Nicotine promotes epithelial to mesenchymal transition and gemcitabine resistance via hENT1/RRM1 signalling in pancreatic cancer and chemosensitizing effects of Embelin-a naturally occurring benzoquinone

Pancreatic cancer is lethal due to poor prognosis with 5-year survival rate lesser than 5 %. Gemcitabine is currently used to treat pancreatic cancer and development of chemoresistance is a major obstacle to overcome pancreatic cancer. Nicotine is a known inducer of drug resistance in pancreatic tumor micro-environment. Present study evaluates chemoresistance triggered by nicotine while treating with gemcitabine and chemosensitization using Embelin. Embelin is a naturally occurring benzoquinone from Embelia ribes possessing therapeutic potency. To develop nicotine-induced chemo-resistance, pancreatic cancer cells PANC-1 and MIA PaCa-2 were continuously treated with nicotine followed by exposure to gemcitabine. Gemcitabine sensitivity assay and immunoblotting was performed to assess the chemo-resistance. Antiproliferative assays such as migration assay, clonogenic assay, Mitochondrial Membrane Potential (MMP) assay, dual staining assay, comet assay, Reactive Oxygen Species (ROS) assay, cell cycle analysis and immunoblotting assays were performed to witness the protein expression involved in chemoresistance and chemosensitization. Epithelial to mesenchymal transition was observed in nicotine induced chemoresistant cells. Gemcitabine sensitivity assay revealed that relative resistance was increased to 6.26 (p < 0.0001) and 6.45 (p < 0.0001) folds in resistant PANC-1 and MIA PaCa-2 compared to parental cells. Protein expression studies confirmed resistance markers like hENT1 and dCK were downregulated with subsequent increase in RRM1 expression in resistant cells. Embelin considerably decreased the cell viability with an IC50 value of 4.03 ± 0.08 μM in resistant PANC-1 and 2.11 ± 0.04 μM in resistant MIA PaCa-2. Cell cycle analysis showed Embelin treatment caused cell cycle arrest at S phase in resistant PANC-1 cells; in resistant MIA PaCa-2 cells there was an escalation in the Sub G1. Embelin upregulated Bax, γH2AX, p53, ERK1/2 and hENT1 expression with concomitant down regulation of Bcl-2 and RRM1. Bioactive molecule embelin, its combination with gemcitabine could provide new vistas to overcome chemo resistance in pancreatic cancer.

Exploring anticancer properties of novel Nano-Formulation of BODIPY Compound, Photophysicochemical, in vitro and in silico evaluations

A new BODIPY complex (C4) composed of meso- thienyl-pyridine substituted core unit diiodinated from 2- and 6- positions and distyryl moieties at 3- and 5- positions is synthesized. Nano-sized formulation of C4 is prepared by single emulsion method using poly(ε-caprolactone)(PCL) polymer. Encapsulation efficiency and loading capacity values of C4 loaded PCL nanoparticles (C4@PCL-NPs) are calculated and in vitro release profile of C4 is determined. The cytotoxicity and anti-cancer activity are conducted on the L929 and MCF-7 cell lines. Cellular uptake study is performed and interaction between C4@PCL-NPs and MCF-7 cell line is investigated. Anti-cancer activity of C4 is predicted with molecular docking studies and the inhibition property on EGFR, ERα, PR and mTOR are investigated for its anticancer properties. Molecular interactions, binding positions and docking score energies between C4 and EGFR, ERα, PR and mTOR targets are revealed using in silico methods. The druglikeness and pharmacokinetic properties of C4 are evaluated using the SwissADME and its bioavailability and toxicity profiles are assessed using the SwissADME, preADMET and pkCSM servers. In conclusion, the potential use of C4 as an anti-cancer agent is evaluated in vitro and in silico methods. Also, photophysicochemical properties are studied to investigate the potential of using Photodynamic Therapy (PDT). In photochemical studies, the calculated singlet oxygen quantum yield (Φ_Δ) value was 0.73 for C4 and in photopysical studies, the calculated fluorescence quantum yield Φ_F value was 0.19 for C4.

Artabotrys odoratissimus Bark Extract Restores Ethanol Induced Redox Imbalance and Toxicity in Hepatocytes and In Vivo Model

Alcohol-induced oxidative stress is a key player in the development of liver diseases, and herbal alternatives are important means of ameliorating the hepatotoxic effects. The study aimed to evaluate the hepatoprotective potentiality of Artabotrys odoratissimus, an important medicinal shrub from the family Annonaceae. The phenolic compounds from bark ethanol extract (BEE) were detected using RP-HPLC. The in vitro hepatoprotective activity against ethanol-induced damage was studied in HepG2 cells with cell viability assays, mitochondrial membrane potential (MMP) assay, reactive oxygen species (ROS) assay, double staining assay and western blotting. The in vivo mice model was used to evaluate the alcohol-induced stress with liver function enzymes, lipid profile and histopathology. All the thirteen phenolic compounds detected with HPLC were docked onto protein targets such as aspartate amino transferase (AST), alkaline phosphatase (ALP) and inducible nitric oxide synthase (NO). The RP-HPLC detected the presence of various phenolics including rutin, chlorogenic acid and catechin, amongst others. Co-administration of BEE with ethanol alleviated cell death, ROS and MMP in HepG2 cells compared to the negative control. The extract also modulated the MAP kinase/caspase-3 pathway, thereby showing protective effects in HepG2 cells. Also, pre-treatment for 14 days with the extract in the mice model before a single toxic dose (5 g/kg body weight) reduced the liver injury by bringing the levels of liver function enzymes, lipid profile and bilirubin to near normal. In silico analysis revealed that rutin showed the best binding affinity with all the target proteins in the study. These results provide evidence that BEE possesses significant hepatoprotective effects against ethanol-induced oxidative stress in hepatic cells and in vivo models, which is further validated with in silico analysis.

Cyto-genotoxicity of crystalline and amorphous niobium (V) oxide nanoparticles in CHO-K1 cells

Niobium (V) oxide nanoparticles (NINPs) have been widely and increasingly applied in various health products and industrial processes. This merits further study of their toxicity. Here, we investigated the potential of NINPs to induce DNA damage, cytotoxicity, and chromosome instability in cultured CHO-K1 cells. NINPs were physico-chemically characterized. As assessed by comet assay, crystalline and amorphous NINPs were genotoxic at the highest concentrations evaluated. The cytokinesis-block micronucleus assay demonstrated that a 24-h treatment with NINPs, for the crystalline and the amorphous samples, significantly reduced the nuclear division cytotoxicity index. In addition, a 4-h treatment period of crystalline NINPs increased micronucleus (MNi) frequencies. MNi, nucleoplasmic bridges and nuclear buds were detected after exposure of the cells for 24 h to crystalline NINPs. In the amorphous sample, chromosome instability was restricted to the induction of MNi, in the 24-h treatment, detected at all tested concentrations. The fluorescence and dark field microscopy demonstrated the uptake of NINPs by CHO-K1 cells and an intracellular distribution outlining the nucleus. Our data advance understanding of the cytotoxic and genotoxic effects of NINPs and should be taken into consideration when setting up guidelines for their use in industrial or health products.

Synthesis and Biological Characterization of Phyto-Fabricated Silver Nanoparticles from Azadirachta indica

Nanoparticles (NPs) have garnered a lot of interest in sectors like medicine, cosmetics, food, and pharmaceuticals for antibacterial catalytic properties, reduced toxicity, and easy production. Biological synthesis of silver nanoparticle (AgNPs) is considered as green, eco-friendly, and cost-effective approach; therefore, Azadirachta indica extracts were utilized for a dual role of fabrication and functionalization of AgNPs. Optical and physical characterizations were achieved for confirming the biosynthesized AgNPs. SEM images detected quasi-spherical AgNPs of 44.04 to 66.50 nm. Some of potent phytochemicals like flavonoids and proteins from Azadirachta indica formed a strong coating or capping on the AgNPs without affecting their secondary structure by interacting with Ag+ and NPs for the formation of AgNPs. AgNPs exhibited strong antibacterial activity (MIC 10 μg/ml) against multidrug-resistant bacteria Enterococcus faecalis; at different concentrations, no IC50 values were recorded for AgNPs as well as Azadirachta indica signifying low cytotoxicity in the exposed concentration range. The DNA degradation activity of AgNPs through the TUNEL assay revealed no significant increase in the overall FITC mean fluorescence intensity as well as a DNA fragmentation index with 5.45% DNA damage (10 μg/ml AgNPs). Drug uptake of AgNPs was also investigated through a permeability assay via Caco-2 cell lines at test concentrations where apparent permeability was detected as moderate.

Entrapment of silver nanoparticles in L-α-phosphatidylcholine/cholesterol-based liposomes mitigates the oxidative stress in human keratinocyte (HaCaT) cells

Encapsulation procedures are used to decrease the contact of toxic nanoparticles with cells; however, this field is still not well explored. Therefore, the aim of this paper was to evaluate the effect of encapsulation of silver nanoparticles in L-α-phosphatidylcholine/cholesterol-based liposomes on a human keratinocyte cell line (HaCaT). The homogenous (PdI = 0.171) spherical (~161 nm diameter) complexes were prepared by thin film hydration with the extrusion method. The UV-Vis scan and Dynamic Light Scattering measurement did not show any "free" silver nanoparticles in solutions, which was confirmed by Transmission Electron Microscope analysis. Moreover, the liposomes were tested on HaCaT cells, showing that the encapsulation process reduced the toxicity by 30%-10% at the 100 nM and 1 pM concentrations, respectively, in comparison to "free" nanoparticles, measured by resazurin reduction and lactate dehydrogenase release assays. Moreover, the caspase-3 activity was lower after 48-h treatment with LipoAgNPs than with AgNPs. The level of reactive oxygen species (ROS) after 1, 6, 48, and 72 h of treatment of HaCaT cells was significantly lower in comparison to cells treated with "bare" silver nanoparticles analyzed with the H₂DCF-DA probe. The metabolic activity was strictly correlated with toxicity, indicating a lower negative impact of encapsulated nanoparticles than the "bare" ones.

Differential Action of Silver Nanoparticles on ABCB1 (MDR1) and ABCC1 (MRP1) Activity in Mammalian Cell Lines

Silver nanoparticles (AgNPs), due to their unique properties have been receiving immense attention in recent years. In addition to their antibacterial and antifungal activities, AgNPs also cause apoptosis, mitochondria disfunction, nucleic acid damage and show potent anticancer properties in both multidrug resistance (MDR) and sensitive tumors. The MDR phenomenon, caused by the presence of ATP-binding cassette (ABC) proteins, is responsible for the failure of chemotherapy. Thus, investigating the influence of widely used AgNPs on ABC transporters is crucial. In the present study, we have examined the cytotoxicity of silver nanoparticles of a nominal size of 20 nm (Ag20) on the cell lines of different tissue origins. In addition, we have checked the ATP-binding cassette transporters’ activity and expression under AgNP exposure. The results indicate that Ag20 shows a toxic effect on tested cells, as well as modulating the expression and transport activity of ABC proteins.

Facile Synthesis of Silver Nanoparticles Using Asian Spider Flower and Its In Vitro Cytotoxic Activity Against Human Breast Carcinoma Cells

Cancer is one of the most dangerous threats to human health and possibly the utmost task for current medicine. Currently, bio-based synthesis of nanoparticles from plants has gained much interest due to its potential medicinal applications. In the present study, a biological approach was employed for biogenic (green) synthesis of silver nanoparticles (AgNPs) using dried leaf extract of Asian spider flower (Asf). The biogenic synthesis of Asf-AgNPs (Asian spider flower-Silver nanoparticles) was established using ultra violet-visible (UV-vis) spectra which exhibited a wide superficial plasmon resonance of AgNPs at 445 nm. These nanoparticles clearly showed the formation of poly-disperse crystalline solids (spherical shape) with particle size range of <50 nm based on observation under a transmission electron microscope (TEM). Infrared spectroscopy (FTIR) revealed carboxylic acids (C = O stretch) known to act as a capping agent and a reductant in plant extracts. Elemental silver signal peak was observed in the graph obtained from energy-dispersive X-ray (EDX) analysis. Biocompatibility tests for Asf-AgNPs at different doses were evaluated against human breast cancer cells (MCF7) for cell viability and apoptotic analysis. According to the evaluation, biosynthesized Asf-AgNPs could prevent the explosion of human breast tumor cells (MCF7) in IC50 at a dose of 40 μg/mL after 48 h of treatment. The results obtained in the IC50 dosage treatments were statistically significant (p < 0.05) when compared with control. Nuclear damage of cells was further investigated using annexin V-FITC/PI dual staining and DAPI (4′,6-diamidino-2-phenylindole) staining method. Bright blue fluorescence with condensed and fragmented chromatin was observed. Western blot analysis showed increased expression levels of caspases-3 and 9 (apoptotic proteins). These results indicate that bio-approached AgNPs synthesized through Asf plant extract could be used as potential therapeutic medications for human cancer cells.

Mutagen-induced phytotoxicity in maize seed germination is dependent on ROS scavenging capacity

Ethidium bromide (EB) and acridine orange (AO) bind to nucleic acids and are thus considered as potential mutagens. In this study, the effects of EB and AO on the germination behaviours of white, yellow, red, and purple maize seeds were investigated. The results indicate that low concentrations of EB (50 μg mL⁻¹) and AO (500 μg mL⁻¹) promote germination, particularly for the white and yellow seeds. However, high concentrations of EB (0.5 mg mL⁻¹) and AO (5 mg mL⁻¹) significantly inhibit germination, with the level of inhibition decreasing in the following order: white > yellow > red > purple. In addition, EB and AO induce H₂O₂ production in a concentration-dependent manner. The effects of these mutagens on seed germination were partly reversed by dimethyl thiourea, a scavenger of reactive oxygen species (ROS), and diphenylene iodonium (DPI), an inhibitor of NADPH oxidase, while the effects were enhanced by treatment with H₂O₂ and 3-amino-1,2,4-triazole, a specific inhibitor of catalase. In addition, AO and EB profoundly increased NADPH oxidase activities in germinating seeds. The treatment of seeds with EB and AO did not affect the growth or drought tolerance of the resultant seedlings. The findings suggest that the mechanism of mutagen toxicity is related to the induction of ROS production.

Graphene oxide induces cytotoxicity and oxidative stress in bluegill sunfish cells

Graphene oxide (GO) is considered a promising material for biological application due to its unique properties. However, the potential toxicity of GO to aquatic organism particularly bluegill sun fish cells (BF-2) is unexplored or remains poorly understood. GO-induced cytotoxicity and oxidative stress in BF-2 cells were assessed using a battery of biomarkers. Two different biological assays (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and neutral red uptake were used to evaluate the cytotoxicity of GO on BF-2 cells. It was found that GO induced dose- and time-dependent cytotoxicity on BF-2 cells. BF-2 cells exposed to lower concentration of GO (40 μg ml^-1 ) for 24 induced morphological changes when compared to their respective controls. As evidence for oxidative stress lipid peroxidation, superoxide dismutase, catalase, reactive oxygen species and 8-hydroxy-2'-deoxyguanosine levels were increased and glutathione levels were found to decline in BF-2 cells after treatment with GO. Our findings demonstrate that GO when exposed to BF-2 fish cells cause oxidative stress.

Role of omics techniques in the toxicity testing of nanoparticles

Nanotechnology is regarded as a key technology of the twenty-first century. Despite the many advantages of nanotechnology it is also known that engineered nanoparticles (NPs) may cause adverse health effects in humans. Reports on toxic effects of NPs relay mainly on conventional (phenotypic) testing but studies of changes in epigenome, transcriptome, proteome, and metabolome induced by NPs have also been performed. NPs most relevant for human exposure in consumer, health and food products are metal, metal oxide and carbon-based NPs. They were also studied quite frequently with omics technologies and an overview of the study results can serve to answer the question if screening for established targets of nanotoxicity (e.g. cell death, proliferation, oxidative stress, and inflammation) is sufficient or if omics techniques are needed to reveal new targets. Regulated pathways identified by omics techniques were confirmed by phenotypic assays performed in the same study and comparison of particle types and cells by the same group indicated a more cell/organ-specific than particle specific regulation pattern. Between different studies moderate overlap of the regulated pathways was observed and cell-specific regulation is less obvious. The lack of standardization in particle exposure, in omics technologies, difficulties to translate mechanistic data to phenotypes and comparison with human in vivo data currently limit the use of these technologies in the prediction of toxic effects by NPs.

Evaluation of therapeutic potential of the silver/silver chloride nanoparticles synthesized with the aqueous leaf extract of Rumex acetosa

Silver nanoparticles were green synthesized with the aqueous leaf extract of the widely consumed green leafy vegetable, Rumex acetosa (sorrel) and the obtained silver nanoparticles (Ag NPs) were tested for their in vitro antioxidant potential, cytotoxicity against human osteosarcoma (HOS) cell lines and antibacterial effects against sixteen human pathogenic clinical isolates. Different analytical techniques viz. UV-vis, FTIR, XRD, SEM-EDX and TEM were employed to characterize the synthesized Ag NPs. Surface Plasmon spectra for the Ag NPs with brownish black color were centered approximately at 448 nm. FTIR analysis revealed the presence of reactive N-H and O-H groups that are effective in reducing Ag(I) ions to Ag(0) which then reacted with the contents of the extract to AgCl/Ag2C2O4. From SEM and TEM analyses, the particles were found to be predominantly spherical in shape and ranged in size from 5 nm to 80 nm, but were largely in the range of 15 nm to 20 nm. Ag NPs showed considerable antioxidant activity, and all the sixteen clinical isolates of human pathogens tested were significantly inhibited. Also, HOS cell lines were significantly (p < 0.05) inhibited at 25% concentration of the Ag NPs extract, while showing a marginal revival at 50% and 100% concentrations.

Nanocaged platforms: modification, drug delivery and nanotoxicity. Opening synthetic cages to release the tiger

Nanocages (NCs) have emerged as a new class of drug-carriers, with a wide range of possibilities in multi-modality medical treatments and theranostics. Nanocages can overcome such limitations as high toxicity caused by anti-cancer chemotherapy or by the nanocarrier itself, due to their unique characteristics. These properties consist of: (1) a high loading-capacity (spacious interior); (2) a porous structure (analogous to openings between the bars of the cage); (3) enabling smart release (a key to unlock the cage); and (4) a low likelihood of unfavorable immune responses (the outside of the cage is safe). In this review, we cover different classes of NC structures such as virus-like particles (VLPs), protein NCs, DNA NCs, supramolecular nanosystems, hybrid metal-organic NCs, gold NCs, carbon-based NCs and silica NCs. Moreover, NC-assisted drug delivery including modification methods, drug immobilization, active targeting, and stimulus-responsive release mechanisms are discussed, highlighting the advantages, disadvantages and challenges. Finally, translation of NCs into clinical applications, and an up-to-date assessment of the nanotoxicology considerations of NCs are presented.

Engineered biomimetic nanoabsorbent for cellular detoxification of chemotherapeutics

An approach to reduce the nonspecific cytotoxicity of chemotherapeutics has been put-forth using a biomimetic nanoabsorbent (NAb) as a detoxifying agent.

Reducing the cytotoxicity while improving the anti-cancer activity of silver nanoparticles through α-tocopherol succinate modification

α-TOS modified Ag NPs could reduce the cytotoxicity while improving the anti-cancer activity of Ag NPs.