Apoptosis and oxidative stress as relevant mechanisms of antitumor activity and genotoxicity of ZnO-NPs alone and in combination with N-acetyl cysteine in tumor-bearing mice

Enhanced glioma cell death with ZnO nanorod flowers and temozolomide combination therapy through autophagy and mitophagy pathways

In recent years, the application of engineered NMts has significantly contributed to various biomedical fields. ZnO NMts (ZnO NMts) are widely utilized due to their biocompatibility, unique physical and chemical properties, stability, and cost-effectiveness for large-scale production. They have emerged as potential materials for anti-cancer applications. This study aims to study the impact of ZnO Nanorod flowers (ZnO NRfs) and their combination with temozolomide (TMZ) on glioma cells. Normal mouse microglia (BV2) will be used as a control to assess the effects on mouse glioma cells (G422) and human glioma cells (LN229). The effects of these substances were evaluated on G422 and LN229 cells through various parameters such as IC50 value, Zn2+ accumulation, ROS production, apoptosis, mitochondrial membrane potential (MMP) depolarization, and examination of organelles like mitochondria and lysosomes. Additionally, hypoxia-inducible factor-1α (HIF-1α), endothelial cell PAS domain protein 1 (EPAS1), autophagy markers (LC3), mitophagy and phagocytosis marker (BNIP3) were assessed. The results demonstrated that the combination of ZnO NRfs and TMZ could influence the expression of HIF-1α, EPAS1, LC3, and BNIP3 proteins, leading to mitophagy in glioma cells. This combination treatment has the potential to effectively eliminate glioma cells by activating the mitophagy pathway, which provides a good prospect for the clinical treatment of glioma.

ZnO NPs induce miR-342-5p mediated ferroptosis of spermatocytes through the NF-κB pathway in mice

BACKGROUND

Zinc oxide nanoparticle (ZnO NP) is one of the metal nanomaterials with extensive use in many fields such as feed additive and textile, which is an emerging threat to human health due to widely distributed in the environment. Thus, there is an urgent need to understand the toxic effects associated with ZnO NPs. Although previous studies have found accumulation of ZnO NPs in testis, the molecular mechanism of ZnO NPs dominated a decline in male fertility have not been elucidated.

RESULTS

We reported that ZnO NPs exposure caused testicular dysfunction and identified spermatocytes as the primary damaged site induced by ZnO NPs. ZnO NPs led to the dysfunction of spermatocytes, including impaired cell proliferation and mitochondrial damage. In addition, we found that ZnO NPs induced ferroptosis of spermatocytes through the increase of intracellular chelatable iron content and lipid peroxidation level. Moreover, the transcriptome analysis of testis indicated that ZnO NPs weakened the expression of miR-342-5p, which can target Erc1 to block the NF-κB pathway. Eventually, ferroptosis of spermatocytes was ameliorated by suppressing the expression of Erc1.

CONCLUSIONS

The present study reveals a novel mechanism in that miR-342-5p targeted Erc1 to activate NF-κB signaling pathway is required for ZnO NPs-induced ferroptosis, and provide potential targets for further research on the prevention and treatment of male reproductive disorders related to ZnO NPs.

ZnO nanomaterials target mitochondrial apoptosis and mitochondrial autophagy pathways in cancer cells

In recent years, the application of engineering nanomaterials has significantly contributed to the development of various biomedical fields. Zinc oxide nanomaterials (ZnO NMts) have gained wide popularity due to their biocompatibility, unique physical and chemical properties, stability, and cost-effectiveness for large-scale production. They have emerged as potential materials for anticancer applications. This article provides a comprehensive review of the synthesis methods of ZnO NMts and highlights the advantages of combining ZnO NMts with anticancer drugs as a nano platform for cancer treatment. Additionally, the article briefly explains the mechanism of action of ZnO NMts in tumor cells, focusing on the mitochondrial pathways that target cell apoptosis and autophagy. It is observed that these pathways are primarily influenced by reactive oxygen species generated through oxidative stress. The article discusses the promising prospects of ZnO NMts combined with anticancer drugs in the field of cancer medicine and emphasizes the need for further in-depth research on the mitochondrial apoptosis and mitochondrial autophagy pathways.

Potential effects of spirulina and date palm pollens on zinc oxide nanoparticles -induced hepatoxicity, oxidative stress, and inflammation in male albino rats

INTRODUCTION

The application of Zinc oxide nanoparticles (ZnO NPs) is substantially growing in industrial products. Therefore, humans are increasingly exposed to ZnO NPs daily due to their extensive range of applications, raising worries about their possible toxicity.

AIM

In this study, the ameliorative effects of raw Phoenix dactylifera L. (date palm) pollens (DPP) and Spirulina platensis (SP) independently against ZnO NPS-induced hepatoxicity in male albino rats were examined.

METHODS

Six groups (6/group) of adult male albino rats received oral treatment using distilled water (control), SP (1000 mg/kg b. wt.), DPP (100 mg/kg b. wt.), ZnO NPs (100 mg/kg b. wt.), ZnO NPs +SP, and ZnO NPs + DPP respectively for 15 days.

RESULTS

The results of the biochemical investigation indicated that the administration of ZnO NPs substantially upregulated (p < 0.05) transaminases, alkaline phosphatase, and bilirubin serum levels. Malondialdehyde and pro-inflammatory cytokine serum levels were also elevated after ZnO NPs administration. Simultaneously, the downregulated catalase and glutathione peroxidase serum activities were significantly suppressed in ZnO NPs treated rats. Moreover, exposure to ZnO NPs induced liver histopathological alterations. The administration of SP and DPP ameliorated the aforementioned effects caused by ZnO NPs. This result can be attributable to the downregulation of hepatic transaminases, alkaline phosphatase, and bilirubin in the serum and the antioxidation system's equilibration, thus alleviating the accumulation of reactive oxygen species.

CONCLUSION

SP and DPP are natural antioxidants with the potential to eliminate inflammation as well as oxidative damage caused by ZnO NPs in hepatic tissue.

Impact of HIF1-α/TGF-β/Smad-2/Bax/Bcl2 pathways on cobalt chloride-induced cardiac and hepatorenal dysfunction

Background

Cobalt chloride (CoCl2) is a ferromagnetic ubiquitous trace element extensively dispersed in the environment. Nevertheless, it may merit human hazard.

Aim

Excess cobalt can harm vital organs this paves the way to elucidate the toxic impact of CoCl2 on the liver, kidney and heart.

Method

CoCl2 was injected in a dose of (60 mg/kg, S.C.) proceeded via Carnosine (200 mg/kg) and/or Arginine (200 mg/kg) treatment 1 month, 24 and 1 h, prior to CoCl2-intoxication.

Results

CoCl2 significantly alleviated hemoglobin concentration and BCl2; meanwhile, protein expression of transforming growth factor (TGF-β), hypoxia-inducible factor (HIF-1α), Mothers against decapentaplegic (Smad-2), AKT protein expression and Bax/Bcl2 ratio was noticeably elevated.

Conclusion

The combination of the aforementioned antioxidants exerted a synergistic anti-apoptotic impact in all target tissues.

Suppression of tumor growth and apoptosis induction by pomegranate seed nano-emulsion in mice bearing solid Ehrlich carcinoma cells

Despite the high antioxidant and penetration ability of pomegranate seed oil (PSO), the in vivo antitumor activity of PSO nano-emulsion has not been well investigated. Therefore, this study was undertaken to estimate the antitumor activity and safety of PSO nano-emulsion in mice bearing Ehrlich solid carcinoma cells. For tumor inoculation, about 2 × 10⁶ viable Ehrlich tumor cells (200 µl) were implanted intramuscularly in the left thigh of hind leg. Once a solid tumor appears on the 10th day of transplantation; the mice were randomly divided into five groups (5 animals/group). Characterization of the PSO nano-emulsion using a Zeta sizer Malvern instrument and transmission electron microscope (TEM) revealed that the PSO nano-droplets were well dispersed with an average particle size of 8.95 nm and a spherical shape. Treatment with PSO nano-emulsions caused a significant reduction in the tumor size and weight, in a dose dependent manner, compared to tumor control group. Marked dose dependent elevations in the DNA damage level together with significant increases in the tumor suppressor p53, Bax and Caspase genes and reductions in the anti-apoptotic Bcl2 gene were also observed in the tumor tissue of mice given PSO nano-emulsions. Histological examination also revealed apoptosis and necrosis of tumor cells and tumor infiltration with inflammatory cells after PSO nano-emulsion treatment. However, high DNA damage was noticed in the liver and kidney tissues of mice given the highest dose of PSO nano-emulsion (400 mg/kg). Therefore, we concluded that PSO nano-emulsion exhibited a potent antitumor activity through induction of DNA breaks that triggers apoptosis of tumor cells but the highest dose caused genotoxicity to liver and kidney tissues, thus it is recommended to use doses lower than 400 mg/kg of PSO nano-emulsion as an alternative drugs for chemotherapy.

TFEB coordinates autophagy and pyroptosis as hepatotoxicity responses to ZnO nanoparticles

Zinc oxide nanoparticles (ZnO NPs) have drawn serious concerns about their biotoxicity due to their extensive applications in biological medicine, clinical therapeutic, daily chemical production, food and agricultural additives. In our present study, we clarified hepatotoxic mechanism of ZnO NPs through investigating the crosstalk between autophagy and pyroptosis, a remaining enigma in hepatocyte stimulated by ZnO NPs. Based on the effects of autophagy intervention by Rapamycin (Rap) and 3-Methyladenine (3-MA), and the observation of pyroptosis morphology and related indexes, the autophagy and pyroptosis simultaneously initiated by ZnO NPs were interrelated and the autophagy characterized by autophagosome production and increased expression of autophagy proteins was identified as a protective response of ZnO NPs against pyroptosis. According to the analysis of protein expression and fluorescence localization, the NLRP3 inflammasome assemble and the classical Caspase-1/GSDMD-dependent pyroptosis induced by ZnO NPs was modulated by autophagy. In this process, the adjustment of TFEB expression and nuclear translocation by gene knockout and gene overexpression, further altered the tendency of ZnO NPs-induced pyroptosis via the regulation of autophagy and lysosomal biogenesis. The knockout of TFEB gene exacerbated the pyroptosis via autophagy elimination and lysosome inhibition. While the alleviation of NLRP3 generation and pyroptosis activation was observed after treatment of TFEB gene overexpression. Additionally, the siRNA interference confirmed that TRAF-6 was involved in the TFEB-mediated global regulation of autophagy-lysosome-pyroptosis in response to ZnO NPs. Accordingly, pyroptosis induced by ZnO NPs in hepatocyte could be significantly avoided by TFEB-regulated autophagy and lysosome, further providing new insights for the risk assessment and therapeutic strategy.

Vitamins A, C, and E Exert Anti-apoptotic Function in the Testis of Rats After Exposure to Zinc Oxide Nanoparticles

Some reports emphasize that zinc oxide nanoparticles (ZnO NPs) are detrimental to the reproductive organs of animals. As such, this research aimed at exploring the apoptotic potential of ZnO NPs on testis along with the beneficial role of Vitamins (V) A, C, and E against ZnO NP-induced damage. To this aim, a population of 54 healthy, male Wistar rats were used in this work and then assigned into nine groups of 6 rats as G1: Control 1 (Water); G2: Control 2 (Olive oil); G3: VA (1000 IU/kg), G4: VC (200 mg/kg), G5: VE (100 IU/kg), G6: ZnO NPs exposed animals (200 mg/kg); and G7, 8 and 9: ZnO NPs-exposed animals that were pre-treated with either VA, C, or E. Apoptosis rates were estimated by measuring the level of apoptotic regulatory markers including Bcl-2-associated X (Bax) and B-cell lymphoma protein 2 (Bcl-2) using western blotting and qRT-PCR assays. The data indicated that ZnO NPs exposure elevates the level of Bax protein and gene expression, whereas the protein and gene expression of Bcl-2 was reduced. Further, the activation of caspase-3,7 occurred after exposure to ZnO NPs, while the above alterations were significantly alleviated in the rats that were co-treated with VA, C, or E and ZnO NPs relative to the rats in the ZnO NPs group. In summary, VA, C, and E exerted anti-apoptotic functions in the testis of rats following administration of ZnO NPs.

Rubus Capped Zinc Oxide Nanoparticles Induce Apoptosis in MCF-7 Breast Cancer Cells

Rubus fairholmianus (RF) has widely been used to treat various ailments, including pain, diabetes, and cancer. Zinc oxide nanoparticles (ZnO NPs) have drawn attention in modern healthcare applications. Hence, we designed this study to synthesize zinc oxide (ZnO) nanoparticles using R. fairholmianus root extract to investigate its synergistic cytotoxic effect on MCF-7 cells and explore the possible cell death mechanism. ZnO NPs were synthesized via green synthesis using R. fairholmianus root extract, and the effect on MCF-7 cells was determined by looking at cellular morphology, proliferation, cytotoxicity, apoptosis, and reactive oxygen species (ROS). The results showed that cellular proliferation was reduced following treatment with R. fairholmianus capped zinc oxide nanoparticles (RFZnO NPs), while cytotoxicity and ROS were increased. There was also an increase in apoptosis as indicated by the significant increase in cytoplasmic cytochrome c and caspase 3/7 (markers of apoptosis), as well as increased levels of pro-apoptotic proteins (p53, Bax) and decreased levels of anti-apoptotic protein (Bcl-2). In conclusion, these results showed that RFZnO NPs induce apoptosis in breast cancer cells via a mitochondria-mediated caspase-dependent apoptotic pathway and suggest the use of acetone root extract of R. fairholmianus for the treatment of cancer-related ailments.

[1,2,4] Triazolo [3,4-a]isoquinoline chalcone derivative exhibits anticancer activity via induction of oxidative stress, DNA damage, and apoptosis in Ehrlich solid carcinoma-bearing mice

Despite the advances made in cancer therapeutics, their adverse effects remain a major concern, putting safer therapeutic options in high demand. Since chalcones, a group of flavonoids and isoflavonoids, act as promising anticancer agents, we aimed to evaluate the in vivo anticancer activity of a synthetic isoquinoline chalcone (CHE) in a mice model with Ehrlich solid carcinoma. Our in vivo pilot experiments revealed that the maximum tolerated body weight-adjusted CHE dose was 428 mg/kg. Female BALB/c mice were inoculated with Ehrlich ascites carcinoma cells and randomly assigned to three different CHE doses administered intraperitoneally (IP; 107, 214, and 321 mg/kg) twice a week for two consecutive weeks. A group injected with doxorubicin (DOX; 4 mg/kg IP) was used as a positive control. We found that in CHE-treated groups: (1) tumor weight was significantly decreased; (2) the total antioxidant concentration was substantially depleted in tumor tissues, resulting in elevated oxidative stress and DNA damage evidenced through DNA fragmentation and comet assays; (3) pro-apoptotic genes p53 and Bax, assessed via qPCR, were significantly upregulated. Interestingly, CHE treatment reduced immunohistochemical staining of the proliferative marker ki67, whereas BAX was increased. Notably, histopathological examination indicated that unlike DOX, CHE treatment had minimal toxicity on the liver and kidney. In conclusion, CHE exerts antitumor activity via induction of oxidative stress and DNA damage that lead to apoptosis, making CHE a promising candidate for solid tumor therapy.

Exposure to zinc oxide nanoparticles affects testicular structure, reproductive development and spermatogenesis in parental and offspring male rats

Background

This study aimed to comprehensively evaluate the toxicity exerted by zinc oxide nanoparticles (ZnO NPs) on rat testis and its effects on fertility and progeny development.

Methods

Different concentrations of ZnO NPs were administered by gavage to Sprague Dawley (SD) rats to examine the adverse effects resulting from pre- and post-natal exposure. Systemic distribution of ZnO NPs, developmental performance, sperm parameters, reproductive performance, histopathological examination, and sex hormone levels were determined scheduled in the experimental rats and their male offspring. The comparative in vitro cytotoxicity of the ZnO NPs was determined among C18-4, TM3, and TM4 cells. The toxicity exerted by ZnO NPs on germ cells in vitro and the effects on the expression of cytoskeleton and blood-testis barrier (BTB)-related proteins were also determined.

Results

After oral gavage, ZnO NPs mainly accumulated in the liver and testes of rats; 350 mg/kg ZnO NPs adversely affected the epididymal weight, sperm motility, and hormone levels but did not affect the fertility of rats. In addition, 350 mg/kg ZnO NPs significantly reduced the reproductive and developmental performance of offspring male rats. Testicular histopathological and electron microscopic ultrastructure examinations showed more significant abnormal structural changes than those observed in parental rats. The results of in vitro cell experiments further showed that ZnO NPs exerted cytotoxic effects on germ cells, and led to DNA damage, nucleoskeleton and cytoskeleton alterations, and could regulate actin changes through changes in LC3B.

Conclusions

It is possible that ZnO NPs act directly on TM4 cells by penetrating the BTB, causing damage to the cytoskeleton and disrupting the dynamic balance of the BTB, thereby destroying the microenvironment necessary for spermatogenesis, which may lead to poor reproduction in rats.

Lethality of Zinc Oxide Nanoparticles Surpasses Conventional Zinc Oxide via Oxidative Stress, Mitochondrial Damage and Calcium Overload: A Comparative Hepatotoxicity Study

Zinc oxide nanoparticles (ZnO NPs) with high bioavailability and excellent physicochemical properties are gradually becoming commonplace as a substitute for conventional ZnO materials. The present study aimed to investigate the hepatotoxicity mechanism of ZnO NPs and traditional non-nano ZnO particles, both in vivo and in vitro, and identify the differences in their toxic effects. The results showed that the extent and conditions of zinc ion release from ZnO NPs were inconsistent with those of ZnO. The RNA-seq results revealed that the expression quantity of differentially expressed genes (DEGs) and differentially expressed transcripts (DETs) affected by ZnO NPs was more than in ZnO, and the overall differences in genes or transcripts in the ZnO NPs group were more pronounced than in the ZnO group. Furthermore, the cell inactivation, oxidative stress, mitochondrial damage, and intracellular calcium overload induced by ZnO NPs were more serious than ZnO in HepG2 cells. Moreover, compared with traditional ZnO, the rat liver damage induced by ZnO NPs was more significant, with evidence of higher AST and ALT levels, weaker antioxidant capacity, and more serious histopathological damage (p < 0.05). In summary, the hepatotoxicity of ZnO NPs was more serious than that of conventional ZnO, which is helpful to understand the hepatotoxicity mechanism of Zn compounds in different states and improve the risk assessment of novel nano ZnO products in a variety of applications.

Interactive effects of ZnO nanoparticles and temperature on molecular and cellular stress responses of the blue mussel Mytilus edulis

Temperature is an important abiotic factor that modulates all aspects of ectotherm physiology, including sensitivity to pollutants. Nanoparticles are emerging pollutants in coastal environments, and their potential to cause toxicity in marine organisms is a cause for concern. Here we studied the interactive effects of temperature (including seasonal and experimental warming) on sublethal toxicity of ZnO nanoparticles (nano-ZnO) in a model marine bivalve, the blue mussel Mytilus edulis. Molecular markers were used to assess the pollutant-induced cellular stress responses in the gills and the digestive gland of mussels exposed for 21 days to 10 μg l^-1 and 100 μg l^-1 of nano-ZnO or dissolved Zn under different temperature regimes including ambient temperature (10 °C and 15 °C in winter and summer, respectively) or experimental warming (+5 °C). Exposure to high concentration (100 μg l^-1) of nano-ZnO caused oxidative injury to proteins and lipids and induced a marked apoptotic response indicated by increased transcript levels of apoptosis-related genes p53, caspase 3 and the MAPK pathway (JNK and p38) and decreased mRNA expression of anti-apoptotic Bcl-2. No significant induction of inflammatory cytokine-related response (TGF-β and NF-κB) of tissues was observed in nano-ZnO exposed-mussels. Furthermore, the oxidative injury and apoptotic response could differentiate the effects of nano-ZnO from those of dissolved Zn in the mussels. This study revealed that oxidative stress and stress-related transcriptional responses to nano-ZnO were strongly modified by warming and season in the mussels. No single biomarker could be shown to consistently respond to nano-ZnO in all experimental groups, which implies that multiple biomarkers are needed to assess nano-ZnO toxicity to marine organisms under the variable environmental conditions of coastal habitats.

Effects of Metal Oxide Nanoparticles in Zebrafish

Metal oxide nanoparticles (MO NPs) are increasingly employed in many fields with a wide range of applications from industries to drug delivery. Due to their semiconducting properties, metal oxide nanoparticles are commonly used in the manufacturing of several commercial products available in the market, including cosmetics, food additives, textile, paint, and antibacterial ointments. The use of metallic oxide nanoparticles for medical and cosmetic purposes leads to unavoidable human exposure, requiring a proper knowledge of their potentially harmful effects. This review offers a comprehensive overview of the possible toxicity of metallic oxide nanoparticles in zebrafish during both adulthood and growth stages, with an emphasis on the role of oxidative stress.

Antitumor activity of zinc nanoparticles synthesized with berberine on human epithelial colorectal adenocarcinoma (Caco-2) cells through acting on Cox-2/NF-kB and p53 pathways

BACKGROUND

Drawbacks and side effects of currently available therapies to colorectal cancer (CRC) devoted the researchers to search for new therapeutic strategies.

OBJECTIVE

This study was designed to investigate the effects of zinc nanoparticles biosynthesized with berberine (ZnNPs-BER) on Caco-2 cells compared to 5-Fluorouracil (5-FU) and explore the possible underlying pathways.

METHODS

Caco-2 and Vero cells were treated with 5-FU, BER, or ZnNPs-BER for 24 h. Cell viability was measured by MTT assay. Oxidative stress and apoptotic markers and cell cycle were determined. Additionally, Cox-2 and NF-kB levels were also measured.

RESULTS

The IC50 of 5-FU, BER, and ZnNPs-BER on Caco-2 cells were 34.65 µM, 19.86 µg/ml and 10.49 µg/ml, respectively by MTT assay. The IC50 value for 5-FU in Vero cells was 21.7 μg/ml, however, BER and BER-ZnNPs treatment showed non-toxic effects to the Vero cells. Further, ZnNPs-BER exerted significant induction of ROS besides exhaustion of the antioxidant capacity of tumor cells indicated by declined GSH and elevated NO and MDA contents. Marked increments in levels of Bax and caspase-3 were detected together with declines in Bcl-2 levels in Caco-2 cells submitted to BER-ZnNPs therapy. On the molecular basis, upregulation in mRNA levels of pro-apoptotic genes (Bax, caspase-3, and tumor suppressor gene p53) with downregulation in the antiapoptotic gene (Bcl-2) were observed in ZnNPs-BER treated Caco-2 cells. Furthermore, ZnNPs-BER showed more pronounced effects on apoptosis increased cell percentage in the S and subG1 phases. In addition, green synthesis of ZnNPs with BER showed notable induction of Cox2 and NF-kB in Caco-2 cells.

CONCLUSION

Therefore, the antitumor potential of ZnNPs-BER in colon cancer cells may be endorsed for induction of oxidative stress, inflammation, and apoptotic changes in tumor cells. Our study documents the new therapeutic potential of Zn nanoparticles conjugated with BER, as a new option for combined chemotherapy.

Evaluation of Induced Apoptosis by Biosynthesized Zinc Oxide Nanoparticles in MCF-7 Breast Cancer Cells Using Bak1 and Bclx Expression

Zinc oxide nanoparticles (ZnO NPs) have peaked interests in many researches in these recent years due to their advantageous application in modern health care applications. Therefore, we successfully synthesized ZnO NPs by Acacia luciana flower extract as stabilizing, reducing and capping agent, to investigate the antiproliferative potential and apoptosis induction in breast cancer cell lines. The involvements of Acacia luciana bioactive compounds in the stabilization of the ZnO NPs were confirmed by FTIR analysis. FESEM and EDS instruments confirmed that biosynthesized nanoparticles have an irregular morphology and mostly composed of Zn, C, and O respectively. The TEM and zeta potential instruments confirmed that biosynthesized nanoparticles have slight negative charges with particle size of 40 nm. The survivorship of MCF-7 cells were examined by MTT assay and revealed that ZnO NPs inhibited cell viability in a dose- and time-dependent effect with IC50 value of 3.1 µg/mL after 72 h exposure. Also, as a novel work onto ZnO NPs obtained by Acacia extracts, the Bak1/Bclx expression ratio was elucidated utilizing RT-PCR technique. The results demonstrated that ZnO NPs could enhance the expression ratio; therefore they have the potential to induce apoptosis in breast cancer cells via mitochondria-mediated apoptotic pathway.

Toxicity mitigation by N-acetylcysteine and synergistic toxic effect of nano and bulk ZnO to Panagrellus redivivus

To better understand the nanosize-relevant toxic effects and underlying mechanisms, N-acetylcysteine (NAC), as a mitigation agent, an ionic form of Zn (ZnCl₂), and the binary mixture of ZnO with different particle sizes (15 nm and 140 nm), was used in toxicity assays with the nematode Panagrellus redivivus. The ZnCl₂ concentrations were applied to show the amount of dissolved Zn ions present in the test system. Reactive oxygen species (ROS) measuring method was developed to fit the used test system. Our studies have shown that NAC can mitigate the toxic effects of both studied particle sizes. In the applied concentrations, ZnCl₂ was less toxic than both of the ZnO particles. This finding indicates that not only ions and ROS produced by the dissolution are behind the toxic effects of the ZnO NPs, but also other particle size-dependent toxic effects, like the spontaneous ROS generation, are also relevant. When the two materials were applied in binary mixtures, the toxic effects increased significantly, and the dissolved zinc content and the ROS generation also increased. It is assumed that the chemical and physical properties of the materials have been mutually reinforcing to form a more reactive mixture that is more toxic to the P. redivivus test organism. Our findings demonstrate the importance of using mitigation agent and mixtures to evaluate the size-dependent toxicity of the ZnO.

Green Synthesis and Biomedical Applications of ZnO Nanoparticles: Role of PEGylated-ZnO Nanoparticles as Doxorubicin Drug Carrier against MDA-MB-231(TNBC) Cells Line

The present study aimed to develop the synthesis of zinc oxide nanoparticles (ZnO-NPs) using the green method, with Aloe barbadensis leaf extract as a stabilizing and capping agent. In vitro antitumor cytotoxic activity, as well as the surface-functionalization of ZnO-NPs and their drug loading capacity against doxorubicin (DOX) and gemcitabine (GEM) drugs, were also studied. Morphological and structural properties of the produced ZnO-NPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersion X-ray diffraction (EDX), UV-Vis spectrophotometry, Fourier-transform infrared analysis (FTIR), and X-ray diffraction (XRD). The prepared ZnO-NPs had a hexagonal shape and average particle size of 20–40 nm, with an absorption peak at 325 nm. The weight and atomic percentages of zinc (50.58% and 28.13%) and oxygen (26.71% and 60.71%) were also determined by EDAX (energy dispersive x-ray analysis) compositional analysis. The appearance of the FTIR peak at 3420 m–1 confirmed the synthesis of ZnO-NPs. The drug loading efficiency (LE) and loading capacity (LC) of unstabilized and PEGylated ZnO-NPs were determined by doxorubicin (DOX) and gemcitabine (GEM) drugs. DOX had superior LE 65% (650 mg/g) and higher LC 32% (320 mg/g) than GEM LE 30.5% (30 mg/g) and LC 16.25% (162 mg/g) on ZnO-NPs. Similar observation was observed in the case of PEG-ZnO-NPs, where DOX had enhanced LE 68% (680 mg/g) and LC 35% (350) mg/g in contrast to GEM, which had LE and LC values of 35% (350 mg/g) and 19% (190 mg/g), respectively. Therefore, DOX was chosen to encapsulate nanoparticles, along with the untreated nanoparticles, to check their in vitro antiproliferative potential against the triple-negative breast cancer (TNBC) cell line (MDA-MB-231) through the MTT (3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide) assay. This drug delivery strategy implies that the PEGylated biogenically synthesized ZnO-NPs occupy an important position in chemotherapeutic drug loading efficiency and can improve the therapeutic techniques of triple breast cancer.

Impact of zinc oxide nanoparticles and thymoquinone in Ehrlich ascites carcinoma induced in mice

BACKGROUND

The field of nanotechnology offers great opportunities for cancer therapy.

OBJECTIVE

This study aimed to compare the therapeutic impact of Zn oxide nanoparticles (ZnO NPs) and thymoquinone (TQ) alone or as cotherapy in Ehrlich ascites carcinoma (EAC) induced in mice.

MATERIALS AND METHODS

This study was performed on 75 female albino mice divided into Group I: EAC-bearing control group, Group II: EAC treated with TQ, Group III: EAC treated with low-dose ZnO NPs, Group IV: EAC treated with high-dose ZnO NPs, Group V: EAC treated with TQ and low-dose ZnO NPs. All groups were subjected to measurement of cell viability, ascites fluid volume, Bcl2 protein expression by Western blot analysis, cyclooxygenase 2 (COX2) gene expression by a real-time polymerase chain reaction, enzyme-linked immunosorbent assay levels of Beclin 1, interferon γ (INFγ), interleukin 13 (IL-13), and estimation of Zn concentrations in EAC cells and liver homogenate to evaluate its toxicity.

RESULTS

Cotherapy has an efficient anticancer effect by enhancing apoptosis and autophagy, resulting in reducing tumor cell viability and ascites fluid volume together with downregulation of Bcl2 protein expression. This cotherapy increases Beclin 1 and INFγ and decreases IL-13. ZnO NPs upregulate COX2 expression, whereas TQ downregulates its expression. High-dose ZnO NPs have more toxic effects on liver enzymes. Using TQ together with ZnO NPs can eliminate ZnO NPs liver toxicity.

CONCLUSION

The cotherapy has an efficient anticancer effect by enhancing apoptosis and autophagy. High-dose ZnO NPs have more toxic effects on liver enzymes. Using TQ together with ZnO NPs can eliminate ZnO NP liver toxicity.

Zinc oxide nanoparticles: A comprehensive review on its synthesis, anticancer and drug delivery applications as well as health risks

In recent years, zinc oxide nanoparticles (ZnONPs) emerged as an excellent candidate in the field of optical, electrical, food packaging and particularly in biomedical research. ZnONPs show cancer cell specific toxicity via the pH-dependent (low pH) dissolution into Zn²⁺ ions, which generate reactive oxygen species and induce cytotoxicity in cancer cells. Further, ZnONPs have also been used as an effective carrier for the targeted delivery of several anticancer drugs into tumor cells. The increasing focus on ZnONPs resulted in the development of various synthesis approaches including chemical, pHysical, and green or biological for the manufacturing of ZnONPs. In this article, at first we have discussed the various synthesis methods of ZnONPs and secondly its biomedical applications. We have extensively reviewed the anticancer mechanism of ZnONPs on different types of cancers considering its size, shape and surface charge dependent cytotoxicity. Photoirradiation with UV light or NIR laser further increase its anticancer activity via synergistic chemo-photodynamic effect. The drug delivery applications of ZnONPs with special emphasis on drug loading mechanism, stimuli-responsive controlled release and therapeutic effects have also been discussed in this review. Finally, its side effects to vital body organs with mechanism via different exposure routes, the future direction of the ZnONPs research and application are also discussed.

Role of inorganic nanoparticle degradation in cancer therapy

Nanomaterials are currently widely exploited for their potential in the development of novel cancer therapies, and so far, mainly nanoparticles (NPs) consisting of liposomes and polymers have made their way into the clinic. However, major bottlenecks for the clinical translation of other types of NPs (i.e. inorganic) are the lack of knowledge concerning their long-term distribution in vivo and their potential toxicity. To counter this, various research groups have worked on soluble NPs, such as zinc oxide (ZnO), copper oxide (CuO), and silver (Ag), which tend to dissolve spontaneously into their ionic form, releasing toxic metal ions and leading to reactive oxygen species (ROS) generation when exposed to cellular environments. By fine-tuning the dissolution kinetics of these NPs, it is possible to control the level of ROS production and thus cytotoxicity to selectively destroy tumor tissue. Specifically, cancer cells tend to exhibit a higher basal level of oxidative stress compared to normal cells due to their higher metabolic rates, and therefore, by engineering NPs that generate sufficient ROS that barely exceed toxic thresholds in cancer cells, normal cells will only experience reversible transient damage. This review focuses on the use of these soluble inorganic NPs for selective cancer therapy and on the various in vitro and in vivo studies that have aimed to control the dissolution kinetics of these NPs, either through particle doping or surface modifications.

N-acetyl-cysteine in combination with celecoxib inhibits Deoxynivalenol induced skin tumor initiation via induction of autophagic pathways in swiss mice

Deoxynivalenol is a trichothecene mycotoxin which naturally contaminates small grain, cereals intended for human and animal consumption. Investigations for dermal toxicity of DON has been needed and highlighted by WHO. Previous studies on dermal toxicity suggest that DON has DNA damaging potential leading to skin tumor initiation in mice skin. However, considering its toxicological manifestations arising after dermal exposure, strategies for its prevention/protection are barely available in literatute. Collectively, our study demonstrated that N-acetylcysteine (NAC), precursor of glutathione, significantly alters the genotoxic potential of DON. Further NAC in combination with Celecoxib (CXB) inhibits tumor growth by altering antioxidant status and increasing autophagy in DON initiated Swiss mice. Despite the broad spectrum use of CXB, its use is limited by the concerns about its adverse effects on the cardiovascular system. Serum parameters and histology analysis revealed that CXB (2 mg) when applied topically for 24 weeks did not impart any cardiovascular toxicity which could be because skin permeation potential of CXB was quite low when analyzed through HPLC analysis. Although the anticancer effects of CXB and NAC have been studied, however, the combination of NAC and CXB has yet not been explored for any cancer treatment. Therefore our observations provide additional insights into the therapeutic effects of combinatorial treatment of CXB and NAC against skin tumor prevention. This approach might form a novel alternative strategy for skin cancer treatment as well as skin associated toxicities caused by mycotoxins such as DON. This combinatorial approach can overcome the limitations associated with the use of CXB for long term as topical application of the same seems to be safe in comparison to the oral mode of administration.

Short time exposure to low concentration of zinc oxide nanoparticles up-regulates self-renewal and spermatogenesis-related gene expression

Extensive application of zinc oxide (ZnO) nanoparticles (NPs) in everyday life results in increased exposure to these NPs. Spermatogonial stem cells (SSCs) guarantee sperm production throughout the male reproductive life by providing a balance between self-renewal and differentiation. We used an in vitro platform to investigate the ZnO NPs effects on SSCs. We successfully synthesized ZnO NPs. In order to investigate these NPs, we isolated SSCs from mouse testes and cultured them in vitro. Our results confirmed the uptake of ZnO NPs by the cultured SSCs. We observed a dose- and time-dependent decrease in SSC viability. Both spherical and nanosheet ZnO NPs had the same cytotoxic effects on the SSCs, irrespective of their shapes. Moreover, we have shown that short time (one day) exposure of SSCs to a low concentration of ZnO NPs (10 μg/mL) promoted expressions of specific genes (Plzf, Gfr α1 and Bcl6b) for SSC self-renewal and differentiation genes (Vasa, Dazl, C-kit and Sycp3) expressed by spermatogonia during spermatogenesis. Our study provides the first insight into ZnO NPs function in SSCs and suggests a new function for ZnO NPs in the male reproductive system. We demonstrated that ZnO NPs might promote spermatogenesis via upregulation of gene expression related to SSC self-renewal and differentiation at low concentrations. Additional research should clarify the possible effect of ZnO NPs on the SSC genome and its effects on human SSCs.

Zinc Oxide Nanoparticle Synergizes Sorafenib Anticancer Efficacy with Minimizing Its Cytotoxicity

Cancer, as a group, represents the most important cause of death worldwide. Unfortunately, the available therapeutic approaches of cancer including surgery, chemotherapy, radiotherapy, and immunotherapy are unsatisfactory and represent a great challenge as many patients have cancer recurrence and severe side effects. Methotrexate (MTX) is a well-established (antineoplastic or cytotoxic) chemotherapy and immunosuppressant drug used to treat different types of cancer, but its usage requires high doses causing severe side effects. Therefore, we need a novel drug with high antitumor efficacy in addition to safety. The aim of this study was the evaluation of the antitumor efficacy of zinc oxide nanoparticle (ZnO-NPs) and sorafenib alone or in combination on solid Ehrlich carcinoma (SEC) in mice. Sixty adult female Swiss-albino mice were divided equally into 6 groups as follows: control, SEC, MTX, ZnO-NPs, sorafenib, and ZnO-NPs+sorafenib; all treatments continued for 4 weeks. ZnO-NPs were characterized by TEM, zeta potential, and SEM mapping. Data showed that ZnO-NPs synergized with sorafenib as a combination therapy to execute more effective and safer anticancer activity compared to monotherapy as showed by a significant reduction (P < 0.001) in tumor weight, tumor cell viability, and cancer tissue glutathione amount as well as by significant increase (P < 0.001) in tumor growth inhibition rate, DNA fragmentation, reactive oxygen species generation, the release of cytochrome c, and expression of the apoptotic gene caspase-3 in the tumor tissues with minimal changes in the liver, renal, and hematological parameters. Therefore, we suggest that ZnO-NPs might be a safe candidate in combination with sorafenib as a more potent anticancer. The safety of this combined treatment may allow its use in clinical trials.

ZnO Nanoparticles Induced Caspase-Dependent Apoptosis in Gingival Squamous Cell Carcinoma through Mitochondrial Dysfunction and p70S6K Signaling Pathway

Zinc oxide nanoparticles (ZnO-NPs) are increasingly used in sunscreens, food additives, pigments, rubber manufacture, and electronic materials. Several studies have shown that ZnO-NPs inhibit cell growth and induce apoptosis by the production of oxidative stress in a variety of human cancer cells. However, the anti-cancer property and molecular mechanism of ZnO-NPs in human gingival squamous cell carcinoma (GSCC) are not fully understood. In this study, we found that ZnO-NPs induced growth inhibition of GSCC (Ca9-22 and OECM-1 cells), but no damage in human normal keratinocytes (HaCaT cells) and gingival fibroblasts (HGF-1 cells). ZnO-NPs caused apoptotic cell death of GSCC in a concentration-dependent manner by the quantitative assessment of oligonucleosomal DNA fragmentation. Flow cytometric analysis of cell cycle progression revealed that sub-G1 phase accumulation was dramatically induced by ZnO-NPs. In addition, ZnO-NPs increased the intracellular reactive oxygen species and specifically superoxide levels, and also decreased the mitochondrial membrane potential. ZnO-NPs further activated apoptotic cell death via the caspase cascades. Importantly, anti-oxidant and caspase inhibitor clearly prevented ZnO-NP-induced cell death, indicating the fact that superoxide-induced mitochondrial dysfunction is associated with the ZnO-NP-mediated caspase-dependent apoptosis in human GSCC. Moreover, ZnO-NPs significantly inhibited the phosphorylation of ribosomal protein S6 kinase (p70S6K kinase). In a corollary in vivo study, our results demonstrated that ZnO-NPs possessed an anti-cancer effect in a zebrafish xenograft model. Collectively, these results suggest that ZnO-NPs induce apoptosis through the mitochondrial oxidative damage and p70S6K signaling pathway in human GSCC. The present study may provide an experimental basis for ZnO-NPs to be considered as a promising novel anti-tumor agent for the treatment of gingival cancer.

The effects of ZnO nanostructures of different morphology on bioenergetics and stress response biomarkers of the blue mussels Mytilus edulis

Biofouling causes massive economical losses in the maritime sector creating an urgent need for effective and ecologically non-harmful antifouling materials. Zinc oxide (ZnO) nanorod coatings show promise as an antifouling material; however, the toxicity of ZnO nanorods to marine organisms is not known. We compared the toxicity of suspended ZnO nanorods (NR) with that of ZnO nanoparticles (NP) and ionic Zn²⁺ in a marine bivalve Mytilus edulis exposed for two weeks to 10 or 100 μg Zn L^-1 of ZnO NPs, NRs or Zn²⁺, or to immobilized NRs. The multi-biomarker assessment included bioenergetics markers (tissue energy reserves, activity of mitochondrial electron transport system and autophagic enzymes), expression of apoptotic and inflammatory genes, and general stress biomarkers (oxidative lesions, lysosomal membrane stability and metallothionein expression). Exposure to ZnO NPs, NRs and Zn²⁺ caused accumulation of oxidative lesions in proteins and lipids, stimulated autophagy, and led to lysosomal membrane destabilization indicating toxicity. However, these responses were not specific for the form of Zn (NPs, NR or Zn²⁺) and showed no monotonous increase with increasing Zn concentrations in the experimental exposures. No major disturbance of the energy status was found in the mussels exposed to ZnO NPs, NRs, or Zn²⁺. Exposure to ZnO NPs and NRs led to a strong induction of apoptosis- and inflammation-related genes, which was not seen in Zn²⁺ exposures. Based on the integrated biomarker response, the overall toxicity as well as the pro-apoptotic and pro-inflammatory action was stronger in ZnO NPs compared with the NRs. Given the stability of ZnO NR coatings and the relatively low toxicity of suspended ZnO NR, ZnO NR coating might be considered a promising low-toxicity material for antifouling paints.