of Paeonia emodi-mediated zinc oxide nanoparticles: In-vitro study

This study was planned to explore the in-vitro and in-vivo therapeutic significance of Paeonia emodi-mediated zinc oxide nanoparticles (ZnO NPs) against the Staphylococcus aureus and Escherichia coli. The texture parameters were derived from nitrogen adsorption-desorption data using Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods, and the surface area (S_BET ) was found to be 214 m² /g with a pore size of 2.3 nm. The crystallographic parameters were investigated through X-ray diffraction analysis, and the calculated crystallite size is 29.13 nm. The microstructure was examined through transmission and scanning electron microscopies (TEM and SEM, respectively), and the average particle size estimated from a TEM image is 44.40 nm. The chemical composition and attached function groups were identified through energy-dispersive X-ray and Fourier transform infrared spectroscopies. The in-vitro minimum inhibitory concentration (MIC) for both bacterial species results was found less than 2 μg/ml. The tolerance limit of mouse models was evaluated by the inoculation of different concentrations of ZnO suspension where the concentration above 23 ppm was proved lethal. The maximum infection was caused in mouse models by inoculation of 3 × 10⁷ CFUs (Colony forming unit) of the both bacterial species. The concentration higher than 3 × 10⁷ CFUs led to the ultimate death of the mice. The histopathological and hematological studies reveal that the after simultaneous inoculation of both ZnO NPs and bacterial suspensions (tolerated amount), no/negligible infection was found in the mice model.

Biocompatibility assessment of silver chloride nanoparticles derived from Padina gymnospora and its therapeutic potential

The objective of the present work was to improve the biological activity of Padina gymnospora. In the current study, silver chloride nanoparticles have been synthesized using the aqueous extract of Padina gymnospora and further characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, x-ray powder diffraction, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy and atomic force microscope. Further, the hemolytic activity and eco-toxicity of silver chloride nanoparticles analyzed. The synthesized silver chloride nanoparticles were found to be mono-dispersed and spherical with an average size of 11.5–32.86 nm. The particles showed an anticancer effect in a dose-dependent manner against breast cancer cell line (MCF-7 cell lines) (IC50 = 31.37 μg ml−1). In addition, it showed the larvicidal activity against Aedes aegypti at a lower dose (3.92 μg ml−1) than that of the aqueous extract (13.01 μg ml−1). Nanoparticles also exhibited greater antimicrobial activity for both bacterial and fungal pathogens. The synthesized silver chloride nanoparticles showed a maximum zone of inhibition, i.e., 31 mm for Candida albicans followed and 27 mm for vancomycin resistance Enterococcus faecalis.The results suggest the possible use of synthesized silver nanoparticles with P. gymnospora as therapeutic agent for breast cancer, dengue vector control and as antimicrobial agent.

Metal oxide nanoparticle synthesis (ZnO-NPs) of Knoxia sumatrensis (Retz.) DC. Aqueous leaf extract and It's evaluation of their antioxidant, anti-proliferative and larvicidal activities

In around the world, mosquito control is considered a most important because of the incapable of synthetic insecticides and the ecological pollution about by them. In this manner, need the eco-friendly insecticides to efficient control the mosquito disease is the need of the hour. We synthesized the eco-friendly of zinc oxide nanoparticles (ZnO-NPs) using the Knoxia sumatrensis aqueous leaf extract (Ks-ALE) as a reducing and stabilizing agent. The synthesis of ZnO-NPs was confirmed by UV with an absorption peak at 354 nm. ZnO-NPs crystal structure was analyzed by X-ray diffraction (XRD). Fourier transform infrared spectroscopy (FT-IR) spectra revealed the chloride, cyclic alcohols, sulfonamies, carboxylic acids, oximes, phosphines, alkenes and alcohol & phenol. Field emission-scanning electron microscopy (FE-SEM) showed that the NP's are rod shaped with 50-80 nm size and also energy dispersive spectra (EDaX) spectra showed presence of zinc. Antioxidant assay showed superior activity and evidenced by DPPH, ABTS and H2O2 radical assays. Furthermore, the ZnO-NPs exhibited strong activity in MCF-7 cell line with IC50 value is 58.87 μg/mL. Mosquito larvicidal activity of ZnO-NPs produced significant activity and excellent larvicidal activity was noticed in Cx. quinquefasciatus with LC50 0.08, mg/mL and LC9019.46 mg/mL. This study suggests that synthesized ZnO-NPs using Knoxia sumatrensis leaf extract have good biological activities and it makes them an ideal candidate for pharmacological studies.

Isolating and identifying fungi to determine whether their biological properties have the potential to control the population density of mosquitoes

Mosquitoes transmit diseases such as dengue, chikungunya, Zika, and yellow fever to humans. Biological control methods are required for these insects because they can be environmentally friendlier, safer, and more cost-effective than chemical or physical methods currently available. The aim of this research is to identify fungi found in mosquito breeding containers that have the potential to control the population density of mosquitoes.

For the identification, water samples were taken from mosquito breeding containers situated in seven districts of Bangkok to obtain pure cultures. Deoxyribonucleic acid (DNA) was extracted from the cultures then sent for sequencing and analyzing. The results show that fourteen strains of fungi were isolated. The most common strain found was Aspergillus spp., which was present in 31 of the 78 fungi samples. The strains Metarhizium anisopliae and Penicilium citrinum were found to be interesting because they may have the potential to act as entomopathogenic fungi. The biological properties of these strains should be further investigated because they could help in the fight against mosquito-borne diseases.