Functional consequences of oxidative membrane damage

Effects of Cigarette-Derived Compounds on the Spread of Antimicrobial Resistance in Artificial Human Lung Sputum Medium, Simulated Environmental Media, and Wastewater

BACKGROUND

Antimicrobial resistance (AMR) and smoking of tobacco products are two of the most important threats to global human health. Both are associated with millions of deaths every year. Surprisingly, the immediate interactions between these two threats remain poorly understood.

OBJECTIVES

We aimed to elucidate the effect of toxic compounds from cigarette smoke, ashes, and filters on the spread of antibiotic resistance genes in human lung and environmental microbiomes.

METHODS

Conjugation experiments using donor and recipient strain pairs of either Pseudomonas putida or Escherichia coli and AMR-encoding plasmids were conducted under exposure to different concentrations of cigarette smoke condensate in lung sputum medium, as well as cigarette ash and filter leachate in environmental media. We further measured reactive oxygen species (ROS) production of the donor strain under exposure to the cigarette-derived compounds to explore whether stress experienced by the bacteria could be one of the underlying mechanisms of change in plasmid transfer frequencies. Furthermore, used cigarette filters were submerged in a wastewater stream for several weeks, and the colonizing communities were analyzed using high-throughput sequencing and high-throughput quantitative polymerase chain reaction and compared with communities colonizing unused control filters.

RESULTS

Exposure to cigarette smoke condensate at relevant concentrations resulted in > 2 -fold higher transfer rates of a multidrug-resistance-encoding plasmid in artificial lung sputum medium. This was associated with higher ROS production as part of the bacterial stress response when exposed to cigarette-derived toxicants. Similar results were obtained for cigarette ash leachate in an environmental medium. Further, used cigarette filters were colonized by different microbial communities compared with unused filters. Those communities were significantly enriched with potential human pathogens and AMR.

DISCUSSION

The results of this study suggest that cigarette-derived compounds can indeed promote the spread of AMR within simulated human lung and environmental conditions. This study highlights that the consumption of cigarettes has not only direct but may also have indirect adverse effects on human health by promoting AMR. https://doi.org/10.1289/EHP14704.

In vitro examination of Piezo1-TRPV4 dynamics: implications for placental endothelial function in normal and preeclamptic pregnancies

Mechanosensation is essential for endothelial cell (EC) function, which is compromised in early-onset preeclampsia (EPE), impacting offspring health. The ion channels Piezo-type mechanosensitive ion channel component 1 (Piezo1) and transient receptor potential cation channel subfamily V member 4 (TRPV4) are coregulated mechanosensors in ECs. Current evidence suggests that both channels could mediate aberrant placental endothelial function in EPE. Using isolated fetoplacental ECs (fpECs) from early control (EC) and EPE pregnancies, we show functional coexpression of both channels and that Ca2+ influx and membrane depolarization in response to chemical channel activation is reduced in EPE fpECs. Downstream of channel activation, Piezo1 alone can induce phosphorylation of endothelial nitric oxide synthase (eNOS) in fpECs, while combined activation of Piezo1 and TRPV4 only affects eNOS phosphorylation in EPE fpECs. Additionally, combined activation reduces the barrier integrity of fpECs and has a stronger effect on EPE fpECs. This implies altered Piezo1-TRPV4 coregulation in EPE. Mechanistically, we suggest this to be driven by changes in the arachidonic acid metabolism in EPE fpECs as identified by RNA sequencing. Targeting of Piezo1 and TRPV4 might hold potential for EPE treatment options in the future.NEW & NOTEWORTHY This study shows Piezo-type mechanosensitive ion channel component 1 (Piezo1) and transient receptor potential cation channel subfamily V member 4 (TRPV4) coexpression and functionality within primary human fetoplacental endothelial cells (fpECs), mediating nitric oxide (NO) production and barrier integrity. In early-onset preeclampsia (EPE), fpEC channel functionality and coregulation are impaired, affecting Ca2+ signaling and endothelial barrier function. Combined channel activation significantly reduces endothelial barrier integrity and increases NO production in EPE. Changes in arachidonic acid metabolism are suggested as a key underlying factor mediating impaired channel functionality in EPE fpECs.

Plasma-Activated Medium Inhibited the Proliferation and Migration of Non-Small Cell Lung Cancer A549 Cells in 3D Culture

Lung cancer is the most common type of malignant tumor worldwide. Plasma-activated medium (PAM) is an innovative cancer treatment method that has received considerable scientific attention. The objective of this study is to evaluate the effects of PAM on the anti-tumor characteristics of non-small cell lung cancer (NSCLC) cells in two-dimensional (2D) and three-dimensional (3D) cultures. The effects of PAM treatment on the proliferative and migratory capabilities of A549 cells in 2D and 3D cultures were assessed using MTT, migration, invasion assays, and cell cycle, respectively. The study also investigated the impact of PAM treatment on the changes in the content of intracellular and extracellular reactive species and analyzed protein expression using the Western Blot method. PAM treatment inhibited the viability, migration, and invasion abilities of A549 cells in both 2D and 3D cultures, suppressed the epithelial-mesenchymal transition (EMT) process, and downregulated the expression of the RAS/ERK signaling pathway, which effectively inhibited tumor spheroid formation. Additionally, the effect of PAM on A549 cells was mediated through ROS-induced oxidative reactions, and PAM treatment exhibited greater cytotoxicity in 2D culture compared to 3D culture. As compared to 2D, the 3D cell culture model provides a viable in vitro cell model for studying the mechanisms of PAM treatment in lung cancer. PAM represents an effective new treatment for NSCLC.

Inactivation of bacteria using synergistic hydrogen peroxide with split-dose nanosecond pulsed electric field exposures

The use of pulsed electric fields (PEF) as a nonthermal technology for the decontamination of foods is of growing interest. This study aimed to enhance the inactivation of Escherichia coli, Listeria innocua, and Salmonella enterica in Gomori buffer using a combination of nsPEF and hydrogen peroxide (H2O2). Three sub-MIC concentrations (0.1, 0.3, and 0.5%) of H2O2 and various contact times ranging from 5-45 min were tested. PEF exposures as both single (1000 pulse) and split-dose (500+500 pulse) trains were delivered via square-wave, monopolar, 600 ns pulses at 21 kV/cm and 10 Hz. We demonstrate that >5 log CFU/mL reduction can be attained from combination PEF/H2O2 treatments with a 15 min contact time for E. coli (0.1%) and a 30 min contact time for L. innocua and S. enterica (0.5%), despite ineffective results from either individual treatment alone. A 5 log reduction in microbial population is generally the lowest acceptable level in consideration of food safety and represents inactivation of 99.999% of bacteria. Split-dose PEF exposures enhance lethality for several tested conditions, indicating greater susceptibility to PEF after oxidative damage has occurred.

Oxidative cell death in cancer: mechanisms and therapeutic opportunities

Reactive oxygen species (ROS) are highly reactive oxygen-containing molecules generated as natural byproducts during cellular processes, including metabolism. Under normal conditions, ROS play crucial roles in diverse cellular functions, including cell signaling and immune responses. However, a disturbance in the balance between ROS production and cellular antioxidant defenses can lead to an excessive ROS buildup, causing oxidative stress. This stress damages essential cellular components, including lipids, proteins, and DNA, potentially culminating in oxidative cell death. This form of cell death can take various forms, such as ferroptosis, apoptosis, necroptosis, pyroptosis, paraptosis, parthanatos, and oxeiptosis, each displaying distinct genetic, biochemical, and signaling characteristics. The investigation of oxidative cell death holds promise for the development of pharmacological agents that are used to prevent tumorigenesis or treat established cancer. Specifically, targeting key antioxidant proteins, such as SLC7A11, GCLC, GPX4, TXN, and TXNRD, represents an emerging approach for inducing oxidative cell death in cancer cells. This review provides a comprehensive summary of recent progress, opportunities, and challenges in targeting oxidative cell death for cancer therapy.

Assessing thallium phycoremediation by applying Anabaena laxa and Nostoc muscorum and exploring its effect on cellular growth, antioxidant, and metabolic profile

Thallium (Tl), a key element in high-tech industries, is recognized as a priority pollutant by the US EPA and EC. Tl accumulation threatens aquatic ecosystems. Despite its toxicity, little is known about its impact on cyanobacteria. This study explores the biochemical mechanisms of Tl(I) toxicity in cyanobacteria, focusing on physiology, metabolism, oxidative damage, and antioxidant responses. To this end, Anabaena and Nostoc were exposed to 400 µg/L, and 800 µg/L of Tl(I) over seven days. Anabaena showed superior Tl(I) accumulation with 7.8% removal at 400 µg/L and 9.5% at 800 µg/L, while Nostoc removed 2.2% and 7.4%, respectively. Tl(I) exposure significantly reduced the photosynthesis rate and function, more than in Nostoc. It also altered primary metabolism, increasing sugar levels and led to higher amino and fatty acids levels. While Tl(I) induced cellular damage in both species, Anabaena was less affected. Both species enhanced their antioxidant defense systems, with Anabaena showing a 175.6% increase in SOD levels under a high Tl(I) dose. This suggests that Anabaena's robust biosorption and antioxidant systems could be effective for Tl(I) removal. The study improves our understanding of Tl(I) toxicity, tolerance, and phycoremediation in cyanobacteria, aiding future bioremediation strategies.

Studying the viability and growth kinetics of vancomycin-resistant Enterococcus faecalis V583 following femtosecond laser irradiation (420-465 nm)

Enterococcus faecalis is among the most resistant bacteria found in infected root canals. The demand for cutting-edge disinfection methods has rekindled research on photoinactivation with visible light. This study investigated the bactericidal activity of femtosecond laser irradiation against vancomycin-resistant Enterococcus faecalis V583 (VRE). The effect of parameters such as wavelength and energy density on the viability and growth kinetics of VRE was studied to design an optimized laser-based antimicrobial photoinactivation approach without any prior addition of exogenous photosensitizers. The most effective wavelengths were 430 nm and 435 nm at a fluence of 1000 J/cm2, causing a nearly 2-log reduction (98.6% and 98.3% inhibition, respectively) in viable bacterial counts. The colony-forming units and growth rate of the laser-treated cultures were progressively decreased as energy density or light dose increased at 445 nm but reached a limit at 1250 J/cm2. At a higher fluence of 2000 J/cm2, the efficacy was reduced due to a photobleaching phenomenon. Our results highlight the importance of optimizing laser exposure parameters, such as wavelength and fluence, in bacterial photoinactivation experiments. To our knowledge, this is the first study to report an optimized wavelength for the inactivation of VRE using visible femtosecond laser light.

Antitumor Immunity Mediated by Photodynamic Therapy Using Injectable Chitosan Hydrogels for Intratumoral and Sustained Drug Delivery

Photodynamic therapy (PDT) is an anticancer therapy with proven efficacy; however, its application is often limited by prolonged skin photosensitivity and solubility issues associated with the phototherapeutic agents. Injectable hydrogels which can effectively provide intratumoral delivery of photosensitizers with sustained release are attracting increased interest for photodynamic cancer therapies. However, most of the hydrogels for PDT applications are based on systems with high complexity, and often, preclinical validation is not provided. Herein, we provide a simple and reliable pH-sensitive hydrogel formulation that presents appropriate rheological properties for intratumoral injection. For this, Temoporfin (m-THPC), which is one of the most potent clinical photosensitizers, was chemically modified to introduce functional groups that act as cross-linkers in the formation of chitosan-based hydrogels. The introduction of -COOH groups resulted in a water-soluble derivative, named PS2, that was the most promising candidate. Although PS2 was not internalized by the target cells, its extracellular activation caused effective damage to the cancer cells, which was likely mediated by lipid peroxidation. The injection of the hydrogel containing PS2 in the tumors was monitored by high-frequency ultrasounds and in vivo fluorescence imaging which confirmed the sustained release of PS2 for at least 72 h. Following local administration, light exposure was conducted one (single irradiation protocol) or three (multiple irradiation protocols) times. The latter delivered the best therapeutic outcomes, which included complete tumor regression and systemic anticancer immune responses. Immunological memory was induced as ∼75% of the mice cured with our strategy rejected a second rechallenge with live cancer cells. Additionally, the failure of PDT to treat immunocompromised mice bearing tumors reinforces the relevance of the host immune system. Finally, our strategy promotes anticancer immune responses that lead to the abscopal protection against distant metastases.

Chlorin-e6 conjugated to the antimicrobial peptide LL-37 loaded nanoemulsion enhances photodynamic therapy against multi-species biofilms related to periodontitis

In our previous studies, Chlorin-e6 (Ce6) demonstrated a significant reduction of microorganisms' viability against multi-species biofilm related to periodontitis while irradiated with blue light. However, the conjugation of Ce6 and antimicrobial peptides, and the incorporation of this photosensitizer in a nanocarrier, is still poorly explored. We hypothesized that chlorin-e6 conjugated to the antimicrobial peptide LL-37 loaded nanoemulsion could inhibit a multi-species biofilm related to periodontitis during photodynamic therapy (PDT), the pre-treatment with hydrogen peroxide was also tested. The nanoemulsion (NE) incorporated with Ce6 was characterized regarding the physiochemical parameters. Images were obtained by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Later, the Ce6 and LL-37 incorporated in NE was submitted to UV-Vis analysis and Reactive Oxygen Species (ROS) assay. Finally, the combined formulation (Ce6+LL-37 in nanoemulsion) was tested against multi-species biofilm related to periodontitis. The formed nanoformulation was kinetically stable, optically transparent with a relatively small droplet diameter (134.2 unloaded and 146.9 loaded), and weak light scattering. The NE system did not impact the standard UV-VIS spectra of Ce6, and the ROS production was improved while Ce6 was incorporated in the NE. The combination of Ce6 and LL-37 in NE was effective to reduce the viability of all bacteria tested. The treatment with hydrogen peroxide previous to PDT significantly impacted bacterial viability. The current aPDT regimen was the best already tested against periodontal biofilm by our research team. Our results suggest that this combined protocol must be exploited for clinical applications in localized infections such as periodontal disease. - Nanoemulsion demonstrated to be an excellent nanocarrier for photodynamic application. - Chlorin-e6 incorporated in nanoemulsion showed great physicochemical and biophotonic parameters. - The combination of chlorin-e6 and LL-37 peptide in nanoemulsion is effective to eliminate periodontal pathogenic bacteria. - The treatment with hydrogen peroxide previous to PDT significantly impacted bacterial viability.

Environmental concentrations of surfactants as a trigger for climax of horizonal gene transfer of antibiotic resistance

Ubiquitous antibiotic resistance genes (ARGs) is a significant global human health concern. Surfactants have been extensively used worldwide, and the consumption of surfactants containing hygiene, cleaning agents and disinfectants was multiplied during COVID-19 pandemic, which have caused significantly increased pollution of surfactants in aquatic environment. Whether such ever-increasing surfactant concentration boost dissemination risk of ARGs still remains unknown. Here the effects of three typical surfactants such as sodium dodecyl sulfate, cetyltrimethylammonium bromide and benzalkonium chloride on the transformation of pUC19 plasmid (2686 bp)-borne ARGs to recipient bacteria E. coli DH5ɑ were investigated. It was found that these surfactants at environmental concentrations facilitated horizonal gene transfer (HGT) via transformation. The transformation triggering concentrations for the three surfactants were 0.25-0.34 mg/L with a maximum increased transformation frequency of 13.51-22.93-fold. The mechanisms involved in activated HGT of ARGs via transformation triggered by surfactants could be mainly attributed to the increased production of reactive oxygen species, which further enhanced cell membrane permeability. These findings provide new sights for understanding of ARG propagation and also imply that the drastic rise of surfactant concentration in aquatic environment may significantly increase the dissemination risk of antibiotic resistance.

Broad-Spectrum Antimicrobial Activity of Ultrafine (BiO)2CO3 NPs Functionalized with PVP That Can Overcome the Resistance to Ciprofloxacin, AgNPs and Meropenem in Pseudomonas aeruginosa

Although it has no known biochemical role in living organisms, bismuth has been used to treat syphilis, diarrhea, gastritis and colitis for almost a century due to its nontoxic nature to mammalian cells. When prepared via a top-down sonication route from a bulk sample, bismuth subcarbonate (BiO)₂CO₃ nanoparticles (NPs) with an average size of 5.35 ± 0.82 nm exhibit broad-spectrum potent antibacterial activity against both the gram-positive and gram-negative bacteria including methicillin-susceptible Staphylococcus aureus (DSSA), methicillin-resistant Staphylococcus aureus (MRSA), drug-susceptible Pseudomonas aeruginosa (DSPA) and multidrug-resistant Pseudomonas aeruginosa (DRPA). Specifically, the minimum inhibitory concentrations (MICs) are 2.0 µg/mL against DSSA and MRSA and 0.75 µg/mL against DSPA and DRPA. In sharp contrast to ciprofloxacin, AgNPs and meropenem, (BiO)₂CO₃ NPs show no sign of developing Bi-resistant phenotypes after 30 consecutive passages. On the other hand, such NPs can readily overcome the resistance to ciprofloxacin, AgNPs and meropenem in DSPA. Finally, the combination of (BiO)₂CO₃ NPs and meropenem shows a synergistic effect with the fractional inhibitory concentration (FIC) index of 0.45.

Role of phase angle in older adults with focus on the geriatric syndromes sarcopenia and frailty

Age-related changes in body composition reflect an increased risk for disease as well as disability. Bioimpedance analysis is a safe and inexpensive bed side method to measure body composition, but the calculation of body compartments with BIA is hampered in older adults. Phase angle, a raw parameter derived from bioimpedance analysis, is free from calculation-inherent errors. It declines with age and disease and is highly predictive of a variety of clinical outcomes as well as mortality. This review summarizes the current evidence linking the phase angle to geriatric syndromes such as malnutrition, sarcopenia and frailty and also investigates whether the phase angle reacts to interventions. Since the majority of studies show an association between the phase angle and these geriatric syndromes, a low phase angle is not suitable to exclusively indicate a specific condition. It does not inform on the underlying cause and as such, a low phase angle mainly indicates increased risk. Phase angle decline over time is reflected by deterioration of e.g. frailty status. It reacts to physical training and detraining, but studies investigating whether these induced changes are also associated with improved outcome are missing.

α-Linolenic acid induced TM4 Sertoli cells proliferation and enhanced total antioxidant capacity

The present study was undertaken to elucidate the direct ALA effects on mice TM4 Sertoli cells proliferation in vitro. Our results showed that TM4 cells viability was significantly stimulated by ALA (p < 0.05). The 50 μM ALA increased the concentration of total antioxidant capacity, induced the mitochondrial membrane hyperpolarized, and markedly decreased the number of apoptosis cells (p < 0.05). ALA also up-regulated G2/Mitotic-specific cyclin-B1 gene and apoptosis suppressive gene Bcl2 expression (p < 0.05). In conclusion, those results indicated that ALA could increase TM4 Sertoli cells antioxidant capacity, induced the mitochondrial membrane hyperpolarized, inhibited cells apoptosis and stimulated TM4 Sertoli cells proliferation in vitro.

Modulation of innate immune responses in the flame scallop Ctenoides scaber (Born, 1778) caused by exposure to used automobile crankcase oils

The used automobile crankcase oils are potential sources of contaminant elements for the coastal-marine ecosystems, affecting mainly the immunological system of organisms that feed by filtration, e. g. scallops. This study examined the effects of a water-soluble fraction of used automobile crankcase oils (WSF-UACO) on innate cellular- and humoral immune responses of the flame scallop Ctenoides scaber. The scallops were exposed to ascending concentrations of 0, 0.001, 0.01, and 0.1 of WSF-UACO under a static system of aquaria during 7 and 13 d. The viability, haemocyte total count (HTC), lysosomal membrane destabilization (LMD), phagocytosis, and protein concentration in hemolymph samples withdrawn taken from the blood sinus as well as lysozyme activity of the digestive gland were measured as immune endpoints. A decrease in cellular immune competence in scallops exposed to WSF-UACO was observed, with significant impairment of viability, HTC, and phagocytosis. LMD index increased about exposure concentrations, and plasma protein concentrations augmented to 0.01 and 0.1% during 13 d. Lysozyme activity increased in scallops exposed to WSF-UVCO during 7 d, to level off in the chronic period. Lysozyme activity and enhanced plasma proteins could act as compensatory responses when cell parameters tend to fall, helping to the regulation of microbial microflora and possible invasion of pathogenic microbes as well as defense against xenobiotics. The results demonstrate that the immunological responses of C. scaber are highly sensitive to the complex chemical mixture of contaminants, and it could be used for evaluating biological risks of hazardous xenobiotics in tropical marine environments. Republic of Ecuador.

Triclosan Promotes Conjugative Transfer of Antibiotic Resistance Genes to Opportunistic Pathogens in Environmental Microbiome

Although triclosan, as a widely used antiseptic chemical, is known to promote the transmission of antibiotic resistance to diverse hosts in pure culture, it is still unclear whether and how triclosan could affect the transmission of broad-host-range plasmids among complex microbial communities. Here, bacterial culturing, fluorescence-based cell sorting, and high-throughput 16S rRNA gene amplicon sequencing were combined to investigate contributions of triclosan on the transfer rate and range of an IncP-type plasmid from a proteobacterial donor to an activated sludge microbiome. Our results demonstrate that triclosan significantly enhances the conjugative transfer of the RP4 plasmid among activated sludge communities at environmentally relevant concentrations. High-throughput 16S rRNA gene sequencing on sorted transconjugants demonstrates that triclosan not only promoted the intergenera transfer but also the intragenera transfer of the RP4 plasmid among activated sludge communities. Moreover, triclosan mediated the transfer of the RP4 plasmid to opportunistic human pathogens, for example, Legionella spp. The mechanism of triclosan-mediated conjugative transfer is primarily associated with excessive oxidative stress, followed by increased membrane permeability and provoked SOS response. Our findings offer insights into the impacts of triclosan on the dissemination of antibiotic resistance in the aquatic environmental microbiome.

The amount of dextran in PLGA nanocarriers modulates protein corona and promotes cell membrane damage

Polymeric nanocarriers (NCs) are efficient vehicles to prevent drug unspecific biodistribution and increase the drug amounts delivered to tumor tissues. However, some toxicological aspects of NCs still lack a comprehensive assessment, such as their effects on cellular processes that lead to toxicity. We evaluate the interaction of poly(lactic-co-glycolic acid) (PLGA) NCs prepared using dextran (Dex) and Pluronic®-F127 as stabilizing agents with myocardial cells (H9C2), breast adenocarcinoma cells (MCF-7) and macrophages (RAW 264.7) to address the effect of Dex in PLGA NC formulations. By an emulsion diffusion method, doxorubicin-loaded NCs were prepared with no Dex (PLGA-DOX), 1% (w/v) Dex (Dex1/PLGA-DOX) and 5% (w/v) Dex (Dex5/PLGA-DOX). Uptake analyses revealed a significant reduction in Dex5/PLGA-DOX NC uptake by H9C2 and MCF-7, as in the case of Dex1/PLGA-DOX NCs in the absence of in vitro protein corona, revealing an effect of dextran concentration on the formation of protein corona. RAW 264.7 cells presented a greater uptake of Dex5/PLGA-DOX NCs than the other NCs likely because of receptor mediated endocytosis, since C-type lectins like SIGN-R1, mannose receptors and scavenger receptor type 1 that are expressed in RAW 264.7 can mediate Dex uptake. Despite the lower uptake, Dex5/PLGA-DOX NCs promote the generation of reactive oxygen species and oxidative membrane damage in MCF-7 and H9C2 even though cellular metabolic activity assessed by MTT was comparable among all the NCs. Our results highlight the importance of an in-depth investigation of the NC-cell interaction considering additional mechanisms of damage apart from metabolic variations, as nanoparticle-induced damage is not limited to imbalance in metabolic processes, but also associated with other mechanisms, e.g., membrane and DNA damage.

Association between classic and specific bioimpedance vector analysis and sarcopenia in older adults: a cross-sectional study

Background

To verify (1) the association between classic and specific bioelectrical impedance vector analysis (BIVA) with body composition, hydration, and physical performance in older adults with and without sarcopenia; (2) which BIVA most accurately distinguishes sarcopenia.

Methods

A sample of 94 older adults with and without sarcopenia (29 men and 65 women, 60–85 years) was evaluated. The classic and specific BIVA procedures, Dual energy X-ray absorptiometry (DXA), and deuterium dilution were performed. Sarcopenia was defined by muscle weakness and low skeletal muscle index, while severity was indicated by low physical performance.

Results

The BIVA's potential to monitor hydration and muscle mass loss in older adults seems feasible. Classic and specific BIVA were able to distinguish sarcopenia in women (p < 0.001), but not in men. When the sarcopenia criteria were individually analyzed, both classic and specific BIVA were able to distinguish low skeletal muscle index in women, while only classic BIVA did for men. For the criterion of slow physical performance, only the classic BIVA showed severity differences for women. The vectors of adults without sarcopenia of both sexes tended to be positioned in the left region of the ellipses, revealing a predominance of soft tissues.

Conclusions

Classic BIVA has a distinct sarcopenic association with body composition, hydration, and physical performance in older adults, while specific BIVA was similar between groups. Both BIVAs are sensible to detect female morphological changes (skeletal muscle index) but not for functional (handgrip, 6-min walk test) sarcopenia criteria. These procedures are promising tools for monitoring sarcopenia risks during aging.

The Modulation of Ubiquinone, a Lipid Antioxidant, on Neuronal Voltage-Gated Sodium Current

Ubiquinone, composed of a 1,4-benzoquinone and naturally produced in the body, actively participates in the mitochondrial redox reaction and functions as an endogenous lipid antioxidant, protecting against peroxidation in the pituitary-dependent hormonal system. However, the questions of if and how ubiquinone directly affects neuronal ionic currents remain largely unsettled. We investigated its effects on ionic currents in pituitary neurons (GH3 and MMQ cells) with the aid of patch-clamp technology. Ubiquinone decreased the peak amplitude of the voltage-gated Na+ current (INa) with a slowing of the inactivation rate. Neither menadione nor superoxide dismutase modified the ubiquinone-induced INa inhibition. In response to an isosceles-triangular ramp pulse, the persistent INa (INa(P)) at high- and low- threshold potentials occurred concurrently with a figure-eight hysteresis loop. With ubiquinone, the INa(P) increased with no change in the intersection voltage, and the magnitude of the voltage-dependent hysteresis of the current was enhanced. Ubiquinone was ineffective in modifying the gating of hyperpolarization-activated cation currents. In MMQ lactotrophs, ubiquinone effectively decreased the amplitude of the INa and the current inactivation rate. In sum, the effects of ubiquinone demonstrated herein occur upstream of its effects on mitochondrial redox processes, involved in its modulation of sodium channels and neuronal excitability.

Effects of atrazine and diuron on life parameters, antioxidant response, and multixenobiotic resistance in non-targeted marine zooplankton

Atrazine and diuron are among the most widely used antifoulant biocides in the world. Due to their persistence in the environment, they can induce adverse effects on non-targeted organisms. In this study, we investigated the chronic in vivo toxicity of atrazine and diuron with further assessments on oxidative stress responses (e.g., oxidative stress, antioxidant) and multixenobiotic resistance (MXR) function in the rotifer Brachionus koreanus, a non-targeted microzooplanktonic grazer at the primary level of the marine food chain. Although similar oxidative response was shown by both biocides, diuron induced stronger retardation on reproduction and population growth rates of B. koreanus while moderate effects were observed by atrazine. This higher toxicity of diuron was shown to be associated with its stronger inhibition of MXR conferred by P-glycoprotein and multidrug resistance proteins which play as a first line of defense by transporting various toxicants out of a cell. Our study provides new insight into non-targeted effects of biocides on marine zooplankton and mechanisms beyond their different degrees of toxicity.

Antidepressants promote the spread of extracellular antibiotic resistance genes via transformation

The development of antibiotic resistance as an unavoidable consequence of the application of antimicrobials is a significant concern for human health. Antidepressants are being increasingly consumed globally. Human gut microbial communities are frequently exposed to antidepressants, yet little is known about the interaction between antidepressants and antibiotic resistance. This study aimed to investigate whether antidepressants can accelerate the dissemination of antibiotic resistance by increasing the rate of the horizontal transfer of antibiotic resistance genes (ARGs). Results demonstrated that some of the commonly-prescribed antidepressants (Duloxetine, Sertraline, Fluoxetine and Bupropion) at clinically relevant concentrations can significantly (n = 9; padj < 0.01) promote the transformation of extracellular ARGs into Acinetobacter baylyi ADP1 for a maximum of 2.3-fold, which is primarily associated with the overproduction of reactive oxygen species. The increased cell membrane permeability and porosity, stimulated transcription and translation of competence, SOS response, universal stress response and ATP synthesis-related genes are also associated with antidepressants-enhanced transformation. This study demonstrated that some antidepressants can speed up the spread of antibiotic resistance by promoting the transformation of ARGs, which emphasizes the necessity to assess the potential risks of antidepressants in spreading antibiotic resistance during clinical antidepressant applications.

Carbazole appended trans-dicationic pyridinium porphyrin finds supremacy in DNA binding/photocleavage over a non-carbazolyl analogue

A carbazolyl appended trans-pyridyl porphyrin (1) was synthesized and its dicationic form 2 was obtained by methylation of the pyridyl group. Copper and zinc complexes of porphyrin 2 (Cu(II), 3; Zn(II), 4) were isolated and characterized by various modern spectroscopic techniques. The DNA binding properties of 2, 3, and 4 have been explored against calf thymus-DNA (CT-DNA). DNA binding was quantized using the intrinsic binding constant (K_b) that was calculated by UV-visible absorption spectroscopy, and the value K_b = 1.6 × 10⁶ M^-1 for compound 2 reveals a better interaction of 2 towards CT-DNA than those of 3 (3.1 × 10⁵ M^-1) and 4 (3.4 × 10⁵ M^-1), which follows the order 2 > 4 > 3. The fluorescence quenching efficiency and ethidium bromide quenching assay also indicated a good binding affinity of all the compounds towards CT-DNA. Furthermore, the spectroscopic data suggest that the possible mode of interaction is intercalation. The docking studies were in accordance with the experimental results. Notably, DNA cleavage studies reveal that 2 shows better damage than 3 and 4 which is in accordance with the binding affinity order 2 > 4 > 3. The observed quantum yield (2: 0.65, 3: 0.33, and 4: 0.97) and no change in DNA cleavage in the presence of NaN₃ reveal the involvement of singlet oxygen. The singlet excited state lifetimes were in the range of 6.3-1.2 ns. Furthermore, these porphyrins can be investigated as interesting photosensitizers in photodynamic therapy and photochemotherapy.

Comparative efficacy of silibinin and nano-silibinin on lead poisoning in Male Wistar rats

Lead (Pb) is an environmental neurotoxin that can lead to toxicity. It has shown that tissues can be exposed to oxidative stress in lead poisoning. Since silymarin is a natural agent with antioxidant effects, this study aimed to investigate the antioxidant and chelation effects of silibinin and nano-silibinin on the oxidative stress status in lead-poisoned rats. Sixty male Wistar rats randomly divided into ten groups (n = 6). Control and Pb groups treated with or without silibinin and nano-silibinin for six days. Following measuring of weight and blood lead levels, biochemical antioxidant parameters evaluated. Finally, a histopathological examination of the liver performed. In this experiment, silibinin and more efficiently nano-silibinin prevented weight loss and blood lead level elevation induced by lead. Also, they increased the attenuated levels of superoxide dismutase (SOD) activity, catalase (CAT), total thiol molecules (TTM), glutathione (GSH), and total antioxidant capacity (TAC). Lead-induced elevation of lipid peroxidation products (MDA) and nitric oxide (NO) normalized to the standard level in silibinin and especially nano-silibinin groups. These data suggested that silibinin and especially nano-silibinin can decrease blood lead levels and prevent weight loss and oxidative stress in the lead-poisoned rat's model.

Synclisia scabrida protects against oxidative stress, hepatotoxicity and hyperglycaemia in alloxan-induced diabetic rats

Background

Synclisia scabrida is commonly used in traditional medical practices for the management of diseases like diabetes and its complications. This study seeks to establish a scientific rationale for this practice.

Methods

Thirty Wistar rats were randomly and equally grouped into six. Alloxan was used to induce diabetes in the rats in groups 2 to 6. The diabetic rats in group 2 were treated with glibenclamide, while those in group 3 were not treated. Also, the diabetic rats in groups 4, 5 and 6 were, respectively, treated with the ethanol extracts of the stem, root and leaf of S. scabrida. After 28 days of treatment, blood and organ samples were collected for biochemical studies.

Results

S. scabrida possesses high amounts of useful phytochemicals. It also exhibits high total reducing capacity, FRAP activity, DPPH and ABTS scavenging ability. The inhibition of the α-glucosidase and α-amylase activities by the methanol extracts of S. scabrida stem, leaf and root were significantly (p < 0.05) higher than that of glibenclamide. Administration of S. scabrida extracts to the alloxan-induced diabetic rats caused significant (p < 0.05) decreases in the blood glucose, total bilirubin, AST, ALT, and ALP of the treated groups as compared to that of the untreated group. Treatment with the extracts also resulted in significantly (p < 0.05) lower LPO and significantly (p < 0.05) higher levels of GSH, SOD and CAT.

Conclusion

S. scabrida extracts exhibited antioxidative, hepatoprotective and hypoglycaemic properties which are similar to that of the standard drug, glibenclamide.

Effects of dehydration speed on the metabolism of membrane lipids and its relation to the browning of the Thompson seedless grape

Xinjiang is the main producing area of raisins and the largest green raisins production base in China. The browning of Thompson seedless grape raisin is extremely serious during drying process, which has become the key issue in the development of Xinjiang raisin industry. Previous studies have shown that the dehydration speed has a great impact on the browning of Thompson seedless grape, but few relevant mechanisms have been studied. Here, we demonstrate the effect of dehydration speed on the lipid metabolism and its relation to the browning of the Thompson seedless grape during drying. Compared to slow dehydration treatment, the rapid dehydration treatment of the Thompson seedless grape exhibited a lower degree of browning and activities of lipoxygenase (LOX), a higher index of unsaturated fatty acids and degree of unsaturated fatty acid. Moreover, the Thompson seedless grape treated with rapid dehydration resulted in a lower rate of superoxide anion production, hydrogen peroxide content, membrane permeability, and malondialdehyde content. These findings demonstrate that rapid dehydration inhibiting the browning of Thompson seedless grapes might be due to the inhibiting activities of LOX and the lower accumulation of reactive oxygen species. These activities can inhibit lipid peroxidation and slow the decomposition of unsaturated fatty acid in the membrane in Thompson seedless grapes, protecting the cellular membrane structural integrity which may result in less contact of polyphenol oxidase with phenolic substrates and less enzymatic browning during drying. The results provide a theoretical basis for the application of rapid dehydration in drying Thompson seedless grapes.

Lipid profiling of coral symbiosomes in response to copper-induced carbon limitation: A metabolic effect of algal symbionts on the host immune status

Copper micropollutants are known to constrain coral's assimilation of carbonate, affecting the carbon available to algal symbionts and thus inducing a light stress. However, little is known regarding the physiological relevance of lipid metabolism in coral symbiotic algae in a carbon-limited state. Membrane lipids exhibit multiple physicochemical properties that are collectively responsible for the dynamic structure of cells depending on the physiological demands of the circumstances. To gain insight into lipid metabolism's importance in this regard, glycerophosphocholine (GPC) profiling of symbiosomes in coral (Seriatopora caliendrum) exposed to environmentally relevant copper levels (2.2-7.5 μg/L) for 4 days was performed in this study. Notably, reducing the number of 22:6-processing GPCs and increasing that of lyso-GPCs likely addressed the demands of metabolizing excess light energy, such as affecting the membrane dynamics to promote mitochondrial uncoupling. The decrease in 22:6-processing GPCs additionally protected cellular membranes from elevated oxidative stress, reducing their susceptibility to peroxidation and offsetting oxidized lipid-induced effects on membrane dynamics. The change in plasmanylcholines specifically localized within the symbiosome membrane also met the membrane requirements for responding to oxidative stress conditions. Moreover, increasing the 20:4-possessing plasmanylcholines and lysoplasmanylcholines and reducing the 22:6-possessing plasmanylcholines likely resulted in an imbalance of the immune reaction, influencing the coral-algae symbiosis given the role of such plasmanylcholines in cell signaling. In summary, carbon limitations induced by copper enrichment lead to a shift in the membrane lipid profile of coral symbiosomes, accommodating themselves to light stress conditions while compromising the symbiosis's stability.

Inactivation of Fluorescent Lipid Bilayers by Irradiation With 300 keV Electrons Using Liquid Cell Transmission Electron Microscopy

Liquid cell transmission electron microscopy allows for imaging of samples in a fully hydrated state at high resolution and has the potential for visualizing static or dynamic biological structures. However, the ionizing nature of the electron beam makes it difficult to discern real physiological dynamics from radiation induced artifacts within liquid cell samples. Electron flux thresholds for achieving high resolution structures from biological samples frozen in ice have been described extensively by the cryo-electron microscopy field, while electron flux thresholds which do not result in a functional change for biological samples within the hydrated environment of a transmission electron microscope liquid cell is less clear. Establishing these functional thresholds for biologically relevant samples is important for accurate interpretation of results from liquid cell experiments. Here we demonstrate the electron damage threshold of fluorescently tagged lipid bilayers by quantifying the change in fluorescence before and after electron exposure. We observe the reduction of fluorescent signal in bilayers by 25% after only 0.0005 e−/Å2 and a reduction of over 90% after 0.01 e−/Å2. These results indicate that the loss of function occurs at irradiation thresholds far below a typical single high resolution (scanning) transmission electron microscopy image and orders of magnitude below fluxes used for preserving structural features with cryo-electron microscopy.

Tinospora cordifolia (Willd.) Miers: Protection mechanisms and strategies against oxidative stress-related diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Tinospora cordifolia (Willd.) Miers (Menispermaceae) is a Mediterranean herb, used in Ayurvedic, Siddha, Unani, and folk medicines. The herb is also used in conventional medicine to treat oxidative stress-related diseases and conditions, including inflammation, pain, diarrhea, asthma, respiratory infections, cancer, diabetes, and gastrointestinal disorders.

AIM OF THE REVIEW

The taxonomy, botanical classification, geographical distribution, and ethnobotanical uses of T. cordifolia, as well as the phytochemical compounds found in the herb, the toxicology of and pharmacological and clinical studies on the effects of T. cordifolia are all covered in this study.

MATERIALS AND METHODS

To gather information on T. cordifolia, we used a variety of scientific databases, including Scopus, Google Scholar, PubMed, and Science Direct. The information discussed focuses on biologically active compounds found in T. cordifolia, and common applications and pharmacological activity of the herb, as well as toxicological and clinical studies on its properties.

RESULTS

The findings of this study reveal a connection between the use of T. cordifolia in conventional medicine and its antioxidant, anti-inflammatory, antihypertensive, antidiabetic, anticancer, immunomodulatory, and other biological effects. The entire plant, stem, leaves, root, and extracts of T. cordifolia have been shown to have a variety of biological activities, including antioxidant, antimicrobial, antiviral, antiparasitic, antidiabetic, anticancer, anti-inflammatory, analgesic and antipyretic, hepatoprotective, and cardioprotective impact. Toxicological testing demonstrated that this plant may have medicinal applications. T. cordifolia contains a variety of biologically active compounds from various chemical classes, including alkaloids, terpenoids, sitosterols, flavonoids, and phenolic acids. Based on the reports researched for this review, we believe that chemicals in T. cordifolia may activate Nrf2, which leads to the overexpression of antioxidant enzymes such as CAT, GPx, GST, and GR, and thereby induces the adaptive response to oxidative stress. T. cordifolia is also able to reduce NF-κB signalling by inhibiting PI3K/Akt, activating AMPK and sirtuins, and downregulating PI3K/Akt.

CONCLUSIONS

Our findings indicate that the pharmacological properties displayed by T. cordifolia back up its conventional uses. Antimicrobial, antiviral, antioxidant, anticancer, anti-inflammatory, antimutagenic, antidiabetic, nephroprotective, gastroprotective, hepatoprotective, and cardioprotective activities were all demonstrated in T. cordifolia stem extracts. To validate pharmacodynamic targets, further research is needed to evaluate the molecular mechanisms of the known compounds against gastrointestinal diseases, inflammatory processes, and microbial infections, as immunostimulants, and in chemotherapy. The T. cordifolia safety profile was confirmed in a toxicological analysis, which prompted pharmacokinetic assessment testing to confirm its bioavailability.

Biophysical experiments reveal a protective role of protein phosphatase Z1 against oxidative damage of the cell membrane in Candida albicans

Protein phosphatase Z1 (Ppz1) has been shown to take part in important physiological functions in fungi including a contribution to virulence of Candida albicans. Although its involvement in the oxidative stress response has also been documented, the exact mechanism of action of its protective effect against oxidative damage remains unknown. By developing a pipeline to analyze the biophysical properties of the cell membrane in fungi, we demonstrate that the plasma membrane of Ppz1-KO Candida albicans displays increased sensitivity to tert-butyl-hydroperoxide-induced oxidative damage. In particular, the response to the oxidizing agent, characterized by increased lipid peroxidation, reduced lipid order, and inhibited lateral mobility of plasma membrane components, is significantly more pronounced in the Ppz1-KO C. albicans strain than in the wild-type counterpart. Remarkably, membrane constituents became almost completely immobile in the phosphatase deletion mutant exposed to oxidative stress. Furthermore, moderately elevated membrane lipid peroxidation accompanied by the aforementioned changes in the biophysical characteristics of the plasma membrane are already detectable in untreated Ppz1-KO cells indicating latent membrane damage even in the absence of oxidative stress. In conclusion, the hypersensitivity of cells lacking Ppz1 to oxidative damage establishes that potential Ppz1 inhibitors may synergize with oxidizing agents in prospective anti-fungal combination therapies.

Jasmonic acid and salicylic acid induce the accumulation of sucrose and increase resistance to chilling injury in peach fruit

BACKGROUND

Salicylic acid (SA) and jasmonic acid (JA) can both enhance resistance of chilling injury (CI) in cold-storage peach fruit, but the regulatory mechanisms involved and whether there is a coordinated regulation between them is unclear. In this study, postharvest peach fruit were treated with an aqueous SA solution for 15 min or an aqueous JA solution for 30 s before storage at 4 °C for 35 days.

RESULTS

SA and JA treatments both delayed and reduced development of internal browning (a symptom of CI) and induced the accumulation of hydrogen peroxide and sucrose. The SA and JA also reduced catalase and peroxidase activities, which are involved in hydrogen peroxide generation. The SA and JA treatments significantly regulated the transcript abundance of genes related to sucrose biosynthesis and degradation consistent with the observed increase in sucrose content.

CONCLUSION

These results intimate that JA and SA may be involved in coordinating the alleviation of CI via increased accumulation of sucrose. © 2021 Society of Chemical Industry.

The effect of femtosecond laser irradiation on the growth kinetics of Staphylococcus aureus: An in vitro study

We investigated the effect of femtosecond laser irradiation on the growth kinetics of Staphylococcus aureus. In order to improve laser-based antimicrobial therapy and develop a clinically viable modality, various laser parameters such as laser light wavelength, laser power, exposure time, and energy density were studied. The INSPIRE HF100 laser system (Spectra Physics) provided the femtosecond laser light, which was pumped by a mode-locked femtosecond Ti: sapphire laser MAI TAI HP (Spectra Physics). The survival of the bacterial cells was monitored after irradiation by determination of growth rate using optical density, which is a rapid, simple, and reliable method. The growth rate of laser-exposed cultures was compared to control cultures. Fifteen minutes of exposure to femtosecond laser radiation with a wavelength of 390 nm and 400 nm at an average power of 50 mW was enough to significantly reduce bacterial viability, with a lag in the growth phase of 5 h longer than the control culture (P < 0.0001 by ANOVA and Tukey test).

Chemical composition, antioxidant activities and antibacterial activities of essential oil from Erythrina caffra Thunb. growing in South Africa

INTRODUCTION

Essential oils from plants are recognized as one of the most promising secondary metabolites for the development of cheap and safer drugs. While Erythrina caffra has been prominently used in folk medicine for the treatment of microbial infections, there is dearth of information on the pharmacological effectiveness and chemical composition of its essential oil. The study, therefore, aimed at identifying the chemical composition and biological activities of the essential oil of Erythrina caffra.

METHODS

In this study, the essential oil was extracted with all-glass Clevenger. The antioxidant activities of the essential oil and antibacterial susceptibility assay by agar well diffusion techniques were assessed while GC-MS analysis was performed to identify the chemical constituents of the essential oil.

RESULTS

The study showed that the radical scavenging activity of the essential oil increases as the concentration of the essential oil increases. All bacterial isolates were susceptible to essential oil with the exception of Salmonella typhimurium and Pseudomonas aeruginosa producing inhibition zones ranging between 22 ± 1.3 and 35 ± 2.1 mm in the susceptible isolates. The GC-MS chromatogram indicated there are 35 bioactive compounds in the essential oil and Caryophyllene oxide (53.54%), [1S-(1α,7α,8aβ)]-1,2,3,5,6,7,8,8a-octa-1 - hydro-1,8a-dimethyl-7-(1-methylethenyl)-Naphthalene (7.81%), Kauran-18-al (6.49%), 10,10-Dimethyl-2,6-dimethylenebicy clo[7.2.0]undecan-5.beta.-ol (5.83%), 10s,11s-Himachala-3(12),4-diene (4.51%), Caryophyllene (3.65%) and 1- Hexanol (3.31%) were the most prominent compounds.

CONCLUSION

Excessive production of free radicals or reactive oxygen species (ROS) causes oxidative stress and disease. Oxidative stress resulting from imbalance between excessive generation of free radicals and inadequate antioxidant defense system has been linked to pathogenesis of many diseases. The essential oil of E. caffra stem bark extract possess antimicrobial and good antioxidant activities and its rich level of phytochemicals can be used as either dietary or complementary agents.

First-Principles Simulations of Biological Molecules Subjected to Ionizing Radiation

Ionizing rays cause damage to genomes, proteins, and signaling pathways that normally regulate cell activity, with harmful consequences such as accelerated aging, tumors, and cancers but also with beneficial effects in the context of radiotherapies. While the great pace of research in the twentieth century led to the identification of the molecular mechanisms for chemical lesions on the building blocks of biomacromolecules, the last two decades have brought renewed questions, for example, regarding the formation of clustered damage or the rich chemistry involving the secondary electrons produced by radiolysis. Radiation chemistry is now meeting attosecond science, providing extraordinary opportunities to unravel the very first stages of biological matter radiolysis. This review provides an overview of the recent progress made in this direction, focusing mainly on the atto- to femto- to picosecond timescales. We review promising applications of time-dependent density functional theory in this context.

Bioallethrin enhances generation of ROS, damages DNA, impairs the redox system and causes mitochondrial dysfunction in human lymphocytes

Bioallethrin is a synthetic pesticide that is widely used to control insect pests. The wide use of bioallethrin has resulted in inevitable human exposure. In this study we report the effect of different concentrations of bioallethrin (10 to 200 µM, 2 h at 37 °C) on human lymphocytes under in vitro conditions. Bioallethrin treatment resulted in loss of cell viability (> 30% at 200 µM bioallethrin). Oxidative stress markers like lipid peroxidation and protein oxidation were significantly increased accompanied by lower ratio of reduced to oxidized glutathione. Enhanced ROS generation was observed through fluorescence spectroscopy and microscopy. Bioallethrin-induced oxidative stress also compromised the antioxidant defence as it reduced antioxidant capacity of cells and inhibited major antioxidant enzymes. Biomolecular modifications and systemic toxicity by bioallethrin resulted in plasma membrane damage with mitochondrial depolarization. Comet assay showed nuclear DNA fragmentation and strand scission with significant increase in tail length and olive tail moment. Apoptosis and necrosis of cells was confirmed through acridine orange/ethidium bromide dual staining and visualization under fluorescence microscope. Thus, bioallethrin causes oxidative damage and compromises the antioxidant system leading to DNA damage, cellular and organelle toxicity, resulting in apoptosis and necrosis of human lymphocytes.

Evaluation of the protective effect of paricalcitol and vitamin D3 at doxorubicin nephrotoxicity in rats with 99mTechnetium-dimercaptosuccinic acid renal scintigraphy and biochemical methods

AIM

The present study aimed to examine the effect of paricalcitol (PRC) and vitamin D3 (vit D3) on doxorubicin (DOX)-induced nephrotoxicity in rats.

MATERIALS AND METHODS

Forty-two Wistar rats were randomly categorized into six groups: control; 2) PRC(0.5 µg/kg) and 3) vit D3(5.000 IU/kg) administered for 14 days; 4) DOX, 18 mg/kg administered on the 12th, 13th and 14th days of the study; 5) PRC (0.5 µg/kg, +DOX(18 mg/kg); vit D3(5.000 IU)+DOX(18 mg/kg). On the 15th day of the experiment, 99mTc-DMSA uptake level and biochemical parameter in serum and tissue were assay.

RESULTS

Activities of 99mTechnetium-Dimercaptosuccinic Acid (99mTc-DMSA) were lower in groups receiving DOX and/or PRC+DOX, vit D3+DOX than in control groups. The 99mTc-DMSA level in the group PRC+DOX and vit D3+DOX were importantly higher than DOX group. DOX caused an important increase in blood urea nitrogen (BUN), creatinine, Tumor Necrosis Factor-α(TNF- α), interleukin-6(IL-6) and nitric oxide(NO) levels compared to control groups. However, PRC and vit D3 pretreatments lowered them. Uptake of 99mTc-DMSA level was higher in groups PRC+DOX than in vit D3+DOX group. Administration of PRC and vit D3 alone did not change alterations all of parameters.

CONCLUSION

The results indicated that PRC administration protects kidney in DOX-induced nephrotoxic rats. In addition, PRC has a stronger nephroprotective effect than vit D3.

Toxicological effects induced by the biocide triclosan on Pseudokirchneriella subcapitata

Triclosan, a widely used biocide broadly found in aquatic environments, is cause of concern due to its unknown effects on non-targets organisms. In this study, a multi biomarker approach was used in order to evaluate the 72 h-effect of triclosan on the freshwater alga Pseudokirchneriella subcapitata (Raphidocelis subcapitata). Triclosan, at environmental relevant concentrations (27 and 37 μg L^-1), caused a decrease of proliferative capacity, which was accompanied by an increase of cell size and a profound alteration of algae shape. It was found that triclosan promoted the intracellular accumulation of reactive oxygen species, the depletion of non-enzymatic antioxidant defenses (reduced glutathione and carotenoids) and a decrease of cell metabolic activity. A reduction of photosynthetic pigments (chlorophyll a and b) was also observed. For the highest concentration tested (37 μg L^-1), a decrease of photosynthetic efficiency was detected along with a diminution of the relative transport rate of electrons on the photosynthetic chain. In conclusion, triclosan presents a deep impact on the microalga P. subcapitata morphology and physiology translated by multiple target sites instead of a specific point (cellular membrane) observed in the target organism (bacteria). Additionally, this study contributes to clarify the toxicity mechanisms of triclosan, in green algae, showing the existence of distinct modes of action of the biocide depending on the microalga.

Antimicrobial effect of photodynamic therapy on intracanal biofilm: A systematic review of in vitro studies

BACKGROUND

Antimicrobial photodynamic therapy (A-PDT), is one of the adjunctive therapies developed to improve the effectiveness of root canal disinfection.. The aim of this study was to analyze the antimicrobial effect of PDT on intracanal biofilm.

METHODS

Two reviewers conducted a literature search in PubMed, MEDLINE, Lilacs, SciELO, EMBASE and Google Scholar using the following search strategy: photochemotherapy "[Mesh] OR (photodynamic therapy) AND" dental plaque "[Mesh] OR (dental biofilm) AND (root canal). The following data were collected: publication year, author's name, study site, type of study, participant number, type of photosensitizer, type of laser, method of data collection, application time and results. Study quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS).

RESULTS

After selection based on title, abstract and full text, 27 studies were included in this systematic review. PDT reduced bacterial viability in most studies when combined with conventional endodontic techniques.

CONCLUSION

PDT reduced bacterial counts in most studies, especially when used as an adjunct to the conventional endodontic technique to treat refractory infection. However, PDT effects on in vitro bacterial biofilm were not accurately quantified because of the numerous biases in the studies reviewed.

Recent Advances in Zinc Oxide Nanostructures with Antimicrobial Activities

This article reviews the recent developments in the synthesis, antibacterial activity, and visible-light photocatalytic bacterial inactivation of nano-zinc oxide. Polycrystalline wurtzite ZnO nanostructures with a hexagonal lattice having different shapes can be synthesized by means of vapor-, liquid-, and solid-phase processing techniques. Among these, ZnO hierarchical nanostructures prepared from the liquid phase route are commonly used for antimicrobial activity. In particular, plant extract-mediated biosynthesis is a single step process for preparing nano-ZnO without using surfactants and toxic chemicals. The phytochemical molecules of natural plant extracts are attractive agents for reducing and stabilizing zinc ions of zinc salt precursors to form green ZnO nanostructures. The peel extracts of certain citrus fruits like grapefruits, lemons and oranges, acting as excellent chelating agents for zinc ions. Furthermore, phytochemicals of the plant extracts capped on ZnO nanomaterials are very effective for killing various bacterial strains, leading to low minimum inhibitory concentration (MIC) values. Bioactive phytocompounds from green ZnO also inhibit hemolysis of Staphylococcus aureus infected red blood cells and inflammatory activity of mammalian immune system. In general, three mechanisms have been adopted to explain bactericidal activity of ZnO nanomaterials, including direct contact killing, reactive oxygen species (ROS) production, and released zinc ion inactivation. These toxic effects lead to the destruction of bacterial membrane, denaturation of enzyme, inhibition of cellular respiration and deoxyribonucleic acid replication, causing leakage of the cytoplasmic content and eventual cell death. Meanwhile, antimicrobial activity of doped and modified ZnO nanomaterials under visible light can be attributed to photogeneration of ROS on their surfaces. Thus particular attention is paid to the design and synthesis of visible light-activated ZnO photocatalysts with antibacterial properties.

Impact of binding to the multidrug resistance regulator protein LmrR on the photo-physics and -chemistry of photosensitizers

Light activated photosensitizers generate reactive oxygen species (ROS) that interfere with cellular components and can induce cell death, e.g., in photodynamic therapy (PDT). The effect of cellular components and especially proteins on the photochemistry and photophysics of the sensitizers is a key aspect in drug design and the correlating cellular response with the generation of specific ROS species. Here, we show the complex range of effects of binding of photosensitizer to a multidrug resistance protein, produced by bacteria, on the formers reactivity. We show that recruitment of drug like molecules by LmrR (Lactococcal multidrug resistance Regulator) modifies their photophysical properties and their capacity to induce oxidative stress especially in 1O2 generation, including rose bengal (RB), protoporphyrin IX (PpIX), bodipy, eosin Y (EY), riboflavin (RBF), and rhodamine 6G (Rh6G). The range of neutral and charged dyes with different exited redox potentials, are broadly representative of the dyes used in PDT.

Antiproliferative activity of the dibenzylideneacetone derivate (E)-3-ethyl-4-(4-nitrophenyl)but‑3-en-2-one in Trypanosoma cruzi

Chagas disease is one of the most prevalent neglected diseases in the world. The illness is caused by Trypanosoma cruzi, a protozoan parasite with a complex life cycle and three morphologically distinct developmental stages. Nowadays, the only treatment is based on two nitro-derivative drugs, benznidazole and nifurtimox, which cause serious side effects. Since the treatment is limited, the search for new treatment options for patients with Chagas disease is highly necessary. In this study we analyzed the substance A11K3, a dibenzylideneacetone (DBA). DBAs have an acyclic dienone attached to aryl groups in both β-positions and studies have shown that they have biological activity against tumors cells, bacteria, and protozoa such as T. cruzi and Leishmania spp. Here we show that A11K3 is active against all three T. cruzi evolutionary forms: the epimastigote (IC₅₀ = 3.3 ± 0.8), the trypomastigote (EC₅₀ = 24 ± 4.3) and the intracellular amastigote (IC₅₀ = 9.3 ± 0.5 µM). A cytotoxicity assay in LLCMK₂ cells showed a CC₅₀ of 239.2 ± 15.7 µM giving a selectivity index (CC₅₀/IC₅₀) of 72.7 for epimastigotes, 9.9 for trypomastigotes and 25.9 for intracellular amastigotes. Morphological and ultrastructural analysis of the parasites treated with A11K3 by TEM and SEM revealed alterations in the Golgi complex, mitochondria, plasma membrane and cell body, with an increase of autophagic vacuoles and lipid bodies. Biochemical assays of A11K3-treated T. cruzi showed an increase of ROS, plasma membrane ruptures, lipid peroxidation, mitochondrial membrane depolarization with a decrease in ATP and accumulation of autophagic vacuoles. The results lead to the hypothesis that A11K3 causes death of the protozoan through events such as plasma membrane and mitochondrial alterations and autophagy, characteristic of cell collapse.

Chemopreventive Potential of Caryophyllane Sesquiterpenes: An Overview of Preliminary Evidence

Chemoprevention is referred to as a strategy to inhibit, suppress, or reverse tumor development and progression in healthy people along with high-risk subjects and oncologic patients through using pharmacological or natural substances. Numerous phytochemicals have been widely described in the literature to possess chemopreventive properties, although their clinical usefulness remains to be defined. Among them, caryophyllane sesquiterpenes are natural compounds widely occurring in nature kingdoms, especially in plants, fungi, and marine environments. Several structures, characterized by a common caryophyllane skeleton with further rearrangements, have been identified, but those isolated from plant essential oils, including β-caryophyllene, β-caryophyllene oxide, α-humulene, and isocaryophyllene, have attracted the greatest pharmacological attention. Emerging evidence has outlined a complex polypharmacological profile of caryophyllane sesquiterpenes characterized by blocking, suppressing, chemosensitizing, and cytoprotective properties, which suggests a possible usefulness of these natural substances in cancer chemoprevention for both preventive and adjuvant purposes. In the present review, the scientific knowledge about the chemopreventive properties of caryophyllane sesquiterpenes and the mechanisms involved have been collected and discussed; moreover, possible structure-activity relationships have been highlighted. Although further high-quality studies are required, the promising preclinical findings and the safe pharmacological profile encourage further studies to define a clinical usefulness of caryophyllane sesquiterpenes in primary, secondary, or tertiary chemoprevention.

Polydopamine Surface Coating Synergizes the Antimicrobial Activity of Silver Nanoparticles

Metal nanoparticles, especially silver nanoparticles (AgNPs), have drawn increasing attention for antimicrobial applications. Most studies have emphasized on the correlations between the antibacterial potency of AgNPs and the kinetics of metallic to ionic Ag conversion, while other antimicrobial mechanisms have been underestimated. In this work, we focused on the surface effects of polydopamine (PDA) coating on the antimicrobial activity of AgNPs. A method of fast deposition of PDA was used to synthesize the PDA-AgNPs with controllable coating thickness ranging from 3 to 25 nm. The antimicrobial activities of the PDA-AgNPs were analyzed by fluorescence-based growth curve assays on Escherichia coli. The results indicated that the PDA-AgNPs exhibited significantly higher antibacterial activities than poly(vinylpyrrolidone)-passivated AgNPs (PVP-AgNPs) and PDA themselves. It was found that the PDA coating synergized with the AgNPs to prominently enhance the potency of the PDA-AgNPs against bacteria. The analysis of X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy elucidated that the synergistic effects could be originated from the interaction/coordination between Ag and catechol group on the PDA coating. The synergistic effects led to increased generation of reactive oxygen species and the consequent bacterial damage. These findings demonstrated the importance of the surface effects on the antimicrobial properties of AgNPs. The underlying molecular mechanisms have shined light on the future development of more potent metal nanoparticle-based antimicrobial agents.

Antidiabetic Potential of Prosopis farcta Roots: In Vitro Pancreatic Beta Cell Protection, Enhancement of Glucose Consumption, and Bioassay-Guided Fractionation

By using the streptozotocin- (STZ-) induced cytotoxicity in β-TC3 cells as an assay model, a bioassay-guided fractionation study was employed to isolate and characterize the potential antidiabetic principles of roots of Prosopis farcta. A combination of open column chromatography on reverse-phase silica gel using a water-ethanol gradient (10 : 90 to 100 : 0) followed by HPLC-based fractionation led to an active compound that appears to be composed of carbohydrate/sugar. When cell viability under STZ was reduced to 49.8 ± 4% (mean ± SD), treatment with the active compound at the concentration of 0.5 mg/mL either as a coadministration or a pretreatment improved the viability to 93 ± 1.9% and 91.5 ± 7%, respectively. The reduction in the mitochondrial membrane potential by STZ (47.34 ± 8.9% of control) was similarly recovered to 84.5 ± 4.3 (coadministration) and 88 ± 5.5% (pretreatment) by the active fraction. The bioassay-guided fractionation, β-cell protective effect, and increased glucose consumption (up to 1.49-fold increase) in hepatocytes by the extracts and active fraction are also discussed.

The potential protective roles of zinc, selenium and glutathione on hypoxia-induced TRPM2 channel activation in transfected HEK293 cells

Hypoxia induces cell death through excessive production of reactive oxygen species (ROS) and calcium (Ca²⁺) influx in cells and TRPM2 cation channel is activated by oxidative stress. Zinc (Zn), selenium (Se), and glutathione (GSH) have antioxidant properties in several cells and hypoxia-induced TRPM2 channel activity, ROS and cell death may be inhibited by the Zn, Se, and GSH treatments. We investigated effects of Zn, Se, and GSH on lipid peroxidation (LPO), cell cytotoxicity and death through inhibition of TRPM2 channel activity in transfected HEK293 cells exposed to hypoxia defined as oxygen deficiency.We induced four groups as normoxia 30 and 60 min evaluated as control groups, hypoxia 30 and 60 min in the HEK293 cells. The cells were separately pre-incubated with extracellular Zn (100 µM), Se (150 nM) and GSH (5 mM). Cytotoxicity was evaluated by lactate dehydrogenase (LDH) release and the LDH and LPO levels were significantly higher in the hypoxia-30 and 60 min-exposed cells according to normoxia 30 and 60 min groups. Furthermore, we found that the LPO and LDH were decreased in the hypoxia-exposed cells after being treated with Zn, Se, and GSH according to the hypoxia groups. Compared to the normoxia groups, the current densities of TRPM2 channel were increased in the hypoxia-exposed cells by the hypoxia applications, while the same values were decreased in the treatment of Zn, Se, and GSH according to hypoxia group. In conclusion, hypoxia-induced TRPM2 channel activity, ROS and cell death were recovered by the Se, Zn and GSH treatments.

Cardioprotective Effect of Paricalcitol on Amitriptyline-Induced Cardiotoxicity in Rats: Comparison of [99mTc]PYP Cardiac Scintigraphy with Electrocardiographic and Biochemical Findings

Taking an overdose of AMT, a commonly prescribed tricyclic antidepressant drug, has an increased risk of sudden cardiac death. The cardiotoxicity of amitriptyline (AMT) is a commonly observed toxicity with high morbidity and mortality rates in emergency departments (ED). Nevertheless, there are still no effective treatment options for AMT-induced cardiotoxicity. The aim of the present study was to evaluate the effects of paricalcitol (PRC), a Vitamin D receptor agonist, using electrocardiographic (ECG), biochemical, and scintigraphic methods. Twenty-eight male Wistar rats were randomly divided into four groups: untreated control (CON), amitriptyline-induced cardiotoxicity (AMT), paricalcitol (PRC), and amitriptyline + paricalcitol (AMT + PRC). Cardiotoxicity was induced by intraperitoneal (i.p) injection of a single-dose AMT (100 mg/kg). PRC was administered as 10 μg/kg (i.p.) after the injection of AMT. We examined ECG, biochemical, and scintigraphic results of PRC administration on AMT-induced changes. Cardiotoxicity of AMT was characterized by conduction abnormalities (increased QRS complex, T wave, and QT interval duration and elevation of ST segment amplitude), elevated ^99mTechnetium Pyrophosphate ([^99mTc]PYP) uptake, and increased cardiac troponin T (cTnT) levels. Treatment with PRC significantly decreased all AMT-associated conduction abnormalities in ECG (p < 0.001), and decreased [^99mTc]PYP uptake (p < 0.001) and serum cTnT level (p < 0.001). The present study indicated that the vitamin D receptor agonist paricalcitol could decrease the AMT-induced cardiotoxicity. This suggests [^99mTc]PYP as a non-invasive method for the evaluation of myocardial injury induced by AMT. According to the results of the present study, PRC has beneficial effects on AMT-induced cardiotoxicity.

Nitrosative Stress Is Associated with Dopaminergic Dysfunction in the HIV-1 Transgenic Rat

Advances in antiretroviral therapy have resulted in significantly decreased HIV-related mortality. HIV-associated neurocognitive disorders, however, continue to be a major problem in infected patients. The neuropathology underlying HIV-associated neurocognitive disorders has not been well characterized, and evidence suggests different contributing mechanisms. One potential mechanism is the induction of oxidative stress. Using the HIV-1 transgenic (Tg) rat model of HIV, we found increased striatal NADPH oxidase-4 and neuronal nitric oxide synthase expression in the adult (7- to 9-month-old) Tg rat compared with control rats but not in the young (1-month-old) Tg rats. This was accompanied by increased 3-nitrotyrosine (3-NT) immunostaining in the adult Tg rats, which worsened significantly in the old Tg rats (18 to 20 months old). There was, however, no concurrent induction of the antioxidant systems because there was no change in the expression of the nuclear factor-erythroid 2-related factor 2 and its downstream targets (thioredoxin and glutathione antioxidant systems). Colocalization of 3-NT staining with neurofilament proteins and evidence of decreased tyrosine hydroxylase and dopamine transporter expression in the old rats support dopaminergic involvement. We conclude that the HIV-1 Tg rat brain shows evidence of nitrosative stress without appropriate oxidation-reduction adaptation, whereas 3-NT modification of striatal neurofilament proteins likely points to the ensuing dopaminergic neuronal loss and dysfunction in the aging HIV-1 Tg rat.

Sublethal effects of waterborne copper and copper nanoparticles on the freshwater Neotropical teleost Prochilodus lineatus: A comparative approach

Copper nanoparticles can contaminate the aquatic environment, but their effects on fish and how they may differ from copper salts is not understood. Thus, in this work we compare the sublethal effects of copper nanoparticles (nCu) and copper chloride (Cu) on the freshwater teleost Prochilodus lineatus, known for its sensitivity to copper. Juveniles (n = 8/group) were exposed to 20 μg L^-1 of copper as CuCl₂ (Cu), 40 μg L^-1 of copper nanoparticles (nCu), or only water (control), for 96 h. These concentrations were chosen to achieve similar dissolved copper concentration in both treatments (Cu: 10.29 ± 0.94 μg L^-1; nCu: 12.16 ± 1.77 μg L^-1). After the exposure, the following biological parameters were evaluated: copper accumulation in the gills, liver, gastrointestinal tract, kidney, and muscle; hematocrit (Ht) and hemoglobin content (Hb); branchial activity of Na⁺-K⁺-ATPase (NaKATP), H⁺-ATPase (HATP), Ca²⁺-ATPase (CaATP), and carbonic anhydrase (CA); glutathione content (GSH) and lipid peroxidation (LPO) in the liver; acetylcholinesterase activity (AChE) in the brain and muscle; and histopathology of the gills and liver. The gills of Cu-exposed fish were adversely affected, with increased copper content, inhibition of H⁺-ATPase and Ca²⁺-ATPase, and histological damage, including proliferation of mitochondria rich cells and/or mucous cells. In addition, LPO levels increased in the liver of Cu-exposed fish, indicating the occurrence of oxidative stress. Exposure to nCu promoted a decrease in Ht and Hb, indicating anemia, and an increase in branchial Na⁺-K⁺-ATPase and H⁺-ATPase activities, which can be an adaptive response to metabolic acidosis. Within the chosen biomarkers and the conditions tested, copper nanoparticles were less toxic than copper. However, the effects promoted by the nanoparticles were different from those promoted by copper. These results emphasize the need for a better understanding of copper nanoparticles toxicity in order to establish safe concentrations and avoid environment impacts.

Evaluation of the protective effect of edaravone on doxorubicin nephrotoxicity by [99mTc]DMSA renal scintigraphy and biochemical methods

To evaluate the nephroprotective effect of edaravone on doxorubicin-induced nephrotoxicity. In this experimental study, twenty-eight Wistar male rats were used. The rats were separated into 4 groups (n = 7); group І (control), rats were treated with saline (4 ml/kg) and group ІІ (doxorubicin), nephrotoxicity was induced by three doses of 18 mg/kg/i.p. doxorubicin, at a 24-h interval on the 12th, 13th, and 14th days. Group ІІІ (edaravone), rats were treated with edaravone (30 mg/kg/for 14 days), and group ІV (edaravone + doxorubicin), rats were treated with edaravone (30 mg/kg/for 14 days) and doxorubicin were injected (18 mg/kg/for 3 days; at a 24-h interval on the 12th, 13th, and 14th days). On the 15th day of the experiment, technetium-99m-labeled dimercaptosuccinic acid ([^99mTc]DMSA) uptake was obtained in both kidneys and biochemical parameters from serum and kidney tissue were measured. Doxorubicin led to nephrotoxicity through elevation of serum blood urea nitrogen (BUN), creatinine and tumor necrosis factor-α (TNF-α), nitric oxide (NO), and interleukin-6 (IL-6) in kidney tissue and decreased [^99mTc]DMSA uptake level in the kidney when compared with control group (p < 0.01). Pretreatment edaravone significantly decreased BUN and creatinine, also kidney tissue TNF-α, IL-6, NO, and increased [^99mTc]DMSA uptake level compared with the doxorubicin. Edaravone has a significant nephroprotective effect through the attenuation of oxidative stress and inflammatory markers during doxorubicin-induced nephrotoxicity in rats.

Modulation of Oxidative Stress and Inflammatory Cytokines as Therapeutic Mechanisms of Ocimum americanum L Extract in Carbon Tetrachloride and Acetaminophen-Induced Toxicity in Rats

Liver diseases have now become a global canker due to increasing drug abuse and several viral infections. The current medicines on the market are woefully inadequate and limited in the application against these diseases. Fortunately, medicinal plants continue to serve as a potential source of drug discovery that could be explored to improve the situation. The present study, therefore, evaluated the hepatoprotective activities of the aqueous extract of various parts (leaves, flower and stem) of Ocimum americanum L on carbon tetrachloride (CCl4)- and acetaminophen-induced toxicity in rats. The protective effect of the plant was assessed using biochemical parameters, histology, levels of liver antioxidants, and expression of some pro-inflammatory cytokines (NF-κβ and IL-1) in the liver. The leaves and stem extracts, orally administered for 7 days at 250 mg/kg, effectively prevented CCl4-induced elevation of serum biochemical parameters, prooxidants, as well as the expression of NFk-B and IL-1, which were comparable to Silymarin (standard drug). A comparative histopathological analyses of the liver exhibited virtually normal architecture compared with CCl4-treated group. The findings showed that the hepatoprotective effect of Ocimum americanum was probably due to the inhibition of oxidative stress and downregulation of proinflammatory cytokines by the effective parts of the medicinal plant.

Effect of Ethylene on Cell Wall and Lipid Metabolism during Alleviation of Postharvest Chilling Injury in Peach

Peach is prone to postharvest chilling injury (CI). Here it was found that exogenous ethylene alleviated CI, accompanied by an increased endogenous ethylene production. Ethylene treatment resulted in a moderately more rapid flesh softening as a result of stronger expression of genes encoding expansin and cell wall hydrolases, especially xylosidase and galactosidase. Ethylene treatment alleviated internal browning, accompanied by changes in expression of polyphenol oxidase, peroxidase and lipoxygenases. An enhanced content of phospholipids and glycerolipids and a reduced content of ceramide were observed in ethylene-treated fruit, and these were associated with up-regulation of lipid phosphate phosphatase, fatty acid alpha-hydroxylase, and golgi-localized nucleotide sugar transporter, as well as down-regulation of aminoalcohol phosphotransferases. Expression of two ethylene response factors (ERFs), ESE3 and ABR1, was highly correlated with that of genes involved in cell wall metabolism and lipid metabolism, respectively. Furthermore, the expression of these two ERFs was strongly regulated by ethylene treatment and the temperature changes during transfer of fruit into or out of cold storage. It is proposed that ERFs fulfill roles as crucial integrators between cell wall modifications and lipid metabolism involved in CI processes ameliorated by exogenous ethylene.