Browsing by Author "Gehan Safwat"

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Calcium hydroxide nanoparticles induce cell death, genomic instability, oxidative stress and apoptotic gene dysregulation on human HepG2 cells
(Nature Publishing Group, 2025-01-23) Hanan R. H. Mohamed; Esraa H. Ibrahim; Shahd E. E. Shaheen; Nesma O. E. Hussein; Ayman Diab; Gehan Safwat
Calcium hydroxide nanoparticles (Ca(OH)2NPs) possess potent antimicrobial activities and unique physical and chemical properties, making them valuable across various fields. However, limited information exists regarding their effects on genomic DNA integrity and their potential to induce apoptosis in normal and cancerous human cell lines. This study thus aimed to evaluate the impact of Ca(OH)2NPs on cell viability, genomic DNA integrity, and oxidative stress induction in human normal skin fibroblasts (HSF) and cancerous hepatic (HepG2) cells. Cell viability and genomic DNA stability were assessed using the Sulforhodamine B (SRB) assay and alkaline comet assay, respectively. Reactive oxygen species (ROS) levels were measured using 2,7-dichlorofluorescein diacetate, while the expression level of apoptosis-related genes (p53, Bax, and Bcl-2) were quantified using real-time PCR (qRT-PCR). The SRB cytotoxicity assay revealed that a 48-hour exposure to Ca(OH)2NPs caused concentration-dependent cell death and proliferation inhibition in both HSF and HepG2 cells, with IC50 values of 271.93 µg/mL for HSF and 291.8 µg/mL for HepG2 cells. Treatment with the IC50 concentration of Ca(OH)2NPs selectively induced significant DNA damage, excessive ROS generation, and marked dysregulation of apoptotic (p53 and Bax) and anti-apoptotic (Bcl-2) gene expression in HepG2 cells, triggering apoptosis. In contrast, exposure of HSF cells to the IC50 concentration of Ca(OH)2NPs caused no significant changes in genomic DNA integrity, ROS generation, or apoptotic gene expression. These findings indicate that Ca(OH)2NPs exhibit concentrationdependent cytotoxicity in both normal HSF and cancerous HepG2 cells. However, exposure to the IC50 concentration was non-genotoxic to normal HSF cells while selectively inducing genotoxicity and apoptosis in HepG2 cancer cells through DNA breaks and ROS-mediated mechanisms. Further studies are required to explore the biological and toxicological properties and therapeutic potential of Ca(OH)2NPs in hepatic cancer treatment.
Calcium titanate nanoparticlesinduced cytotoxicity, genotoxicity and oxidative stress in human nonsmall lung cancer cells
(Nature Publishing Group, 2025-02-21) Hanan R. H. Mohamed; Shahd E. E. Shaheen; Esraa H. Ibrahim; Nesma O. E. Hussein; Gehan Safwat
Calcium titanate nanoparticles (CaTiO3NPs) have garnered significant attention due to their unique properties and excellent biocompatibility, which have led to their increased use in various fields and consumer products. This rise in application necessitates a better understanding of their biological and toxicological effects. However, there is limited data on the cytotoxicity and genotoxicity of CaTiO3NPs in human normal skin fibroblasts (HSF) and non-small lung cancer (A-549) cells. Consequently, this study aimed to explore the effect of 48-hour exposure to CaTiO3NPs on cell viability, genomic DNA integrity, and oxidative stress induction in human cancer A-549 cells, compared to normal HSF cells. The cytotoxicity and genotoxicity of CaTiO3NPs were assessed using the Sulforhodamine B (SRB) cytotoxicity and Alkaline Comet assays, respectively. To estimate possible oxidative stress induction and variation in apoptotic gene expression, reactive oxygen species (ROS) analysis and quantitative real-time polymerase chain reaction (qRT-PCR) were also performed. Our findings demonstrated that exposure to CaTiO3NPs for 48 h resulted in low toxicity toward both normal HSF and cancer A-549 cells, with cell death observed only at high concentrations (100 and 1000 µg/ml). The IC50 value of CaTiO3NPs in both HSF and A-549 cells was greater than 1000 µg/ml; specifically, the IC50 value in A-549 cells at 48 h was 1670.65 µg /ml. However, treatment with CaTiO3NPs for 48 h at the IC50 concentration of 1670.65 µg /ml resulted in significant genomic DNA damage and excessive ROS generation, along with a notable disturbance in the expression level of apoptotic (p53 and Bax) and anti-apoptotic Bcl2 genes in A-549 cells. In contrast, no significant changes were observed in HSF cells treated for 48 h with the same concentration (1670.65 µg /ml) of CaTiO3NPs. Collectively, these findings indicated that despite short-term exposure to CaTiO3NPs causing low cytotoxicity in both normal HSF and A-549 cells. CaTiO3NPs were selectively genotoxic toward A-549 cells. This genotoxicity was mediated through excessive ROS generation, which disrupted genomic DNA integrity and altered the expression of apoptotic genes, triggering apoptosis in A-549 cells. Further in vitro and in vivo studies are needed to fully understand the toxicological and biological properties of CaTiO3NPs.
Cobalt oxide nanoparticles induce cytotoxicity and excessive ROS mediated mitochondrial dysfunction and p53-independent apoptosis in melanoma cells
(Nature Publishing Group, 2025-01-06) Hanan R. H. Mohamed; Basma A. Mohamed; George M. Hakeem; Shahd H. Elnawasani; Maria Nagy; Rawan Essam; Ayman Diab; Gehan Safwat
Nanotherapy has emerged as a promising strategy for the targeted and efficient treatment of melanoma, the most aggressive and lethal form of skin cancer, with minimized systemic toxicity. However, the therapeutic efficacy of cobalt oxide nanoparticles (Co3O4NPs) in melanoma treatment remains unexplored. This study aimed to assess the therapeutic potential of Co3O4NPs in melanoma treatment by evaluating their impact on cell viability, genomic DNA and mitochondrial integrity, reactive oxygen species (ROS) generation and apoptosis induction in melanoma A-375 cells. Our findings demonstrated a concentration-dependent reduction in cell viability upon treatment with five Co3O4NP concentrations (0.2, 2, 20, 200, and 2000 µg/ml), with an IC50 value of 303.80 µg/ml. Treatment with this IC50 concentration significantly increased ROS generation, induced dramatic DNA damage, and disrupted mitochondrial membrane potential integrity. Flow cytometric analysis revealed apoptosis and necrosis induction following Co3O4NP exposure at the IC50 concentration value. Results of qRT-PCR analysis demonstrated remarkable dysregulation of apoptotic and mitochondrial genes, including a significant downregulation of apoptotic p53 and mitochondrial ND3 genes and marked upregulation of the anti-apoptotic gene Bcl2. These findings highlight the novel potential of Co3O4NPs as potent inducers of melanoma A-375 cell death in a concentration-dependent manner through excessive ROS production, genomic instability, mitochondrial dysfunction and dysregulation of apoptotic and mitochondrial gene expression, ultimately promoting apoptosis in A-375 cells. This study thus underscores the potential of Co3O4NPs as a promising nanotherapeutic candidate for melanoma treatment, warranting further exploration to elucidate their full biological and clinical applicability.
Evaluation of the effect of grape seed extract loaded-chitosan nanoparticles on cryptosporidiosis in dexamethasone immunosuppressed male mice
(Elsevier B.V, 2025-02-25) Karim Tarek; Gehan Safwat; Alyaa Farid
Cryptosporidiosis is a worldwide health problem that results in an economic loss. The disease is caused by the protozoan Cryptosporidium spp. Individuals with suppressed immunity, like those with organ transplantation, cancer and human immunodeficiency virus syndrome, suffer from the infection that may lead to the death. Nitazoxanide (NTZ) is the approved FDA treatment for cryptosporidiosis in immunocompetent individuals. There is an urgent need to find a new natural treatment that can replace NTZ in immunosuppressed hosts. The study aimed to use grape seed extract loaded chitosan nanoparticles (GSEx-CHNPs) in treatment of cryptosporidiosis in immunosuppressed male mice. GSEx was prepared by the alcoholic extraction method followed by the identification of its bioactive components. GSEx-CHNPs were synthesized by ionic gelation method and physically characterized then their activities were examined in vitro. The experimental groups, included immunocompetent and immunosuppressed groups, was treated with NPs for 14 days post infection (PI). The results showed the presence of many phenolic compounds in the GSEx. GSEx-CHNPs significantly improved the loss in animals body weight, cleared the infection and amolerated the serum cytokines levels. GSEx-CHNPs showed anti-cryptosporidial activity especially in immunosuppressed mice model. Where, it amolerated the disturbance in the cytokine profile leading to an anti-inflammatory response.
Preparation of bee venom-loaded chitosan nanoparticles for treatment of streptozotocin-induced diabetes in male Sprague Dawley rats
(Beni-Suef University Journal of Basic and Applied Sciences, 2024) Alyaa Farid; Adham Mohamed; Ayten Ahmed; Farah Mehanny; Gehan Safwat
Background Diabetes mellitus (DM) can be defned as an increase in the blood sugar level and a disturbance in protein, fat and carbohydrate metabolism. Bee venom (BV) is useful for treating and preventing diabetic rats’ histological and biochemical problems. Although the medical advantages of BV have been identifed, its safety has remained a substantial barrier for its application. Consequently, the goal of our work was to prepare bee venom-loaded chitosan (BV-CS) nanoparticles (NPs), which would then be physically characterized. This was followed by examining the efect of the synthetized BV-CS NPs on oxidation, infammation and coagulation in vitro. In diabetic rats’ model [induced by streptozotocin (STZ)], the produced BV-CS NPs were tested as an anti-diabetic medication. Results In vivo testing on pancreatic tissue homogenates showed that BV-CS NPs have antioxidant and antiinfammatory properties. The results showed that BV-CS NPs can be used as a safe and efcient therapy for diabetes. Up to a concentration of 250 µg/ml, the generated NPs demonstrated potential antioxidant, membrane stabilizing, and non-cytotoxic capabilities. Our fndings indicated that the administration of BV-CS NPs signifcantly controlled blood glucose levels and metabolic abnormalities that accompanied diabetes induction. Conclusions BV-CS NPs were successful in treating STZ-induced diabetes in rats, stimulated insulin secretion and were safe to be used in vivo. Key points 1. BV-CS NPs demonstrated potential in vitro antioxidant and non-cytotoxic capabilities. 2. BV-CS NPs increased insulin secretion and decreased blood sugar level. 3. BV-CS NPs reduced oxidative stress and infammation in vivo.
Retinoic acid inhibition of cell proliferation via activation of CDKN1B signaling in the forebrain and spinal cord during mouse embryonic development
(Springer Science and Business Media Deutschland GmbH, 2024-12-03) Ahmed Said; Amira S. AbdElkhalek; Mariam Sherief; Lydia Amir; Maysem Samy; Mariam S. Nabil; Gehan Safwat; Ayman A. Diab; Karima Nasraldin
Background: The active metabolite of vitamin A (retinol) is retinoic acid (RA). RA is essential for developing several organs as a signaling molecule that is tightly regulated during embryogenesis. We explored the teratogenic effects of RA on forebrain and spinal cord development modified by cyclin-dependent kinase inhibitor 1B (CDKN1B), as the mechanism underlying RA's teratogenic impacts requires further investigation. The study involved four groups of pregnant mice: the negative control group, the positive control group treated with dimethyl sulfoxide (DMSO) diluted in sunflower oil, the RA-treated group receiving a low dosage (5 mg/kg), and the RA-treated group receiving a high dosage (10 mg/kg). The treatment groups received daily intraperitoneal RA dissolved in DMSO and diluted with sunflower oil on gestational days 10.5, 11.5, and 12.5. On day 13.5 of pregnancy, the pregnant mice were euthanized by cervical dislocation, and immunohistochemical analyses of brain and spinal cord tissues were performed. Results: Morphologically, we observed a decrease in the number of implantation sites and the presence of hematomas in several uterus areas in the high-dose RA (10 mg/kg) group. Additionally, RA was shown to cause adverse changes in uterine weight and length. RA treatment indicated elevated levels of CDKN1B expression in spinal cord development, the diencephalon, and the telencephalon. Conclusion: Our findings demonstrated that by activating CDKN1B as an RA target gene for cell cycle arrest, an excess of RA during brain development in mouse embryos can induce cell undifferentiation during development.