Concentration-dependent Increase Research Articles

Dynamic alterations in physiological and biochemical indicators of Cirrhinus mrigala hatchlings: A sublethal exposure of triclosan

Triclosan (TCS), a biocide used in various day-to-day products, has been associated with several toxic effects in aquatic organisms. In the present study, biochemical and hematological alterations were evaluated after 14 d (sublethal) exposure of tap water (control), acetone (solvent control), 5, 10, 20, and 50 μg/L (environmentally relevant concentrations) TCS to the embryos/hatchlings of Cirrhinus mrigala, a major freshwater carp distributed in tropic and sub-tropical areas of Asia. A concentration-dependent increase in the content of urea and protein carbonyl, while a decrease in the total protein, glucose, cholesterol, triglycerides, uric acid, and bilirubin was observed after the exposure. Hematological analysis revealed a decrease in the total erythrocyte count, hemoglobin, and partial pressure of oxygen, while there was an increase in the total leucocyte count, carbon dioxide, and partial pressure of carbon dioxide and serum electrolytes. Comet assay demonstrates a concentration-dependent increase in tail length, tail moment, olive tail moment, and percent tail DNA. An amino acid analyzer showed a TCS-dose-dependent increase in various amino acids. Sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis revealed different proteins ranging from 6.5 to 200 kDa, demonstrating TCS-induced upregulation. Fourier transform infrared spectra analysis exhibited a decline in peak area percents with an increase in the concentration of TCS in water. Curve fitting of amide I (1,700–1600 cm−1) showed a decline in α-helix and turns and an increase in β-sheets. Nuclear magnetic resonance study also revealed concentration-dependent alterations in the metabolites after 14 d exposure. TCS caused alterations in the biomolecules and heamatological parameters of fish, raising the possibility that small amounts of TCS may change the species richness in natural aquatic habitats. In addition, consuming TCS-contaminated fish may have detrimental effects on human health. Consequently, there is a need for the proper utilisation and disposal of this hazardous compound in legitimate quantities.

Cardiac Troponin Activator CK-963 Increases Cardiac Contractility in Rats.

Novel cardiac troponin activators were identified using a high throughput cardiac myofibril ATPase assay and confirmed using a series of biochemical and biophysical assays. HTS hit 2 increased rat cardiomyocyte fractional shortening without increasing intracellular calcium concentrations, and the biological target of 1 and 2 was determined to be the cardiac thin filament. Subsequent optimization to increase solubility and remove PDE-3 inhibition led to the discovery of CK-963 and enabled pharmacological evaluation of cardiac troponin activation without the competing effects of PDE-3 inhibition. Rat echocardiography studies using CK-963 demonstrated concentration-dependent increases in cardiac fractional shortening up to 95%. Isothermal calorimetry studies confirmed a direct interaction between CK-963 and a cardiac troponin chimera with a dissociation constant of 11.5 ± 3.2 μM. These results provide evidence that direct activation of cardiac troponin without the confounding effects of PDE-3 inhibition may provide benefit for patients with cardiovascular conditions where contractility is reduced.

AhR Agonistic Components in Urban Particulate Matter Regulate Astrocytic Activation and Function.

Exposure to atmospheric particulate matter (PM) has been found to accelerate the onset of neurological disorders via the induction of detrimental neuroinflammatory responses. To reveal how astrocytes respond to urban atmospheric PM stimulation, a commercially available standard reference material (SRM1648a) was tested in this study on the activation of rat cortical astrocytes. The results showed that SRM1648a stimulation induced both A1 and A2 phenotypes in astrocytes, as characterized by the exposure concentration-dependent increases in Fkbp5, Sphk1, S100a10, and Il6 mRNA levels. Studying the functional alterations of astrocytes indicated that the neurotrophic factors of Gdnf and Ngf were transcriptionally upregulated due to astrocytic A2-type activation. SRM1648a also promoted autonomous motility of astrocytes and elevated the expressions of chemokines. The aryl hydrocarbon receptor (AhR) agonistic components, such as polycyclic aromatic hydrocarbons (PAHs), were recognized to greatly contribute to SRM1648a-induced effects on astrocytes, which was confirmed by the attenuation of PM-disturbed astrocytic effects via AhR blockage. This study, for the first time, uncovered the direct regulation of urban atmospheric PM on astrocytic activation and function and traced the containing bioactive components (e.g., PAHs) with AhR agonistic activity. The findings provided new knowledge on understanding the ambiguous neurological disturbance from ambient fine PM pollution.

Comprehensive in vitro and in vivo investigations of the therapeutic potential of Jeju lava seawater salt in osteoarthritis

Salts play a crucial role in maintaining human health by regulating fluid levels and supporting various physiological processes. However, conventional seawater-derived salts are associated with microplastic pollution and pose potential health risks. Jeju lava seawater (JLS), sourced exclusively from Jeju Island, has emerged as a unique alternative, free of microplastics and enriched with essential minerals such as magnesium, calcium, zinc, and iron. In this study, we investigated the effects of JLS on osteoarthritis (OA) pathogenesis, focusing on chondrocyte metabolism and OA development. We performed surgical destabilization of the medial meniscus to establish a murine model of OA. We examined the expression of catabolic and anabolic factors in JLS-treated chondrocytes. Our cell viability assay revealed that JLS treatment was not cytotoxic to chondrocytes at concentrations ≤ 0.5%. Additionally, JLS treatment resulted in a concentration-dependent increase in the expression of anabolic factors like aggrecan, SOX9, and COL2A1 while decreasing the expression of catabolic factors such as MMP3, MMP13, ADAMTS4, and ADAMTS5 in the chondrocytes stimulated with pro-inflammatory cytokines. Although not statistically significant compared to the control group, JLS intake slightly attenuated the OARSI score, osteophyte score, synovitis score, subchondral bone thickness, and osteophyte size in the mouse model of OA. Conclusively, these results suggest that JLS ameliorates OA by positively influencing chondrocyte metabolism, making it a promising therapeutic candidate for OA management.

Fluorometric and Colorimetric Method for SARS-CoV-2 Detection Using Designed Aptamer Display Particles.

SARS-CoV-2, the virus responsible for the COVID-19 pandemic, has spurred the urgent need for practical diagnostics with high sensitivity and selectivity. Although advanced diagnostic tools have emerged to efficiently control pandemics, they still have costly limitations owing to their reliance on antibodies or enzymes and require high-tech equipment. Therefore, there is still a need to develop rapid and low-cost diagnostics with high sensitivity and selectivity. In this study, we generated aptamer display particles (AdP), enabling easy fabrication of a SARS-CoV-2 detection matrix through particle PCR, and applied it to diagnosis using fluorometric and colorimetric assays. We designed two AdPs, C1-AdP and C4-AdP, displayed with SpS1-C1 and SpS1-C4 aptamers, respectively, and showed their high binding ability against SARS-CoV-2 spike protein with a concentration-dependent fluorescence increase. This enabled detection even at low concentrations (0.5 nM). To validate its use as a diagnostic tool for SARS-CoV-2, we designed a sandwich-type assay using two AdPs and high-quality aptamers targeting SARS-CoV-2 pseudoviruses. The fluorometric assay achieved a detection limit of 3.9 × 103 pseudoviruses/mL. The colorimetric assay using an amplification approach exhibited higher sensitivity, with a detection limit of 1 × 101 pseudoviruses/mL, and a broad range of over four orders of magnitude was observed.

Elucidating the mechanisms of novel thiazole-based corrosion inhibitors in carbon steel/HCl interface: An integrated approach combining experimental and computational studies

Corrosion inhibitors serve as a paramount strategy in the domain of metal protection. This study investigates the efficacy of two thiazole derivatives, namely methyl (E)-5-(4-chlorophenyl)-2-((2-(1-hydroxynaphthalen-2-yl)vinyl)amino)thiazole-4-carboxylate (ThN), and methyl (E)-5-(4-chlorophenyl)-2-((2-hydroxystyryl)amino)thiazole-4-carboxylate (ThP) in mitigating corrosion of carbon steel in a 1 mol/L hydrochloric acid medium. Electrochemical Impedance Spectroscopy (EIS), Potentiodynamic Polarization (PDP), Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy (SEM-EDX), and X-ray Diffraction analysis (XRD) were used to experimentally assess the corrosion inhibition performance of compounds under study. Experimental results revealed a concentration-dependent increase in the corrosion inhibition efficiencies of the thiazole derivatives, with ThP achieving 90 % and ThN attaining 93 %. The adsorption of both compounds adhered to the Langmuir adsorption model, indicating a physicochemical inhibition mechanism. PDP analyses revealed a mixed-type inhibitory behavior. Furthermore, SEM-EDX assessments validated the ability of the thiazole derivatives to enhance corrosion resistance. XRD studies revealed a marked decrease in corrosion-associated peaks upon the introduction of thiazole derivatives. The potential of zero charge (PZC) for the carbon steel was ascertained via EIS, clarifying the adsorption mechanism. Employing Conductor like Screening Model for Realistic Solvents (COSMO-RS), the solvation properties of the compounds were evaluated, while Quantum Chemical Calculations (QCCs) and Molecular Dynamics (MD) simulations contributed insights into reactivity descriptors and adsorption configurations on the Fe(110) surface. This study highlighted the impact of the aryl group on the adsorption and corrosion inhibition characteristics of investigated compounds, offering valuable guidance for future design and development.

Comparative Analysis of Physiochemical Properties and In Vitro Antioxidant Potency Among Morphotypes of Centella asiatica Grown in Sri Lanka

Centella asiatica commonly referred as Gotukola, is recognized for its extensive application in traditional medicine owing to its remarkable health benefits. This study investigated the differences in pH, ash content, moisture content, and in vitro antioxidant potential among three prevalent vine- type morphotypes of C. asiatica: Wel Gotukola, Meerigima Gotukola, and Yodha Gotukola, indigenous to Sri Lanka. C. asiatica plants of the same age (100 days) at their first harvestable matured stage, were randomly collected from domestic gardens in Gampaha District, Sri Lanka. Three replicates of each morphotype were sampled. Moisture and ash content were analysed using the standard AOAC method, and pH was measured using the potentiometric method. DPPH (2,2- Diphenyl-1-picrylhydrazyl) radical scavenging capacity assay was used to determine the antioxidant activity. To thoroughly compare antioxidant potential among morphotypes, the ANOVA test was utilized followed by post-hoc Tukey HSD tests. Following results were obtained for the average moisture content of Wel Gotukola (83.41%±1.16%), Yodha Gotukola (74.33%±2.23%), and Meerigama Gotukola (79.46%±1.89%), alongside average ash content of Wel Gotukola (11.60%±1.02%), Yodha Gotukola (13.12%±2.57%), and Meerigama Gotukola (12.17%±2.01%). Additionally, an average pH of Wel Gotukola (6.00±0.21), Yodha Gotukola (5.75±0.25), and Meerigama Gotukola (5.98±0.14) was observed. The antioxidant activity of C. asiatica extracts exhibited concentration dependent increases in radical scavenging capacity. Notably, the DPPH radical scavenging potency, denoted by the minimum IC50 value, exhibited significant variations across different Gotukola varieties (p<0.05): Wel Gotukola (6.4 ± 0.54 µg/mL), Yodha Gotukola (8.56±0.35 µg/mL), and Meerigama Gotukola (7.0±0.75 µg/mL). Post-hoc Tukey tests showed antioxidant activity was significantly higher in Wel Gotukola compared to that of Meerigama and Yodha Gotukola morphotypes (p<0.05). Furthermore, Wel Gotukola demonstrated the highest average pH, moisture content, and the lowest mineral content. Conversely, Yodha Gotukola exhibited the lowest pH, moisture content, and the highest ash content. These findings underscore the potential of chemical parameters in elucidating the distinctive attributes of the three Gotukola varieties. Specifically, the significantly higher antioxidant potential observed in Wel Gotukola suggests its potential as an optimal candidate for herbal product development. This study imparts valuable insights into optimizing the therapeutic efficacy of formulations based on the specific C. asiatica employed in such endeavours.
 
 Keywords: Antioxidant activity, Centella asiatica, Morphotypes, Proximate analysis

Ethanol-based solubility-enabling oral drug formulation development: Accounting for the solubility-permeability interplay

The aim of the current work was to investigate the key factors that govern the success/failure of an ethanol-based solubility-enabling oral drug formulation, including the effects of the ethanol on the solubility of the drug, the permeability across the intestinal membrane, the drug's dissolution in the aqueous milieu of the gastrointestinal tract (GIT), and the resulting solubility-permeability interplay. The concentration-dependent effects of ethanol-based vehicles on the solubility, the in-vitro Caco-2 permeability, the in-vivo rat permeability, and the biorelevant dissolution of the BCS class II antiepileptic drug carbamazepine were studied, and a predictive model describing the solubility-permeability relationship was developed. Significant concentration-dependent solubility increase of CBZ was obtained with increasing ethanol levels, that was accompanied by permeability decrease, both in Caco-2 and in rat perfusion studies, demonstrating a tradeoff between the increased solubility afforded by the ethanol and a concomitant permeability decrease. When ethanol absorption was accounted for, an excellent agreement was achieved between the predicted permeability and the experimental data. Biorelevant dissolution studies revealed that minimal ethanol levels of 30 % and 50 % were needed to fully dissolve 1 and 5 mg CBZ dose respectively, with no drug precipitation.In conclusion, key factors to be accounted for when developing ethanol-based formulation include the drug's solubility, permeability, the solubility-permeability interplay, and the drug dose intended to be delivered. Only the minimal amount of ethanol sufficient to solubilize the drug dose throughout the GIT should be used, and not more than that, to avoid unnecessarily permeability loss, and to maximize overall drug absorption.

Вплив амфіфільних сполук на форму та ериптоз еритроцитів людини в умовах постгіпертонічного шоку

The search for protective substances that can be used during red blood cell thawing and the study of their effects on red blood cells contribute to increasing the number and quality of viable cells after the cryopreservation cycle. We studied the effect of posthypertonic shock and amphiphilic compounds on the shape and eryptosis of human erythrocytes. The method of flow cytometry was used, this allows analyzing two parameters simultaneously, which increases the efficiency of research. The shape was assessed by the sphericity index (SphI), and eryptosis by the redistribution of phosphatidylserine to the membrane outer surface. It has been shown that sodium decylsulfate and chlorpromazine reduce erythrocyte damage in posthypertonic shock by 3.6 and 4.2 times, respectively. Sodium decylsulfate helps to preserve the shape of cells (SphI coefficient remains the same), while when chlorpromazine is used, the shape changes towards spherical (SphI coefficient changes 2 times). The study of the level of Annexin V FITC binding to phosphatidylserine in outer layer of membrane revealed a concentration-dependent increase in fluorescence when sodium decylsulfate was used, indicating a disorder of the bilayer asymmetry. In contrast, chlorpromazine did not change the distribution of phosphatidylserine. Comparison of two parameters of cell viability - the sphericity coefficient and anexin binding - allowed us to choose the conditions that are optimal for the use of the studied protective substances. Namely, it is advisable to use the lowest effective concentration of sodium decylsulfate (200 mcmol/l) for protective purposes. This ensures the preservation of the cell shape and minimal impact on the membrane asymmetry.

Tris(1,3-dichloro-2-propyl) phosphate disrupts cellular metabolism within human embryonic kidney (HEK293) cells

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is a widely used, additive flame retardant that migrates from end-use products, leading to ubiquitous exposure of humans around the world. However, little is known about whether TDCIPP disrupts the physiology of human embryonic cells. Therefore, the objective of this study was to determine whether TDCIPP alters cell viability, cellular metabolism, cytosine methylation, and reactive oxygen species (ROS) levels within human embryonic kidney (HEK293) cells. Relative to vehicle controls, TDCIPP (0.015–0.1225 µM) resulted in a concentration-dependent increase in cell viability, a finding that was driven by an increase in relative ATP abundance. Interestingly, TDCIPP (0.061–0.98 µM) increased the rate of glycolysis – an adaptive mechanism consistent with the Warburg effect exhibited by tumorigenic cells. Moreover, relative to vehicle-treated cells, TDCIPP (0.245–15.63 µM) exposure for 48 h (but not 24 h) resulted in a significant, concentration-dependent decrease in ROS in situ, and TDCIPP (0.245 µM) exposure significantly increased carnosine within the histidine metabolism pathway. However, TDCIPP did not affect global 5-methylcytosine (5-mC) methylation (0.015–15.63 µM), cell membrane integrity (0.061–0.98 µM), nor the abundance of mitochondria (0.061–1.95 µM). Overall, our findings with TDCIPP point to a novel mechanism of action that may be relevant to human embryonic stem cells.

P1212 Effects of Enterococcus faecalis-derived Gelatinase E on HCT116 colorectal cancer cells

Abstract Background The leading cause of death in colorectal cancer (CRC) patients is metastasis to crucial organs, such as the lung, brain and liver. The tumour microenvironment (TME) influences metastasis heavily. One important component in the TME of CRC is the microbiota. Microbiota can affect several pathways related to the origin of metastasis and reorganization of the extracellular matrix. One of the possible contributors to early CRC metastasis is Enterococcus faecalis. E. faecalis produces Gelatinase E (GelE), a quorum-sensing protein with collagenolytic properties. The primary goal of our study was to determine the effect of GelE on CRC behaviour, and especially on migration and invasion in HCT-116 human CRC cells. Moreover, we aimed to uncover the underlying pathways by which GelE influences CRC cells. Methods Extracellular GelE was purified from E. faecalis strain V583 from the culture medium. HCT-116 cells were cultured and exposed to different concentrations of GelE. We performed a viability assay using CCK-8 to assess potential toxicity of GelE. To test effects of GelE on collagen structure, we measured stiffness of collagen-I. A transwell assay was used to assess the influence of GelE on invasive capacity of cells through a collagen-I matrix. GelE exposed cells were assessed for shape and motility markers using immunofluorescent staining for β-catenin (cell shape) and loss of E-cadherin (cell motility marker). For mechanistic insight of GelE exposure on HCT116, we performed proteomics analysis on the cells. Results GelE treatment did not affect relative cell viability of HCT116 cells up to a concentration of 100 μg/ml. Exposure to GelE caused a concentration-dependent increase in HCT-116 cell invasion through collagen-I. The immunostainings showed a downregulation of E-cadherin, indicating an induction of cell motility. Immunostaining for β-catenin showed a statistically significant effect on cell shape, becoming more elongated, an additional indication of cell motility. Proteomics showed possible mechanistic pathways that explain the increased motility including activation of the SMAD pathway, RhoGTPAse activation and activation the urokinase-plasminogen system. Reactome database analysis on the proteomics data also revealed an increase in cell-cycle related pathways. Conclusion Our results indicate that E. faecalis-derived GelE drives HCT-116 invasion with an elongated motility. Therefore, drugs inhibiting the activity of GelE could decrease the risk of metastasis in patients with a high E. faecalis V583 abundance in the TME.

Azadirachta indica (AI) leaf extract coated ZnO-AI nanocore–shell particles for enhanced antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA)

With the rise in microbial resistance to traditional antibiotics and disinfectants, there is a pressing need for the development of novel and effective antibacterial agents. Two major approaches being adopted worldwide to overcome antimicrobial resistance are the use of plant leaf extracts and metallic nanoparticles (NPs). However, there are no reports on the antibacterial potential of NPs coated with plant extracts, which may lead to novel ways of treating infections. This study presents an innovative approach to engineer antibacterial NPs by leveraging the inherent antibacterial properties of zinc oxide NPs (ZnO NPs) in combination with Azadirachta indica (AI) leaf extract, resulting in enhanced antibacterial efficacy. ZnO NPs were synthesised by the precipitation method and subsequently coated with AI leaf extract to produce ZnO-AI nanocore–shell structures. The structural and morphological characteristics of the bare and leaf extract coated ZnO NPs were analysed by x-ray diffraction and field emission scanning electron microscopy, respectively. The presence of an AI leaf extract coating on ZnO NPs and subsequent formation of ZnO-AI nanocore–shell structures was verified through Fourier transform infrared spectroscopy and photoluminescence techniques. The antibacterial efficacy of both ZnO NPs and ZnO-AI nanocore–shell particles was evaluated against methicillin-resistant Staphylococcus aureus using a zone of inhibition assay. The results showed an NP concentration-dependent increase in the diameter of the inhibition zone, with ZnO-AI nanocore–shell particles exhibiting superior antibacterial properties, owing to the combined effect of ZnO NPs and the poly phenols present in AI leaf extract. These findings suggest that ZnO-AI nanocore–shell structures hold promise for the development of novel antibacterial creams and hydrogels for various biomedical applications.

Behavioral, Biometric and Oxidative Stress-Induced Alterations in Clarias gariepinus Juveniles Exposed to Chlorpyrifos

Chlorpyrifos is an organophosphate pesticide used to kill wide range of pest including insect and worms. The present study investigates the behavioral, biometric and oxidative stress alterations in Clarias gariepinus juveniles exposed to chlorpyrifos. The 96 h LC50 values of the pesticide estimated by probit analysis was 4.67 mg/L while the toxic unit was 21.41 indicating that the pesticide is very toxic. Fish were exposed to chlorpyrifos sublethal concentrations of 0.43 mg/L and 0.93 mg/L and the behavioral, biometric and oxidative stress parameters were determined on day 1, 5, 10, and 15. The results indicate changes in the behavior and hepatosomatic indices in C. gariepinus at different chlorpyrifos concentrations and time. There were concentration and duration dependent increase in lipid peroxidation, protein and glucose but mixed trends in catalase values. The use of chlopyrifos in the environment especially near aquatic ecosystem should be strictly monitored to avoid the hazards associated with its application.

Palmitate induces integrated stress response and lipoapoptosis in trophoblasts

Maternal obesity increases the risk of childhood obesity and programs the offspring to develop metabolic syndrome later in their life. Palmitate is the predominant saturated free fatty acid (FFA) that is transported across the placenta to the fetus. We have recently shown that saturated FFA in the maternal circulation as a result of increased adipose tissue lipolysis in third trimester of pregnancy induces trophoblast lipoapoptosis. Here, we hypothesized that palmitate induces integrated stress response by activating mitogen-activated protein kinases (MAPKs), endoplasmic reticulum (ER) stress and granular stress and lipoapoptosis in trophoblasts. Choriocarcinoma-derived third-trimester placental trophoblast-like cells (JEG-3 and JAR) referred as trophoblasts were exposed to various concentrations of palmitate (PA). Apoptosis was assessed by nuclear morphological changes and caspase 3/7 activity. Immunoblot and immunofluorescence analysis was performed to measure the activation of MAPKs, ER stress and granular stress response pathways. Trophoblasts exposed to pathophysiological concentrations of PA showed a concentration-dependent increase in trophoblast lipoapoptosis. PA induces a caspase-dependent trophoblast lipoapoptosis. Further, PA induces MAPK activation (JNK and ERK) via phosphorylation, and activation of ER stress as evidenced by an increased phosphorylation eIF2α & IRE1α. PA also induces the activation of stress granules formation. Two pro-apoptotic transcriptional mediators of PA-induced trophoblast lipoapoptosis, CHOP and FoxO3 have increased nuclear translocation. Mechanistically, PA-induced JNK is critical for trophoblast lipoapoptosis. However, PA-induced activation of ERK and stress granule formation were shown to be cell survival signals to combat subcellular stress due to PA exposure. In conclusion, PA induces the activation of integrated stress responses, among which small molecule inhibition of JNK demonstrated that activation of JNK is critical for PA-induced trophoblast lipoapoptosis and small molecule activation of stress granule formation significantly prevents PA-induced trophoblast lipoapoptosis.

Neurotoxic pesticides change respiratory parameters in early gill-breathing, but not in skin-breathing life-stages of zebrafish (Danio rerio)

Neurotoxic compounds can interfere with active gill ventilation in fish, which might lead to premature death in adult fish, but not in skin-breathing embryos of zebrafish, since these exclusively rely on passive diffusion across the skin. Regarding lethality, this respiratory failure syndrome (RFS) has been discussed as one of the main reasons for the higher sensitivity of adult fish in the acute fish toxicity test (AFT), if compared to embryos in the fish embryo toxicity test (FET). To further elucidate the relationship between the onset of gill respiration and death by a neurotoxic mode of action, a comparative study into oxygen consumption (MO2), breathing frequency (fv) and amplitude (fampl) was performed with 4 d old skin-breathing and 12 d old early gill-breathing zebrafish. Neurotoxic model substances with an LC50 FET/AFT ratio of > 10 were used: chlorpyrifos, permethrin, aldicarb, ziram, and fluoxetine. Exposure to hypoxia served as a positive control, whereas aniline was tested as an example of a narcotic substance interfering non-specifically with gill membranes. In 12 d old larvae, all substances caused an increase in MO2, fv and partly fampl, whereas effects were minor in 4 d old embryos. An increase of fv in 4 d old embryos following exposure to chlorpyrifos, aldicarb and hypoxia could not be correlated with an increased MO2 and might be attributed either to (1) to the successfully postponed decrease of arterial partial pressure of oxygen (PO2) through support of skin respiration by increased fv, (2) to an unspecific stimulation of the sphincter muscles at the base of the gill filaments, or (3) to the establishment of oxygen sensing for later stages. In gill-breathing 12 d old zebrafish, a concentration-dependent increase of fv was detected for aniline and chlorpyrifos, whereas for aldicarb, fluoxetine and permethrin, a decline of fv at higher substance concentrations was measured, most likely due to the onset of paralysis and/or fatigue of the gill filament sphincter muscles. Since alterations of fv serve to postpone the decrease in arterial PO2 and MO2 increased with decreasing fv, the respiratory failure syndrome could clearly be demonstrated in 12 d old zebrafish larvae. Passive respiration across the skin in zebrafish embryos could thus be confirmed as a probable reason for the lower sensitivity of early life-stages to neurotoxicants. Integration of respiratory markers into existing testing protocols with non-protected developmental stages such as embryos might help to not underestimate the toxicity of early life-stages of fish.

Polyethylene microplastics affect behavioural, oxidative stress, and molecular responses in the Drosophila model.

The escalating presence of microplastic pollution poses a significant environmental threat, with far-reaching implications for both ecosystems and human health. This study investigated the toxicological impact of polyethylene microplastics (PE MPs) using Drosophila melanogaster, fruit flies, as a model organism. Drosophila were exposed to PE MPs orally at concentrations of 1 mg ml-1 and 10 mg ml-1 agar food. The study assessed behavioural parameters and biochemical markers including reactive oxygen species (ROS), superoxide dismutase (SOD), and glutathione-S-transferase (GST) activity. The expression levels of key genes (Hsp70Bc, rpr, and p53) were also analysed using the RT-qPCR technique. Results indicated a significant decline in climbing activity among adult flies and crawling behaviour in larvae, indicating potential disruption of motor function. Biochemical analysis revealed elevated ROS levels, indicative of oxidative stress, in both larval and fly stages. Moreover, the antioxidant defence system exhibited decreased SOD activity and a concentration-dependent increase in GST activity indicating the functioning of a quick xenobiotic clearance mechanism. Gene expression analysis demonstrated upregulation of rpr, p53, and Hsp70Bc genes, suggesting activation of cell death pathways and stress response mechanisms. Overall, these findings underline the adverse effects of PE MPs on Drosophila, including behavioural impairment, oxidative stress, and activation of stress response pathways.

Study on SH-SY5Y autophagy inhibition and apoptosis induced by methanol extract of Zanthoxylum armatum DC. based on mTOR signal pathway

Abstract Background Zanthoxylum armatum DC. (ZADC) is a novel food raw material resource, offering both edible and medicinal properties. Recent research has unveiled the toxic nature of ZADC, particularly its close association with the nervous system. In a prior study, we observed that administering methanol extract of Zanthoxylum armatum DC. (MZADC) to rats via gavage at a dose of 1.038 g/kg resulted in various neurotoxicity symptoms, including excessive salivation, reduced mobility, unsteady gait, muscle twitching, and altered respiratory rates. Materials and methods We conducted cell-based research to assess the safety of ZADC and elucidate its potential toxic mechanism. In addition, we used experimental methods such as Cell Counting Kit-8, Western blot, and Flow cytometry to detect cytotoxicity in SH-SY5Y cells after intervention with MZADC. Results Following exposure of SY-SY5Y cells with MZADC, a substantial decline in cell viability was observed, accompanied by a concentration-dependent increase in intracellular reactive oxygen species (ROS) levels. Additionally, MZADC induced cellular oxidative stress, leading to elevated malonic dialdehyde (MDA) and superoxide dismutase (SOD) concentrations while decreasing glutathione (GSH) levels. Furthermore, MZADC induced apoptosis at varying doses (20, 40, and 60 μg/mL), and this effect was associated with increased Caspase-3, Bax expressions, and reduced Bcl2 and Bcl2/Bax expressions. In addition, the investigation revealed that MZADC induced autophagy inhibition in SH-SY5Y cells by activating the mTOR signaling pathway, resulting in a decrease in LC3II/LCI and Beclin-1, while increasing p-mTOR/mTOR, p62. Conclusion Consequently, this study suggests that MZADC triggers the mTOR pathway through oxidative stress in SH-SY5Y cells, ultimately leading to apoptosis. Understanding the toxicity mechanisms associated with ZADC can offer a valuable theoretical and experimental basis for its development and utilization.

Modulation of Aβ 16-22 aggregation by glucose.

The self-assembly of amyloid-beta (Aβ) peptides into fibrillar structures in the brain is a signature of Alzheimer's disease. Recent studies have reported correlations between Alzheimer's disease and type-2 diabetes. Structurally, hyperglycemia induces covalent protein crosslinkings by advanced glycation end products (AGE), which can affect the stability of Aβ oligomers. In this work, we leverage physics-based coarse-grained molecular simulations to probe alternate thermodynamic pathways that affect peptide aggregation propensities at varying concentrations of glucose molecules. Similar to previous experimental reports, our simulations show a glucose concentration-dependent increase in Aβ aggregation rates, without changes in the overall secondary structure content. We discovered that glucose molecules prefer partitioning onto the aggregate-water interface at a specific orientation, resulting in a loss of molecular rotational entropy. This effectively hastens the aggregation rates, as peptide self-assembly can reduce the available surface area for peptide-glucose interactions. This work introduces a new thermodynamic-driven pathway, beyond chemical cross-linking, that can modulate Aβ aggregation.

Detection of γ-OHPdG in Circulating Tumor Cells of Patients With Hepatocellular Carcinoma as a Potential Prognostic Biomarker of Recurrence

Background and AimsBlood-based biomarkers for hepatocellular carcinoma (HCC) and its recurrence is lacking. We previously showed that hepatic γ-hydroxy-1,N2-propano-2′-deoxyguanosine (γ-OHPdG), an endogenous DNA adduct derived from acrolein by lipid peroxidation, increased during hepatocarcinogenesis. Additionally, higher hepatic γ-OHPdG from HCC patients after surgery were strongly associated with poor survival (P < .0001) and recurrence-free survival (P = .007) (Fu Y et al., Hepatology, 2018). These findings suggest that γ-OHPdG is a potential prognostic biomarker for HCC and its recurrence. To attain the goal of using γ-OHPdG as a biomarker in future preventive and therapeutic trials, we developed a blood-based method to detect γ-OHPdG in circulating liver tumor cells from HCC patient blood. MethodsWe first established the specificity of anti-γ-OHPdG antibody by determining its dose-response in HepG2 cells treated with acrolein. Then, HepG2 cells in spiked blood of healthy volunteers (HV) and circulating tumor cells (CTCs) from 32 HCC patients were isolated using a RosetteSep™ CD45 Depletion Cocktail and Ficoll Paque. The HCC CTCs identified with anti-asialoglycoprotein receptor 1, a surface protein expressed solely in hepatocytes, were stained with an anti-γ-OHPdG antibody. The number of total HCC CTCs and γ-OHPdG-positive CTCs, as well as the staining intensity, were quantified using a MetaMorph software. As an initial effort toward its clinical application, we also evaluated γ-OHPdG in CTCs from these patients along with certain clinical features. ResultsThe γ-OHPdG antibody specificity was demonstrated by an acrolein concentration-dependent increase of γ-OHPdG-positive HepG2 cells and the intensity of γ-OHPdG staining. The recovery of HepG2 cells from spiked blood was ∼50-60%, and the positivity rate of CTCs in blood from 32 patients with advanced HCC was 97%. The MetaMorph analysis showed a wide variation among patients in total number of CTCs, γ-OHPdG positivity, and staining intensity. Statistical analysis revealed γ-OHPdG in CTCs of these patients appear to be associated with multifocality and poor differentiation. ConclusionsA blood-based method was developed and applied to HCC patients to evaluate the potential of γ-OHPdG in CTCs as a prognostic biomarker.

Evaluation of the Insecticidal Efficacy of Aloe vera L. Leaf Powder on Adult Bean Weevil (Callosobruchus maculatus (F.))

In Sub-Saharan Africa, Callosobruchus maculatus is a significant pest that grossly reduces cowpea yield, leading to economic crop losses and shortages in cowpea supply. Traditional plant powders prepared from indigenous plant parts have been used to provide ecologically tolerable and potentially safe pesticides against this pest. This study evaluated the insecticidal efficiency of Aloe vera leaf powder against adult C. maculatus in cowpea. The toxicity of A. vera leaf powder was assessed using contact toxicity method in cowpea variety black eye at 48 hours and 30 days post treatment. Seed damage rate of C. maculatus was assessed at six treatments (0g/20g, 0.5 g/20 g, 1.0 g/20 g, 1.5 g/20 g, 2.0 g/20 g and 2.5 g/20 g cowpea seeds) using a randomized design, estimating parameters like percentage damage, seed weight loss and adult exit hole after 30 days. The study found no mortality of C. maculatus after 48 hours of infested cowpea seed exposure to A. vera leaf powder. However, a concentration dependent increase in toxicity and decrease in seed damage was observed after 30 days exposure to A. vera leaf powder. Furthermore, maximum mortality of 10.33%, resulting in a 3.33% seed damage reduction, was observed at 2.0 grams of A. vera treatment. The results suggest that A. vera has a low insecticidal effects and low efficacy in protecting against C. maculatus seed damage rates. The bioactive chemicals of the A. vera leaf extracts should be explored to create a potent biopesticide for preventing cowpea loss and enhancing food security.