Identification of Phytochemicals from Arabian Peninsula Medicinal Plants as Strong Binders to SARS-CoV-2 Proteases (3CLPro and PLPro) by Molecular Docking and Dynamic Simulation Studies.

We provide promising computational (in silico) data on phytochemicals (compounds 1-10) from Arabian Peninsula medicinal plants as strong binders, targeting 3-chymotrypsin-like protease (3CLPro) and papain-like proteases (PLPro) of SARS-CoV-2. Compounds 1-10 followed the Lipinski rules of five (RO5) and ADMET analysis, exhibiting drug-like characters. Non-covalent (reversible) docking of compounds 1-10 demonstrated their binding with the catalytic dyad (CYS145 and HIS41) of 3CLPro and catalytic triad (CYS111, HIS272, and ASP286) of PLPro. Moreover, the implementation of the covalent (irreversible) docking protocol revealed that only compounds 7, 8, and 9 possess covalent warheads, which allowed the formation of the covalent bond with the catalytic dyad (CYS145) in 3CLPro and the catalytic triad (CYS111) in PLPro. Root-mean-square deviation (RMSD), root-mean-square fluctuation (RMSF), and radius of gyration (Rg) analysis from molecular dynamic (MD) simulations revealed that complexation between ligands (compounds 7, 8, and 9) and 3CLPro and PLPro was stable, and there was less deviation of ligands. Overall, the in silico data on the inherent properties of the above phytochemicals unravel the fact that they can act as reversible inhibitors for 3CLPro and PLPro. Moreover, compounds 7, 8, and 9 also showed their novel properties to inhibit dual targets by irreversible inhibition, indicating their effectiveness for possibly developing future drugs against SARS-CoV-2. Nonetheless, to confirm the theoretical findings here, the effectiveness of the above compounds as inhibitors of 3CLPro and PLPro warrants future investigations using suitable in vitro and in vivo tests.

Covalent Inhibitors from Saudi Medicinal Plants Target RNA-Dependent RNA Polymerase (RdRp) of SARS-CoV-2.

COVID-19, a disease caused by SARS-CoV-2, has caused a huge loss of human life, and the number of deaths is still continuing. Despite the lack of repurposed drugs and vaccines, the search for potential small molecules to inhibit SARS-CoV-2 is in demand. Hence, we relied on the drug-like characters of ten phytochemicals (compounds 1-10) that were previously isolated and purified by our research team from Saudi medicinal plants. We computationally evaluated the inhibition of RNA-dependent RNA polymerase (RdRp) by compounds 1-10. Non-covalent (reversible) docking of compounds 1-10 with RdRp led to the formation of a hydrogen bond with template primer nucleotides (A and U) and key amino acid residues (ASP623, LYS545, ARG555, ASN691, SER682, and ARG553) in its active pocket. Covalent (irreversible) docking revealed that compounds 7, 8, and 9 exhibited their irreversible nature of binding with CYS813, a crucial amino acid in the palm domain of RdRP. Molecular dynamic (MD) simulation analysis by RMSD, RMSF, and Rg parameters affirmed that RdRP complexes with compounds 7, 8, and 9 were stable and showed less deviation. Our data provide novel information on compounds 7, 8, and 9 that demonstrated their non-nucleoside and irreversible interaction capabilities to inhibit RdRp and shed new scaffolds as antivirals against SARS-CoV-2.

Marine Natural Compound (Neviotin A) Displays Anticancer Efficacy by Triggering Transcriptomic Alterations and Cell Death in MCF-7 Cells.

We investigated the anticancer mechanism of a chloroform extract of marine sponge (Haliclona fascigera) (sample C) in human breast adenocarcinoma (MCF-7) cells. Viability analysis using MTT and neutral red uptake (NRU) assays showed that sample C exposure decreased the proliferation of cells. Flow cytometric data exhibited reactive oxygen species (ROS), nitric oxide (NO), dysfunction of mitochondrial potential, and apoptosis in sample C-treated MCF-7 cells. A qPCR array of sample C-treated MCF-7 cells showed crosstalk between different pathways of apoptosis, especially BIRC5, BCL2L2, and TNFRSF1A genes. Immunofluorescence analysis affirmed the localization of p53, bax, bcl2, MAPKPK2, PARP-1, and caspase-3 proteins in exposed cells. Bioassay-guided fractionation of sample C revealed Neviotin A as the most active compound triggering maximum cell death in MCF-7, indicating its pharmacological potency for the development of a drug for the treatment of human breast cancer.

Iron oxide nanoparticles induced cytotoxicity, oxidative stress, cell cycle arrest, and DNA damage in human umbilical vein endothelial cells.

BACKGROUND: Nanotechnology and material science have developed enormously fast in recent years. Due to their excellent magnetic properties, iron oxide nanoparticles (IONPs) have been broadly applied in the field of bioengineering and biomedical. Thus, it is important to evaluate the safety issues and health effects of these nanomaterials. The present investigation was aimed to evaluate the adverse effects of IONPs on human umbilical vein endothelial cells (HUVECs). METHODS: The cytotoxic potential of IONPs was assessed by MTT and neutral red uptake (NRU) assays. The impact of IONPs on oxidative stress markers (glutathione (GSH) and lipid peroxidation (LPO)), reactive oxygen species (ROS) production, and mitochondrial membrane potential (MMP) was also examined. Furthermore, the toxic effect of IONPs was quantified by assessing DNA damage, cell cycle arrest, and apoptosis by quantitative real time PCR. RESULTS: We found that IONPs induce a dose-dependent cytotoxicity on HUVECs with IC50 value of 79.13 µg/mL. The results also displayed that IONPs induce oxidative stress, ROS production, and mitochondrial membrane dysfunction. The comet assay results exhibited IONPs induces DNA damage in HUVECs. We found significant cell cycle arrest at SubG1 phase in treated cells and consequent cell death was evidenced by microscopic analysis. Moreover, IONPs display substantial up-regulation of pro-apoptotic genes and down-regulation of anti-apoptotic gene evidenced by real time qPCR. CONCLUSION: Overall, our results clearly demonstrated that IONPs have the potential to induce cytotoxicity, DNA damage, cell cycle arrest, and apoptosis in HUVECs mediated through oxidative stress and ROS production. Thus, IONPs are cytotoxic and it should be handled with proper care.

Effectiveness of Nonfunctionalized Graphene Oxide Nanolayers as Nanomedicine against Colon, Cervical, and Breast Cancer Cells.

Recent studies in nanomedicine have intensively explored the prospective applications of surface-tailored graphene oxide (GO) as anticancer entity. However, the efficacy of nonfunctionalized graphene oxide nanolayers (GRO-NLs) as an anticancer agent is less explored. In this study, we report the synthesis of GRO-NLs and their in vitro anticancer potential in breast (MCF-7), colon (HT-29), and cervical (HeLa) cancer cells. GRO-NLs-treated HT-29, HeLa, and MCF-7 cells showed cytotoxicity in the MTT and NRU assays via defects in mitochondrial functions and lysosomal activity. HT-29, HeLa, and MCF-7 cells treated with GRO-NLs exhibited substantial elevations in ROS, disturbances of the mitochondrial membrane potential, an influx of Ca2+, and apoptosis. The qPCR quantification showed the upregulation of caspase 3, caspase 9, bax, and SOD1 genes in GRO-NLs-treated cells. Western blotting showed the depletion of P21, P53, and CDC25C proteins in the above cancer cell lines after GRO-NLs treatment, indicating its function as a mutagen to induce mutation in the P53 gene, thereby affecting P53 protein and downstream effectors P21 and CDC25C. In addition, there may be a mechanism other than P53 mutation that controls P53 dysfunction. We conclude that nonfunctionalized GRO-NLs exhibit prospective biomedical application as a putative anticancer entity against colon, cervical, and breast cancers.

Drug repositioning to discover novel ornithine decarboxylase inhibitors against visceral leishmaniasis.

Visceral leishmaniasis (VL) is caused by Leishmania donovani (Ld), and most cases occur in Brazil, East Africa, and India. The treatment for VL is limited and has many adverse effects. The development of safer and more efficacious drugs is urgently needed. Drug repurposing is one of the best processes to repurpose existing drugs. Ornithine decarboxylase (ODC) is an important target against L. donovani in the polyamine biosynthesis pathway. In this study, we have modeled the 3D structure of ODC and performed high-throughput virtual screening of 8630 ZINC database ligands against Leishmania donovani ornithine decarboxylase (Ld ODC), selecting 45 ligands based on their high binding score. It is further validated through molecular docking simulation and the selection of the top two lead molecules (ceftaroline fosamil and rimegepant) for Molecular Dynamics (MD) simulation, Density functional theory (DFT), and molecular mechanics generalized born surface area (MMGBSA) analysis. The results showed that the binding affinities of ceftaroline fosamil, and rimegepant are, respectively, -10.719 and 10.159 kcal/mol. The docking complexes of the two lead compounds, ceftaroline fosamil, and rimegepant, with the target ODC, were found stable during molecular dynamics simulations. Furthermore, the analysis of MMGBSA revealed that these compounds had a high binding free energy. The DFT analysis showed that the top lead molecules were more reactive than the standard drug (pentamidine). In-silico findings demonstrated that ceftaroline fosamil, and rimegepant might be recognized as potent antagonists against ODC for the treatment of VL.

L-cysteine embedded core-shell ZnO microspheres composed of nanoclusters enhances anticancer activity against liver and breast cancer cells.

Nano-based products have become an apparent and effective option to treat liver cancer, which is a deadly disease, and minimize or eradicate these problems. The Core-shell ZnO microspheres composed of nanoclusters (ZnOMS-NCs) have shown that it is very worthwhile to administer the proliferation rate in HepG2 and MCF-7 cancer cells even at a very low concentration (5 µg/mL). ZnOMS-NCs were prepared through hydrothermal solution process and well characterized. The MTT assay revealed that the cytotoxic effects were dose-dependent (2.5 µg/mL-100 µg/mL) on ZnOMS-NCs. The diminished activity in cell viability induces the cytotoxicity response to the ZnOMS-NCs treatment of human cultured cells. The qPCR data showed that the cells (HepG2 and MCF-7) were exposed to ZnOMS-NCs and exhibited up-and downregulated mRNA expression of apoptotic and anti-apoptotic genes, respectively. In conclusion, flow cytometric data exhibited significant apoptosis induction in both cancer cell lines at low concentrations. The possible mechanism also describes the role of ZnOMS-NCs against cancer cells and their responses.

Neodymium oxide nanostructures and their cytotoxic evaluation in human cancer cells.

Neodymium oxide exhibits a unique property, which facilitates and largely utilized as an industrial applications. A number of cytotoxic study is available but very limited information is available to understand their biological activity with neodymium oxide at a very low conc- entration of the material. The present work was designed to understand the cytotoxicity against liver (HepG-2) and lung (A-549) cancer cells. Initially, Neodymium oxides (Nd2O3) were prepared and characterized with various instruments. The crystallinity and morphology of Nd2O3 powder were examined with instruments such as X-Ray Diffraction (XRD), scanning electron microscope (SEM), Transmission electron microscopy (TEM), Energy Dispersive X-Ray Analysis (EDX) respectively, revealed the size of curved nanostructure are ~140 ± 2 in diameter whereas length goes upto ~700 nm with elemental composition. The cytotoxicity study was conducted with MTT, NRU assay with genotoxicity study via ROS, cell cycle and qPCR analysis. The cells cytotoxic assessment were analysed via MTT(3-(4,5-Dimethylthiazol-2-yl)- 2,5-Diphenyl tetra zolium Bromide) and Neutral Red Uptake (NRU) assay with neodymium oxide (Nd2O3), which indicates the reduction in cell viability. Additionally, cell-cycle analysis showed an increase in the apoptotic peak after a 24-h. Quantitative real-time PCR (RT-PCR) data revealed that apoptotic genes such as p53, bax, and caspase-3 were up regulated, whereas bcl-2, an anti-apoptotic gene, was down regulated; therefore, apoptosis was mediated through ROS and genotoxicity pathways. The experiments of cytotoxicity was tested and concludes that the Nd2O3 express a moderate and dose dependent effect on cancer cells. The ROS, cell cycle analysis and qPCR showed that Nd2O3 exhibit the capability to cells death via ROS generation and genotoxicity study pathways.

Cyto-Genotoxic and Transcriptomic Alterations in Human Liver Cells by Tris (2-Ethylhexyl) Phosphate (TEHP): A Putative Hepatocarcinogen.

Tris (2-ethylhexyl) phosphate (TEHP) is an organophosphate flame retardant (OPFRs) which is extensively used as a plasticizer and has been detected in human body fluids. Contemporarily, toxicological studies on TEHP in human cells are very limited and there are few studies on its genotoxicity and cell death mechanism in human liver cells (HepG2). Herein, we find that HepG2 cells exposed to TEHP (100, 200, 400 µM) for 72 h reduced cell survival to 19.68%, 49.83%, 58.91% and 29.08%, 47.7% and 57.90%, measured by MTT and NRU assays. TEHP did not induce cytotoxicity at lower concentrations (5, 10, 25, 50 µM) after 24 h and 48 h of exposure. Flow cytometric analysis of TEHP-treated cells elevated intracellular reactive oxygen species (ROS), nitric oxide (NO), Ca++ influx and esterase levels, leading to mitochondrial dysfunction (ΔΨm). DNA damage analysis by comet assay showed 4.67, 9.35, 13.78-fold greater OTM values in TEHP (100, 200, 400 µM)-treated cells. Cell cycle analysis exhibited 23.1%, 29.6%, and 50.8% of cells in SubG1 apoptotic phase after TEHP (100, 200 and 400 µM) treatment. Immunofluorescence data affirmed the activation of P53, caspase 3 and 9 proteins in TEHP-treated cells. In qPCR array of 84 genes, HepG2 cells treated with TEHP (100 µM, 72 h) upregulated 10 genes and downregulated 4 genes belonging to a human cancer pathway. Our novel data categorically indicate that TEHP is an oxidative stressor and carcinogenic entity, which exaggerates mitochondrial functions to induce cyto- and genotoxicity and cell death, implying its hepatotoxic features.

Clinical response of carboplatin-based chemotherapy and its association to genetic polymorphism in lung cancer patients from North India - A clinical pharmacogenomics study.

Purpose: Lung cancer mostly diagnosed at advanced inoperable stages; thereby, the chemo-, radiation-, targeted or immune-therapy alone or in combination remains the treatment of choice. In chemotherapy, platinum-based compounds such as cisplatin and carboplatin and third-generation drugs such as docetaxel, paclitaxel, gemcitabine, and vinorelbine are widely used. The beneficial therapeutic outcome of the chemotherapy alone or in combination with radiation (chemoradiation) and/or development of drug resistance depends on the inter-individual genetic differences. Hence, this study was carried out to find gene biomarker that could be useful in the diagnosis of the disease and to predict the outcome of chemo/chemoradiation therapy in ethnic North Indian population. Materials and Methods: In this clinical study, lung cancer (n = 52) patients from North Indian population were recruited. All the patients were treated with carboplatin target area under curve-5 in combination with third-generation drugs (gemcitabine 1.2 mg/m2; paclitaxel 175 mg/m2; and etopside 100 mg/m2) and radiation therapy. The genomic DNA was isolated from the blood sample and performed polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. Results: We found hazard ratio to be significantly higher for XPDLys751Gln (hazard ratio [HR] =2.11, 95% confidence interval [CI]: 0.98-4.53, P = 0.056) and IL1 ß511C/T (HR = 9.9, 95% CI: 2.55-38.40, P = 0.001). GSTT1 null (HR = 0.39, 95%CI: 0.18-0.84, P = 0.017) genotype has better response to chemotherapy. Generalized multidimensional reduction model suggested that IL1RN (cross-validation consistency [CVC] =10/10, P = 0.054) and XRCC1399Gln, GSTM1 (CVC = 10/10, P = 0.001) as best predicted model in lung cancer patients to the treatment response. Conclusion: Genetic polymorphisms and single nucleotide polymorphisms in DNA repair gene (XRCC1, XPD) and drug-metabolizing gene (GSTM1 and GSTT1) could serve as genetic biomarkers in lung cancer patients treated with the above indicated chemotherapy. Based on genotype and chemotherapy treatments, the toxicity effects can be minimized, this will help in the development of personalized medicine in future with better efficacy.

Tris(2-butoxyethyl) phosphate (TBEP): A flame retardant in solid waste display hepatotoxic and carcinogenic risks for humans.

Recent reports have confirmed that tris(2-butoxyethyl) phosphate (TBEP), an organophosphorous flame retardants (OPFRs), profoundly detected in the dust from solid waste (SW), e-waste dumping sites, landfills, and wastewater treatment facilities. Herein, we evaluated the hepatotoxic and carcinogenic potential of TBEP in human liver cells (HepG2). HepG2 cells exhibited cytotoxicity after 3 days of exposure, especially at greater concentrations (100-400 µM). TBEP induced severe DNA damage and cell cycle disturbances that trigger apoptosis in HepG2. TBEP treated cells showed an elevated level of esterase, nitric oxide (NO), reactive oxygen species (ROS), and influx of Ca2+ in exposed cells. Thereby, causing oxidative stress and proliferation inhibition. TBEP exposed HepG2 cells exhibited dysfunction in mitochondrial membrane potential (ΔΨm). Immunofluorescence analysis demonstrated cytoplasmic and nucleolar localization of DNA damage (P53) and apoptotic (caspase 3 and 9) proteins in HepG2 grown in the presence of TBEP for 3 days. Within the cohort of 84 genes of cancer pathway, 10 genes were upregulated and 3 genes were downregulated. The transcriptomic and toxicological data categorically emphasize that TBEP is hepatotoxic, and act as a putative carcinogenic agent. Thereby, direct or indirect ingestion of TBEP containing dusts by workers involved in handling and disposal of SW, as well as residents living nearby the disposal areas are prone to its adverse health risks.

Copper Oxide Nanoparticles Exhibit Cell Death Through Oxidative Stress Responses in Human Airway Epithelial Cells: a Mechanistic Study.

Copper oxide nanoparticles (CuONPs) are purposefully used to inhibit the growth of bacteria, algae, and fungi. Several studies on the beneficial and harmful effects of CuONPs have been conducted in vivo and in vitro, but there are a few studies that explain the toxicity of CuONPs in human airway epithelial cells (HEp-2). As a result, the purpose of this study is to look into the dose-dependent toxicity of CuONPs in HEp-2 cells. After 24 h of exposure to 1-40 µg/ml CuONPs, the MTT and neutral red assays were used to test for cytotoxicity. To determine the mechanism(s) of cytotoxicity in HEp-2 cells, additional oxidative stress assays (LPO and GSH), the amount of ROS produced, the loss of MMP, caspase enzyme activities, and apoptosis-related genes were performed using qRT-PCR. CuONPs exhibited dose-dependent cytotoxicity in HEp-2 cells, with an IC50 value of ~ 10 µg/ml. The morphology of HEp-2 cells was also altered in a dose-dependent manner. The involvement of oxidative stress in CuONP-induced cytotoxicity was demonstrated by increased LPO levels and ROS generation, as well as decreased levels of GSH and MMP. Furthermore, activated caspase enzymes and altered apoptotic genes support CuONPs' ability to induce apoptosis in HEp-2 cells. Overall, this study demonstrated that CuONPs can cause apoptosis in HEp-2 cells via oxidative stress; therefore, CuONPs may pose a risk to human health and should be handled and used with caution.

Organophosphorus Flame Retardant TDCPP Displays Genotoxic and Carcinogenic Risks in Human Liver Cells.

Tris(1,3-Dichloro-2-propyl)phosphate (TDCPP) is an organophosphorus flame retardant (OPFR) widely used in a variety of consumer products (plastics, furniture, paints, foams, and electronics). Scientific evidence has affirmed the toxicological effects of TDCPP in in vitro and in vivo test models; however, its genotoxicity and carcinogenic effects in human cells are still obscure. Herein, we present genotoxic and carcinogenic properties of TDCPP in human liver cells (HepG2). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and neutral red uptake (NRU) assays demonstrated survival reduction in HepG2 cells after 3 days of exposure at higher concentrations (100-400 µM) of TDCPP. Comet assay and flow cytometric cell cycle experiments showed DNA damage and apoptosis in HepG2 cells after 3 days of TDCPP exposure. TDCPP treatment incremented the intracellular reactive oxygen species (ROS), nitric oxide (NO), Ca2+ influx, and esterase level in exposed cells. HepG2 mitochondrial membrane potential (ΔΨm) significantly declined and cytoplasmic localization of P53, caspase 3, and caspase 9 increased after TDCPP exposure. qPCR array quantification of the human cancer pathway revealed the upregulation of 11 genes and downregulation of two genes in TDCPP-exposed HepG2 cells. Overall, this is the first study to explicitly validate the fact that TDCPP bears the genotoxic, hepatotoxic, and carcinogenic potential, which may jeopardize human health.

Strontium-Doped Nickel Oxide Nanoparticles: Synthesis, Characterization, and Cytotoxicity Study in Human Lung Cancer A549 Cells.

In this manuscript, the grown and annealed strontium-doped nickel oxide nanoparticles (SrNiONPs) were synthesized using a precipitation method with nickel nitrate and strontium nitrate as precursor agents with trisodium citrate. Various characterization techniques, including X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV-visible, and zeta sizer, were used to thoroughly examine the samples. The XRD pattern (21 nm) was used to calculate the size, phases, and crystallinity of the material (SrNiONPs). In addition to characterization, the material was tested for cytotoxicity in lung cancer cells (A549). The viability test in A549 cells was performed using [3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide] (MTT) and Neutral Red Uptake (NRU) assay with SrNiONPs concentration ranging from 1 to 100 µg/mL. According to the MTT and NRU data, the toxicity studies are dose-dependent. SrNiONPs also increased reactive oxygen species (ROS) and were involved in apoptosis (A549 cells). Furthermore, quantitative PCR (qPCR) data revealed that the mRNA levels of apoptotic genes marker like p53, bax, and caspase-3 were upregulated, whereas bcl-2, an anti-apoptotic gene, was downregulated. As a result, apoptosis was mediated by the p53, bax, caspase3, and bcl-2 pathways, implying a potential mechanism by which SrNiONPs mediate their toxicity.

Carbofuran cytotoxicity, DNA damage, oxidative stress, and cell death in human umbilical vein endothelial cells: Evidence of vascular toxicity.

Carbofuran is a broad-spectrum carbamate insecticide, which principally inhibits the acetylcholinesterase (AChE) enzyme in the nervous system. Nonetheless, their selective action is not restricted to a single species and expanded to humans. No studies are available on the toxicological effects of carbofuran in the endothelial cells (ECs), which first confronts the toxicants in blood vessels. Hence, we have exposed the human umbilical vein ECs (HUVECs) with carbofuran for 24 h, which significantly reduced the cell survival to 25.16% and 33.48% at 500 and 1,000 µM analyzed by MTT assay. In the neutral red uptake (NRU) assay, 16.68%, 30.99%, and 58.11% survival decline was found at 250, 500, and 1,000 µM of carbofuran. HUVECs exposed to carbofuran showed significant increase in the intracellular reactive oxygen species (ROS), indicating oxidative stress at low concentrations. In parallel, HUVECs showed hyperpolarization effects in the mitochondrial membrane potential (ΔΨm) upon carbofuran exposure. Carbofuran induced DNA damage in HUVECs measured as 8.80, 11.82, 35.56, and 79.69 Olive tail moment (OTM) in 100-, 250-, 500-, and 1,000-µM exposure groups. Flow cytometric analysis showed apoptotic peak (SubG1) and G2M arrest in the HUVECs exposed to carbofuran. Overall, our novel data confirm that carbofuran is toxic for the EC cells, especially at the higher concentrations, which may affect the vascular functions and possibly angiogenesis. Hence, carbofuran should be applied judiciously, and detailed vascular studies are warranted to gain an in-depth information focusing the transcriptomic and translation changes employing suitable in vivo and in vitro test models.

Oxidative Stress Mediated Cytotoxicity, Cell Cycle Arrest, and Apoptosis Induced by Rosa damascena in Human Cervical Cancer HeLa Cells.

Rosa damascena Mill (Damask rose), belonging to the Rosaceae family, is known for medicinal purposes in traditional medicine system. However, its anticancer activity has not been studied yet in detail. Herein, we aimed to investigate the cytotoxic effects of R. damascena hexane (RA-HE) and methanolic (RA-ME) extracts against human breast (MCF-7), lung epithelial (A-549), and cervical (HeLa) cancer cells. The RA-HE and RA-ME showed more potent cytotoxic effects against HeLa cells with an IC50 of 819.6 and 198.4 µg/ml, respectively. Further, cytotoxic concentrations of most effective extract (RA-ME) were used to evaluate the mechanism of cytotoxicity involved in HeLa cells. A concentration-dependent induction of lipid peroxidation (LPO) and reduction of glutathione (GSH) in HeLa cells treated with 250-1000 µg/ml of RA-ME confirms the association of oxidative stress. We also detected a noteworthy increase in reactive oxygen species (ROS) production and a decline in mitochondrial membrane potential (MMP) level in RA-ME-exposed HeLa cells. Flow cytometric data showed a strong dose-response relationship in cell cycle analysis between subG1 phase in HeLa cells and RA-ME treatment. Similarly, a concentration-dependent increase was recorded with Annexin V assay in HeLa cells going to late apoptosis. In conclusion, our findings suggest that RA-ME-induced cytotoxicity and apoptosis in HeLa cells are mediated by oxidative stress.

Cytotoxicity and genotoxicity of methomyl, carbaryl, metalaxyl, and pendimethalin in human umbilical vein endothelial cells.

Pesticides have adverse effects on the cellular functionality, which may trigger myriad of health consequences. However, pesticides-mediated toxicity in the endothelial cells (ECs) is still elusive. Hence, in this study, we have used human umbilical vein endothelial cells (HUVECs) as a model to quantify the cytotoxicity and genotoxicity of four pesticides (methomyl, carbaryl, metalaxyl, and pendimethalin). In the MTT assay, HUVECs exposed to methomyl, carbaryl, metalaxyl, and pendimethalin demonstrated significant proliferation inhibition only at higher concentrations (500 and 1000 µM). Likewise, neutral red uptake (NRU) assay also showed proliferation inhibition of HUVECs at 500 and 1000 µM by the four pesticides, confirming lysosomal fragility. HUVECs exposed to the four pesticides significantly increased the level of intracellular reactive oxygen species (ROS). Comet assay and flow cytometric data exhibited DNA damage and apoptotic cell death in HUVECs after 24 h of exposure with methomyl, metalaxyl, carbaryl, and pendimethalin. This is a first study on HUVECs signifying the cytotoxic-genotoxic and apoptotic potential of carbamate insecticides (methomyl and carbaryl), fungicide (metalaxyl), and herbicide (pendimethalin). Overall, these pesticides may affect ECs functions and angiogenesis; nonetheless, mechanistic studies are warranted from the perspective of vascular biology using in vivo test models.

Protective effects of Nigella sativa extract against H2 O2 -induced cell death through the inhibition of DNA damage and cell cycle arrest in human umbilical vein endothelial cells (HUVECs).

Oxidative stress is known to induce cytotoxicity and apoptosis in endothelial cells and indorse development of atherosclerosis. The aim of this research was to assess the cytoprotective effects of ethanolic extract of Nigella sativa (NSE) against H2 O2 -induced cell death in human umbilical vein endothelial cells (HUVECs) and also study the probable mechanisms through which NSE exhibited cyto-protection. The cytotoxicity was measured by exposing the HUVECs with NSE (10-200 µg/ml) and H2 O2 (25-1000 µM) for 24 h. Then, the HUVECs were pretreated with noncytotoxic doses (10-50 µg/ml) of NSE for 24 h before administration of 200 µM H2 O2 for 24 h. The MTT, NRU, and morphological assays were performed to assess the cytotoxicity and cyto-protection. Potential antioxidant activity of NSE on oxidative stress marker (glutathione [GSH] and lipid peroxidation [LPO]) was also evaluated. The fluorescence probe, DCF-DA, and Rh123 were applied to measure the reactive oxygen species (ROS) level and mitochondrial membrane potential. Moreover, flow cytometric analysis and comet assay were used to study the cell cycle arrest and DNA damage, respectively. The concentrations (10, 30, and 50 µg/ml) of NSE were found to protect HUVECs against H2 O2 (200 µM)-induced cytotoxicity in HUVECs. Pretreatment of HUVECs with NSE significantly reduced the LPO and ROS levels and restored the GSH and loss of MMP induced by H2 O2 . Furthermore, NSE inhibited H2 O2 -induced cell cycle arrest and cellular DNA damage in HUVECs. Altogether, these results suggest that NSE can prevent H2 O2 -induced cell death, and NSE could be a potential candidate that can prevent HUVECs against toxicants.

Neuroprotective Effects of Withania somnifera on 4-Hydroxynonenal Induced Cell Death in Human Neuroblastoma SH-SY5Y Cells Through ROS Inhibition and Apoptotic Mitochondrial Pathway.

The antioxidant, anti-inflammatory, and anticancer activities of Withania somnifera (WS) are known for a long time. This study was aimed to examine whether WS also diminishes 4-hydroxy-trans-2-nonenal (HNE)-induced neurotoxicity in human neuroblastoma (SH-SY5Y) cell line. The cytotoxic response of HNE (0.1-50 µM) and WS (6.25-200 µg/ml) was measured by MTT assay after exposing SH-SY5Y cells for 24 h. Then neuroprotective potential was assessed by exposing the cells to biologically safe concentrations of WS (12.5, 25, and 50 µg/ml) then HNE (50 µM). Results showed a concentration-dependent protective effect of WS at 12.5, 25, and 50 µg/ml against HNE (50 µM) induced cytotoxicity and cell inhibition. Pre-exposure to WS resulted in a strong inhibition of 24, 55 and 83% in malondialdehyde (MDA) level; 5, 27 and 60% in glutathione (GSH) level; 12, 36 and 68% in catalase activity; 11, 33 and 67% in LDH leakage; and 40, 80 and 120% in cellular LDH activity at 12.5, 25, and 50 µg/ml, respectively, induced by 50 µM HNE in SH-SY5Y cells. The HNE-mediated cellular changes (cell shrinkage, rounded bodies, and inhibition of outgrowth) and increased caspase-3 activity were also prevented by WS. The HNE-induced upregulation of proapoptotic markers (p53, caspase-3, and -9, and Bax) and downregulation of antiapoptotic marker Bcl-2 genes were also blocked by pretreatment with WS. Altogether, our findings indicate that WS possesses a protective potential against HNE-induced neurotoxicity.