Physiological and molecular mechanisms of ZnO quantum dots mitigating cadmium stress in Salvia miltiorrhiza.

This study delved into the physiological and molecular mechanisms underlying the mitigation of cadmium (Cd) stress in the model medicinal plant Salvia miltiorrhiza through the application of ZnO quantum dots (ZnO QDs, 3.84 nm). A pot experiment was conducted, wherein S. miltiorrhiza was subjected to Cd stress for six weeks with foliar application of 100 mg/L ZnO QDs. Physiological analyses demonstrated that compared to Cd stress alone, ZnO QDs improved biomass, reduced Cd accumulation, increased the content of photosynthetic pigments (chlorophyll and carotenoids), and enhanced the levels of essential nutrient elements (Ca, Mn, and Cu) under Cd stress. Furthermore, ZnO QDs significantly lowered Cd-induced reactive oxygen species (ROS) content, including H2O2, O2-, and MDA, while enhancing the activity of antioxidant enzymes (SOD, POD, APX, and GSH-PX). Additionally, ZnO QDs promoted the biosynthesis of primary and secondary metabolites, such as total protein, soluble sugars, terpenoids, and phenols, thereby mitigating Cd stress in S. miltiorrhiza. At the molecular level, ZnO QDs were found to activate the expression of stress signal transduction-related genes, subsequently regulating the expression of downstream target genes associated with metal transport, cell wall synthesis, and secondary metabolite synthesis via transcription factors. This activation mechanism contributed to enhancing Cd tolerance in S. miltiorrhiza. In summary, these findings shed light on the mechanisms underlying the mitigation of Cd stress by ZnO QDs, offering a potential nanomaterial-based strategy for enhancing Cd tolerance in medicinal plants.

Reproductive performance of freshwater snail, Helisoma duryi under the effect of bulk and nano zinc oxide.

Nanotechnology has been used to apply nanoparticle essential elements to enhance the ability of animals to absorb these elements and consequently improve their reproductive performance. High concentrations of nanoparticles (NPs) can directly harm a range of aquatic life forms, ultimately contributing to a decline in biodiversity. Helisoma duryi snails are a good model for studying the toxicological effects of bulk zinc oxide (ZnO-BPs) and nano zinc oxide (ZnO-NPs) on freshwater gastropods. This study aimed to compare the toxic effects of ZnO-BPs and ZnO-NPs on H. duryi snails and explore how waterborne and dietary exposure influenced the reproductive performance of this snail. ZnO-BPs and ZnO-NPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray powder (XRD). This study revealed that the size of ZnO-BPs and ZnO-NPs were 154 nm and 11-31 nm, respectively. The results showed that exposure of adult snails to sub-lethal concentrations of both ZnO forms (bulk and nano) for 24 h/week for 4 weeks markedly changed their reproductive performance in a concentration-dependent manner, where fecundity was negatively affected by high concentrations. It was concluded that dietary exposure to the lowest tested concentration of ZnO-NPs (1 ppm) has a positive effect as the number of eggs and egg masses/snails increased and the incubation period decreased. Also, poly-vitelline eggs (The formation of twins) were observed. ZnO-NPs at low concentrations positively affect the reproductive performance of snails, especially after dietary exposure. The results revealed that 1 ppm ZnO-NPs could be supplementary provided to snails to improve their fertility, reduce the developmental time course, increase hatchability percentage, and produce poly-vitelline eggs.

Review of Zinc Oxide Nanoparticles: Toxicokinetics, Tissue Distribution for Various Exposure Routes, Toxicological Effects, Toxicity Mechanism in Mammals, and an Approach for Toxicity Reduction.

Zinc oxide (ZnO) nanoparticles (NPs) are widely used as a sunscreen, antibacterial agent, dietary supplement, food additive, and semiconductor material. This review summarizes the biological fate following various exposure routes, toxicological effects, and toxicity mechanism of ZnO NPs in mammals. Furthermore, an approach to reduce the toxicity and biomedical applications of ZnO NPs are discussed. ZnO NPs are mainly absorbed as Zn2+ and partially as particles. Regardless of exposure route, elevated Zn concentration in the liver, kidney, lungs, and spleen are observed following ZnO NP exposure, and these are the target organs for ZnO NPs. The liver is the main organ responsible for ZnO NP metabolism and the NPs are mainly excreted in feces and partly in urine. ZnO NPs induce liver damage (oral, intraperitoneal, intravenous, and intratracheal exposure), kidney damage (oral, intraperitoneal, and intravenous exposure) and lung injury (airway exposure). Reactive oxygen species (ROS) generation and induction of oxidative stress may be a major toxicological mechanism for ZnO NPs. ROS are generated by both excess Zn ion release and the particulate effect resulting from the semiconductor or electronic properties of ZnO NPs. ZnO NP toxicity can be reduced by coating their surface with silica, which prevents Zn2+ release and ROS generation. Due to their superior characteristics, ZnO NPs are expected to be used for biomedical applications, such as bioimaging, drug delivery, and anticancer agents, and surface coatings and modification will expand the biomedical applications of ZnO NPs further.

Zinc Oxide Nanoparticles Significant Role in Poultry and Novel Toxicological Mechanisms.

Zinc oxide nanoparticles (ZnO NPs) have involved a lot of consideration owing to their distinctive features. The ZnO NPs can be described as particularly synthesized mineral salts via nanotechnology, varying in size from 1 to 100 nm, while zinc oxide (ZnO), it is an inorganic substrate of zinc (Zn). The Zn is a critical trace element necessary for various biological and physiological processes in the body. Studies have revealed ZnO NPs' efficient immuno-modulatory, growth-promoting, and antimicrobial properties in poultry birds. They offer increased bioavailability as compared to their traditional sources, producing better results in terms of productivity and welfare and consequently reducing ecological harm in the poultry sector. However, they have also been reported for their toxicological effects, which are size, shape, concentration, and exposure route dependent. The investigations done so far have yielded inconsistent results, therefore, a lot of additional studies and research are required to clarify the harmful consequences of ZnO NPs and to bring them to a logical end. This review explores an overview of efficient possible role of ZnO NPs, while comparing them with other nutritional Zn sources, in the poultry industry, primarily as dietary supplements that effect the growth, health, and performance of the birds. In addition to the anti-bacterial mechanisms of ZnO NPs and their promising role as antifungal, and anti-colloidal agent, this paper also covers the toxicological mechanisms of ZnO NPs and their consequent toxicological hazards to vital organs and the reproductive system of poultry birds.

Invitro- invivo evaluations of green synthesized zinc oxide (ZnO) nanoparticles using Ipomoea aquatica leaf extract as matric and fillers.

The current study details the green synthesis of zinc oxide nanoparticles utilizing the aqueous leaf extract of Ipomoea aquatica. A straightforward, economically viable, and consistent green synthesis technique was devised for producing these nanoparticles. The resulting Zinc oxide nanoparticles underwent comprehensive characterization through XRD, FESEM, EDS, FT-IR, TGA, and DSC analyses. Additionally, the study encompassed In- vitro and In- vivo assessments, including examinations of anti-microbial effects, hemocompatibility, anti-inflammatory responses, oral toxicity in mice, and fish toxicity using the Danio rerio model. The toxicological evaluations were done using the Danio rerio model (fish toxicity) and oral toxicity studies on mice. The particle size and zeta potential were verified using a DLS study, while EDS analyses validated the elemental composition of the nanoparticles. The crystalline nature of the nanoparticles was confirmed through distinctive peaks in the XRD pattern. The HR-TEM results confirmed the particle size range obtained by the Light scattering technique. Encouraging results were observed across the range of pharmacological activities conducted, demonstrating positive outcomes in terms of anti-microbial, hemocompatibility, anti-inflammatory attributes, In-vitro cytotoxicity, oral toxicity, and fish toxicity. This study not only showcased an eco-friendly and cost-efficient method for synthesizing Zinc oxide nanoparticles but also highlighted their potential implications.

Ameliorative effects of Dunaliella salina microalgae on nanoparticle (ZnO NPs)-induced toxicity in fish.

Dunaliella salina (D. salina) is a well-known microalga that contains considerable amounts of nutritious and medicinal bioactive components. This work studied the modulatory role of D. salina against zinc oxide nanoparticle (ZnO NPs)-induced neurotoxic effects in adult zebrafish. Fishes were subjected to 0.69 mg L-1 (1/5th 96-h LC50) for 4 weeks; then, fishes were supplemented with D. salina in the diet for 2 weeks at two levels (15 and 30%). Exposure to ZnO NPs induced a significant increase in the levels of reactive oxygen species (ROS), hydrogen peroxide (H2O2), malondialdehyde (MDA), and 8-hydroxy-2-deoxyguanosine (8-OH-dG) while accompanied with downregulation of antioxidant genes in the brain of exposed fishes. Brain neurochemistry and enzyme activities were also altered following ZnO NP exposure. ZnO NPs significantly reduced the neurotransmitters and acetylcholinesterase (AchE) activity while increasing Alzheimer's disease-related proteins and inflammatory response via upregulation of tumor necrosis factor (TNF-α). Additionally, ZnO NPs increased the indices of brain's DNA oxidative damage, increasing brain tissue's metallothionein (MT) and zinc residues. ZnO NPs upregulated the transcription patterns of apoptosis-related genes (casp3 and p53). D. salina dietary co-supplementation with ZnO NPs alleviated the ZnO NPsZnO NP-induced neuro-oxidative damages by lowering the lipid, DNA damage, and inflammatory biomarkers. Besides, D. salina alleviating responses were linked with increasing the levels of the assessed antioxidants. Conclusively, D. salina dietary supplementation induced potential alleviating effects of the ZnO NP-induced neurotoxicity in adult zebrafish.

Protective effect of quercetin and thymoquinone against genotoxicity and oxidative stress induced by ZnO nanoparticles in the Wistar rat model.

Zinc oxide nanoparticles (ZnO-NPs) are increasingly used in a variety of consumer and other commercial products. Hence, man faces the risk of exposure to ZnO-NPs and the consequent adverse health effects. Mitigation/prevention of such effects using natural products has drawn the attention of scientists. Therefore, the aim of the present study has been to find the toxic effects associated with exposure to ZnO-NPs, and the protective role of the phytochemicals thymoquinone (TQ) and quercetin (QCT) in the rat model. ZnO-NPs were administered to male Wistar rats through oral route; TQ / QCT was concurrently administered through intra-peritoneal route. The response in the animal was analyzed adopting chromosomal aberration test, micronucleus test, and comet assay of bone marrow cells to assess the genotoxicity, and biochemical assays of superoxide dismutase (SOD), catalase (CAT), lipid peroxidation (LPO), total extractable protein of liver, and reduced glutathione (GSH) of liver homogenate to monitor the changes in the antioxidant defense mechanism in response to the oxidative stress. Treatment of 300 mg/kg body weight (bw) of ZnO-NPs produced adverse effects on all aspects analyzed viz., structural chromosomal aberrations, micronuclei formation, DNA damage, SOD, catalase, lipid peroxidation, GSH, and extractable total protein of liver. Co-treatment of TQ / QCT offered protection against the toxicity induced by ZnO-NPs. The most optimum doses of TQ and QCT that offered the best protection were 18 mg/kg bw and 500 mg/kg bw, respectively. The study reveals that TQ / QCT supplementation is beneficial in the context of toxic effects of ZnO-NPs.

Effects of Zinc Oxide Nanoparticles on Neural Tube Development in Early Chicken Embryos.

AIM: To investigate the effect of zinc oxide nanoparticles (ZnO-NPs) on neural tube development in early chicken embryos. MATERIAL AND METHODS: Fifty pathogen-free fertilized eggs were initially incubated for thirty hours. The eggs were divided into 5 groups. In the control group (C) the egg?s apex was opened and closed without any administration. In the distilled water group (DW), 10 microliters of distilled water were injected into the sub-blastodermic area. ZnO-NP suspensions were prepared in distilled water and injected sub-blastodermically into the low, medium and high dose ZnO-NP groups (10 mg/kg, 30 mg/kg, and 50 mg/kg, respectively). Incubation was completed in 72 hours, and embryological and neural tube development was evaluated histologically with a light microscope. RESULTS: Embryos in all groups were evaluated according to the Hamburger-Hamilton (HH) staging. It was observed that the staging progressed by the developmental process between 68-72 hours, which is equivalent to the 19-20th stage of HH. Differentiated otic vesicle, optic cup, lens vesicle, pharynx, and Rathke?s pouch were all observed in embryo sections. Both forebrain and hindbrain vesicles were easily distinguished in the sections by cranial flexion. Neural tube closure defect was not detected in any of the groups. CONCLUSION: In our observations, ZnO-NPs did not affect neural tube development at the applied dose ranges. We believe that additional studies with higher doses using a higher number of subjects will help clarify the conflicting data in the literature.

In vitro genotoxicity assessment of biosynthesized zinc oxide nanoparticles.

There are various studies on the toxicological potentials of conventionally synthesized zinc oxide (ZnO) nanoparticles, which are useful tools for many medical applications. However, knowledge about the biologically synthesized ones is still limited. In this study, the potential of producing ZnO nanoparticles via a green synthesis method, which enables safer, environmentally, economical and controlled production by using the Symphoricarpos albus L. plant, was investigated. For this purpose, aqueous extract was obtained from the fruits of the plant and reacted with zinc nitrate precursor. Characterization of the synthesized product was carried out by SEM and EDAX analyzes. In addition, the biosafety of the product was also investigated by using the Ames/Salmonella, E. coli WP2, Yeast DEL, seed germination, and RAPD test systems. The results obtained from SEM studies showed that spherical nanoparticles with an average diameter of 30 nm were synthesized as a result of the reaction. EDAX findings confirmed that these nanoparticles were composed of Zn and O elements. On the other hand, according to the findings of the biocompatibility tests, the synthesized nanoparticle did not show any toxic and genotoxic effects up to a concentration of 640 µg/ml in any of the test systems. Accordingly, considering the findings of our study, it was concluded that the aqueous extract of S. albus fruits can be used for the green synthesis of ZnO nanoparticles, the products obtained successfully passed the biocompatibility tests in our study, and additionally, more comprehensive biocompatibility tests should be performed before industrial scale production.

Modulatory effect of thymol on the immune response and susceptibility to Aeromonas hydrophila infection in Nile tilapia fish exposed to zinc oxide nanoparticles.

Zinc oxide nanoparticles (ZnO-NPs) have many exciting properties that make their use in a continuous increase in various biomedical, industrial, and agricultural applications. This is associated with accumulation in the aquatic ecosystems and fish exposure with consequent deleterious effects. To determine the potential of thymol to counteract the immunotoxic effects of ZnO-NPs, Oreochromis niloticus was exposed to ZnO-NPs (⅕ LC50 =1.14 mg/L, for 28 days) with or without feeding a thymol-incorporated diet (1 or 2 g/kg diet). Our data demonstrated a reduction of aquaria water quality, leukopenia, and lymphopenia with a decrease in serum total protein, albumin, and globulin levels in exposed fish. At the same time, the stress indices (cortisol and glucose) were elevated in response to ZnO-NPs exposure. The exposed fish also revealed a decline in serum immunoglobulins, nitric oxide, and the activities of lysozyme and myeloperoxidase, in addition to reduced resistance to the Aeromonas hydrophila challenge. The RT-PCR analysis showed downregulation of antioxidant (SOD) superoxide dismutase and (CAT) catalase gene expression in the liver tissue with overexpression of the immune-related genes (TNF-α and IL-1ß). Importantly, we found that thymol markedly protected against ZnO-NPs-induced immunotoxicity in fish co-supplemented with thymol (1 or 2 g/kg diet) in a dose-dependent manner. Our data confirm the immunoprotective and antibacterial effects of thymol in ZnO-NPs exposed fish, supporting the potential utility of thymol as a possible immunostimulant agent.

Transformation of zinc oxide nanoparticles in the presence of aluminum oxide with pre-sorbed phosphorus ligands.

Naturally occurring oxides could react with zinc oxide (ZnO) nanoparticles (NPs) and then change its transformation and toxicity to ecological receptors. The reaction may be affected by a variety of environmental factors, yet the relevant processes and mechanisms are limitedly investigated. Natural prevalent ligands, as an important factor, can sorb on natural oxide minerals and change its surface property, finally affecting ZnO NP transformation. This study investigated the interactions of ZnO NPs with phosphorus ligands (i.e., phytate and orthophosphate) pre-sorbed γ-alumina (γ-Al2O3) via batch experiments and multi-technique analyses. A limited amount of aqueous Zn2+ is observed when the concentration of ZnO NPs is relatively low (<64.8 mg L-1) in the presence of phytate pre-sorbed γ-Al2O3. Solid Zn(II) species includes binary/ternary surface Zn(II) complexes on γ-Al2O3 with minor amounts of zinc phytate precipitates. As the concentration of ZnO NPs increases, surface Zn(II) complexes gradually transform into zinc phytate and Zn-Al layered double hydroxide (Zn-Al LDH) precipitates. The quantitative analysis indicates that, as the concentration of ZnO NPs increases from 32.4 to 388.8 mg L-1, the proportion of Zn(II) species as binary/ternary surface complexes decreases from 81.9 to 30.2%; and the proportion as zinc phytate and Zn-Al LDH increases from 17.9 to 27.6% and 0 to 43.8%, respectively. The pre-sorption of orthophosphate can also inhibit ZnO NP transformation into Zn-Al LDH precipitates on γ-Al2O3. This study suggests that natural ligands pre-existed on natural oxide minerals could greatly influence the solubility, stability, transformation, and fate of easily dissoluble metal oxides (e.g., ZnO) in the environments.

Biochar and metal-tolerant bacteria in alleviating ZnO nanoparticles toxicity in barley.

The constant use of zinc oxide nanoparticles (ZnO NPs) in agriculture could increase their concentration in soil, and cause a threat to sustainable crop production. The present study was designed to determine the role of spore-forming and metal-tolerant bacteria, and biochar in alleviating the toxic effects of a high dose of ZnO NPs (2000 mg kg-1) spiked to the soil (Haplic Chernozem) on barley (Hordeum sativum L). The mobile compounds of Zn in soil and their accumulation in H. sativum tissues were increased significantly. The addition of biochar (2.5% of total soil) and bacteria (1010 CFU kg-1) separately and in combination showed a favorable impact on H. sativum growth in ZnO NPs polluted soil. The application of bacteria (separately) to the contaminated soil reduced the mobility of Zn compounds by 7%, due to loosely bound Zn compounds, whereas only biochar inputs lowered Zn mobile compounds mobility by 33%, even the combined application of biochar and bacteria also suppressed the soil Zn mobile compounds. Individual application of biochar and bacteria reduced the Zn plant uptake, i.e., underground parts (roots) by 44% and 20%, and in the above-ground parts of H. sativum plants by 39% and 13%, respectively, compared to ZnO NPs polluted soil treatments. Biochar, both separately and in combination with bacteria improved the root length by 48 and 85%, and plant height by 53 and 40%, respectively, compared to the polluted control. The root length and plant height decreased by 52 and 40% in ZnO NPs spiked soil compared clean soil treatments. Anatomical results showed an improvement in the structural organization of cellular-sub-cellular tissues of root and leaf. The changes in ultrastructural organization of assimilation tissue cells were noted all treatments due to the toxic effects of ZnO NPs compared with control treatment. The results indicate that metal-tolerant bacteria and biochar could be effective as a soil amendment to reduce metal toxicity, enhance crop growth, and improve soil health.

Evaluation of the gut microbiome alterations in healthy rats after dietary exposure to different synthetic ZnO nanoparticles.

AIMS: Although synthetic ZnO nanoparticles (Nano-ZnO) as an alternative of ZnO compounds have been extensively used such as in livestock production, the increased consuming of Nano-ZnO has raised considerable concerns in environmental pollution and public health. Because of the low digestion of Nano-ZnO, the systematic studies on their interactions with gut microbiota remain to be clarified. MATERIALS AND METHODS: Nano-ZnOs were prepared by co-precipitation (ZnO-cp) and high temperature thermal decomposition (ZnO-td) as well as the commercial type (ZnO-s). Transmission electron microscopy (TEM) was used to monitor the morphology of Nano-ZnO. CCK-8 assay was used for cytotoxicity evaluation. Total antioxidant capacity assay, total superoxide dismutase assay, and lipid peroxidation assay were used to evaluate oxidative states of rats. 16S rRNA was used to study the impact of Nano-ZnO on the rat gut microbiome. KEY FINDINGS: Both ZnO-cp and ZnO-td exhibited low cytotoxicity while ZnO-s and ZnO-td exhibited prominent antibacterial activities. After a 28-day oral feeding with 1000 mg/kg Zn at dietary dosage, ZnO-s showed slight effect on causing oxidative stress in comparison with that of ZnO-cp and ZnO-td. Results of 16S rRNA sequencing analysis indicated that ZnO-td as a promising short-term nano-supplement can increase probiotics abundances like strains belonged to the genus Lactobacillus and provide the antipathogenic effect. SIGNIFICANCE: The results of the gut microbiome alteration by synthetic Nano-ZnO not only provide solution to exposure monitoring of environmental hazard, but rationalize their large-scale manufacture as alternative additive in the food chain.

Pristine and sulfidized zinc oxide nanoparticles alter bacterial communities and metabolite profiles in soybean rhizocompartments.

A better understanding of bacterial communities and metabolomic responses to pristine zinc oxide manufacture nanoparticles (ZnO MNPs) and its sulfidized product (s-ZnO MNPs), as well as their corresponding Zn ions in rhizocompartments, critical in the plant-microbe interactions, could contribute to the sustainable development of nano-enabled agriculture. In this study, soybean (Glycine max) were cultivated in soils amended with three Zn forms, namely ZnSO4·7H2O, ZnO MNPs and s-ZnO MNPs at 0, 100 and 500 mg·kg-1 for 70 days. Three Zn forms exposures profoundly decreased the bacterial alpha diversity in roots and nodules. High dose (500 mg·kg-1) groups had a stronger impact on the bacterial beta diversity than low dose (100 mg·kg-1) groups. In the rhizosphere soil and roots, 500 mg·kg-1 of ZnSO4 and s-ZnO MNPs treatments showed the largest shifts in bacterial community structure, respectively. In addition, several significant changed bacterial taxa and metabolites were found at the high dose groups, which were associated with carbon and nitrogen metabolism. PLS-DA plot showed good discrimination in metabolomic profiles of rhizosphere soil and roots between three Zn forms treatments and control. Most metabolic pathways perturbed were closely linked to oxidative stress. Overall, our study indicates either dissolved or nano-particulate Zn exposure at high dose can drastically affected bacterial communities and metabolite profiles in soybean rhizocompartments.

Antagonistic impact on cadmium stress in alfalfa supplemented with nano-zinc oxide and biochar via upregulating metal detoxification.

Eco-toxicological estimation of cadmium induced damages by morpho-physiological and cellular response could be an insightful strategy to alleviate negative impact of Cd in agricultural crops. The current study revealed novel patterns of Cd-bioaccumulation and cellular mechanism opted by alfalfa to acquire Cd tolerance under various soil applied zinc oxide nanoparticles (nZnO) doses (0, 30, 60, 90 mg kg-1), combined with 2% biochar (BC). Herein, the potential impact of these soil amendments was justified by decreased Cd and increased Zn-bioaccumulation into roots by 38 % and 48 % and shoots by 51 % and 72 % respectively, with co-exposure of nZnO with BC. As, the transmission electron microscopy (TEM) and scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) ultrastructural observations confirmed that Cd-exposure induced stomatal closure, and caused damage to roots and leaves ultrastructure as compared to the control group. On the contrary, the damages to the above-mentioned traits were reversed by a higher nZnO dose, and the impact was further aggravated by adding BC along nZnO. Furthermore, higher nZnO and BC levels efficiently alleviated the Cd-mediated reductions in alfalfa biomass, antioxidant enzymatic response, and gaseous exchange traits than control. Overall, soil application of 90 mg kg-1 nZnO with BC (2 %) was impactful in averting Cd stress damages and ensuring better plant performance. Thereby, applying soil nZnO and BC emerge as promising green remediation techniques to enhance crop tolerance in Cd-polluted soil.

The role of selenium and zinc oxide nanoparticles on mitigating side effects of obesity in rats.

Obesity and related diseases represent greatest threats to human health. Nanoparticles (NPs) serve to reduce toxicity; reinforce bioactivity and improve targeting. This study was intended to investigate the antiobesity and antioxidant activities of selenium and zinc oxide nanoparticles. METHODS: Twenty four adult male rats were divided into four groups, group1 control rats fed normal diet and the other three groups were fed high fat diet (HFD) for 10 weeks to induce obesity and injected intraperitoneally with saline, SeNPs (30µg/kg b.wt) and ZnONPs (5mg/kg b.wt) respectively on the last two weeks of feeding (9th and 10th). RESULTS: HFD increased body weight, oxidative stress as indicated by elevated lipid peroxidation and decreased glutathione and catalase levels, increased significantly serum lipid fractions, leptin, liver enzymes, creatinine and uric acid. While causing a substantial decrease in HDL-C and thyroid hormone T4 levels. The results confirmed that treatment with SeNPs and ZnONPs significantly reduced body weight, MDA and improved liver and kidney functions, ameliorated serum lipid fractions level and significantly increased glutathione, catalase, HDL-C and thyroid hormone. CONCLUSION: SeNPs and ZnONPs significantly mitigate hyperlipidemia and oxidative stress. So, they might be potential candidate for obesity amelioration.

In-vivo (Albino Mice) and in-vitro Assimilation and Toxicity of Zinc Oxide Nanoparticles in Food Materials.

Purpose: Recent advances in nanotechnology have given rise to the potential utilization of nanoparticles as food, nano-medicine/biomedicines. Patient: The study aimed to investigate the effects of nano-zinc oxide (nano-zinc) on the bio-assimilation of mineral (Zn) in mice, aged 3-6 weeks. Methods: ZnO nanoparticles were added to the basal diet as a supplement at amounts of 0.07, 0.14 and 0.21 mg/kg. The synthesized material was characterized by Fourier transform infrared spectrophotometer, particle size, scanning electron microscope, Thermogravimetric Analysis Thermal, X-ray diffraction spectrophotometer and Zeta potential. Results: In-vitro bioavailability of synthesized group ZnO (120 nm) was 43%, whereas for standard group ZnO (50 nm) was reported as 55%. In-vivo bioavailability of zinc oxide illustrated the maximum absorption level compared with the control. In-vivo toxicity was characterized as damage done to the liver and spleen tissues with a high dose of 0.21 mg/kg, while smaller doses indicated no toxic effects. Conclusion: The study provided important insights on the toxicological effects of ZnO nanoparticles, depending on dose rate and bio-assimilation, as well as particles, under various conditions (in-vitro and in-vivo). These findings will motivate further detailed research on nano-based medicine for alleviating malnutrition conditions.

Aluminum oxide and zinc oxide induced nanotoxicity in rat brain, heart, and lung.

Nanomaterials or nanoparticles are commonly used in the cosmetics, medicine, and food industries. Many researchers studied the possible side effects of several nanoparticles including aluminum oxide (Al2O3-nps) and zinc oxide nanoparticles (ZnO-nps). Although, there is limited information available on their direct or side effects, especially on the brain, heart, and lung functions. This study aimed to investigate the neurotoxicity, cardiotoxicity, and lung toxicity induced by Al2O3-nps and ZnO-nps or in combination via studying changes in gene expression, alteration in cytokine production, tumor suppressor protein p53, neurotransmitters, oxidative stress, and the histological and morphological changes. Obtained results showed that Al2O3-nps, ZnO-nps and their combination cause an increase in 8-hydroxy-2´-deoxyguanosine (8-OHdG), cytokines, p53, oxidative stress, creatine kinase, norepinephrine, acetylcholine (ACh), and lipid profile. Moreover, significant changes in the gene expression of mitochondrial transcription factor-A (mtTFA) and peroxisome proliferator activator receptor-gamma-coactivator-1alpha (PGC-1alpha) were also noted. On the other hand, a significant decrease in the levels of antioxidant enzymes, total antioxidant capacity (TAC), reduced glutathione (GSH), paraoxonase 1 (PON1), neurotransmitters (dopamine - DA, and serotonin - SER), and the activity of acetylcholine esterase (AChE) in the brain, heart, and lung were found. Additionally, these results were confirmed by histological examinations. The present study revealed that the toxic effects were more when these nanoparticle doses are used in combination. Thus, Al2O3-nps and ZnO-nps may behave as neurotoxic, cardiotoxic, and lung toxic, especially upon exposure to rats in combination.

Enhanced photodegradation of rifampicin and co-trimoxazole by ZnO/ZnMn2O4/ZnS-PVA and its genotoxicity studies on Allium cepa.

Oxygen vacancies and its associated defect states have a great influence on the electronic and structural aspects of semiconductor photocatalysts, yet there is paucity of investigations about the influence of the defect states on their photocatalytic properties. Herein, this study reports the hierarchical fabrication of oxygen vacancy enriched ZnO/ZnMn2O4/ZnS-PVA nanocomposite (NCs) for the enhanced photodegradation of rifampicin and co-trimoxazole. The formation of lattice expansion induced oxygen vacancies and its associated Urbach tail energy, and n-p-n heterojunction-based S-scheme charge transfer path synergistically contributed to the boosted photocatalytic performance of the as prepared NCs. The photocatalytic performance of the nanomaterial towards rifampicin and co-trimoxazole has been determined to be 80% and 90% under visible light irradiation, respectively. Furthermore, various operating parameters including the concentration of NCs and drug, pH and interference of various ions have been evaluated. The degraded product intermediates have been elucidated by GC-MS analysis. The toxicity of the as-prepared nanomaterials has been evaluated by treating the samples with root tips of Allium cepa, where the NCs was found to be non-toxic. The study provides a new-fangled insight on the preparation and fabrication of non-toxic and defect rich nanomaterials which may help stimulate this area of research.

Different cellular mechanisms from low- and high-dose zinc oxide nanoparticles-induced heart tube malformation during embryogenesis.

With the wide application of nanometer materials in daily life, people pay more attention to the potential toxicity of nanoparticles to human fetal development once the nanoparticles are absorbed into the human body during pregnancy. However, there was no directly solid evidence for ZnO NPs-caused congenital heart defects. Hence, we investigated the effect of ZnO NPs exposure on early cardiogenesis using the chicken/mouse embryo models. First, we showed ZnO NPs reduced H9c2 cell viability in a dose- and time-dependent manner, while cell autophagy was significantly activated too on the same pattern. During early cardiogenesis, ZnO NPs exposure increased the chance of heart tube malformation, while precardiac cell apoptosis rises in the phenotype of closure defect and Bifida. The hypertrophy was also observed in late-stage chicken/mouse survival embryos exposed to ZnO NPs. Apart from cell apoptosis, high-dose ZnO NPs exposure led to massive programmed necrosis, and further experiments verified that ferroptosis remained primarily in ZnO NPs-induced programmed necrosis. We also revealed that the toxicology of low-dose ZnO NPs was mainly featured in the changes of expressions of key genes instead of causing precardiac cell death. MYL2 and CSRP3 could work as the downstream molecules of the above key genes in the context of ZnO NPs exposure to early cardiogenesis based on RNA sequencing. Taken together, this study for the first time revealed the potential risk of heart tube malformation induced by ZnO NPs exposure through different cellular mechanisms, which depended on low- or high-dose ZnO NPs.