scholarly journals The Radiosensitizing Effect of Zinc Oxide Nanoparticles in Sub-Cytotoxic Dosing Is Associated with Oxidative Stress In Vitro

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4062
Author(s):  
Till Jasper Meyer ◽  
Agmal Scherzad ◽  
Helena Moratin ◽  
Thomas Eckert Gehrke ◽  
Julian Killisperger ◽  
...  

Radioresistance is an important cause of head and neck cancer therapy failure. Zinc oxide nanoparticles (ZnO-NP) mediate tumor-selective toxic effects. The aim of this study was to evaluate the potential for radiosensitization of ZnO-NP. The dose-dependent cytotoxicity of ZnO-NP20 nm and ZnO-NP100 nm was investigated in FaDu and primary fibroblasts (FB) by an MTT assay. The clonogenic survival assay was used to evaluate the effects of ZnO-NP alone and in combination with irradiation on FB and FaDu. A formamidopyrimidine-DNA glycosylase (FPG)-modified single-cell microgel electrophoresis (comet) assay was applied to detect oxidative DNA damage in FB as a function of ZnO-NP and irradiation exposure. A significantly increased cytotoxicity after FaDu exposure to ZnO-NP20 nm or ZnO-NP100 nm was observed in a concentration of 10 µg/mL or 1 µg/mL respectively in 30 µg/mL of ZnO-NP20 nm or 20 µg/mL of ZnO-NP100 nm in FB. The addition of 1, 5, or 10 µg/mL ZnO-NP20 nm or ZnO-NP100 nm significantly reduced the clonogenic survival of FaDu after irradiation. The sub-cytotoxic dosage of ZnO-NP100 nm increased the oxidative DNA damage compared to the irradiated control. This effect was not significant for ZnO-NP20 nm. ZnO-NP showed radiosensitizing properties in the sub-cytotoxic dosage. At least for the ZnO-NP100 nm, an increased level of oxidative stress is a possible mechanism of the radiosensitizing effect.

2021 ◽  
Vol 64 (2) ◽  
pp. 239-249
Author(s):  
Fatai O. Balogun ◽  
Anofi O.T. Ashafa

The study evaluated the effects of green absorbed zinc oxide nanostructures on oxidative stress-mediated free radicals and carbohydrate-hydrolysing enzymes. The synthesised Lessertia montana zinc oxide nanoparticles were characterised using different spectroscopic, microscopic, and diffraction techniques. The activity of L. montana ZnONPs against 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid (ABTS), metal chelating assay, alpha-amylase and alphaglucosidase were determined using standard methods. L. montana ZnONPs were stable nanoparticles (NPs), appeared cubical (predominantly) in shape, and in nanometre range sizes. The synthesised NPs are very active (p < 0.05) against DPPH and alpha-glucosidase (0.120 and 0.037 g/L, respectively) when compared with other samples and controls, quercetin (0.349 g/L) and acarbose (0.065 g/L). However, their interaction with quercetin revealed a good ABTS (0.093 g/L) scavenging and an excellent metal chelating (0.027 g/L) effect compared to other samples. The mode of inhibition of alpha-amylase and alpha-glucosidase enzymes by L. montana ZnONPs was competitive and non-competitive, respectively. The study outcomes revealed that the synthesised ZnONPs possessed the potential to mitigate oxidative stress and diabetes in vitro.


2019 ◽  
Vol 20 (16) ◽  
pp. 4042 ◽  
Author(s):  
Jingcao Shen ◽  
Dan Yang ◽  
Xingfan Zhou ◽  
Yuqian Wang ◽  
Shichuan Tang ◽  
...  

Zinc oxide nanoparticles (ZnO NPs) have shown adverse health impact on the human male reproductive system, with evidence of inducing apoptosis. However, whether or not ZnO NPs could promote autophagy, and the possible role of autophagy in the progress of apoptosis, remain unclear. In the current study, in vitro and in vivo toxicological responses of ZnO NPs were explored by using a mouse model and mouse Leydig cell line. It was found that intragastrical exposure of ZnO NPs to mice for 28 days at the concentrations of 100, 200, and 400 mg/kg/day disrupted the seminiferous epithelium of the testis and decreased the sperm density in the epididymis. Furthermore, serum testosterone levels were markedly reduced. The induction of apoptosis and autophagy in the testis tissues was disclosed by up-regulating the protein levels of cleaved Caspase-8, cleaved Caspase-3, Bax, LC3-II, Atg 5, and Beclin 1, accompanied by down-regulation of Bcl 2. In vitro tests showed that ZnO NPs could induce apoptosis and autophagy with the generation of oxidative stress. Specific inhibition of autophagy pathway significantly decreased the cell viability and up-regulated the apoptosis level in mouse Leydig TM3 cells. In summary, ZnO NPs can induce apoptosis and autophagy via oxidative stress, and autophagy might play a protective role in ZnO NPs-induced apoptosis of mouse Leydig cells.


Biomolecules ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 918 ◽  
Author(s):  
Afifa Zaeem ◽  
Samantha Drouet ◽  
Sumaira Anjum ◽  
Razia Khurshid ◽  
Muhammad Younas ◽  
...  

Linum usitatissimum biosynthesizes lignans and neolignans that are diet and medicinally valuable metabolites. In recent years, zinc oxide nanoparticles (ZnONPs) have emerged as potential elicitors for the enhanced biosynthesis of commercial secondary metabolites. Herein, we investigated the influence of biogenic ZnONPs on both seedlings and stem-derived callus of L. usitatissimum. Seedlings of L. usitatissimum grown on Murashige and Skoog (MS) medium supplemented with ZnONPs (1–1000 mg/L) presented the highest antioxidant activity, total phenolic content, total flavonoid content, peroxidase and superoxide dismutase activities at 500 mg/L, while the maximum plantlet length was achieved with 10 mg/L. Likewise, the high-performance liquid chromatography (HPLC) analysis revealed the enhanced production of secoisolariciresinol diglucoside, lariciresinol diglucoside, dehydrodiconiferyl alcohol glucoside and guaiacylglycerol-β-coniferyl alcohol ether glucoside in the plantlets grown on the 500 mg/L ZnONPs. On the other hand, the stem explants were cultured on MS media comprising 1-naphthaleneacetic acid (1 mg/L) and ZnONPs (1–50 mg/L). The highest antioxidant and other activities with an enhanced rooting effect were noted in 25 mg/L ZnONP-treated callus. Similarly, the maximum metabolites were also accumulated in 25 mg/L ZnONP-treated callus. In both systems, the dose-dependent production of reactive oxygen species (ROS) was recorded, resulting in oxidative damage with a more pronounced toxic effect on in vitro cultures. Altogether, the results from this study constitute a first comprehensive view of the impact of ZnONPs on the oxidative stress and antioxidant responses in seedlings vs. in vitro cultures.


2020 ◽  
Vol 21 (6) ◽  
pp. 488-501 ◽  
Author(s):  
Reham Z. Hamza ◽  
Fawziah A. Al-Salmi ◽  
Hebatullah Laban ◽  
Nahla S. El-Shenawy

Background and Objective: This study was designed to estimate the long-term effects of zinc oxide nanoparticles/green tea (ZnONPs/GTE) complex against monosodium glutamate (MSG). The antioxidant/oxidative status, testosterone levels, DNA damage, and histopathological changes of testis were evaluated. Methods: The rats were divided into eight groups that were treated as follows: saline, the lower dosage of MSG (6.0 mg/kg), the higher dosage of MSG (17.5 mg/Kg), GTE, ZnONPs, ZnONPs/GTE and the last two groups were treated with the lower dosage of MSG or the higher dosage of MSG with ZnONPs/GTE complex. The data showed minimal toxicity in testicular tissue after the administration of ZnONPs. Results: The MSG treatment in the adult male rats reduced testosterone levels and disrupted testicular histology, which revealed dose-dependence of MSG. Also, ZnONPs induced testicular dysfunction through the interference of antioxidant/oxidant balance and suppression of testosterone levels as well as induction of cellular damage of testis. The combination of ZnONPs with GTE complex significantly protects against MSG or ZnONPs toxicity by decreasing the DNA damage, oxidative stress, and enhancement of antioxidant as well as histological structure of testis. Conclusion: We could recommend using ZnONPs/GTE complex to reduce the toxicity of ZnONPs and MSG on the testis at the cellular and oxidative stress levels.


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