Cell Membrane Lipid Peroxidation Research Articles

Synergistic bactericidal effect of ultrasound combined with citral nanoemulsion on Salmonella and its application in the preservation of purple kale.

In this study, a novel citral nanoemulsion (CLNE) was prepared by ultrasonic emulsification. The synergistic antibacterial mechanism of ultrasound combined with CLNE against Salmonella Typhimurium and the effect on the physicochemical properties of purple kale were investigated. The results showed that the combined treatment showed obviously inactivate effect of S. Typhimurium. Treatment with 0.3mg/mL CLNE combined with US (20kHz, 253W/cm2) for 8min reduced S. Typhimurium populations in phosphate-buffered saline (PBS) by 9.05 log CFU/mL. Confocal laser scanning microscopy (CLSM), flow cytometry (FCM), protein and nucleic acid release assays showed that the US combination CLNE disrupt the integrity of S. Typhimurium membranes. Reactive oxygen species (ROS) and malondialdehyde (MDA) detection indicated that US+CLNE exacerbated oxidative stress and lipid peroxidation in cell membranes. The morphological changes of cells after different treatments by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) illustrated that the synergistic effect of US+CLNE treatment changed the morphology and internal microstructure of the bacteriophage cells. Application of US+CLNE on purple kale leaves for 6min significantly (P<0.05) reduced the number of S. Typhimurium, but no changes in the physicochemical properties of the leaves were detected. This study elucidates the synergistic antibacterial mechanism of ultrasound combined with CLNE and provides a theoretical basis for its application in food sterilization.

Ferroptosis and glaucoma: implications in retinal ganglion cell damage and optic nerve survival.

Ferroptosis and glaucoma: implications in retinal ganglion cell damage and optic nerve survival.

Risk Factors of Cholangiocarcinogenesis in Parasitization of a Natural Focal Ecopathogen Helminth &lt;i&gt;Opisthorchis felineus&lt;/i&gt;

Epidemiological researches, carried out by professor A.A. Shain in Ob-Irtysh basin of Tyumen region, have allowed to consider chronic opisthorchiasis as facultative liver precancer and develop the original concept of cholangiocarcinogenesis on the background of long-term invasion by trematode Opisthorchis felineus of hepatobiliary system of the body. According to this concept, the initiating role in cholangiocyte transformation belongs to endogenous factors secondary bile acids, having mutagenic/carcinogenic properties, which formation is mediated by helminthosis-related exogenous intestinal microflora in intrahepatic bile ducts. Obtained data confirmed content of endogenous carcinogenic factors secondary bile acids in duct bile of chronic opistorchosis patients. Cholestasis, caused by long-term parasitization of helminth Opisthorchis felineus in hepatobiliary system of the body, mediates formation of the host promoter factors, contributing to cholangiocarcinoma progression. These include: high concentration in duct bile of bile acids, products of helminths activity and lipid peroxidation of somatic cell membranes. Promoter factors of cholangiocanerogenesis are also disorders of cholangiocyte membranes structure, tissue regulation of their regeneration, DNA repair and anti-tumorigenic protection of the body. The results of the study confirm the concept of occurrence and development of the process of cholangiocarcinogenesis in chronic opistorchosis infestation, proposed by Professor A.A. Shain and allow to reasonably develop approaches to the correction of homeostasis regulation systems of the organism in the specified helminthiasis. Which also determines the secondary prevention of malignant process in ductal epithelium of hepatobiliary system in posthelminthic period.

Cellular and molecular responses to ethyl-parathion in undifferentiated SH-SY5Y cells provide neurotoxicity pathway indicators for organophosphorus impacts.

High-fidelity nonanimal screening methods are needed that can rapidly and accurately characterize organophosphorus compound (OP)-induced neurotoxicity. Herein, the efficacy of human neuroblastoma cell line (SH-SY5Y) to provide molecular and cellular responses characteristic of the OP neurotoxicity pathway was investigated in response to the OP-model compound, ethyl-parathion. Undifferentiated SH-SY5Y cells were exposed to ethyl-parathion for 30 min at 0 (control), 0.5, 2.5, 5, 10, and 25 µg/ml. Dose-responsive reductions in cell viability were observed with significant reductions at ≥10 µg/ml. From these results, ethyl-parathion exposures of 0 (control), 5, and 10 µg/ml were selected to examine bioindicators underlying the OP neurotoxicity pathway including: reactive oxygen species (ROS), cell membrane peroxidation, mitochondrial membrane potential (MMP), and apoptosis. Ethyl-parathion elicited highly significant increases in ROS relative to controls (p < .01) at both exposure concentrations, confirmed using N-acetyl cysteine (NAC) as a ROS quencher which alleviated ROS increases. A response characteristic of increased ROS exposure, cell membrane-lipid peroxidation, significantly increased (p < .05) at the highest ethyl-parathion exposure (10 µg/ml). As a likely consequence of membrane-lipid peroxidation, ethyl-parathion-induced reductions in MMP were observed with significant effects at 10 µg/ml, reducing MMP by 58.2%. As a culmination of these cellular-damage indicators, apoptosis progression was investigated by phosphatidylserine translocation where ethyl-parathion-induced dose-responsive, highly significant (p < .01) increases at both 5 and 10 µg/ml. Overall, the mechanistic responses observed in undifferentiated SH-SY5Y cells corresponded with in vivo mammalian results demonstrating potential for this nonanimal model to provide accurate OP neurotoxicology screening.

Responses of the growth, photosynthetic characteristics, endogenous hormones and antioxidant activity of Carpinus betulus L. seedlings to different light intensities.

Light is an important ecological factor that affects plant growth, survival and distribution. Carpinus betulus L. is native to central Europe and is used as an ornamental plant with strong adaptability. It is an important tree species for landscaping and timber use. What's more, the antioxidant- and anticancer-related properties of C. betulus leaf extracts are remarkable, that make it a possible raw material for medicine. Light intensity is an important environmental factor affecting the growth and physicochemical changes of C. betulus, but the mechanism of its effect on this species still remains unknown. In this study, the growth, photosynthetic characteristics, endogenous hormones and antioxidant activity responses of C. betulus seedlings to four light intensity gradients (T0: normal light; T1: 75%; T2: 50%; T3: 25% of normal light) were studied after 60 days of shading treatments. The results showed a significant effect of low light intensity on the values of the growth and physiological parameters of C. betulus. The low light intensity caused the inhibition of plant biomass accumulation and the degradation of photosynthetic capacity and stomatal behavior and aggravated the cell membrane lipid peroxidation. However, the plant height growth, leaf area, specific leaf area, photosynthetic pigment content, and contents of GA3 and ABA of C. betulus increased with decreasing light intensity. We found that C. betulus can tolerate mild (T1) and moderate (T2) shading stress by developing photoprotective mechanisms and maintaining relatively high concentrations of organic osmolytes and high antioxidant enzyme activities (superoxide dismutase, peroxidase, catalase and ascorbate peroxidase), but the ability of C. betulus to synthesize osmotic substances and enzymatic antioxidants was impaired under severe shading conditions (T3). Our results suggest that C. betulus can make effective use of low light resources by adjusting its morphology, material distribution, photosynthetic rate and antioxidant enzyme system in suitable low-light environments (50%~75% of normal light); however, light intensity levels that are too low (25% of normal light) will have adverse effects on plant growth. The results of this study provide not only new insights into the response mechanisms of C. betulus to light intensity but also a scientific basis for the cultivation and application of C. betulus in China.

HIF-1α promotes paraquat induced acute lung injury and implicates a role NF-κB and Rac2 activity

Paraquat (PQ) is a bipyridine herbicide and oral exposure is the main way of PQ exposure with a very high mortality. At present, it is believed that large number of oxygen free radicals are generated and cause lipid peroxidation of tissue and organ cell membranes after PQ is absorbed. PQ exposure could cause multiple organ dysfunction, among which acute lung injury is the most common and most serious. However, its specific mechanism is still unclear. In this study, the C57BL/6J mouse (alveolar epithelial cell-specific knockout HIF-1α) model of acute lung injury (40 mg/kg PQ) at several time pointes and a model of acute type II alveolar epithelial cell (A549, 800 μM PQ) injury constructed. The oxidative stress (ROS, MDA) and inflammatory response (IL-1β, IL-6, TNF-α) were significantly inhibited in the alveolar epithelial cell-specific knockout of HIF-1α mice and siRNA technology to inhibit HIF-1α in alveolar epithelial cells. Further proteomic analysis showed that the expression of Rac2 protein, which is closely related to oxidative stress, was significantly increased after PQ exposure. And the inhibition of Rac2 expression in vitro significantly alleviated PQ-induced oxidative stress and inflammatory response. The expression of Rac2 protein was regulated by HIF-1α. The above suggests that HIF-1α may promote oxidative stress and inflammatory response in alveolar epithelial cells by regulating the expression of Rac2, and then participate in the promotion of PQ exposure-induced acute lung injury.

Glutathione peroxidase 4 inhibition induces ferroptosis and mTOR pathway suppression in thyroid cancer

Papillary thyroid carcinoma (PTC) demonstrates significantly reduced patient survival with metastatic progression. Tumor progression can be influenced by metabolism, including antioxidant glutathione (GSH). Glutathione peroxidase 4 (GPX4) is a selenoenzyme that uses GSH as a co-factor to regulate lipid peroxidation of cell membranes during increased oxidative stress. GPX4 suppression in tumor cells can induce ferroptosis. This study aims to examine ferroptosis as a potentially critical pathway in effective targeting of thyroid cancer (TC) cells. We treated human TC cells (K1, MDA-T68, MDA-T32, TPC1) with (1S,3R)-RSL3 (RSL3), a small-molecule inhibitor of GPX4 and examined the effects on ferroptosis, tumor cell survival and migration, spheroid formation, oxidative stress, DNA damage repair response, and mTOR signaling pathway in vitro. GPX4 inhibition activated ferroptosis, inducing TC cell death, rapid rise in reactive oxygen species and effectively arrested cell migration in vitro. Suppression of mTOR signaling pathway triggered autophagy. GPX4 genetic knockdown mirrored RSL3 effect on mTOR pathway suppression. RSL3 subdued DNA damage repair response by suppressing phosphorylation of nucleophosmin 1 (NPM1). Thus, observed potent induction of ferroptosis, GPX4-dependent novel suppression of mTOR pathway and DNA damage repair response in preclinical in vitro model of TC supports GPX4 targeting for therapeutic benefit in advanced therapy-resistant thyroid cancers.

Regulation of enzymatic and non-enzymatic antioxidants in rice seedlings against chromium stress through sodium hydrosulfide and sodium nitroprusside.

Hydrogen sulfide (H2S) and nitric oxide (NO) play a well-organized protective mechanism in coping with oxidative stress induced by toxic metals. However, the comparative effects of H2S and NO on enzymatic and non-enzymatic antioxidants in plants under Cr(III) stress have not been defined. In this study, we mathematically evaluate the importance of sodium hydrosulfide (NaHS) and sodium nitroprusside (SNP) on these two antioxidant systems in rice seedlings under Cr(III) stress. The results displayed that the optimal dose of NaHS and SNP was 100μM and 75μM, respectively, in rice tissues under Cr(III) stress, judging by the reactive oxygen species (ROS) levels in rice tissues. When rice seedlings wereexposed to Cr(III) atconcentrations of3.57, 7.24, 26.52mg Cr/l, Cr-inducedROS accumulationhad a significant (p < 0.05)effecton the lipid peroxidation of cell membrane in rice tissues, and decreasedthe response of SOD, CAT, Pro, GSH, and AsA in rice tissues. Application of exogenous NaHS and SNP effectively (p < 0.05) alleviated the toxic effects of Cr(III) in rice seedlings by activating different antioxidants. A novel physiological response model suggested that the regulatory effect of NaHS and SNP on non-enzymatic antioxidants was stronger than that of enzymatic antioxidants. Moreover, NaHS-mediated response intensity of both enzymatic and non-enzymatic antioxidants was greater than that of SNP, suggesting the importance of utilizing NaHS over SNP as antioxidant regulators during detoxification of Cr(III) in rice seedlings.

Multivariate characterization of biochemical and physiological attributes of quinoa (Chenopodium quinoa Willd.) genotypes exposed to nickel stress: implications for phytoremediation.

Nickel (Ni) is an essential element for plants; however, excessive uptake of Ni causes phytotoxicity in plants. The phytotoxic effects of Ni onthe growth of quinoa and the underlaying mechanisms for Ni tolerance and phytoremediation are unknown. Hence, the present study investigated Ni tolerance and accumulation potential of two quinoa genotypes (Puno and Vikinga). Both genotypes were exposed to Ni (0, 100, 200, 300, and 400μM) in half-strength Hoagland nutrient solution for three weeks. Results revealed that shoot and root lengths, biomass, stomatal conductance, and chlorophyll contents were decreased with the increase of Ni concentration. Excessive uptake of Ni resulted in the limited uptake of K by root and its translocation to shoot. Ni caused oxidative stress in plants by overproduction of H2O2 leading to lipid peroxidation of cell membranes. Genotype Puno showed greater tolerance to Ni than Vikinga based on tolerance index, lower bioconcentration factor, and translocation factor. Greater tolerance of Puno was mainly attributed to improved physiological responses and amelioration of oxidative stress by induction of antioxidant enzymes such as peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX). It was revealed through multivariate analysis that Ni had strong negative correlations with growth and physiological attributes and positive associations with oxidative stress attributes. The study demonstrated genotypic variation in response to varying Ni concentrations and Puno performed better than Vikinga for phytostabilization of Ni-contaminated soils.

The Effect of Ramadan Fasting on Serum Malondialdehyde Levels as Indicator of Oxidative Stress and Cellular Damage

Background: Ramadan fasting is one of five pillars of Islam. Fasting is to refrain from eating and drinking from sunrise (sahur) to sunset (ifthar). Ramadan fasting has been shown to impact on body systems in different manners. One of the benefits of Ramadan fasting is protection against oxidative stress and cellular damage. Malondialdehyde (MDA) is a product of free radicals (hydroxil radicals) with polyunsaturated fatty acids (PUFAs) produced from lipid peroxidation of cell membranes. This paper aims to determine the effect of Ramadan fasting on serum MDA levels.Methods: The design of this study is quasiexperimental with one group pre and post design. The sample of this study was 16 preclinical students of FK UIN Syarif Hidayatullah Jakarta who performed Ramadan fasting for 17 consecutive days. Blood samples were taken 1 day before Ramadan fasting and 18 days of Ramadan fasting to measure serum MDA levels. The study was conducted in the biochemical laboratory of FK UIN Syarif Hidayatullah.Results: The mean serum MDA levels before fasting was 0.90 ± 0.54 nmol/mL. The median value of serum MDA levels after fasting was 0.43 nmol/mL, with a range between 0.03 - 2.75 nmol/mL. Ramadan fasting decreases serum MDA levels, but the decrease that occurs on the 17th day of Ramadan fasting was not significant (p&gt; 0.05). There was an increase in serum MDA levels in 4 subjects (25%) after Ramadan fasting.Conclusion: Ramadan fasting can reduce serum MDA levels as a marker of oxidative stress and cell damage. Further study is needed to investigate the various results in serum MDA levels after fasting.

Ferroptosis Inducers in Thyroid Cancer.

Papillary thyroid carcinoma (PTC) progression imparts reduced patient survival. Tumor resistance and progression can be influenced by Glutathione (GSH) metabolism. Glutathione peroxidase 4 (GPX4) regulates GSH oxidation to prevent lipid peroxidation of cell membranes during increased oxidative stress and regulates ferroptosis cell death pathway in tumor cells. This study examines the differential ferroptosis effects by GPX4 inhibitors in thyroid cancer cell and 3-D spheroid in vitro models. We examined differential effects of GPX4 inhibitors on PTC cells (K1, MDA-T32, MDA-T68) with BRAF and RAS mutations, and TERT promoter and PIK3CA co-mutations. The effects of GPX4 inhibitors on ferroptosis activation, proliferation, oxidative stress, and activation of signaling pathways were assessed by Western blot, total (GSH) and oxidized glutathione (GSSG) levels, ROS induction, RT-qPCR, migration, and proliferation assays. GPX4 inhibitors induced ferroptosis, rising ROS, GSH depletion, arrested tumor cell migration, increased DNA damage, suppressed mTOR pathway and DNA repair responsein PTC cells in vitro. Differential responses to DNA damage and GPX4 levels were observed between 3-D PTCspheroids andthyroid cancer cells in amonolayermodel. Effective GPX4 inhibition with various inhibitors induced a robust but differential activation of ferroptosis in monolayerthyroid tumor cell and 3-D PTCspheroid models. Our study is the first of its kind to determine the differential effects of GPX4 inhibitors on thyroid cancer cells with diverse mutational signatures. We have identified a novel mechanism of action of GPX4 inhibition in preclinical in vitro models of thyroid cancer that can be further exploited for therapeutic benefit in advanced therapy-resistant thyroid cancers.

Abscisic acid involved in trehalose improved melon photosynthesis via regulating oxidative stress tolerance and cell morphology structure under cold stress

Melon is a thermophilic vegetable crop with high economic benefits. Cold stress is often encountered in the growth period of melon seedlings in early spring and limits the normal growth and development of seedlings. Exogenous trehalose (Tre) is a green and healthy sugar, known as the ‘sugar of life’, and has a significant role in regulating crop cold tolerance. In this study, we explored whether exogenous Tre induced abscisic acid (ABA) signal involved in regulating melon photosynthesis under cold tolerance and clarified the associated regulatory mechanism. Melon seedlings were pre-treated with nordihydroguaiaretic acid (NDGA), a synthetic inhibitor of the key enzyme 9-cis-epoxycarotenoid dioxygenase for ABA synthesis, followed by spraying with exogenous Tre and then treated with normal temperature or cold stress. Results showed that exogenous Tre induced the up-regulation of CmNCED3 gene expression and increase in ABA level under normal temperature conditions. Cold stress treatment significantly caused leaf membrane lipid peroxidation damage; reduced relative water content, net photosynthetic rate, transpiration rate, stomatal conductance, water use efficiency and the spongy ratio of leaves; caused chloroplast structure damage. The use of NDGA in inhibiting the synthesis of endogenous ABA further aggravated the damages compared with cold treatment alone. Exogenous Tre treatment alleviated the inhibitory effects of cold stress and NDGA and maintained relatively normal cell morphology structure and photosynthesis. Therefore, we speculate that exogenous Tre pretreatment increases the level of endogenous ABA by up-regulating the expression of the CmNCED3 gene and triggers the defence system of melon plants. Under cold stress, cell membrane lipid peroxidation damage in the melon seedlings was significantly reduced by Tre treatment. Meanwhile, the absorption and utilisation of water maintained the relative integrity of the structure and function of mesophyll cells and chloroplasts, thereby reducing the inhibitory effect of cold stress on plant photosynthesis. In conclusion, ABA participates in exogenous Tre-enhanced melon oxidative stress tolerance and alleviation of cell morphology structure damage, which combined to improve melon cold tolerance and photosynthesis. • Exogenous trehalose triggers endogenous ABA levels. • ABA are involved in exogenous Tre-alleviated melon oxidative stress damage. • ABA participate in the Tre-regulated maintenance of cell integrity and function under cold stress.

Mechanisms of cerebral vasospasm and cerebral ischaemia in subarachnoid haemorrhage.

Subarachnoid haemorrhage (SAH) is a cerebrovascular emergency associated with significant morbidity and mortality. SAH is characterized by heterogeneity, interindividual variationand complexity of pathophysiological responses following extravasation of blood from cerebral circulation. The purpose of this review is to integrate previously established pre-existing factors, pathophysiological pathways and to develop a concept map of mechanisms of SAH-induced cerebral vasospasm and delayed cerebral ischaemia using a systematic approach. We conducted an extensive mapping of a hypothesized sequence of pathophysiological events. Documentation of supporting evidence was done alongside a concept map building. After finalizing the model, we conducted an analysis of the consequences and connections of pathophysiological events. We included the findings of experimental research, focusing on pathophysiological processes. We focused on SAH-induced cerebral vasospasm and delayed cerebral ischaemia as a component of cerebral injury and potential systemic consequences. SAH-induced brain injury occurs within 72 h following haemorrhage. Pathophysiology of cerebral vasospasm may include reduction in NOproduction, direct activation of calcium channels, upregulating genes involved with inflammation and extracellular matrix remodelling, triggering oxidative stress and free radical damage to smooth muscle and lipid peroxidation of cell membranes, cortical spreading depolarizations, sympathetic activation, finally resulting in the failure of cerebral autoregulation, microthrombosis and cerebral ischaemic injury. This cascade of events might explain why medical therapy often fails to reverse resistant cerebral vasospasm and to prevent cerebral ischaemia.

Anti-browning effects of citronellal on fresh-cut taro (Colocasia esculenta) slices under cold storage condition

The browning on the cut surface is a big problem reducing the quality of fresh-cut taro (FCT), which causes severe postharvest losses and may raise environmental impacts. Citronellal (CA) is a natural compound in several aromatic plants. This study investigated the effects of CA treatments in different concentrations (0.2, 0.5, and 1 mL/L) on the browning of FCT under cold storage at 5°C. The results indicated that low-dose (0.2 mL/L) CA treatment showed best anti-browning effects, reflecting at the maintained L* values but the reduced a*, b* and browning index values by CA treatment during cold storage. A repeated experiment using 0.2 mL/L CA confirmed fine anti-browning effects again. Furthermore, CA (0.2 mL/L) treatment markedly reduced the contents of total phenolic compounds and soluble quinones, restrained the activities of phenylalanine ammonia lyase, peroxidase and polyphenol oxidase, down-regulated the gene expression of 18 browning-related enzymes in FCT. These results together strongly demonstrate the validity of CA on FCT browning prevention. Given that CA is a natural compound existing in plants, low concentration of CA possesses strong anti-browning effects on FCT and also inhibitory effects on pathogens, implying that its application has potentiality to preserve high quality of fresh-cut produce for processing and storage. Moreover, CA treatment significantly decreased malondialdehyde contents and lipoxygenase activity. Correlation analysis indicated that the lipid peroxidation of cell membrane was mostly correlated with FCT browning. The results suggest that membrane lipid peroxidation was a possible reason for FCT browning and CA treatment reduced browning, in part, through alleviating the lipid peroxidation of cell membrane. Overall, our results demonstrate that CA is a novel browning mitigator for FCT under cold storage condition.

Impact of vanillin on postharvest disease control of apple.

Apple fruits are susceptible to infection by postharvest fungal pathogens, which may cause fruit decay and severe economic losses. This study investigated the antifungal spectrum of vanillin against common decay pathogens of apple and explored the antifungal mechanisms of vanillin in vitro. In vivo experiments were carried out to evaluate the effects of vanillin on apple postharvest disease control and fruit quality. Moreover, the induced resistance mechanism of vanillin on apple fruit was preliminarily explored. The results showed that vanillin has broad-spectrum antifungal effects, especially on Alternaria alternata. Vanillin could significantly inhibit the growth rate, mycelium biomass, and spore germination of pathogenic fungi by increasing the cell membrane permeability and lipid peroxidation. Importantly, vanillin treatment reduced the incidence of apple decay caused by A. alternata and Penicillium expansum, and contributed to improve fruit quality. Further studies indicated that vanillin could induce elevation in the activities of defense-related enzymes in apple fruit, such as phenylalanine ammonia-lyase (PAL), chitinase (CHI) and β-1,3-glucanase (β-1,3-GA), and increase total phenols and flavonoids contents. Generally, these results suggest that vanillin may contribute to the induced resistance of apple fruits to pathogenic fungi. To conclude, the results of this research provide theoretical foundations for the application of vanillin in the control of apple postharvest decay caused by fungal pathogens.

Evaluation of supplementation of cryopreservation medium with gallic acid as an antioxidant in quality of post-thaw human spermatozoa.

Human sperm cryopreservation is a way to preserve sperm in the clinic. But, the production of reactive oxygen species (ROS) during cryopreservation, has certain negative impacts on the quality of sperm and its reproductive capacity. The goal of this study is to see how sperm cryopreserved in media enriched with gallic acid alter post-thaw morphology, motility, viability, DNA structure, and plasma membrane lipid peroxidation. Four groups were considered for performing this study: (1) Fresh sperm before cryopreservation; (2) cryopreserved control sperm without any supplementation; (3) cryopreserved sperm using freezing media supplemented with 50 μg/ml gallic acid and (4) cryopreserved sperm using freezing media supplemented with 100 μg/ml gallic acid. This study's results indicated that the addition of doses of 50 μg/ml gallic acid to cryopreservation medium significantly improved sperm morphology, motility, vitality, and DNA integrity and reduced DNA fragmentation and lipid peroxidation as compared to the medium without any gallic acid supplementation (p< 0.05); but, the concentration of 100 μg/ml gallic acid had no significant effects on the mentioned sperm parameters (p> 0.05). This study's findings represent the possibility of enhancing sperm characteristics and lowering detrimental effects of ROS on sperm DNA structure during cryopreservation by supplementing sperm freezing medium with gallic acid as a natural antioxidant. Therefore, Gallic acid may help improve the quality and subsequently fertilization potential of cryopreserved human sperm.

Polarity-Sensitive and Membrane-Specific Probe Quantitatively Monitoring Ferroptosis through Fluorescence Lifetime Imaging.

As a new form of regulated cell death, ferroptosis is closely related to various diseases. To interpret this biological behavior and monitor related pathological processes, it is necessary to develop appropriate detection strategies and tools. Considering that ferroptosis is featured with remarkable lipid peroxidation of various cell membranes, it is logical to detect membranes' structural and environmental changes for the direct assessment of ferroptosis. For this sake, we designed novel polarity-sensitive fluorescent probes Mem-C1C18 and Mem-C18C18, which have superior plasma membrane anchorage, high brightness, and sensitive responses to environmental polarity by changing their fluorescence lifetimes. Mem-C1C18 with much less tendency to aggregate than Mem-C18C18 outperformed the latter in high resolution fluorescence labeling of artificial vesicle membranes and plasma membranes of live cells. Thus, Mem-C1C18 was selected to monitor plasma membranes damaged along ferroptosis process for the first time, in combination with the technique of fluorescence lifetime imaging (FLIM). After treating HeLa cells with Erastin, a typical ferroptosis inducer, the mean fluorescence lifetime of Mem-C1C18 displayed a considerable increase from 3.00 to 4.93 ns, with a 64% increase (corresponding to the polarity parameter Δf increased from 0.213 to 0.232). Therefore, our idea to utilize a probe to quantitate the changes in polarity of plasma membranes proves to be an effective method in the evaluation of the ferroptosis process.

Exogenous melatonin promotes the growth of alfalfa (Medicago sativa L.) under NaCl stress through multiple pathways

Salinity is one of the most common factors affecting alfalfa (Medicago sativa L.), and NaCl is one of the main factors of salinity stress which can cause heavy losses in agricultural production in the world. The application of exogenous melatonin (MT) plays a major role in numerous plants against various stress environments. The effects of exogenous MT on the NaCl tolerance of alfalfa treated with the control, 100 µmol L−1 MT, 150 mmol L−1 NaCl, or 150 mmol L−1 NaCl+ 100 µmol L−1 MT were investigated. The results showed that MT increased growth parameters, inhibited chlorophyll degradation and promoted photosynthetic gas exchange parameters (photosynthetic rate, conductance to H2O, and transpiration rate) and stomatal opening under NaCl stress. Osmotic regulation substances such as soluble sugar, proline and glycine betaine were the highest in the NaCl treatment and the second in the NaCl+MT treatment. Nitrogen, phosphorus, potassium, calcium and magnesium were reduced and sodium was increased by NaCl, whereas these levels were reversed by the NaCl+MT treatment. MT inhibited cell membrane imperfection, lipid peroxidation and reactive oxygen species (ROS) accumulation caused by NaCl stress. MT up-regulated the gene expression and activity of antioxidant enzymes and increased the content of antioxidant non-enzyme substances to scavenge excessive ROS in NaCl-treated plants. In addition, all indicators interacted with each other to a certain extent and could be grouped according to the relative values. All variables were divided into PC 1 (89.2 %) and PC 2 (4 %). They were clustered into two categories with opposite effects, and most of them were significant variables. Hence, these findings reveal that exogenous MT alleviates the inhibitory effects of NaCl stress on photosynthesis, stomata opening, osmotic adjustment, ion balance and redox homeostasis, enhancing tolerance and growth of alfalfa. Furthermore, it suggests that MT could be implemented to improve the NaCl tolerance of alfalfa.

L. monocytogens exhibited less cell membrane damage, lipid peroxidation, and intracellular reactive oxygen species accumulation after plasma-activated water treatment compared to E. coli O157:H7 and S. Typhimurium

This study investigated the bactericidal activity of plasma-activated water (PAW) generated with a remote discharge reactor against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes. PAW-40, -80, and −120, prepared by activating distilled water for 40, 80, and 120 min, respectively, showed inactivation activity against pathogenic bacteria, which increased as the activation time increased due to decrease in pH and increase in oxidation-reduction potential and reactive oxygen/nitrogen species (RONS) of PAW. In addition, Gram-positive bacteria L. monocytogenes showed superior resistance to PAW than Gram-negative bacteria E. coli O157:H7 and S. Typhimurium. Compared with E. coli O157:H7 and S. Typhimurium, L. monocytogens exhibited less cell membrane damage, lipid peroxidation, and intracellular ROS accumulation after PAW treatment, which indicated that L. monocytogenes exhibited greater resistance because the thick cell wall buffered RONS diffusion into the cell. PAW also showed a control effect on the pathogenic bacteria on cherry tomato, and the effect was maintained throughout five repeated applications; thus, proposing high reusability of PAW. The results of this study propose that PAW generated with a remote discharge reactor can be utilized for pathogen control and provides basic data for related research and practical industrial applications.

Synergistic effect of Ag2S nanoparticles and spiny MoS2 anchored on palygorskite for boosting light-driven antibacterial activity

Palygorskite (Pal), with its abundant resources and low price, is an excellent carrier of antibacterial materials. Using a simple one-step hydrothermal method, silver sulfide/molybdenum disulfide/palygorskite (Ag2S/MoS2/Pal) nanocomposites were synthesized and employed as light-driven antibacterial materials in this study. It was shown that the Ag2S/MoS2/Pal nanocomposites had excellent antibacterial activity under different illuminations, and the minimum inhibitory concentrations (MIC) of the Ag2S/MoS2/Pal nanocomposites against Escherichia coli (E. coli) and Staphylococci aureus (S. aureus) were 0.3 mg/mL and 0.5 mg/mL, respectively. The physical interaction of the spiny MoS2 in Ag2S/MoS2/Pal nanocomposites could destroy the bacterial cell membrane. Then, a large number of reactive oxygen species (ROS) were produced by the Ag2S/MoS2/Pal nanocomposites, which resulted in the cell membrane lipid peroxidation. In addition, Ag2S/MoS2/Pal nanocomposites possess an outstanding photothermal effect. Thus, the synergistic effects of physical puncture, photodynamic, and photothermal effects lead to rapid bacterial death. The efficient antibacterial performance is attributed to the enhanced active center and interfacial carrier transfer. This study provides new pathways for the development of new functional clay materials in the future, as well as for meeting the demands of an increasingly bacterial issue.