Changes In Membrane Permeability Research Articles

Lysosomal disruption, mitochondrial impairment, histopathological and oxidative stress in rat's nervous system after exposure to a neonicotinoid (imidacloprid).

Imidacloprid (IMI), a neonicotinoid pesticide, has been widely used due to its high efficiency against insect pests. However, its prolonged exposure may pose significant risks to non-target organisms, including mammals. Recent studies have raised concerns about its potential neurotoxicity, yet the underlying mechanisms remain poorly understood. This study aimed to assess the neurotoxic effects of chronic Imidacloprid exposure in Wistar rats, focusing on oxidative stress, mitochondrial dysfunction, and lysosomal disruption. Wistar rats were orally administered two doses of Imidacloprid (5mg/kg and 50mg/kg body weight) for three months. Neurotoxic effects were assessed by measuring key biochemical markers such as the enzymatic activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), and glutathione S-transferase (GST). Non-enzymatic markers, including glutathione (GSH) levels and malondialdehyde (MDA) index, were also evaluated. Mitochondrial function was assessed by analyzing oxygen consumption, swelling, and membrane permeability and histopathological changes. Lysosomal stability was examined using the Neutral Red Retention Time (NRRT) assay. Neutral red is a dye that accumulates in the acidic environment of lysosomes. Healthy lysosomes retain the dye, while compromised lysosomes lose it, indicating destabilization. By measuring the amount of neutral red retained in lysosomes, the NRRT assay assesses lysosomal integrity. Lysosomal pH variations were also monitored to evaluate functional changes. Microscopic analysis provided insight into structural changes in lysosomes and other cell components. Lysosomal destabilization was further confirmed by morphological alterations observed through light microscopy, revealing a progressive, time-dependent degeneration of lysosomal structures, including lysosomal expansion, neutral red dye leakage, and cell rounding. These changes reflected a temporal evolution of lysosomal damage, progressing from minor structural disruptions to more severe alterations as exposure continued, observable at the microscopic level. During the study, clinical observations of intoxicated rats included symptoms such as lethargy, reduced activity levels, and impaired motor coordination. High-dose Imidacloprid exposure led to noticeable behavioral changes, including decreased exploratory behavior and altered grooming patterns. Additionally, signs of neurotoxic effects, such as tremors or ataxia, were observed in the rats exposed to the higher dose, reflecting the systemic impact of chronic pesticide exposure. The results revealed a significant decrease in the enzymatic activities of CAT, GPx, and SOD, accompanied by an increase in GST activity. A notable reduction in glutathione levels and a rise in MDA index were observed, indicating enhanced oxidative stress in the brain. Mitochondrial impairment was evidenced by disturbances in oxygen consumption, increased swelling, and altered membrane permeability. Lysosomal destabilization was confirmed by reduced retention of neutral red dye, structural changes in lysosomes, and a significant rise in lysosomal pH in the IMI-exposed groups. In addition, the histopathological features indicate that imidacloprid at the given dose and exposure duration may have caused notable neurotoxic effects in Wistar rat brain tissue. Chronic exposure to Imidacloprid induces oxidative stress, mitochondrial dysfunction, lysosomal disruption and histopathological alterations in the central nervous system of Wistar rats. These findings provide valuable insights into the neurotoxic mechanisms of neonicotinoid pesticides, highlighting the need for further research to understand the long-term effects of Imidacloprid exposure on mammalian health.

Membrane-Targeting Amphiphilic Honokiol Derivatives Containing an Oxazole Moiety as Potential Antibacterials against Methicillin-Resistant Staphylococcus aureus.

Infections with methicillin-resistant Staphylococcus aureus (MRSA) are becoming increasingly serious, making the development of novel antimicrobials urgent. Here, we synthesized some amphiphilic honokiol derivatives bearing an oxazole moiety and investigated their antibacterial and hemolytic activities. Bioactivity evaluation showed that E17 possessed significant in vitro antibacterial activity against S. aureus and MRSA, along with low hemolytic activity. Moreover, E17 exhibited rapid bactericidal properties and was not susceptible to resistance. Mechanistic studies indicated that E17 interacts with phosphatidylglycerol and cardiolipin of bacterial cell membranes, leading to changes in cell membrane permeability and polarization, increased intracellular ROS, and leakage of DNA and proteins, thus accelerating bacterial death. Transcriptome analysis further demonstrated that E17 has membrane-targeting effects, affecting the expression of genes related to cell membranes and ABC transporter proteins. Notably, in vivo activity showed that E17 has prominent anti-MRSA efficacy, comparable to vancomycin, and is expected to be a new anti-MRSA drug candidate.

Antibacterial Activity and Mechanism of Taxillμs chinensis (DC.) Danser and Its Active Ingredients

Taxillμs chinensis (DC.) Danser is a traditional Chinese herbal medicine. It has not been reported regarding antibacterial active ingredients and mechanisms of action. However, the Chinese patent medicine Yinhua Miyanling Tablets containing Taxillμs chinensis has an obvious anti-infective effect in our patent. Therefore, we speculate that Taxillμs chinensis may have antibacterial activity. The purpose of this paper is to study the antibacterial effect and mechanism of Taxillμs chinensis and find active compounds with antibacterial activity and a mechanism. We studied the antibacterial effect and mechanism of Taxillμs chinensis extract. The compounds in the ethyl acetate extract of Taxillμs chinensis were preliminarily identified by UPLC-Q-Orbitrap and analyzed by mass spectrometry. Above all, the antibacterial effect and antibacterial mechanism of the active components of Taxillμs chinensis were determined. Finally, we found, for the first time, that Taxillμs chinensis has a good antibacterial effect and ethyl acetate extract has the best effect. In addition, we found, for the first time, that it has an active component, 4-indolecarbaldehyde, and the component has a good broad-spectrum antibacterial effect. Above all, the active chemical 4-indolecarbaldehyde of Taxillμs chinensis can destroy the bacterial structure, make it unable to maintain normal morphology, and significantly increase the number of deaths. In short, Taxillμs chinensis has an antibacterial effect, and one of its main antibacterial components is 4-indolecarbaldehyde. The antibacterial mechanism of Taxillμs chinensis and 4-indolecarbaldehyde is related to the change in bacterial membrane permeability.

Antifungal effect of cinnamon essential oil against Penicillium oxalicum on rice noodles.

Plant essential oils have been extensively investigated for their application in food industry due to their broad antimicrobial spectrum and safety. However, rare studies investigated their application in decontaminating rice noodles from fungal contamination. In this study, the cinnamon essential oil was screened out among 12 species of plant essential oils, and its antifungal activity against Penicillium oxalicum isolated from rice noodles was investigated. Our study revealed that cinnamon essential oil inhibited the spore germination in a concentration-dependent manner, and a dosage of 0.025% (v/v) could entirely disable the spore germination. The disruption of the fungal plasma membrane was evidenced by the change of plasma membrane permeability and the leakage of cellular components. The cinnamon essential oil in vapor phase (0.00625% [v/v]) could totally inhibit the growth of fungi inoculated on rice noodles. In addition to the potential application in inactivating fungi germination on rice noodles, this study also demonstrated the feasibility of cinnamon essential as an environmental disinfectant. This study is the first report that cinnamon essential oil has been studied for decontaminating rice noodles from fungal contamination with P. oxalicum, which not only broadens the application field of plant essential oil but also provides an alternative approach for rice noodle preservation.

Antivirulence activities of Rutin-loaded chitosan nanoparticles against pathogenic Staphylococcus aureus

BackgroundStaphylococcus aureus is an infectious bacterium that is frequently found in healthcare settings and the community. This study aimed to prepare rutin-loaded chitosan nanoparticles (Rut-CS NPs) and assess their antibacterial activity against pathogenic strains of S. aureus.ResultsThe synthesized Rut-CS NPs exhibited an amorphous morphology with a size ranging from 160 to 240 nm and a zeta potential of 37.3 mV. Rut-CS NPs demonstrated significant antibacterial activity against S. aureus strains. Following exposure to Rut-CS NPs, the production of staphyloxanthin pigment decreased by 43.31–89.63%, leading to increased susceptibility of S. aureus to hydrogen peroxide. Additionally, visual inspection of cell morphology indicated changes in membrane integrity and permeability upon Rut-CS NPs exposure, leading to a substantial increase (107.07–191.08%) in cytoplasmic DNA leakage in the strains. Furthermore, ½ MIC of Rut-CS NPs effectively inhibited the biofilm formation (22.5–37.5%) and hemolytic activity (69–82.59%) in the S. aureus strains.ConclusionsOur study showcases that Rut-CS NPs can serve as a novel treatment agent to combat S. aureus infections by altering cell morphology and inhibiting virulence factors of S. aureus.

Azobenzene-based liposomes with nanomechanical action for cytosolic chemotherapeutic drug delivery

The stimuli-responsive nano-carriers are at the forefront of research in nanotechnology and materials science. These advanced systems are designed to alter their physicochemical properties upon exposure to specific stimuli, enabling controllable and targeted delivery of therapeutic agents. Nevertheless, limited endosomal escape reduces the drug bioavailability in clinical use. We herein report azobenzene (Azo)-based liposomes, prepared by co-assembling the photoisomerizable cationic Azo lipids and helper lipids, which achieve controllable doxorubicin (Dox) release and enhanced cytosolic transport upon light irradiation. Azo lipids undergo reversible isomerization between cis-isomers and trans-isomer when received UV and visible (Vis) light irradiation, causing liposomal membrane permeability changes for controlled drug release. Moreover, the nanomechanical action created by the isomerization of Azo lipids promotes the endosomal escape of the liposomes. DSPC-Azo liposomes, with minimal Dox leakage, showed significant tumor cell killing upon irradiation. For in vivo study, we co-encapsulated the upconverting nanoparticles (UCNPs), which can convert the near-infrared (NIR) light into UV/Vis emissions, facilitating Azo units activation. UCNP/Dox-loaded DSPC-Azo liposomes inhibited tumor growth under NIR irradiation in a 4T1 tumor-bearing mouse model.

Discovery of new antimicrobial thiophene derivatives with activity against drug-resistant Gram negative-bacteria.

Our aim is to identify new small molecules with antimicrobial potential, especially against colistin-resistant (Col-R) Acinetobacter baumannii and Escherichia coli. After initial hits identification by fingerprint similarity, MIC of 24 heterocyclic derivatives for A. baumannii and E. coli reference strains, and bactericidal activity of selected thiophenes against Col-R strains were determined. We analyzed changes in bacterial membrane permeability and the OMPs profile. Additionally, we determined bacterial adherence to host cells and performed molecular docking studies to assess their binding to bacterial targets. The compounds' MICs ranged from 4 to >64mg/L. Thiophene derivatives 4, 5 and 8 exhibited MIC50 values between 16 and 32mg/L for Col-R A. baumannii and 8 and 32mg/L for Col-R E. coli. The time-kill curve assay demonstrated that thiophenes 4 and 8 had bactericidal effects against Col-R A. baumannii and E. coli. Furthermore, treatment with them resulted in increased membrane permeabilization and reduced adherence of these isolates to host cells. Finally, the docking studies showed a stronger binding affinity to CarO1 and Omp33 of A. baumannii and OmpW and OmpC of E. coli. These findings indicate that thiophene derivatives possess antibacterial activity against Col-R A. baumannii and E. coli, suggesting that they may enhance the repertoire of drug treatments against bacteria.

Antibiofilm and wound healing efficacy of rhamnolipid biosurfactant against pathogenic bacterium Staphylococcus aureus

The present study evaluates the in-vitro antibiofilm activity against the biofilm formed by Staphylococcus aureus, and the wound-healing efficacy of two different types of rhamnolipids produced by Pseudomonas aeruginosa strain JS29 in S.aureus infected wounds. The biosurfactant production was carried out in a mineral salt medium supplemented with 2 % Glucose and 2 % Glycerol individually and thus were designated as RL-Glu and RL-Gly respectively. 0.5 mg/ml of RL-Glu and RL-Gly demonstrated 90 % growth inhibition of S. aureus while exhibiting bactericidal activity at 4 mg/ml of RL-Glu and 1 mg/ml of RL-Gly. Both types of rhamnolipid cause changes in membrane permeability leading to pathogens’ non-viability. 90 % inhibition of biofilm formation by S. aureus was observed at 2 mg/ml of RL-Glu and 0.5 mg/ml of RL-Gly, while 0.5 mg/ml of both rhamnolipid disrupted 90 % of the preformed biofilm. 0.5 mg/ml of RL-Glu and RL-Gly decreases the production of exopolysaccharides and also causes structural alteration. 0.5 mg/ml of RL-Glu and RL-Gly were found to exhibit effective wound healing efficacy in S. aureus infected wounds within 7 days of treatment. Histopathological studies of wound sites revealed efficient wound management by both the rhamnolipid. LCMS and GCMS characterization of the biosurfactant revealed that JS29 produces different rhamnolipid congeners when grown on different carbon sources, thereby influencing the antimicrobial, antibiofilm, and wound healing efficacy of rhamnolipid.

Silver Nanoparticles with Modified Synthesis Use Sodium Borohydride Reducing Agent and Okra (Abelmoschus Esculentus L.) Raw Polysaccharide Extract as an Anti-Colon Cancer

Nanomedicine using nanoparticles has become a new trend in the treatment of colon cancer. Nanosilver is known to have antibacterial, antifungal, antidiabetic, and anticancer properties. The most common and easy way to make nanosilver is using the reducing agent sodium borohydride, but this inorganic compound element has high toxicity to the body. Polysaccharides have long been known as anticancer agents with low toxicity and few side effects. Okra (Abelmoschus esculentus L.), a flowering plant from the Malvaceae family found in tropical and subtropical areas, and the crude polysaccharide extract from the pods has the highest polysaccharide content. This research aims to determine the effect of raw okra polysaccharide extract (ORPE) as a reducing agent for making nanosilver on its ability as an anti-colon cancer cell line HCT 116. Experiments were carried out by modifying and optimizing the manufacture of AgNPs by reducing NaBH4 with ORPE, 16 concentrations each with repetition 3 times. Characteristic tests were carried out using UV-Vis Spectrophotometry, Particle Size Analyzer, Scanning Electron Microscopy, Transmission Electron Microscopy, cell viability testing with MTT assay, and evaluation of potential apoptosis and necrosis using Annexin V-PI flow cytometry. PSA test for average particle size. Two groups 1 (AgNP-NaBH4) and 2 (AgNP-ORPE) each had repeated measurements 3 times in 16 concentrations. The mean PSA test and zeta potential value for group 1 = 232.5 ± 25.47 nm / –42.23 ± 1.45 mV and 2 = 779.66 ± 112.45 nm / –23.15 ± 3.65 mV. TEM showed that the size of Group 1 was 50.85 nm (ꭓ = 113.14 nm) and Group 2 was 121.43 nm (ꭓ = 248.52 nm). SEM showed that the morphology of both groups was round in shape (group 2 with slight agglomeration). The absorbance spectrum is formed at a wavelength of 389 nm (group 1) and 281.5 nm (group 2). The IC50 value obtained by group 1 = 76.68 mmol/L with 60.3 % apoptotic cells, 3.74 % necrosis and group 2 = 92.58 mmol/L with 81.4 % apoptotic cells and 4.95 % necrosis. ORPE as a nanosilver-reducing agent has been proven to have the potential to induce cell death and cause changes in mitochondrial membrane permeability in the intrinsic pathway of apoptosis.

Vernicia fordii leaf extract inhibited anthracnose growth by downregulating reactive oxygen species (ROS) levels in vitro and in vivo.

Colletotrichum fructicola is a predominant anthracnose species in Camellia oleifera, causing various adverse effects. Traditional intercropping Vernicia fordii with C. oleifera may enhance anthracnose resistance, but the mechanism remains elusive. We utilized UPLC-MS/MS and acid-base detection to identify the major antimicrobial alkaloid components in the V. fordii leaf extract. Subsequently, by adding different concentrations of V. fordii leaf extract for cultivating C. fructicola, with untreated C. fructicola as a control, we investigated the impact of the V. fordii leaf extract, cell wall integrity, cell membrane permeability, MDA, and ROS content changes. Additionally, analysis of key pathogenic genes of C. fructicola confirmed that the V. fordii leaf extract inhibits the growth of the fungus through gene regulation. This study discovered the alkaloid composition of V. fordii leaf extract by UPLC-MS/MS and acid-base detection, such as trigonelline, stachydrine, betaine, and O-Phosphocholine. V. fordii leaf extract successfully penetrated C. fructicola mycelia, damaged cellular integrity, and increased ROS and MDA levels by 1.75 and 2.05 times respectively, thereby inhibiting C. fructicola proliferation. By analyzing the key pathogenic genes of C. fructicola, it was demonstrated that the antifungal function of V. fordii leaf extract depends mainly on the regulation of RAB7 and HAC1 gene expression. Therefore, this study elucidates the mechanism of V. fordii -C. oleifera intercropping in strengthening anthracnose resistance in C. oleifera, contributing to efficient C. oleifera cultivation.

Effect of terahertz radiation on drug activity in bacterial cells

Terahertz (THz) waves have been reported to change membrane permeability and induce conformational changes in protein molecules. Drugs action on cells involves membrane permeability, and we therefore investigated the effect of THz waves on the activity of the cytotoxic drug bleomycin on Escherichia coli. 0.46 THz radiation with an average power of 2.5 W/cm2 was noncytotoxic to E. coli cells. However, 0.46 THz radiation enhanced the cytotoxic activity of bleomycin in E. coli cells, and the drug-enhancing effect depended on the power density of the THz waves. Then, the activity of the drug remaining in the culture medium after THz radiation did not differ from that remaining after non-radiation. This indicates that THz radiation does not affect the bacterial cell-membrane permeability to bleomycin. Thus, these results suggest that 0.46 THz radiation enhances the cytotoxicity of bleomycin to E. coli cells and may influence the mechanism of bleomycin action within cells rather than affecting drug uptake.

Scatalysis: Exploring the mechanism of photocatalytic algal removal

Photocatalytic algal removal is an environmentally friendly and low-cost algal bloom control technology. In this work, carbon nitride nanosheets based on morphology control were synthesized, and a ternary Z-scheme photocatalyst was designed through heterojunction engineering for photocatalytic removal of harmful algae and their organic matter, and the removal rate of chlorophyll a was close to 100 % in 300 min. Three-dimensional fluorescence spectrograms and cellular SEM maps revealed the removal of algae and their organic matter, and the mechanism of Ag/AgCl/ZIF-8/SCN photocatalytic algal removal was explored in conjunction with the changes in membrane permeability and various physiological functions. Mechanistic studies showed that excess O2·− played a crucial role in cell inactivation and organic matter degradation. Oxidative stress caused by O2·− promoted the accumulation of H2O2 in cells and accelerates cell death. This study provides new ideas and support for the application of harmful algal bloom control and the mechanism of algal cell inactivation in real water bodies.

Preliminary Exploration of the Biophysical Mechanisms of Pulsed Magnetic Field- Induced Cell Permeabilization.

Pulsed magnetic field treatment can enhance cell membrane permeability, allowing large molecular substances that normally cannot pass through the cell membrane to enter the cell. This research holds significant prospects for biomedical applications. However, the mechanism underlying pulsed magnetic field-induced cell permeabilization remains unclear, impeding further progress in research related to pulsed magnetic field. Currently, hypotheses about the mechanism are struggling to explain experimental results. Therefore, this study developed a parameter-adjustable pulsed magnetic field generator and designed experiments. Starting from the widely accepted hypothesis of "induced electric fields by pulsed magnetic field," we conducted a preliminary exploration of the biophysical mechanisms underlying pulsed magnetic field-induced cell permeabilization. Finally, we have arrived at an intriguing conclusion: under the current technical parameters, the impact of the pulsed magnetic field itself is the primary factor influencing changes in cell membrane permeability, rather than the induced electric field. This conclusion holds significant implications for understanding the biophysical mechanisms behind pulsed magnetic field therapy and its potential biomedical applications.

Changes in Mitochondrial Membrane Potential in In Vitro Electroporation with Nano- and Microsecond Pulses.

With the introduction of nanosecond (ns) pulses, it was suggested that such pulses could be used to permeabilize intracellular membranes, including the mitochondrial membrane. The results presented thus far, however, are not conclusive. Interestingly, the effect of longer microsecond (μs) pulses on changes in mitochondria has never been investigated. We, therefore, investigated the changes in mitochondrial membrane permeability through changes in mitochondrial membrane potential (MMP) in CHO and H9c2 cells after electroporation with 4 ns, 200 ns, and 100 μs pulses. In the range of reversible electroporation, the decrease in MMP generally depended on the cell line. In CHO, ns pulses decreased MMP at lower electroporation intensities than μs. In H9c2, ns and μs were equally effective. In the range of irreversible electroporation, MMP decreased even further, regardless of pulse duration and cell type. The analysis at different time points showed that the changes in MMP within the first hour after pulse treatment are dynamic. Our results on the efficacy of ns pulses are consistent with published data, but with this study we show that μs pulses cause similar changes in MMP as ns pulses, demonstrating that electroporation affects MMP regardless of pulse duration. At the same time, however, differences in MMP changes were observed between different cell lines, indicating some dependence of MMP changes on cell type.

Curcumin‐loaded nanoparticles effectively prevent T4‐induced oxidative stress in rat heart

AbstractIn this study, we report the cardioprotective effect of the glycerol monooleate (GMO) based nanocurcumin in both in vitro and in vivo conditions under a hyperthyroid state. The heart is one of the primary target organs sensitive to the action of thyroid hormone, and slight variations in the thyroid hormone serum concentrations result in measurable changes in cardiac performance. Hyperthyroidism‐induced hypermetabolism is associated with oxidative stress and is an important mechanism responsible for the progression of heart failure. Curcumin has been known to play a protective role against oxidative stress‐related diseases like Alzheimer's, asthma, and aging due to its antioxidant properties. Nevertheless, its potent biological activity has been hindered due to its poor bioavailability. To overcome this drawback, a GMO‐based biodegradable nanoparticle (NP) formulation loaded with curcumin has been developed, and the protective effect of curcumin‐loaded NPs was compared against the native drug. Oxidative stress parameters like reactive oxygen species (ROS) release, change in mitochondrial membrane permeability, lipid peroxidation (LPx), lactate dehydrogenase (LDH) release, and the activity and protein expression of the endogenous antioxidant enzymes like superoxide dismutase, catalase (CAT) and glutathione peroxidase were evaluated. The results from in vitro showed that curcumin‐loaded NPs showed better DPPH and NO radical scavenging activity than native curcumin in a concentrations range of 2.5–20 µM. It was also observed that the nanoparticulate curcumin was comparatively more effective than native curcumin in protecting against ROS‐induced membrane damage by reducing LPx and LDH leakage at low concentrations of 5–10 µM. Further, curcumin NPs performed better in facilitating the activities of antioxidant enzymes under in vitro and in vivo conditions with respect to time and concentrations, resulting in reduced cellular ROS levels. In this scenario, we anticipate that curcumin‐loaded NPs can serve as a better antioxidant than its native counterpart in protecting the heart from oxidative stress‐related diseases.

Protium spruceanum Extract Enhances Mupirocin Activity When Combined with Nanoemulsion-Based Hydrogel: A Multi-Target Strategy for Treating Skin and Soft Tissue Infections.

The treatment of skin and soft tissue infections (SSTIs) can be challenging due to bacterial resistance, particularly from strains like MRSA and biofilm formation. However, combining conventional antibiotics with natural products shows promise in treating SSTIs. The objective of this study is to develop a nanoemulsion-based hydrogel containing Protium spruceanum extract and mupirocin and evaluate its potential for the treatment of SSTIs. The nanoemulsion was obtained by phase inversion and subsequently characterized. The antibacterial activity was evaluated in vitro against S. aureus MRSA, including the synergism of the combination, changes in membrane permeability using flow cytometry, and the anti-biofilm effect. In addition, the irritative potential was evaluated by the HET-CAM assay. The combination exhibited synergistic antibacterial activity against S. aureus and MRSA due to the extract enhancing membrane permeability. The hydrogel demonstrated suitable physicochemical properties, inhibited biofilm formation, and exhibited low irritation. The formulation was nanometric (176.0 ± 1.656 nm) and monodisperse (polydispersity index 0.286 ± 0.011). It exhibited a controlled release profile at 48 h and high encapsulation efficacy (94.29 ± 4.54% for quercitrin and 94.20 ± 5.44% for mupirocin). Therefore, these findings suggest that the hydrogel developed could be a safe and effective option for treating SSTIs.

Comparative physiological and transcriptomic analysis of sono-biochemical control over post-acidification of Lactobacillus delbrueckii subsp. bulgaricus

Thermosonication (UT) prestress treatments combining with varied fermentation patterns has been revealed as an effective method to regulate post-acidification as exerted by Lactobacillus delbrueckii subsp. bulgaricus (L. delbrueckii), but sono-biochemical controlling mechanisms remain elusive. This study employed physiological and transcriptomic analysis to explore the response mechanism of L. delbrueckii to UT-induced microstress (600 W, 33 kHz, 10 min). UT stress-induced inhibition of acidification of L. delbrueckii during (post)-fermentation was first confirmed, relying on the UT process parameters such as stress exposure duration and UT power. The significantly enhanced membrane permeability in cells treated by 600 W for 10 min than the microbes stressed by 420 W for 20 min suggested the higher dependence of UT-derived stresses on the treatment durations, relative to the ultrasonic powers. In addition, ultrasonication treatment-induced changes in cell membrane integrity enhanced and/or disrupted permeability of L. delbrueckii, resulting in an imbalance in intracellular conditions associated with corresponding alterations in metabolic behaviors and fermentation efficiencies. UT-prestressed inoculum exhibited a 21.46% decrease in the membrane potential during the lag phase compared to untreated samples, with an intracellular pH of 5.68 ± 0.12, attributed to the lower activities of H+-ATPase and lactate dehydrogenase due to UT stress pretreatments. Comparative transcriptomic analysis revealed that UT prestress influenced the genes related to glycolysis, pyruvate metabolism, fatty acid synthesis, and ABC transport. The genes encoding 3-oxoacyl-[acyl-carrier-protein] reductases I, II, and III, CoA carboxylase, lactate dehydrogenase, pyruvate oxidase, glucose-6-phosphate isomerase, and glycerol-3-phosphate dehydrogenase were downregulated, thus identifying the relevance of the UT microstresses-downregulated absorption and utilization of carbohydrates with the attenuated fatty acid production and energy metabolisms. These findings could contribute to provide a better understanding of the inactivated effects on the post-acidification of L. delbrueckii by ultrasonic pretreatments, thus providing theoretical basis for the targeted optimization of acidification inhibition efficiencies for yogurt products during chilled preservation processes.

Oxidized guanosines induce mitochondrial dysfunction and loss of viability in β-cells

The production of reactive oxygen species and oxidative stress promote β-cell dysfunction and impair insulin secretion, thereby contributing to the pathogenesis of type 2 diabetes mellitus (T2DM). The nucleobase guanine is highly sensitive to oxidation, which results in the formation of 8-oxoguanosine (8oxoG) and 8-oxodeoxyguanosine (8oxodG). The urinary excretion of 8oxoG is associated with the risk of mortality in people with T2DM, including from diabetic complications such as cardiovascular disease. However, the cellular mechanisms responsible for this association are poorly defined. Therefore, in this study, we examined the effect of 8oxoG, 8oxodG and other oxidized guanosine derivatives, on the INS-1E β-cell line. Exposure of INS-1E cells to 8oxoG and 8oxodG decreased metabolic activity and promoted cell death by apoptosis. The change in cell viability was similar to that induced by treatment of INS-1E cells with the inflammatory cytokines interleukin 1β (Il-1β) and tumour necrosis factor α (TNFα). Changes in mitochondrial membrane permeability and superoxide radical formation were also observed with 8oxoG, but there was no significant change in the oxidation state of mitochondrial cytochromes or hydrogen peroxide levels in the INS-1E cells. Interestingly, exposure to 8oxoG and 8-oxodG also increased the mRNA expression of stress response genes, including NADPH dehydrogenase quinone 1 (NQO1), and thioredoxin-interacting protein (TXNIP). Together, these results support a potential role of oxidized guanosine derivatives in the induction of β-cell dysfunction, which could be relevant to the pathogenesis of T2DM.

Isoquercitrin alleviates pirarubicin-induced cardiotoxicity in vivo and in vitro by inhibiting apoptosis through Phlpp1/AKT/Bcl-2 signaling pathway.

Introduction: Due to the cardiotoxicity of pirarubicin (THP), it is necessary to investigate new compounds for the treatment of THP-induced cardiotoxicity. Isoquercitrin (IQC) is a natural flavonoid with anti-oxidant and anti-apoptosis properties. Thus, the present study aimed to investigate the influence of IQC on preventing the THP-induced cardiotoxicity in vivo and in vitro. Methods: The optimal concentration and time required for IQC to prevent THP-induced cardiomyocyte damage were determined by an MTT assay. The protective effect was further verified in H9c2 and HCM cells using dichlorodihydrofluorescein diacetate fluorescent probes, MitoTracker Red probe, enzyme-linked immunosorbent assay, JC-1 probe, and real time-quantitative polymerase chain reaction (RT-qPCR). Rats were administered THP to establish cardiotoxicity. An electrocardiogram (ECG) was performed, and cardiac hemodynamics, myocardial enzymes, oxidative stress indicators, and hematoxylin-eosin staining were studied. Voltage-dependent anion channel 1 (VDAC1), adenine nucleotide translocase 1 (ANT1), and cyclophilin D (CYPD) were detected by qRT-PCR, and the Phlpp1/AKT/Bcl-2 axis proteins were detected by western blot, confirming that IQC markedly increased cell viability and superoxide dismutase (SOD) levels, diminished the levels of ROS and MDA, and elevated mitochondrial function and apoptosis in vivo and in vitro. Results: Results showed that IQC reduced THP-induced myocardial histopathological injury, electrocardiogram (ECG) abnormalities, and cardiac dysfunction in vivo. IQC also decreased serum levels of MDA, BNP, CK-MB, c-TnT, and LDH, while increasing levels of SOD and GSH. We also found that IQC significantly reduced VDAC1, ANT1, and CYPD mRNA expression. In addition, IQC controlled apoptosis by modulating Phlpp1/AKT/Bcl-2 signaling pathways. IQC markedly increased H9c2 and HCM cell viability and SOD levels, diminished the levels of ROS and MDA, and elevated mitochondrial function in H9c2 and HCM cells to defend against THP-induced cardiomyocyte apoptosis in vitro. The AKT inhibitor IMQ demonstrated that IQC lacked antioxidant and anti-apoptotic properties. Moreover, our data showed that IQC regulates Phlpp1 expression, thereby influencing the expression levels of p-AKT, cytochrome c, caspase-3, caspase-9, Bcl-2, and Bax. Discussion: In conclusion, our results indicate that IQC protects the changes in mitochondrial membrane permeability in cardiomyocytes by regulating the Phlpp1/AKT/Bcl-2 signaling pathway, inhibits the release of cytc from the mitochondrial inner membrane to the cytoplasm, forms apoptotic bodies, induces cell apoptosis, and reduces THP induced cardiotoxicity.

Synthesis and antibacterial properties of alkyl substituted sulfonium salt

The development of new antibacterial agents is particularly important in the battle against pathogenic microorganisms. In this study, sulfonium ions were used as the structural core to synthesize alkyl-substituted ionic compounds as antibacterial agents. The antimicrobial activity of sulfonium ionic compounds against Escherichia coli and Staphylococcus aureus was analyzed by measurement of the minimum inhibitory concentration and minimum bactericidal concentration. The effects of sulfonium salts on cell membrane integrity and permeability were investigated by detecting the extracellular proteins leakage of E. coli and S. aureus upon contact treatment, and observing the bacteria’s ultrastructural changes with transmission electron microscopy. The results showed that all the sulfonium salts exhibited resistant activity. Sulfonium salt with alkyl chain length of 16 carbon presented the strongest resistance with MIC of 30 and 3.75 μmol/L, and MBC of 120 and 60 μmol/L against E. coli and S. aureus, respectively. After treatment with sulfonium salts, the permeability of the membrane of E. coli and S. aureus cells changed, and the exudation of extracellular proteins increased significantly. The transmission electron microscope showed that the surface of the bacteria had shrunk and the cell walls had burst. The group of sulfonium salt compounds can destroy the integrity of cell membrane and change membrane permeability to achieve antibacterial purposes.