Hisham Alhadlaq | King Saud University (original) (raw)
Papers by Hisham Alhadlaq
Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 2012
Zinc oxide (ZnO) nanoparticles are finding applications in a wide range of products including cos... more Zinc oxide (ZnO) nanoparticles are finding applications in a wide range of products including cosmetics, food packaging, imaging, etc. This increases the likelihood of human exposure to these nanoparticles through dermal, inhalation and oral routes. Presently, the majority of the studies concerning ZnO nanoparticle toxicity have been conducted using in vitro systems which lack the complex cell-cell, cell-matrix interactions and hormonal effects found in the in vivo scenario. The present in vivo study in mice was aimed at investigating the oral toxicity of ZnO nanoparticles. Our results showed a significant accumulation of nanoparticles in the liver leading to cellular injury after sub-acute oral exposure of ZnO nanoparticles (300 mg/kg) for 14 consecutive days. This was evident by the elevated alanine aminotransferase (ALT) and alkaline phosphatase (ALP) serum levels and pathological lesions in the liver. ZnO nanoparticles were also found to induce oxidative stress indicated by an increase in lipid peroxidation. The DNA damage in the liver and kidney cells of mice was evaluated by the Fpg-modified Comet assay which revealed a significant (p<0.05) increase in the Fpg-specific DNA lesions in liver indicating oxidative stress as the cause of DNA damage. The TUNEL assay revealed an induction of apoptosis in the liver of mice exposed to ZnO nanoparticles compared to the control. Our results conclusively demonstrate that sub-acute oral exposure to ZnO nanoparticles in mice leads to an accumulation of nanoparticles in the liver causing oxidative stress mediated DNA damage and apoptosis. These results also suggest the need for a complete risk assessment of any new engineered nanoparticle before its arrival into the consumer market.
Clinical Biochemistry, 2011
Cell & Bioscience, 2015
Background: Zinc ferrite nanoparticles (NPs) have shown potential to be used in biomedical field ... more Background: Zinc ferrite nanoparticles (NPs) have shown potential to be used in biomedical field such as magnetic resonance imaging and hyperthermia. However, there is limited information concerning the biological response of zinc ferrite NPs. This study was designed to evaluate the cytotoxicity of zinc ferrite NPs in three widely used in vitro cell culture models: human lung epithelial (A549), skin epithelial (A431) and liver (HepG2) cells. Zinc ferrite NPs were characterized by electron microscopy and dynamic light scattering. Cell viability, cell membrane damage, reactive oxygen species (ROS), glutathione (GSH), mitochondrial membrane potential (MMP), transcriptional level of apoptotic genes were determined in zinc ferrite NPs exposed cells.
Scientific Reports, 2015
. Pure and Al-doped ZnO nanoparticles were prepared by a simple sol-gel method. Characterization ... more . Pure and Al-doped ZnO nanoparticles were prepared by a simple sol-gel method. Characterization study confirmed the formation of single phase of Al x Zn 1-x O nanocrystals with the size range of 33-55 nm. Al-doping increased the band gap energy of ZnO nanoparticles (from 3.51 eV for pure to 3.87 eV for Al-doped ZnO). Al-doping also enhanced the cytotoxicity and oxidative stress response of ZnO nanoparticles in MCF-7 cells. The IC50 for undoped ZnO nanoparticles was 44 μg/ml while for the Al-doped ZnO counterparts was 31 μg/ml. Up-regulation of apoptotic genes (e.g. p53, bax/bcl2 ratio, caspase-3 & caspase-9) along with loss of mitochondrial membrane potential suggested that Al-doped ZnO nanoparticles induced apoptosis in MCF-7 cells through mitochondrial pathway. Importantly, Aldoping did not change the benign nature of ZnO nanoparticles towards normal cells suggesting that Al-doping improves the selective cytotoxicity of ZnO nanoparticles toward MCF-7 cells without affecting the normal cells. Our results indicated a novel approach through which the inherent selective cytotoxicity of ZnO nanoparticles against cancer cells can be further improved.
Nanomedicine, 2015
Copper oxide nanoparticles (CuO NPs) are being used in several industrial and commercial products... more Copper oxide nanoparticles (CuO NPs) are being used in several industrial and commercial products. Inhalation is one of the most significant routes of metal oxide NP exposure. Hence, the toxicity of CuO NPs in lung tissues is of great concern. In vitro studies have indicated that CuO NPs induce cytotoxicity, oxidative stress and genetic toxicity in cultivated human lung cells. Leaching of Cu ions, reactive oxygen species generation and autophagy appear to be the underlying mechanisms of Cu NP toxicity in lung cells. In vivo studies on the lung toxicity of CuO NPs are largely lacking. Some studies have shown that intratracheal instillation of CuO NPs induced oxidative stress, inflammation and neoplastic lesions in rats. This review critically assessed the current findings of the toxicity of CuO NPs in the lung.
Archives of Toxicology, 2015
Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Ber... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Berlin Heidelberg. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Journal of colloid and interface science, Jan 15, 2015
Nanotechnology based therapeutics can offer an alternative platform in a wide variety of biomedic... more Nanotechnology based therapeutics can offer an alternative platform in a wide variety of biomedical applications. Here we report novel cytotoxicity preventive potential of molybdenum nanoparticles (Mo NPs) in human breast (MCF-7) and fibrosarcoma (HT-1080) cells compromised with oxidant exposure. Physicochemical properties such as size, crystallinity, purity and band gap (an optical characteristic) of Mo NPs were characterized respectively by field emission transmission electron microscopy (FETEM), X-ray diffraction (XRD), energy dispersive spectrum (EDS) and UV-vis absorption spectroscopy. The average size of crystalline Mo NPs was found to be 35nm with a band gap of 1.4eV. Potential cytotoxicity of Mo NPs was evaluated by a battery of cell viability and oxidative stress parameters. Cell viability and oxidative stress data suggested Mo NPs to be reasonably non-cytotoxic. Cytotoxic preventive and GSH restoring potential of Mo NPs was determined against cytotoxicity and oxidative str...
Chemosphere, 2015
Nickel ferrite nanoparticles (NPs) have received much attention for their potential applications ... more Nickel ferrite nanoparticles (NPs) have received much attention for their potential applications in biomedical fields such as magnetic resonance imaging, drug delivery and cancer hyperthermia. However, little is known about the toxicity of nickel ferrite NPs at the cellular and molecular levels. In this study, we investigated the cytotoxic responses of nickel ferrite NPs in two different types of human cells (i.e., liver HepG2 and breast MCF-7). Nickel ferrite NPs induced dose-dependent cytotoxicity in both types of cells, which was demonstrated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazoliumbromide (MTT), neutral red uptake (NRU) and lactate dehydrogenase (LDH) assays. Nickel ferrite NPs were also found to induce oxidative stress, which was evident by the depletion of glutathione and the induction of reactive oxygen species (ROS) and lipid peroxidation. The mitochondrial membrane potential due to nickel ferrite NP exposure was also observed. The mRNA levels for the tumor suppressor gene p53 and the apoptotic genes bax, CASP3 and CASP9 were up-regulated, while the anti-apoptotic gene bcl-2 was down-regulated following nickel ferrite NP exposure. Furthermore, the activities of apoptotic enzymes (caspase-3 and caspase-9) were also higher in both types of cells treated with nickel ferrite NPs. Cytotoxicity induced by nickel ferrite was efficiently prevented by N-acetyl cysteine (ROS scavenger) treatment, which suggested that oxidative stress might be one of the possible mechanisms of nickel ferrite NP toxicity. We also observed that MCF-7 cells were slightly more susceptible to nickel ferrite NP exposure than HepG2 cells. This study warrants further investigation to explore the potential mechanisms of different cytotoxic responses of nickel ferrite NPs in different cell lines.
Journal of Colloid and Interface Science, 2015
Recently, cerium oxide nanoparticles (CeO 2 NPs) has been reported for multi-enzyme mimetic activ... more Recently, cerium oxide nanoparticles (CeO 2 NPs) has been reported for multi-enzyme mimetic activities like that of superoxide dismutase and catalase. Here, we report glutathione (GSH) replenishing response by CeO 2 NPs in human breast (MCF-7) and fibrosarcoma (HT-1080) cells. CeO 2 NPs were found to be mostly cuboidal in shape with average diameter of 25 nm. Effects on cell viability, reactive oxygen species (ROS) generation, and mitochondrial outer membrane potential (MOMP) suggested CeO 2 NPs to be reasonably non-cytotoxic. Data on membrane damage and lipid peroxidation correlated well with the cell viability results suggesting NPs of CeO 2 to be biocompatible. Interestingly, CeO 2 NPs significantly increased intracellular GSH in cells challenged with oxidants. Replenishment of depleted GSH in oxidatively challenged cells was comparable with the GSH restoring potential of known antioxidant N-acetyl cysteine (NAC), a precursor of GSH. Like NAC, CeO 2 NPs significantly replenished depleted GSH in both cell types challenged with hydrogen peroxide (H 2 O 2 ) and zinc oxide (ZnO) NPs. Moreover, CeO 2 NPs treated cells were significantly protected from cytotoxicity caused by H 2 O 2 and ZnO NPs. Our findings, therefore, suggest CeO 2 NPs as a potential antioxidant rather than a toxic material.
Colloids and Surfaces B: Biointerfaces, 2015
The present investigation was aimed to study the cytotoxicity, oxidative stress, and genotoxicity... more The present investigation was aimed to study the cytotoxicity, oxidative stress, and genotoxicity induced by molybdenum nanoparticles (Mo-NPs) in mouse skin fibroblast cells (L929). Cells were exposed to different concentrations (1-100 μg/ml) of Mo-NPs (size 40 nm) for 24 and 48 h. After the exposure, different cytotoxicity assays (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide, MTT; neutral red uptake, NRU; and cellular morphology) and oxidative stress markers (lipid peroxidation, LPO; glutathione, GSH; and catalase) were studied. Further, Mo-NPs-induced intracellular reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP), cell cycle arrest, and DNA damage were also studied. L929 cells treated with Mo-NPs showed a concentration- and time-dependent decrease in cell viability and a loss of the normal cell morphology. The percentage cell viability was recorded as 25%, 42%, and 58% by MTT assay and 24%, 46%, and 56% by NRU assay at 25, 50, and 100 μg/ml of Mo-NPs, respectively after 48 h exposure. Furthermore, the cells showed a significant induction of oxidative stress. This was confirmed by the increase in LPO and ROS generation, as well as the decrease in the GSH and catalase levels. The decrease in MMP also confirms the impaired mitochondrial membrane. The cell cycle analysis and comet assay data revealed that Mo-NPs induced G2/M arrest and DNA damage in a concentration-dependent manner. Our results demonstrated, for the first time, Mo-NPs induced cytotoxicity, oxidative stress and genotoxicity in L929 cells. Thus, data suggest the potential hazardous nature of Mo-NPs.
Clinica Chimica Acta, 2014
OncoTargets and Therapy, 2014
Despite the widespread application of nickel nanoparticles (Ni NPs) in industrial, commercial, an... more Despite the widespread application of nickel nanoparticles (Ni NPs) in industrial, commercial, and biomedical fields, their response to human cells has not been clearly elucidated. In the study reported here, Ni NPs with a 28 nm diameter were used to study their interaction with human breast carcinoma (MCF-7) cells. Dose-dependent decreased cell viability and damaged cell membrane integrity showed the cytotoxic potential of the Ni NPs. We further found that Ni NPs induce oxidative stress in a dose-dependent manner, as evidenced by glutathione depletion and reactive oxygen species (ROS) generation. Comet assay indicated the dose-dependent induction of DNA damage due to Ni NP exposure. The level of messenger RNA, as well as activity of caspase-3 enzyme, was higher in MCF-7 cells exposed to Ni NPs than in control cells. Moreover, we observed statistically significant correlations of ROS with cell viability (R 2 =0.984), DNA damage (% tail DNA) (R 2 =0.982), and caspase-3 enzyme activity (R 2 =0.991).
Toxicology and industrial health, Jan 5, 2013
Copper oxide nanoparticles (CuO NPs) are of great interest in nanoscience and nanotechnology beca... more Copper oxide nanoparticles (CuO NPs) are of great interest in nanoscience and nanotechnology because of their broad industrial and commercial applications. Therefore, toxicity of CuO NPs needs to be thoroughly understood. The aim of this study was to investigate the cytotoxicity, genotoxicity, and oxidative stress induced by CuO NPs in human lung epithelial (A549) cells. CuO NPs were synthesized by solvothermal method and the size of NPs measured under transmission electron microscopy (TEM) was found to be around 23 nm. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) and lactate dehydrogenase (LDH) assays showed that CuO NPs (5-15 µg/ml) exert cytotoxicity in A549 cells in a dose-dependent manner. Comet assay suggested concentration-dependent induction of DNA damage due to the exposure to CuO NPs. The comet tail moment was 27% at 15 µg/ml of CuO NPs, whereas it was 5% in control (p < 0.05). The flow cytometry data revealed that CuO NPs induced micronuclei (M...
Abstract Iron oxide (Fe 3 O 4) nanoparticles (NPs) are increasingly recognized for their utility ... more Abstract Iron oxide (Fe 3 O 4) nanoparticles (NPs) are increasingly recognized for their utility in biomedical applications. However, little is known about the anticancer activity of Fe 3 O 4 NPs. This study was designed to investigate whether Fe 3 O 4 NPs induced toxicity in a cell-specific manner and determine the possible mechanisms of toxicity caused by Fe 3 O 4 NPs in cancer cells. Fe 3 O 4 NPs used in this study were synthesized by green method using α-d-glucose as a reducing agent.
Abstract Articular cartilage has a unique molecular structure along its thin depth with three def... more Abstract Articular cartilage has a unique molecular structure along its thin depth with three defined histological zones: superficial, transitional, and radial. External mechanical stress will alter collagen fiber orientation within cartilage matrix. Fourteen specimens from two beagle humeral heads were excised from the central load-bearing area: nine specimens were compressed at different levels of strain [5-65%] and were prepared for histology while compressed, and five specimens were served as control.
Copper oxide nanoparticles (CuO NPs) are increasingly used in various applications. Recent studie... more Copper oxide nanoparticles (CuO NPs) are increasingly used in various applications. Recent studies suggest that oxidative stress may be the cause of the cytotoxicity of CuO NPs in mammalian cells.
Abstract The PhET Interactive Simulations Project partnered with the Excellence Research Center o... more Abstract The PhET Interactive Simulations Project partnered with the Excellence Research Center of Science and Mathematics Education at King Saud University with the joint goal of making simulations useable worldwide. One of the main challenges of this partnership is to make PhET simulations and the website easily translatable into any language. The PhET project team overcame this challenge by creating the Translation Utility.
Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 2012
Zinc oxide (ZnO) nanoparticles are finding applications in a wide range of products including cos... more Zinc oxide (ZnO) nanoparticles are finding applications in a wide range of products including cosmetics, food packaging, imaging, etc. This increases the likelihood of human exposure to these nanoparticles through dermal, inhalation and oral routes. Presently, the majority of the studies concerning ZnO nanoparticle toxicity have been conducted using in vitro systems which lack the complex cell-cell, cell-matrix interactions and hormonal effects found in the in vivo scenario. The present in vivo study in mice was aimed at investigating the oral toxicity of ZnO nanoparticles. Our results showed a significant accumulation of nanoparticles in the liver leading to cellular injury after sub-acute oral exposure of ZnO nanoparticles (300 mg/kg) for 14 consecutive days. This was evident by the elevated alanine aminotransferase (ALT) and alkaline phosphatase (ALP) serum levels and pathological lesions in the liver. ZnO nanoparticles were also found to induce oxidative stress indicated by an increase in lipid peroxidation. The DNA damage in the liver and kidney cells of mice was evaluated by the Fpg-modified Comet assay which revealed a significant (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) increase in the Fpg-specific DNA lesions in liver indicating oxidative stress as the cause of DNA damage. The TUNEL assay revealed an induction of apoptosis in the liver of mice exposed to ZnO nanoparticles compared to the control. Our results conclusively demonstrate that sub-acute oral exposure to ZnO nanoparticles in mice leads to an accumulation of nanoparticles in the liver causing oxidative stress mediated DNA damage and apoptosis. These results also suggest the need for a complete risk assessment of any new engineered nanoparticle before its arrival into the consumer market.
Clinical Biochemistry, 2011
Cell & Bioscience, 2015
Background: Zinc ferrite nanoparticles (NPs) have shown potential to be used in biomedical field ... more Background: Zinc ferrite nanoparticles (NPs) have shown potential to be used in biomedical field such as magnetic resonance imaging and hyperthermia. However, there is limited information concerning the biological response of zinc ferrite NPs. This study was designed to evaluate the cytotoxicity of zinc ferrite NPs in three widely used in vitro cell culture models: human lung epithelial (A549), skin epithelial (A431) and liver (HepG2) cells. Zinc ferrite NPs were characterized by electron microscopy and dynamic light scattering. Cell viability, cell membrane damage, reactive oxygen species (ROS), glutathione (GSH), mitochondrial membrane potential (MMP), transcriptional level of apoptotic genes were determined in zinc ferrite NPs exposed cells.
Scientific Reports, 2015
. Pure and Al-doped ZnO nanoparticles were prepared by a simple sol-gel method. Characterization ... more . Pure and Al-doped ZnO nanoparticles were prepared by a simple sol-gel method. Characterization study confirmed the formation of single phase of Al x Zn 1-x O nanocrystals with the size range of 33-55 nm. Al-doping increased the band gap energy of ZnO nanoparticles (from 3.51 eV for pure to 3.87 eV for Al-doped ZnO). Al-doping also enhanced the cytotoxicity and oxidative stress response of ZnO nanoparticles in MCF-7 cells. The IC50 for undoped ZnO nanoparticles was 44 μg/ml while for the Al-doped ZnO counterparts was 31 μg/ml. Up-regulation of apoptotic genes (e.g. p53, bax/bcl2 ratio, caspase-3 & caspase-9) along with loss of mitochondrial membrane potential suggested that Al-doped ZnO nanoparticles induced apoptosis in MCF-7 cells through mitochondrial pathway. Importantly, Aldoping did not change the benign nature of ZnO nanoparticles towards normal cells suggesting that Al-doping improves the selective cytotoxicity of ZnO nanoparticles toward MCF-7 cells without affecting the normal cells. Our results indicated a novel approach through which the inherent selective cytotoxicity of ZnO nanoparticles against cancer cells can be further improved.
Nanomedicine, 2015
Copper oxide nanoparticles (CuO NPs) are being used in several industrial and commercial products... more Copper oxide nanoparticles (CuO NPs) are being used in several industrial and commercial products. Inhalation is one of the most significant routes of metal oxide NP exposure. Hence, the toxicity of CuO NPs in lung tissues is of great concern. In vitro studies have indicated that CuO NPs induce cytotoxicity, oxidative stress and genetic toxicity in cultivated human lung cells. Leaching of Cu ions, reactive oxygen species generation and autophagy appear to be the underlying mechanisms of Cu NP toxicity in lung cells. In vivo studies on the lung toxicity of CuO NPs are largely lacking. Some studies have shown that intratracheal instillation of CuO NPs induced oxidative stress, inflammation and neoplastic lesions in rats. This review critically assessed the current findings of the toxicity of CuO NPs in the lung.
Archives of Toxicology, 2015
Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Ber... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Berlin Heidelberg. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Journal of colloid and interface science, Jan 15, 2015
Nanotechnology based therapeutics can offer an alternative platform in a wide variety of biomedic... more Nanotechnology based therapeutics can offer an alternative platform in a wide variety of biomedical applications. Here we report novel cytotoxicity preventive potential of molybdenum nanoparticles (Mo NPs) in human breast (MCF-7) and fibrosarcoma (HT-1080) cells compromised with oxidant exposure. Physicochemical properties such as size, crystallinity, purity and band gap (an optical characteristic) of Mo NPs were characterized respectively by field emission transmission electron microscopy (FETEM), X-ray diffraction (XRD), energy dispersive spectrum (EDS) and UV-vis absorption spectroscopy. The average size of crystalline Mo NPs was found to be 35nm with a band gap of 1.4eV. Potential cytotoxicity of Mo NPs was evaluated by a battery of cell viability and oxidative stress parameters. Cell viability and oxidative stress data suggested Mo NPs to be reasonably non-cytotoxic. Cytotoxic preventive and GSH restoring potential of Mo NPs was determined against cytotoxicity and oxidative str...
Chemosphere, 2015
Nickel ferrite nanoparticles (NPs) have received much attention for their potential applications ... more Nickel ferrite nanoparticles (NPs) have received much attention for their potential applications in biomedical fields such as magnetic resonance imaging, drug delivery and cancer hyperthermia. However, little is known about the toxicity of nickel ferrite NPs at the cellular and molecular levels. In this study, we investigated the cytotoxic responses of nickel ferrite NPs in two different types of human cells (i.e., liver HepG2 and breast MCF-7). Nickel ferrite NPs induced dose-dependent cytotoxicity in both types of cells, which was demonstrated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazoliumbromide (MTT), neutral red uptake (NRU) and lactate dehydrogenase (LDH) assays. Nickel ferrite NPs were also found to induce oxidative stress, which was evident by the depletion of glutathione and the induction of reactive oxygen species (ROS) and lipid peroxidation. The mitochondrial membrane potential due to nickel ferrite NP exposure was also observed. The mRNA levels for the tumor suppressor gene p53 and the apoptotic genes bax, CASP3 and CASP9 were up-regulated, while the anti-apoptotic gene bcl-2 was down-regulated following nickel ferrite NP exposure. Furthermore, the activities of apoptotic enzymes (caspase-3 and caspase-9) were also higher in both types of cells treated with nickel ferrite NPs. Cytotoxicity induced by nickel ferrite was efficiently prevented by N-acetyl cysteine (ROS scavenger) treatment, which suggested that oxidative stress might be one of the possible mechanisms of nickel ferrite NP toxicity. We also observed that MCF-7 cells were slightly more susceptible to nickel ferrite NP exposure than HepG2 cells. This study warrants further investigation to explore the potential mechanisms of different cytotoxic responses of nickel ferrite NPs in different cell lines.
Journal of Colloid and Interface Science, 2015
Recently, cerium oxide nanoparticles (CeO 2 NPs) has been reported for multi-enzyme mimetic activ... more Recently, cerium oxide nanoparticles (CeO 2 NPs) has been reported for multi-enzyme mimetic activities like that of superoxide dismutase and catalase. Here, we report glutathione (GSH) replenishing response by CeO 2 NPs in human breast (MCF-7) and fibrosarcoma (HT-1080) cells. CeO 2 NPs were found to be mostly cuboidal in shape with average diameter of 25 nm. Effects on cell viability, reactive oxygen species (ROS) generation, and mitochondrial outer membrane potential (MOMP) suggested CeO 2 NPs to be reasonably non-cytotoxic. Data on membrane damage and lipid peroxidation correlated well with the cell viability results suggesting NPs of CeO 2 to be biocompatible. Interestingly, CeO 2 NPs significantly increased intracellular GSH in cells challenged with oxidants. Replenishment of depleted GSH in oxidatively challenged cells was comparable with the GSH restoring potential of known antioxidant N-acetyl cysteine (NAC), a precursor of GSH. Like NAC, CeO 2 NPs significantly replenished depleted GSH in both cell types challenged with hydrogen peroxide (H 2 O 2 ) and zinc oxide (ZnO) NPs. Moreover, CeO 2 NPs treated cells were significantly protected from cytotoxicity caused by H 2 O 2 and ZnO NPs. Our findings, therefore, suggest CeO 2 NPs as a potential antioxidant rather than a toxic material.
Colloids and Surfaces B: Biointerfaces, 2015
The present investigation was aimed to study the cytotoxicity, oxidative stress, and genotoxicity... more The present investigation was aimed to study the cytotoxicity, oxidative stress, and genotoxicity induced by molybdenum nanoparticles (Mo-NPs) in mouse skin fibroblast cells (L929). Cells were exposed to different concentrations (1-100 μg/ml) of Mo-NPs (size 40 nm) for 24 and 48 h. After the exposure, different cytotoxicity assays (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide, MTT; neutral red uptake, NRU; and cellular morphology) and oxidative stress markers (lipid peroxidation, LPO; glutathione, GSH; and catalase) were studied. Further, Mo-NPs-induced intracellular reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP), cell cycle arrest, and DNA damage were also studied. L929 cells treated with Mo-NPs showed a concentration- and time-dependent decrease in cell viability and a loss of the normal cell morphology. The percentage cell viability was recorded as 25%, 42%, and 58% by MTT assay and 24%, 46%, and 56% by NRU assay at 25, 50, and 100 μg/ml of Mo-NPs, respectively after 48 h exposure. Furthermore, the cells showed a significant induction of oxidative stress. This was confirmed by the increase in LPO and ROS generation, as well as the decrease in the GSH and catalase levels. The decrease in MMP also confirms the impaired mitochondrial membrane. The cell cycle analysis and comet assay data revealed that Mo-NPs induced G2/M arrest and DNA damage in a concentration-dependent manner. Our results demonstrated, for the first time, Mo-NPs induced cytotoxicity, oxidative stress and genotoxicity in L929 cells. Thus, data suggest the potential hazardous nature of Mo-NPs.
Clinica Chimica Acta, 2014
OncoTargets and Therapy, 2014
Despite the widespread application of nickel nanoparticles (Ni NPs) in industrial, commercial, an... more Despite the widespread application of nickel nanoparticles (Ni NPs) in industrial, commercial, and biomedical fields, their response to human cells has not been clearly elucidated. In the study reported here, Ni NPs with a 28 nm diameter were used to study their interaction with human breast carcinoma (MCF-7) cells. Dose-dependent decreased cell viability and damaged cell membrane integrity showed the cytotoxic potential of the Ni NPs. We further found that Ni NPs induce oxidative stress in a dose-dependent manner, as evidenced by glutathione depletion and reactive oxygen species (ROS) generation. Comet assay indicated the dose-dependent induction of DNA damage due to Ni NP exposure. The level of messenger RNA, as well as activity of caspase-3 enzyme, was higher in MCF-7 cells exposed to Ni NPs than in control cells. Moreover, we observed statistically significant correlations of ROS with cell viability (R 2 =0.984), DNA damage (% tail DNA) (R 2 =0.982), and caspase-3 enzyme activity (R 2 =0.991).
Toxicology and industrial health, Jan 5, 2013
Copper oxide nanoparticles (CuO NPs) are of great interest in nanoscience and nanotechnology beca... more Copper oxide nanoparticles (CuO NPs) are of great interest in nanoscience and nanotechnology because of their broad industrial and commercial applications. Therefore, toxicity of CuO NPs needs to be thoroughly understood. The aim of this study was to investigate the cytotoxicity, genotoxicity, and oxidative stress induced by CuO NPs in human lung epithelial (A549) cells. CuO NPs were synthesized by solvothermal method and the size of NPs measured under transmission electron microscopy (TEM) was found to be around 23 nm. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) and lactate dehydrogenase (LDH) assays showed that CuO NPs (5-15 µg/ml) exert cytotoxicity in A549 cells in a dose-dependent manner. Comet assay suggested concentration-dependent induction of DNA damage due to the exposure to CuO NPs. The comet tail moment was 27% at 15 µg/ml of CuO NPs, whereas it was 5% in control (p < 0.05). The flow cytometry data revealed that CuO NPs induced micronuclei (M...
Abstract Iron oxide (Fe 3 O 4) nanoparticles (NPs) are increasingly recognized for their utility ... more Abstract Iron oxide (Fe 3 O 4) nanoparticles (NPs) are increasingly recognized for their utility in biomedical applications. However, little is known about the anticancer activity of Fe 3 O 4 NPs. This study was designed to investigate whether Fe 3 O 4 NPs induced toxicity in a cell-specific manner and determine the possible mechanisms of toxicity caused by Fe 3 O 4 NPs in cancer cells. Fe 3 O 4 NPs used in this study were synthesized by green method using α-d-glucose as a reducing agent.
Abstract Articular cartilage has a unique molecular structure along its thin depth with three def... more Abstract Articular cartilage has a unique molecular structure along its thin depth with three defined histological zones: superficial, transitional, and radial. External mechanical stress will alter collagen fiber orientation within cartilage matrix. Fourteen specimens from two beagle humeral heads were excised from the central load-bearing area: nine specimens were compressed at different levels of strain [5-65%] and were prepared for histology while compressed, and five specimens were served as control.
Copper oxide nanoparticles (CuO NPs) are increasingly used in various applications. Recent studie... more Copper oxide nanoparticles (CuO NPs) are increasingly used in various applications. Recent studies suggest that oxidative stress may be the cause of the cytotoxicity of CuO NPs in mammalian cells.
Abstract The PhET Interactive Simulations Project partnered with the Excellence Research Center o... more Abstract The PhET Interactive Simulations Project partnered with the Excellence Research Center of Science and Mathematics Education at King Saud University with the joint goal of making simulations useable worldwide. One of the main challenges of this partnership is to make PhET simulations and the website easily translatable into any language. The PhET project team overcame this challenge by creating the Translation Utility.