An automated micro-fluorometric assay for monitoring oxidative burst activity of phagocytes

Rhodamine B, an organic environmental pollutant induces reproductive toxicity in parental and teratogenicity in F1 generation in vivo

This study investigated the reproductive toxicity of rhodamine B in zebrafish and its transgenerational effects on the F1 generation. In silico toxicity predictions revealed high toxicity of rhodamine B, mainly targeting pathways associated with the reproductive and endocrine systems. In vivo experiments on zebrafish demonstrated that rhodamine B exposure at a concentration of 1.5 mg/L led to significant impairments in fecundity parameters, particularly affecting females. Histopathological analysis revealed distinct changes in reproductive organs, further confirming the reproductive toxicity of rhodamine B, with females being more susceptible than males. Gene expression studies indicated significant suppression of genes crucial for ovulation in rhodamine B-treated female fish, highlighting hormonal imbalance as a potential mechanism of reproductive toxicity. Furthermore, bioaccumulation studies showed the presence of rhodamine B in both adult fish gonads and F1 generation samples, suggesting transgenerational transfer of the dye. Embryotoxicity studies on F1 generation larvae demonstrated reduced survival rates, lower hatching rates, and increased malformations in groups exposed to rhodamine B. Moreover, rhodamine B induced oxidative stress in F1 generation larvae, as evidenced by elevated levels of reactive oxygen species and altered antioxidant enzyme activity. Neurotoxicity assessments revealed reduced acetylcholinesterase activity, indicating potential neurological impairments in F1 generation larvae. Additionally, locomotory defects and skeletal abnormalities were observed in F1 generation larvae exposed to rhodamine B. This study provides comprehensive evidence of the reproductive toxicity of rhodamine B in adult zebrafish and its transgenerational effects on the F1 generation.

Secretory Phospholipase A2 (sPLA2) Isozymes as Potential Targets in Tobacco Condensate- induced Colon Damage

AIMS

To find out the role of secretory phospholipase A2 (sPLA2) isozymes as potential targets in tobacco condensate-induced colon damage.

BACKGROUND

The effects of cigarette smoke condensate (CSC) and the molecular mechanisms involved in the regulation of phospholipase A2 (PLA2) and its isozymes in colon cells, which are still unclear and emerging, are studied.

OBJECTIVES

The study aimed to check the effect of CSC on cell viability and reactive oxygen species (ROS) and superoxide. Also, the effect of CSC on gene expression of different secretory phospholipase A2 (sPLA2) was evaluated. Moreover, the impact of inhibition of sPLA2 on various cell properties i.e. cell viability, cell proliferation, membrane damage and free radicals' generation is also studied.

METHODS

CSC-induced changes were evaluated in cell viability by MTT assay, followed by the evaluation of membrane modulation by flow cytometry, free radical generation by fluorescent dyes, PLA2 isoforms gene expression patterns and their suppression by small interfering RNA (siRNA) studied in HCT-15 male and HT-29 female colon cells.

RESULTS

Our results demonstrate that HCT-15 and HT-29 cells treated with CSC significantly reduced the cell viability by 50% within 48 h and significantly enhanced the total reactive oxygen species (ROS) by 2 to 10-fold, and mitochondrial ROS (mtROS) and superoxide radicals (SOR) by 2-fold each. Treatment with CSC significantly unregulated secretory phospholipase A2 (sPLA2) IID group and down-regulated IB and cytosolic phospholipase (cPLA2) IVA groups in HCT-15 cells without affecting them in HT-29 cells. Silencing the sPLA2 IID group results in an increase in cell viability and a decrease in ROS. Silencing the PLA2 IVA gene in the HCT-15 cells showed a reduced expression which had no impact on the CSC-induced cell proliferation, membrane damage and free radicals (ROS, mtROS, and SOR) generation.

CONCLUSION

Therefore, identifying cell-specific sPLA2 isozymes seems to play a key role in controlling the ROSinduced damage by CSC and helps develop specific therapeutic strategies.

Neuroprotective effect of Biochanin a against Bisphenol A-induced prenatal neurotoxicity in zebrafish by modulating oxidative stress and locomotory defects

Exogenous toxicants cause oxidative stress and damage to brain cells, resulting in inflammation. Neuroinflammation is important in the pathobiology of various neurological illnesses, including Alzheimer's disease (AD). In this context, Bisphenol A (BPA), a common toxin, causes oxidative damage and has been linked to neurological problems. An O-methylated isoflavone known as Biochanin A (5,7-dihydroxy-4'-methoxy-isoflavone, BCA) is considered to be a phytoestrogen, which is abundant in some legume plants and soy which have preventive effects against cancer, osteoporosis, menopausal symptoms and oxidative stress. However, the mechanism by which BCA protected the prenatal neurological stress are not known. So that, in this study we investigated the BCA neuroprotective effect against BPA-induced neuroinflammation in zebrafish embryo models. For this study, fertilized zebrafish embryos are exposed to BPA (1 µM) with or without BCA. Our finding suggested that BCA co-exposure prevented the depletion of antioxidant defense enzymes by BPA and reduced the production of intracellular ROS production, superoxide anion (O₂^-), lipid peroxidation (LPO), lactate dehydrogenase (LDH) and nitric oxide (NO) levels in the head that aided in safeguarding neuronal development. Baseline locomotion was rendered and a total distance was calculated to assess the motor function. Exposure to BCA increased acetylcholinestrase (AChE) and improved motor neuron functions. It also reduced the pro-inflammatory response expression and prevented neuroinflammation. Our study suggests that BCA has a positive role in the attenuation or amelioration of neuronal oxidative damage and locomotory behaviour induced by BPA.

Toxicological effects of the mixed iron oxide nanoparticle (Fe3O4 NP) on murine fibroblasts LA-9

The increase in large-scale production of magnetic nanoparticles (NP) associated with the incomplete comprehensive knowledge regarding the potential risks of their use on environmental and human health makes it necessary to study the biological effects of these particles on organisms at the cellular level. The aim of this study to examine the cellular effects on fibroblast lineage LA-9 after exposure to mixed iron oxide NP (Fe₃O₄ NP). The following analyses were performed: field emission gun-scanning electron microscopy (SEM-FEG), dynamic light scattering (DLS), zeta potential, ultraviolet/visible region spectroscopy (UV/VIS), and attenuated total reactance-Fourier transform infrared (ATR-FTIR) spectroscopy analyses for characterization of the NP. The assays included cell viability, morphology, clonogenic potential, oxidative stress as measurement of reactive oxygen species (ROS) and nitric oxide (NO) levels, cytokines quantification interleukin 6 (IL-6) and tumor necrosis factor (TNF), NP uptake, and cell death. The size of Fe₃O₄ NP was 26.3 nm when evaluated in water through DLS. Fe₃O₄ NP did not reduce fibroblast cell viability until the highest concentration tested (250 µg/ml), which showed a decrease in clonogenic potential as well as small morphological changes after exposure for 48 and 72 hr. The NP concentration of 250 µg/ml induced enhanced ROS and NO production after 24 hr treatment. The uptake assay exhibited time-dependent Fe₃O₄ NP internalization at all concentrations tested with no significant cell death. Hence, exposure of fibroblasts to Fe₃O₄ NP-induced oxidative stress but not reduced cell viability or death. However, the decrease in the clonogenic potential at the highest concentration demonstrates cytotoxic effects attributed to Fe₃O₄ NP which occurred on the 7^th day after exposure.

Amelioration of acrylamide induced neurotoxicity by benzo[b]thiophene analogs via glutathione redox dynamics in zebrafish larvae

Acrylamide is a thermal process contaminant, which gets global attention due to its neurotoxic nature and its omnipresence in carbohydrate-rich foods. Chronic exposure to acrylamide leads to neuronal deterioration and motor dysfunction. Acrylamide could severely affect the antioxidant defense system, especially in the developing brain leading to premature neurological disorders. Acrylamide forms adduct in presynaptic neurons leading to neuroinflammation which is also a factor to consider. In this present study, we have explored whether our benzo[b]thiophene analogs, 1-(3-hydroxybenzo[b]thiophen-2-yl) ethanone (BP) and 1-(3-hydroxybenzo[b]thiophen-2-yl) propan-1-one hydrate (EP) with antioxidant activity, could inhibit the acrylamide-induced neurotoxicity-like behavior in zebrafish larvae. The experiment was set up to expose 3 days post fertilized (dpf) larvae to acrylamide (0.75 mM) for 3 days with or without compounds (80 µM). Locomotion behavioral analysis, antioxidants, glutathione, and acetylcholineesterase activity in the head region were analyzed after one day of the experimental procedure. We witnessed a restoration effect on glutathione redox dynamics. Since glutathione plays a crucial role in the detoxification of acrylamide, it is necessary to maintain the glutathione redox cycle to eliminate acrylamide from the body. BP and EP reduced the pro-inflammatory transcript in the head, which correlates with the reduction in oxidative stress. Finally, BP and EP showed a positive effect on synaptic vesicle cycling transcript and partially restores the motor neuron response to stimuli. Findings in this study showed the ability of compound BP and EP possess therapeutic value in oxidative stress-associated neurological disorders.

L-Cysteine capped zinc oxide nanoparticles induced cellular response on adenocarcinomic human alveolar basal epithelial cells using a conventional and organ-on-a-chip approach

Zinc oxide nanoparticles (ZnO NPs) are among the well-characterized nanomaterials with multifaceted biomedical applications, including biomedical imaging, drug delivery, and pharmaceutical preparations. The high surface charge of ZnO NPs leads to the agglomeration of the particles. Therefore, surface coating with a suitable ligand can increase colloidal stability. In this present study, in-vitro responses of ZnO NPs capped with a sulfur-containing amino acid, L-cysteine (Cys-ZnO NPs), on A549 cells was investigated. Fourier Transform Infrared Spectroscopy (FTIR) studies were carried out to confirm the capping of ZnO NPs with L-cysteine. Cytotoxic studies using A549 cells demonstrated reduced cytotoxicity in comparison with already reported pristine Zinc Oxide nanoparticles. The cellular uptake is confirmed by fluorescent cytometry. However, a higher concentration (160 µg/mL) of Cys-ZnO NPs led to apoptotic cell death marked by nuclear condensation, mitochondrial membrane depolarization, actin filament condensation, lysosomal damage LDH leakage, intracellular ROS production, blebbing, upregulation of Bax and downregulation of Bcl-2 gene expression. Cys-ZnO NPs treatment was also carried out in cells cultured in a microfluidic lung-on-a-chip device under a physiologically relevant flow rate. The study concluded that the microfluidic-based lung-on-a-chip culture resulted in reduced cell death compared to the conventional condition.

New Multi-Walled carbon nanotube of industrial interest induce cell death in murine fibroblast cells

The search for new nanomaterials has brought to the multifactorial industry several opportunities for use and applications for existing materials. Carbon nanotubes (CNT), for example, present excellent properties which allow us to assume a series of applications, however there is concern in the industrial scope about possible adverse health effects related to constant exposure for inhalation or direct skin contact. Thus, using cell models is the fastest and safest way to assess the effects of a new material. The aim of this study was to investigate the cytotoxic profile in LA9 murine fibroblast lineage, of a new multi-walled carbon nanotube (MWCNT) that was functionalized with tetraethylenepentamine (TEPA) to obtain better physical-chemical characteristics for industrial use. The modifications presented in the CNT cause concern, as they can change its initial characteristics, making this nanomaterial harmful. HR-TEM, FE-SEM and zeta potential were used for the characterization. Cytotoxicity and cell proliferation tests, oxidative and nitrosative stress analyzes and inflammatory cytokine assay (TNF-α) were performed. The main findings demonstrated a reduction in cell viability, increased release of intracellular ROS, accompanied by an increase in TNF-α, indicating an important inflammatory profile. Confirmation of the data was performed by flow cytometry and ImageXpress with apoptosis/necrosis markers. These data provide initial evidence that OCNT-TEPA has a cytotoxic profile dependent on the concentration of LA9 fibroblasts, since there was an increase in free radicals, inflammation induction and cell death, suggesting that continuous exposure to this nanoparticle can cause damage to different tissues in the organism.

Photo induced mechanistic activity of GO/Zn(Cu)O nanocomposite against infectious pathogens: Potential application in wound healing

Treating infection causing microorganisms is one of the major challenges in wound healing. These may gain resistance due to the overuse of conventional antibiotics. A promising technique is antimicrobial photodynamic therapy (aPDT) used to selectively cause damage to infectious pathogenic cells via generation of reactive oxygen species (ROS). We report on biocompatable nanomaterials that can serve as potential photosensitizers for aPDT. GO/Zn(Cu)O nanocomposite was synthesized by co-precipitation method. Graphene Oxide (GO) is known for its high surface to volume ratio, excellent surface functionality and enhanced antimicrobial property. ZnO nanoparticle induces the generation of reactive oxygen species (ROS) under light irradiation and it leads to recombination of electron-hole pair. Nanocomposites of GO and Cu doped ZnO increases visible light absorption and enhances the photocatalytic property. It generates more ROS and increases the bacterial inhibition. GO/Zn(Cu)O nanocomposite was tested against Staphylococcus aureus (S. aureus), Enterococcus faecium (E. faecium), Escherichia coli (E. coli), Salmonella typhi (S. typhi), Shigella flexneri (S. flexneri) and Pseudomonas aeruginosa (P. aeruginosa) by well diffusion method, growth curve, colony count, biofilm formation under both dark and visible light condition. Reactive Oxygen Species assay (ROS), Lactate dehydrogenase leakage (LDH) assay, Protein estimation assay and membrane integrity study proves the mechanism of inhibition of bacteria. Inhibition kinetics shows the sensitivity between bacteria and GO/Zn(Cu)O nanocomposite.

Toxicity assessment of synthesized titanium dioxide nanoparticles in fresh water algae Chlorella pyrenoidosa and a zebrafish liver cell line

This study aims to assess the toxicity of the commonly-spread titanium dioxide nanoparticles (TiO₂ NPs) by evaluating the exposure impact of the particles on both freshwater algae Chlorella pyrenoidosa and zebrafish liver cell line (ZFL), the two common in vitro models in toxicological studies. To compare the toxic effects of TiO₂ NPs with different physiochemical properties, three types of manufactured TiO₂ were used: bulk TiO₂, Degussa P25 TiO₂, and ultrafine TiO₂ NPs. Both short and long-term biological responses of green algae, such as the effect on the cell growth rate, pigment autofluorescence, and esterase activity were investigated. The dosage, physical property of TiO₂ particles, and their interactions with algal cells affect cellular growth, especially after short-term exposure. The hydrodynamic size plays a critical role in determining the acute toxicity to C. pyrenoidosa in terms of autofluorescence and esterase activity, while all types of TiO₂ NPs show toxic effects after exposure for 14 days. However, this observation is not seen when studying the effect of introduced particles in ZFL, for the precipitated Degussa P25 TiO₂ showed the highest cellular inhibition. Interestingly, despite the obvious overall toxicity toward C. pyrenoidosa, the photocatalytical properties of TiO₂ NPs may contribute to the enhanced photosynthesis in the low concentration range (<40 µg mL^-1). Overall, we found that the physical interactions between TiO₂ particles and the cells, particles' size and dispersibility play critical role in the cytotoxic effect for both algal and ZFL cells, while the photocatalytical properties of TiO₂ particles may produce mixed effects on the cytotoxicity of green algae.

Pentachlorophenol and ciprofloxacin present dissimilar joint toxicities with carbon nanotubes to Bacillus subtilis

Discharged carbon nanotubes (CNTs) likely interact with co-existing organic contaminants (OCs) and pose joint toxicity to environmental microbes. Herein, hydrophobic pentachlorophenol (PCP) and hydrophilic ciprofloxacin (CIP) were used as representative OCs and their joint toxicities with CNTs to Bacillus subtilis were systematically investigated at cellular, biochemical, and omics levels. The 3-h bacterial growth half inhibitory concentrations of CNTs, PCP, and CIP were 12.5 ± 2.6, 3.5 ± 0.5, and 0.46 ± 0.03 mg/L, respectively, and they all could damage cell membrane, increase intracellular oxidative stress, and alter bacterial metabolomics and transcriptomics; while CNTs-PCP and CNTs-CIP binary exposures exhibited distinct additive and synergistic toxicities, respectively. CNTs increased bacterial bioaccumulation of PCP and CIP via destabilizing and damaging cell membrane. PCP reduced the bioaccumulation of CNTs, while CIP had no significant effect; this difference could be owing to the different effects of the two OCs on cell-surface hydrophobicity and CNTs electronegativity. The additive toxicity outcome upon CNTs-PCP co-exposure could be a result of the balance between the increased toxicity from increased PCP bioaccumulation and the decreased toxicity from decreased CNTs bioaccumulation. The increased bioaccumulation of CIP contributed to the synergistic toxicity upon CNTs-CIP co-exposure, as confirmed by the increased inhibition of topoisomerase Ⅳ activity and interference in gene expressions regulating ABC transporters and lysine biosynthesis. The findings provide novel insights into environmental risks of CNTs.

Zinc oxide nanoparticles synthesized from Aspergillus terreus induces oxidative stress-mediated apoptosis through modulating apoptotic proteins in human cervical cancer HeLa cells

OBJECTIVES

This study was aimed to analyze the cytotoxicity of biogenic zinc oxide nanoparticles (ZnO NPs) in human cervical epithelial cancer HeLa.

METHODS

The ZnO NPs was synthesized from the culture filtrated of Aspergillus terreus, and examined by UV-spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), energy-dispersive X-ray (EDX) and Fourier transform infrared (FTIR) analysis. The cytotoxicity of synthesized ZnO NPs was analyzed by the MTT assay, and the expression of apoptotic proteins was examined by Western blot analyses.

KEY FINDINGS

The ZnO NPs exhibited concentration-dependent cytotoxicity on HeLa cells and induced the apoptosis as evidenced by reduced superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) levels, and increased reactive oxygen species (ROS) and diminished mitochondrial membrane potential (MMP) was noticed in ZnO NPs treated HeLa cells. Western blot analyses explored that the Bcl-2 expression was significantly downregulated, whereas, the expression of p53, Bax, Caspase-3, Caspase-9 and Cytochrome-c were significantly upregulated in ZnO NPs treated cells.

CONCLUSION

Consequently, the mycosynthesized ZnO NPs induces apoptosis in HeLa cells by persuading oxidative damage and modulating the apoptotic proteins. Therefore, A. terreus synthesized ZnO NPs could be used as an effective chemotherapeutic agent for cervical cancer treatment.

Artesunate-Based Multifunctional Nanoplatform for Photothermal/Photoinduced Thermodynamic Synergistic Anticancer Therapy

Thermodynamic therapy (TDT), one that uses heat to activate thermosensitizers and produce reactive oxygen species (ROS), has recently emerged as an attractive approach for cancer therapy. However, the development of safe and efficient thermosensitizers for TDT remains a big challenge. Here, we have found that artesunate (ARS) could produce ROS upon heating. Based on this interesting result, we have designed and prepared a pH-sensitive liposomal nanoplatform (ICG-ARS@NPs) composed of indocyanine green (ICG) and ARS for photoinduced TDT as well as photothermal therapy (PTT). Under the slightly acidic conditions in tumor tissues, the pH-sensitive liposomal ICG-ARS@NPs were able to release their drug cargos. Upon near-infrared irradiation, the photothermal agent ICG generated in situ hyperthermia and triggered the thermal sensitizing activity of ARS to produce ROS, resulting in damage to cancer cells and tumor tissues. The heat-induced ROS generation of ARS was also confirmed both in vitro and in vivo. In addition, because of their specific tumor targeting and synergistic photothermal and thermodynamic effects, ICG-ARS@NPs exhibited highly efficient anticancer therapeutic efficacy in H22 tumor-bearing mice. We believe that this work will promote the exploration of TDT for cancer therapy as well as the application of the old drug, artemisinin.

Multi-omics analyses reveal molecular mechanisms for the antagonistic toxicity of carbon nanotubes and ciprofloxacin to Escherichia coli

With the increasing production and application, engineered nanomaterials (ENMs) are being discharged into the environment, where they can interact with co-existing contaminants, causing complicated joint toxicity to organisms that needs to be studied. The case study of ENMs-contaminant joint toxicity and the understanding of relative mechanisms are very insufficient, particularly the mechanisms of molecular interactions and governing processes. Herein, a typical ENMs, carbon nanotubes (CNTs, 0-60 mg/L), and a common antibiotic, ciprofloxacin (CIP, 0-900 mg/L), were selected as the analytes. Their joint toxicity to a model microbe Escherichia coli was specifically investigated via biochemical, transcriptomics, and metabolomics approaches. The result revealed an antagonistic effect on growth inhibition between CNTs and CIP. Mitigations in cell membrane disruption and oxidative stress were involved in the antagonistic action. CIP (48.8-244 mg/L) decreased the bioaccumulation of CNTs (7.2 mg/L) via reducing cell-surface hydrophobicity and hindering the bio-nano interaction, which could attenuate the toxicity of CNTs to bacteria. CNTs (7.2 and 14.4 mg/L) alleviated the disturbance of CIP (122 and 244 mg/L) to gene expressions especially related to nitrogen compound metabolism, oxidoreductase activity, and iron-sulfur protein maturation, probably through relieving the CIP-induced inhibition of DNA gyrase activity. Further, CNTs (7.2 and 14.4 mg/L) offset the impact of CIP (122 and 244 mg/L) on bacterial metabolome via the regulation of biosynthesis of unsaturated fatty acids and metabolisms of some amino acids and glutathione. The findings shed new light on the molecular mechanisms by which ENMs present joint effect on contaminant toxicity, and provide important information for risk assessments of CNTs and fluoroquinolones in the environment.

Biochemical and genotoxic biomarkers and cell cycle assessment in the zebrafish liver (ZF-L) cell line exposed to the novel metal-insecticide magnesium-hespiridin complex

The flavonoid metal-insecticide magnesium-hesperidin complex (MgHP) has recently been considered as a novel insecticide to replace some persistent pesticides. However, it is important to evaluate its action on non-target species, mainly those living in an aquatic environment, as these ecosystems are the final receptors of most chemicals. Reactive oxygen species, antioxidant and oxidative stress biomarkers, genotoxicity as well as cell cycle was evaluated in the liver cell line from zebrafish (Danio rerio; ZF-L) exposed to 0, 0.1, 1, 10, 100 and 1000 ng mL^-1 MgHP. MgHP affected cell stability by increasing reactive oxygen species (ROS) in both exposure times (24 and 96 h) at high concentrations. Catalase (CAT) activity decreased after 24 h exposure, and glutathione and metallothionein values increased, avoiding the lipid peroxidation. Genotoxicity increased as MgHP concentration increased, after 24 h exposure, exhibiting nuclear abnormalities; it was recovered after 96 h exposure, evidencing possible stimulation of DNA repair mechanisms. The alteration in the cell cycle (increasing in the Sub-G1 phase and decreasing in the S-phase) was associated with chromosomal instability. In conclusion, the responses of ROS and the antioxidant defense system depended on MgHP concentration and time exposure, while DNA exhibited some instability after 24 h exposure, which was recovered after 96 h.

Zinc oxide nanoparticles synthesized from Allium cepa prevents UVB radiation mediated inflammation in human epidermal keratinocytes (HaCaT cells)

The extensive relevance of nanoparticles arouses the requirement for manufacturing although the predictable technique are frequently perilous and energy saving. In the current study, zinc oxide nanoparticles manufactured from Allium cepa avert UVB radiation interceded irritation in human epidermal keratinocytes (HaCaT cells). In the current study, the zinc oxide nanoparticles (ZnO-NPs) was synthesized from the extract of A. cepa. The optimized ZnO-NPs hence attained and was enumerated and exemplified by UV visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscope (SEM) and EDAX impending analysis. In addition, amalgamated ZnO-NPs were experienced for cell viability (MTT), formation of reactive oxygen species (ROS), apoptosis, and antioxidant and lipid peroxidation (TBARS) levels. Also, we explored the effect of A. cepa ZnO-NPs in molecular level by evaluating the inflammatory and apoptotic markers, in which ZnO-NPs reinstated the interleukins 6, 10 and related signaling molecules like iNOS, COX-2 levels. Ultimately, ZnO-NPs induce apoptotic markers (Bax, Bcl-2) and also recommended that ZnO-NPs might aggravate cancer cell apoptosis in HaCaT cells.

Therapeutic potential of arachidonyl trifluromethyl ketone, a cytosolic phospholipaseA2 IVA specific inhibitor, in cigarette smoke condensate-induced pathological conditions in alveolar type I & II epithelial cells

Cigarette smoke is responsible for multiple disorders and causes almost 10 million annual deaths globally but underlying mechanisms are still underexplored. Continuous exposure of Cigarette smoke condensate (CSC) leads to cytosolic phospholipase A2 (cPLA2) mediated high free radicals where cPLA2s seems to play crucial role in generated various patho-physiological conditions such as chronic inflammation, oxidative stress and cancer. In this view, we assessed the therapeutic potential of arachidonyl trifluromethyl ketone (ATK), a cPLA2 inhibitor, via pharmacological inhibition of most expressible CSC-induced cPLA2 group IVA in type-I and type-II alveolar epithelial cells. The In Vitro inhibitory effect of ATK on CSC-induced PLA2 activity and its cellular role were assessed in terms of cell viability, fluorescein diacetate (FDA) dye uptake assay for membrane integrity, reactive oxygen species (ROS)/reactive nitrogen species (RNS) levels and pro apoptotic as well as anti apoptosis markers via flow cytometry, along with extracellular signal-regulated kinases (ERK) levels using enzyme-linked immunosorbent assay (ELISA). The experimental findings demonstrated that ATK acts as potent inhibitor of cPLA2 activity and shown its effectiveness as therapeutic agent by significantly mimicking CSC-induced levels of free radicals, primary apoptosis, ratio of pro-apoptotic/apoptotic proteins and levels of ERK whereas protected cells from loss of cell viability and membrane integrity. Thus, this study is an important step towards the opening up of avenues for the applicability of the cPLA2 isoform specific inhibitors such as ATK for pre-clinical and clinical studies and could be beneficial during smoking-induced lung pathological conditions.

Effect of Varying Proportions of Lignin and Cellulose Supplements on Immune Function and Lymphoid Organs of Layer Poultry (Gallus gallus)

To determine the benefits of different types or proportions of insoluble fiber components on growth and immunity, 4-week-old commercial layer pullets were fed supplements containing different proportions of purified lignin and cellulose or a commercial lignocellulose supplement. The 64 Hy-Line Brown pullets were provided basal diets supplemented with 1 g fiber per 100 g diet. The supplements included a commercial lignocellulose, Arbocel® RC fine (group A) with cellulose to lignin ratio of approximately 3:1, cellulose (group Ce), a 3:1 mixture of cellulose: lignin (group Ce3Lig1), and a 2:1 mixture of cellulose: lignin (group Ce2Lig1). After 3 weeks, innate immune function was measured in terms of heterophil phagocytosis and oxidative burst (n=8). After 4 weeks, ex vivo stimulated lymphocyte proliferation was determined for assessment of cell-mediated immune function (n=7). All pullets were killed at 9 weeks of age and lymphoid organs were weighed (n=16) and small intestinal Peyer's patches (PP) were measured (n=8). Pullets in both A and Ce3Lig1 groups had heavier (P<0.05) body and bursa of Fabricius weights. The number of PP in group A was higher (P<0.05) than in group Ce. The percentage of heterophil phagocytosis in A and Ce3Lig1 groups were higher (P<0.05) than in group Ce, and oxidative burst of group A was higher (P<0.05) than that of group Ce. Addition of 1% Arbocel or 1% Ce3Lig1 to the diet of layer pullets from 4 to 9 weeks of age significantly improved their growth and innate immune function compared to group Ce. This suggests that lignin either modulates the effect of cellulose or has specific mechanisms of action in the gut that improves growth and immunity. The proportion of lignin to cellulose may also be important for growth and immune function.

Berberine chloride mediates its antileishmanial activity by inhibiting Leishmania mitochondria

Berberine chloride, a plant-derived isoquinoline alkaloid, has been demonstrated to have leishmanicidal activity, which is mediated by generation of a redox imbalance and depolarization of the mitochondrial membrane, resulting in a caspase-independent apoptotic-like cell death. However, its impact on mitochondrial function remains to be delineated and is the focus of this study. In UR6 promastigotes, berberine chloride demonstrated a dose-dependent increase in generation of reactive oxygen species and mitochondrial superoxide, depolarization of the mitochondrial membrane potential, a dose-dependent inhibition of mitochondrial complexes I-III and II-III, along with a substantial depletion of ATP, collectively suggesting inhibition of parasite mitochondria. Accordingly, the oxidative stress induced by berberine chloride resulting in an apoptotic-like cell death in Leishmania can be exploited as a potent chemotherapeutic strategy, mitochondria being a prime contributor.

The leishmanicidal activity of artemisinin is mediated by cleavage of the endoperoxide bridge and mitochondrial dysfunction

Endoperoxides kill malaria parasites via cleavage of their endoperoxide bridge by haem or iron, leading to generation of cytotoxic oxygen-centred radicals. In view of the Leishmania parasites having a relatively compromised anti-oxidant defense and high iron content, this study aims to establish the underlying mechanism(s) accounting for the apoptotic-like death of Leishmania promastigotes by artemisinin, an endoperoxide. The formation of reactive oxygen species was confirmed by flow cytometry and was accompanied by inhibition of mitochondrial complexes I-III and II-III. However, this did not translate into a generation of mitochondrial superoxide or decrease in oxygen consumption, indicating minimal impairment of the electron transport chain. Artemisinin caused depolarization of the mitochondrial membrane along with a substantial depletion of adenosine triphosphatase (ATP), but it was not accompanied by enhancement of ATP hydrolysis. Collectively, the endoperoxide-mediated radical formation by artemisinin in Leishmania promastigotes was the key step for triggering its antileishmanial activity, leading secondarily to mitochondrial dysfunction indicating that endoperoxides represent a promising therapeutic strategy against Leishmania worthy of pharmacological consideration.

Redox Signaling by Reactive Electrophiles and Oxidants

The concept of cell signaling in the context of nonenzyme-assisted protein modifications by reactive electrophilic and oxidative species, broadly known as redox signaling, is a uniquely complex topic that has been approached from numerous different and multidisciplinary angles. Our Review reflects on five aspects critical for understanding how nature harnesses these noncanonical post-translational modifications to coordinate distinct cellular activities: (1) specific players and their generation, (2) physicochemical properties, (3) mechanisms of action, (4) methods of interrogation, and (5) functional roles in health and disease. Emphasis is primarily placed on the latest progress in the field, but several aspects of classical work likely forgotten/lost are also recollected. For researchers with interests in getting into the field, our Review is anticipated to function as a primer. For the expert, we aim to stimulate thought and discussion about fundamentals of redox signaling mechanisms and nuances of specificity/selectivity and timing in this sophisticated yet fascinating arena at the crossroads of chemistry and biology.

Graphene oxide–chloroquine nanoconjugate induce necroptotic death in A549 cancer cells through autophagy modulation

Aim: Chloroquine (Chl) has shown its potential in cancer therapy and graphene oxide (GO) exhibited excellent tumor-targeting ability, biocompatibility and low toxicity. We have endeavored to conjugate Chl to GO sheets and investigated the nonproliferation action on A549 cell lines along with cell signaling pathways. Materials & methods: Cellular toxicity, autophagic flux modulation and cell death mechanism induced by GO–Chl have been investigated on A549 cell lines. Results & conclusion: GO–Chl induces accumulation of autophagosomes (monodansylcadaverine staining, green fluorescence protein-tagged LC3 plasmid and transmission electron microscopy observations) in A549 cells through the blockade of autophagic flux that serves as scaffold for necrosome assembling and activates necroptotic cell death. GO–Chl nanoconjugate could be used as an effective cancer therapeutic agent, by targeting the autophagy necroptosis axis.

Nano titanium exposure induces dose- and size-dependent cytotoxicity on human epithelial lung and colon cells

The productions as well as use of Titanium dioxide nanoparticles (TNPs) were rapidly increasing in the present nano-world. The TNP becomes an inevitable part our daily life in the form of cosmeceutical, bio-medical, and nano-pharmaceutical applications. The TNPs are either inhaled or ingested into the human body through common routes of exposure like the lungs and the oral-gastrointestinal tract (GIT). Human lung and colon were exposed to test particles, TNP 18 nm (TNP 18), TNP 30 nm (TNP 30), and TNP 87 nm (TNP 87) with a dose range 0.1-100 µg/ml. The effect of exposure was determined using MTT, LDH, and DCFH-DA methods. The TNP 18, TNP 30, and TNP 87 significantly (p < 0.001) reduced cell viability in a dose- and a size-dependent manner in 60 and 100 µg/ml. The lowest IC₅₀ values 21.80 and 24.83 µg/ml were observed in A549 and Caco-2 for the smallest size, TNP 18. Further, for TNP 30, IC₅₀ values were 23.30 and 28.59 µg/ml compared to Nano QTZ 43.82 and 45.86 µg/ml. The EC₂₅ values of LDH leakage were 5.83 and 9.50 µg/ml for TNP 18 in lung and colon cells. Besides, ROS levels increased significantly at doses 60 (p < 0.01) and 100 (p < 0.001) µg/ml in two cells. The smaller size particle, TNP 18 has produced a significant (p < 0.05) toxic effect at the lowest dose i.e., 10 µg/ml. Therefore, we conclude that TNP 18, TNP 30, and TNP 87 induced a dose- and size-dependent cytotoxicity via decreased cell viability, increased LDH and ROS levels by in vitro methods.

Potential anticancer activity of biogenic silver nanoparticles using leaf extract of Rhynchosia suaveolens: an insight into the mechanism

The present study reports a simple and eco-friendly synthesis of silver nanoparticles (AgNPs) using leaf extract of Rhynchosia suaveolens. UV-Vis analysis of R. suaveolens synthesized AgNPs (RS-AgNPs) showed surface plasmon resonance (SPR) peak at 426 nm. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis revealed that RS-AgNPs were 10-30 nm in size with spherical shape. X-ray diffraction (XRD) analysis of RS-AgNPs confirmed the crystalline nature with face-centered cubic (FCC) lattice. Fourier transform infrared (FTIR) interprets that polyphenols and proteins take part in bioreduction and capping of RS-AgNPs. RS-AgNPs exhibited dose-dependent inhibition of proliferation of different cancer cells including DU145 and PC-3(human prostate carcinoma cell lines), SKOV3 (human ovarian carcinoma) and A549 (human lung adenocarcinoma)with IC₅₀ values of 4.35, 7.72, 4.2 and 24.7 μg/mL, respectively. The plausible reasons behind anticancer activity of RS-AgNPs were explained using different assays on the most susceptible SKOV3 cells. RS-AgNPs induced oxidative stress in SKOV3 cells by generating reactive oxygen species (ROS), enhancing lipid peroxidation (LPO) levels and decreasing glutathione (GSH) levels. RS-AgNPs induced the apoptosis of SKOV3 cells by up regulating the caspase-3, caspase -8, caspase -9, p53 and BAX and down regulating the antiapoptotic protein Bcl-2. Further, RS-AgNPs showed elevation of caspase 3/7 activity and also exhibited antimigratory effect by inhibiting the migration of SKOV3 cells into the wounded area. The findings suggested that biogenic RS-AgNPs provide an alternative approach to overcome several limitations of chemotherapy.

Supplementing the feeds of layer pullets, at different ages with two different fiber sources improves immune function

Two experiments were conducted to study the effects of lignocellulose supplementation on immune function in layer pullets at different stages of growth. Four-wk-old pullets (Experiment 1) were fed a control, diet (Diet C); Diet C plus 1% mixed soluble/insoluble fiber (Diet MF), or plus 1% insoluble fiber (Diet IF). At 7.5 wk-of-age, heterophil phagocytosis, and oxidative burst in Groups MF (328.5 beads/100 cells; 4,330.0 ΔRFU; relative fluorescent units) and IF (350.3; 5,264.4) were greater (P < 0.05) than Controls (303.4; 3,509.0). At 8 wk-of-age, Group MF and IF relative weights of bursa of Fabricius (0.57 g/100 g BW; 0.58 g /100 g BW), thymus glands (0.77; 0.78), and areas of Peyer's patches (PP) (2.7 cm2; 2.9 cm2) were higher (P < 0.05) than Controls (bursa, 0.50 g; thymus, 0.70 g; PP area, 1.8 cm2). In Experiment 2, 10-wk-old pullets were fed a control diet or diets containing 1.5% MF or IF for 8 wk. At 14 wk-of-age IF pullets had higher (P < 0.05) heterophil phagocytosis efficiency (447.9 beads/100 cells) than Controls (376.4) and MF and IF had greater (P < 0.05) oxidative burst (1,302.9 and 1,857.7 ΔRFU) than Controls (744.1). At 17 wk-of-age MF and IF had increased (P < 0.05) proliferation of T-lymphocytes (ConcanavalinA-stimulated) (100.4 and 103.1% of unstimulated cells) and B-lymphocytes (lipopolysaccharide-stimulated) (122.4 and 129.0) than Controls (ConA, 79.4; lipopolysaccharide, 106.6). At 18 wk-of-age, IF pullets were heavier (1,607.5 g, P < 0.05) than Controls (1,506.5 g), had heavier (P < 0.05) bursa of Fabricius (1.12 g) than MF and Control groups (0.98 g; 0.92 g) and cecal tonsils of MF (0.38 g) and IF (0.39 g) weighted more (P < 0.05) than Controls (0.33 g). Number of jejunal and ileal PP (10.0) in IF pullets was higher (P < 0.05) than Controls (7.1). These results indicate that both MF and IF can improve development of the immune system of young and grower pullets during periods of maturation and involution of lymphoid organs.

Impaired lysosomal activity mediated autophagic flux disruption by graphite carbon nanofibers induce apoptosis in human lung epithelial cells through oxidative stress and energetic impairment

Background

Graphite carbon nanofibers (GCNF) have emerged as a potential alternative of carbon nanotubes (CNT) for various biomedical applications due to their superior physico-chemical properties. Therefore in-depth understanding of the GCNF induced toxic effects and underlying mechanisms in biological systems is of great interest. Currently, autophagy activation by nanomaterials is recognized as an emerging toxicity mechanism. However, the association of GCNF induced toxicity with this form of cell death is largely unknown. In this study, we have assessed the possible mechanism; especially the role of autophagy, underlying the GCNF induced toxicity.

Methods

Human lung adenocarcinoma (A549) cells were exposed to a range of GCNF concentrations and various cellular parameters were analyzed (up to 48 h). Transmission electron microscopy, immunofluorescent staining, western blot and quantitative real time PCR were performed to detect apoptosis, autophagy induction, lysosomal destabilization and cytoskeleton disruption in GCNF exposed cells. DCFDA assay was used to evaluate the reactive oxygen species (ROS) production. Experiments with N-acetyl-L-cysteine (NAC), 3-methyladenine (3-MA) and LC3 siRNA was carried out to confirm the involvement of oxidative stress and autophagy in GCNF induced cell death. Comet assay and micronucleus (MN) assay was performed to assess the genotoxicity potential.

Results

In the present study, GCNF was found to induce nanotoxicity in human lung cells through autophagosomes accumulation followed by apoptosis via intracellular ROS generation. Mechanistically, impaired lysosomal function and cytoskeleton disruption mediated autophagic flux blockade was found to be the major cause of accumulation rather than autophagy induction which further activates apoptosis. The whole process was in line with the increased ROS level and their pharmacological inhibition leads to mitigation of GCNF induced cell death. Moreover the inhibition of autophagy attenuates apoptosis indicating the role of autophagy as cell death process. GCNF was also found to induce genomic instability.

Conclusion

Our present study demonstrates that GCNF perturbs various interrelated signaling pathway and unveils the potential nanotoxicity mechanism of GCNF through targeting ROS-autophagy-apoptosis axis. The current study is significant to evaluate the safety and risk assessment of fibrous carbon nanomaterials prior to their potential use and suggests caution on their utilization for biomedical research.

Electronic supplementary material

The online version of this article (doi:10.1186/s12989-017-0194-4) contains supplementary material, which is available to authorized users.

Biological effects induced by Gadolinium nanoparticles on Lymphocyte A20 cell line

Gadolinium nanoparticles (GdNPs) are potential agents for MRI of lymph nodes. The aim of this study was to evaluate the in vitro effects of 1 μM, 2.5 μM and 5 μM of GdDOTA⊂CS-TPP/HA and GdDOTP⊂CS-TPP/HA NPs on A20 lymphocyte cells exposed for 6 and 24 hours. The total cellular biomass (SRB), lactate dehydrogenase activity (LDH) and oxidative stress parameters, such as reactive oxygen species generation (ROS), reduced glutathione (GSH), malondialdehyde (MDA) and advanced oxidation protein products (AOPP) were analyzed by spectrophotometric and fluorimetric methods. After cells exposure to 1 μM, 2.5 μM and 5 μM of GdDOTP⊂CS-TPP/HA NPs their viability decreased in a time- and dose-dependent manner, whereas for GdDOTA⊂CS-TPP/HA no significant changes were noticed. Both NPs formulations in doses of 1 μM, 2.5 μM, 5 μM did not affect the plasma membrane at each time point tested. The levels of ROS, MDA and AOPP increased proportionally with the concentration and exposure time. GSH concentration decreased significantly for all doses of both NPs tested. Taken together our data suggest that, GdDOTP⊂CS-TPP/HA and GdDOTA⊂CS-TPP/HA NPs induced oxidative stress in A20 lymphocyte cells which was counteracted by the cells antioxidant defense system to a certain extend.

Physico-chemical properties based differential toxicity of graphene oxide/reduced graphene oxide in human lung cells mediated through oxidative stress

Goraphene derivatives (GD) are currently being evaluated for technological and biomedical applications owing to their unique physico-chemical properties over other carbon allotrope such as carbon nanotubes (CNTs). But, the possible association of their properties with underlying in vitro effects have not fully examined. Here, we assessed the comparative interaction of three GD - graphene oxide (GO), thermally reduced GO (TRGO) and chemically reduced GO (CRGO), which significantly differ in their lateral size and functional groups density, with phenotypically different human lung cells; bronchial epithelial cells (BEAS-2B) and alveolar epithelial cells (A549). The cellular studies demonstrate that GD significantly ineternalize and induce oxidative stress mediated cytotoxicity in both cells. The toxicity intensity was in line with the reduced lateral size and increased functional groups revealed more toxicity potential of TRGO and GO respectively. Further, A549 cells showed more susceptibility than BEAS-2B which reflected cell type dependent differential cellular response. Molecular studies revealed that GD induced differential cell death mechanism which was efficiently prevented by their respective inhibitors. This is prior study to the best of our knowledge involving TRGO for its safety evaluation which provided invaluable information and new opportunities for GD based biomedical applications.

Spatane diterpinoid from the brown algae, Stoechospermum marginatum induces apoptosis via ROS induced mitochondrial mediated caspase dependent pathway in murine B16F10 melanoma cells

Spatane diterpinoids isolated from the brown marine algae Stoechospermum marginatum were known to have cytotoxic effects in human cancerous cell lines and murine melanoma cells; the underling apoptotic mechanism of diterpinoids still remains unclear so far. Thus, in the present study, the apoptotic mechanism of a spatane diterpinoid, 5(R), 19-diacetoxy-15,18(R and S), dihydro spata-13, 16(E)-diene (DDSD) was investigated mainly in B16F10 melanoma cells because they were most susceptible to DDSD than THP1, U937, COLO205, and HL60 cells. The treatment of B6F10 cells with DDSD resulted in morphological alterations, nuclear condensation, and DNA fragmentation, which leads to cell growth inhibition in a concentration-dependent manner. Data indicate that DDSD induced the generation of ROS, consequentially caused alteration in Bax/Bcl-2 ratio that disrupted the inner mitochondrial transmembrane potential (ΔΨm) resulting in cytochrome c redistribution to the cytoplasm and activation of caspase-mediated apoptotic pathway. Flow cytometric analysis clearly indicated that the DDSD inducing phosphatidylserine externalization and mediated "S-phase" arrest in cell cycle. In addition, results also found that DDSD induced apoptosis through deregulating PI3K/AKT signaling pathway. The anti-tumor activity of DDSD was evaluated in C57BL/6 mice bearing B16F10 melanoma. It effectively inhibited tumor growth (volume and weight) in a dose dependent manner, yet without apparent toxic effects. Morphology and apoptotic status of tumor tissues in the treated mice were assessed by microscopy and TUNEL assay, respectively. Our study shows a therapeutic potential of DDSD for the treatment of malignant melanoma and a new source of anticancer drugs. © 2016 Wiley Periodicals, Inc.

Redox-Sensitive Cerium Oxide Nanoparticles Protect Human Keratinocytes from Oxidative Stress Induced by Glutathione Depletion

Cerium oxide nanoparticles (CeNPs) have gathered much attention in the biomedical field due to its unique antioxidant property. It can protect cells and tissues from oxidative stress induced damage due to its autoregenerative redox cycle. Our study explores the antioxidant and antigenotoxic behavior of PEGylated CeNPs toward oxidative insult produced by buthionine sulfoximine (BSO) in human keratinocytes (HaCaT cells). BSO inhibits the γ-glutamylcysteinesynthetase (γ-GCS) enzyme and thus acts as a glutathione (GSH) depleting agent to modulate the cellular redox potential. GSH is a natural ROS scavenger present in the mammalian cells, and its depletion causes generation of reactive oxygen species (ROS). In this study, we challenged HaCaT cells (keratinocytes) with BSO to alter the redox potential within the cell and monitored toxicity, ROS generation, and nuclear fragmentation. We also followed changes in expressions of related proteins and genes. We found that PEGylated CeNPs can protect HaCaT cells from BSO-induced oxidative damage. BSO-exposed cells, preincubated with PEGylated CeNPs, showed better cell survival and significant decrease in the intracellular levels of ROS. We also observed decrease in lactate dehydrogenase (LDH) release and nuclear fragmentation in CeNP-treated cells that were challenged with BSO as compared to treatment with BSO alone. Exposure of HaCaT cells with BSO leads to altered expression of antioxidant genes and proteins, i.e., thioredoxin reductase (TrxR) and peroxiredoxin 6 (Prx6) whereas, in our study, pretreatment of PEGylated CeNPs reduces the need for induction of genes that produce enzymes involved in the defense against oxidative stress. Since, growing evidence argued the involvement of ROS in mediating death of mammalian cells in several ailments, our finding reinforces the use of PEGylated CeNPs as a potent pharmacological agent under the lower cellular GSH/GSSG ratios for the treatment of diseases mediated by free radicals.

Cytosolic phospholipase A2 (cPLA2) IVA as a potential signature molecule in cigarette smoke condensate induced pathologies in alveolar epithelial lineages

BACKGROUND

Smoking is one of the leading causes of millions of deaths worldwide. During cigarette smoking, most affected and highly exposed cells are the alveolar epithelium and generated oxidative stress in these cells leads to death and damage. Several studies suggested that oxidative stress causes membrane remodeling via Phospholipase A2s but in the case of cigarette smokers, mechanistically study is not yet fully defined. In view of present perspective, we evaluated the involvement of cytosolic phospholipase A2 (cPLA2) IVA as therapeutic target in cigarette smoke induced pathologies in transformed type I and type II alveolar epithelial cells.

METHODS

Transformed type I (WI26) and type II (A549) alveolar epithelial cells were used for the present study. Cigarette smoke condensate (CSC) was prepared from most commonly used cigarette (Gold Flake with filter) by the Indian population. CSC-induced molecular changes were evaluated through cell viability using MTT assay, reactive oxygen species (ROS) measurement using 2,7 dichlorodihydrofluorescin diacetate (DCFH-DA), cell membrane integrity using fluorescein diacetate (FDA) and ethidium bromide (EtBr) staining, super oxide dismutase (SOD) levels, cPLA2 activity and molecular involvement of specific cPLA2s at selected 24 h time period.

RESULTS

CSC-induced response on both type of epithelial cells shown significantly reduction in cell viability, declined membrane integrity, with differential escalation of ROS levels in the range of 1.5-15 folds and pointedly increased cPLA2 activity (p < 0.05). Likewise, we observed distinction antioxidant potential in these two types of lineages as type I cells had considerably higher SOD levels when compared to type II cells (p < 0.05). Further molecular expression of all cPLA2s increased significantly in a dose dependent manner, specifically cytosolic phospholipase A2 IVA with maximum manifestation of 3.8 folds. Interestingly, CSC-induced ROS levels and cPLA2s expression were relatively higher in A549 cells as compared to WI26 cells.

CONCLUSIONS

The present study indicates that among all cPLA2s, specific cPLA2 IVA are the main enzymes involved in cigarette smoke induced anomalies in type I and type II lung epithelial cells and targeting them holds tremendous possibilities in cigarette smoke induced lung pathologies.

1,3,4-Thiadiazole derivatives of R-(+)-limonene benzaldehyde-thiosemicarbazones cause death in Trypanosoma cruzi through oxidative stress

This work evaluated the in vitro and in vivo activity of TDZ 2 on Trypanosoma cruzi amastigotes and determined the possible mechanism of action of this compound on T. cruzi death. TDZ 2 inhibited T. cruzi proliferation in vitro and had low haemolytic potential. It also induced morphological and ultrastructural alterations. We observed a reduction of cell volume, the depolarization of the mitochondrial membrane, an increase in ROS production, lipoperoxidation of the cell membrane, lipid bodies formation and production of nitric oxide, a decrease in reduced thiols levels and, presence of autophagic vacuoles. The in vivo study found a reduction of parasitemia in animals treated with TDZ 2 alone or combined with benznidazole. Altogether, the alterations induced by TDZ 2 point to an oxidative stress condition that lead to T. cruzi cell death.

Aluminum Activates PERK-EIF2α Signaling and Inflammatory Proteins in Human Neuroblastoma SH-SY5Y Cells

Aluminum is the third most abundant element present in the earth's crust and human exposure to it is possible due to industrialization, utensils, medicines, antiperspirants, etc. Evidences suggest involvement of aluminum in a variety of neurodegenerative disorders including Alzheimer's disease. Endoplasmic reticulum (ER) stress has been implicated in various neurological disorders. ER stress may be a result of impaired calcium homeostasis due to perturbed redox balance and is known to elicit inflammation through the activation of unfolded protein response (UPR). In the present study, we aimed to investigate the role of aluminum in ER stress-mediated activation of inflammatory responses in neuroblastoma cells. Lactate dehydrogenase (LDH) release assay revealed that aluminum compromised the membrane integrity of neuroblastoma cells, probably due to membrane damage, as indicated by enhanced levels of lipid peroxidation (LPO). Besides this, our results clearly demonstrated elevated reactive oxygen species (ROS) levels and a weakened antioxidant defence system manifested by decrease in catalase (CAT) activity and cellular glutathione (GSH). Moreover, we studied the expression of key apoptosis-related proteins, ER stress-mediated activation of UPR, and its downstream inflammatory pathway. It was observed that aluminum potentially enhanced protein levels of PERK, EIF2α, caspase 9, caspase 3, and inflammatory markers like NF-κB, NLRP3, HMGB1, and nitric oxide (NO). Furthermore, aluminum altered TNFα, IL1β, IL6, and IL10 mRNA levels as well. The overall findings indicated that aluminum mediates UPR activation through ER stress, which results in induction of inflammatory pathway and apoptotic proteins in neuronal cells.

Mitigation in the toxicity of graphene oxide nanosheets towards Escherichia coli in the presence of humic acid

GO nanosheets have been reported to show strong cytotoxicity towards Escherichia coli (E. coli) in aqueous solution. Natural organic matters (NOMs) in water may probably coat on the surface of GO nanosheets, which possibly influence its cytotoxicity. In this study, we illustrated how humic acid (HA), a ubiquitous NOM, mitigated the toxicity of GO nanosheets towards E. coli based on the cytotoxicity mechanism of GO nanosheets. Adsorption and cell viability tests proved that HA was adsorbed by GO nanosheets and decreased the toxicity of GO nanosheets towards E. coli. It was found that HA was adsorbed on the surface of GO nanosheets by polar groups, which prevented E. coli from contacting with GO nanosheets and weakened the toxicity of GO nanosheets. Besides, HA exerted an antioxidant role in maintaining the activity of the antioxidant enzyme and decreasing the ROS generation according to the results of oxidative stress experiments. The work revealed that HA relieved the toxicity of GO nanosheets and decreased the ecological risks induced by GO nanosheets.

Cell cycle dependent cellular uptake of zinc oxide nanoparticles in human epidermal cells

Metal oxide nanoparticles (NPs), including zinc oxide (ZnO) NPs have shown success for use as vehicles for drug delivery and targeting gene delivery in many diseases like cancer. Current anticancer chemotherapeutics fail to effectively differentiate between cancerous and normal cells. There is an urgent need to develop novel drug delivery system that can better target cancer cells while sparing normal cells and tissues. Particularly, ZnO NPs exhibit a high degree of cancer cell selectivity and induce cell death, oxidative stress, interference with the cell cycle progression and genotoxicity in cancerous cells. In this scenario, effective cellular uptake of NP seems to be crucial, which is shown to be affected by cell cycle progression. In the present study, the cytotoxic potential of ZnO NPs and the effect of different cell cycle phases on the uptake of ZnO NPs were examined in A431 cells. It is shown that the ZnO NPs led to cell death and reactive oxygen species generation and were able to induce cell cycle arrest in S and G2/M phase with the higher uptake in G2/M phase compared with other phases.

Functions of innate and acquired immune system are reduced in domestic pigeons (Columba livia domestica) given a low protein diet

Racing pigeons are exposed to and act as carriers of diseases. Dietary protein requirement for their maintenance has not been determined experimentally despite their being domesticated for over 7000 years. A maintenance nitrogen (protein) requirement (MNR) for pigeons was determined in a balance study using diets containing 6, 10 and 14% crude protein (CP). Then, the effects of feeding the diets were investigated to determine whether they were adequate to sustain innate and acquired immune functions. Nitrogen intake from the 6% CP diet was sufficient to maintain nitrogen balance and body weight in pigeons. However, the immune functions of phagocytosis, oxidative burst and lymphocyte proliferation in pigeons fed this diet were reduced compared with those fed 10 and 14% CP diets. Pigeons given the 6 and 10% CP diets had lower antibody titres following inoculation against Newcastle disease (ND) than those on the 14% CP diet. A confounding factor found on autopsy was the presence of intestinal parasites in some of the pigeons given the 6 and 10% CP diets; however, none of the pigeons used to measure MNR or acquired immunity to ND were infested with parasites. In conclusion, neither the 6 nor 10% CP diets adequately sustained acquired immune function of pigeons.

PM2.5-induced oxidative stress increases adhesion molecules expression in human endothelial cells through the ERK/AKT/NF-κB-dependent pathway

The aim of this study was to explore the intracellular mechanisms underlying the cardiovascular toxicity of air particulate matter (PM) with an aerodynamic diameter of less than 2.5 µm (PM2.5) in a human umbilical vein cell line, EA.hy926. We found that PM2.5 exposure triggered reactive oxygen species (ROS) generation, resulting in a significant decrease in cell viability. Data from Western blots showed that PM2.5 induced phosphorylation of Jun N-terminal kinase (JNK), extracellular signal regulatory kinase (ERK), p38 mitogen-activated protein kinase (MAPK) and protein kinase B (AKT), and activation of nuclear factor kappa B (NF-κB). We further observed a significant increase in expressions of intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) in a time- and dose-dependent manner. Moreover, the adhesion of monocytic THP-1 cells to EA.hy926 cells was greatly enhanced in the presence of PM2.5 . However, N-acetylcysteine (NAC), a scavenger of ROS, prevented the increase of ROS generation, attenuated the phosphorylation of the above kinases, and decreased the NF-κB activation as well as the expression of ICAM-1 and VCAM-1. Furthermore, ERK inhibitor (U0126), AKT inhibitor (LY294002) and NF-κB inhibitor (BAY11-7082) significantly down-regulated PM2.5 -induced ICAM-1 and VCAM-1 expression as well as adhesion of THP-1 cells, but not JNK inhibitor (SP600125) and p38 MAPK inhibitor (SB203580), indicating that ERK/AKT/NF-κB is involved in the signaling pathway that leads to PM2.5 -induced ICAM-1 and VCAM-1 expression. These findings suggest PM2.5 -induced ROS may function as signaling molecules triggering ICAM-1 and VCAM-1 expressions through activating the ERK/AKT/NF-κB-dependent pathway, and further promoting monocyte adhesion to endothelial cells.

Resveratrol–ZnO nanohybrid enhanced anti-cancerous effect in ovarian cancer cells through ROS

The use of nanotechnology in medicine and more specifically in drug delivery is expected to spread rapidly.

The Chromone Alkaloid, Rohitukine, Affords Anti-Cancer Activity via Modulating Apoptosis Pathways in A549 Cell Line and Yeast Mitogen Activated Protein Kinase (MAPK) Pathway

The field of cancer research and treatment has made significant progress, yet we are far from having completely safe, efficient and specific therapies that target cancer cells and spare the healthy tissues. Natural compounds may reduce the problems related to cancer treatment. Currently, many plant products are being used to treat cancer. In this study, Rohitukine, a natural occurring chromone alkaloid extracted from Dysoxylum binectariferum, was investigated for cytotoxic properties against budding yeast as well as against lung cancer (A549) cells. We endeavored to specifically study Rohitukine in S. cerevisiae in the context of MAPK pathways as yeast probably represents the experimental model where the organization and regulation of MAPK pathways are best understood. MAPK are evolutionarily conserved protein kinases that transfer extracellular signals to the machinery controlling essential cellular processes like growth, migration, differentiation, cell division and apoptosis. We aimed at carrying out hypothesis driven studies towards targeting the important network of cellular communication, a critical process that gets awry in cancer. Employing mutant strains of genetic model system Saccharomyces cerevisiae. S. cerevisiae encodes five MAPKs involved in control of distinct cellular responses such as growth, differentiation, migration and apoptosis. Our study involves gene knockouts of Slt2 and Hog1 which are functional homologs of human ERK5 and mammalian p38 MAPK, respectively. We performed cytotoxicity assay to evaluate the effect of Rohitukine on cell viability and also determined the effects of drug on generation of reactive oxygen species, induction of apoptosis and expression of Slt2 and Hog1 gene at mRNA level in the presence of drug. The results of this study show a differential effect in the activity of drug between the WT, Slt2 and Hog1 gene deletion strain indicating involvement of MAPK pathway. Further, we investigated Rohitukine induced cytotoxic effects in lung cancer cells and stimulated the productions of ROS after exposure for 24 hrs. Results from western blotting suggest that Rohitukine triggered apoptosis in A549 cell line through upregulation of p53, caspase9 and down regulation of Bcl-2 protein. The scope of this study is to understand the mechanism of anticancer activity of Rohitukine to increase the repertoire of anticancer drugs, so that problem created by emergence of resistance towards standard anticancer compounds can be alleviated.