Cellular Antioxidant Research Articles

Nanochitosan-encapsulated melatonin: an eco-friendly strategy to delay petal senescence in cut gerbera flowers

BackgroundThe preservation of cut flowers, particularly Gerbera jamesonii, is crucial for maintaining their aesthetic value and extending vase life in the floriculture industry. To address this challenge, this study investigated the effects of melatonin (Mel) and encapsulated melatonin with nanochitosan (nCS-Mel) as preservative solutions on cut Gerbera jamesonii cv. ‘Terra kalina’ flowers. In research, we examined various physiological and biochemical parameters, including relative water content, membrane stability index, carbohydrate content, and antioxidant enzyme activities, to evaluate the efficacy of these treatments in prolonging the vase life and quality of cut gerbera flowers under controlled environmental conditions.ResultsOur results demonstrated that cut Gerbera jamesonii flowers maintained in vase solutions containing 0.1 and 0.5 mM nCS-Mel exhibited enhanced preservation of cell membrane integrity and anthocyanin content, while also maintaining higher levels of carbohydrates and total flavonoids in petals at the conclusion of their vase life. A decline in petal relative water content and protein levels was observed concomitantly with petal senescence, whereas total phenolic compounds showed an increase. The hydrogen peroxide (H2O2) content in petals exhibited an upward trend during vase life in control specimens, but this effect was mitigated in treatments containing melatonin. Although malondialdehyde (MDA) content generally increased throughout the vase life period, flowers subjected to either Mel or nCS-Mel treatments displayed reduced MDA accumulation. The activity of catalase (CAT) demonstrated an increasing trend during vase life, with the maximum activity observed in Gerbera flowers treated with 0.1 mM nCS-Mel. A similar upward trend was noted for superoxide dismutase (SOD) activity, with flowers in 0.5 mM nCS-Mel treatment exhibiting peak SOD values on day 12 relative to control and other treatments. Peroxidase (POD) activity also increased across all treatments, with particularly pronounced effects in vase solutions containing 0.1 mM Mel and nCS-Mel. Notably, flowers placed in vase solutions containing 0.1 mM nCS-Mel, followed by 0.5 mM nCS-Mel and 0.1 mM Mel, exhibited the most prolonged vase life, extending up to 12, 10.66, and 10.33 days, respectively, under room temperature conditions.ConclusionsThe application of nanoencapsulated melatonin as a vase solution for cut Gerbera jamesonii flowers demonstrates significant potential in extending vase life and maintaining flower quality through enhanced preservation of cellular integrity, antioxidant activity, and biochemical parameters. This innovative approach not only outperforms conventional treatments but also presents a more environmentally friendly alternative to traditional antimicrobial preservatives and sugars, offering a promising solution for the floriculture industry to improve cut flower longevity and reduce ecological impact.

Role of sumoylation modification of sirtuin 3 in hypertension-associated

Abstract Objective The present study was designed to investigate whether mitochondrial dysfunction and oxidative stress in HTN-injured cardiomyocytes are associated with SIRT3 SUMOylation and whether SIRT3 deSUMOylation can ameliorate the related cardiomyocyte injury. Design and method The human cardiomyocyte AC16 cell line was used for the study. The SIRT3-K288R cell line was constructed by lentiviral transfection;The expression of SOD2, acetyl-SOD2 (MnSOD), protein acetylation level, inflammatory vesicle NLRP3, etc. in different subgroups were detected by Western Blot, and the roles of SUMOylation modification and SIRT3 deacetylation in HTN-associated cell injury were investigated by flow cytometry. Results (1) Western Blot results showed that compared to the HTN cell injury model, the cardiomyocytes in the SIRT3-K288R intervention group had increased Acetyl- SOD2/SOD2 levels were increased (p < 0.05) and protein acetylation levels were decreased in the SIRT3-K288R intervention group compared with the HTN cell injury model, indicating that SIRT3 increased the deacetylation effect on mitochondria and increased cellular antioxidant stress enzyme activity; (2) Western Blot results showed that compared with the HTN cell injury model, cardiomyocytes in the SIRT3-K288R intervention group NLRP3 and NOX4 levels were significantly reduced, indicating that SIRT3 deSUMOylation could improve the inflammatory response to Ang-II-related cell injury. (3) Flow cytometry results showed that K288R transfection ameliorated the reduction of cellular membrane potential, suggesting that deSUMOylation modification of SIRT3 reduces Ang-II damage to mitochondrial membrane potential. Conclusions In the HTN-associated cell injury model, the removal of SUMOylation modification by viral transfection could improve oxidative stress, protein acetylation levels and associated inflammatory responses in HTN-injured cardiomyocytes, indicating that SIRT3 SUMOylation may play an important mechanism in HTN-associated cell injury, and reducing SIRT3 SUMOylation modification may be a possible direction for future research.

Selenocysteine tRNA methylation promotes oxidative stress resistance in melanoma metastasis.

Selenocysteine-containing proteins play a central role in redox homeostasis. Their translation is a highly regulated process and is dependent on two tRNASec isodecoders differing by a single 2'-O-ribose methylation called Um34. Here we characterized FTSJ1 as the Um34 methyltransferase and show that its activity is required for efficient selenocysteine insertion at the UGA stop codon during translation. Specifically, loss of Um34 leads to ribosomal stalling and decreased UGA recoding. FTSJ1-deficient cells are more sensitive to oxidative stress and show decreased metastatic colonization in xenograft models of melanoma metastasis. We found that FTSJ1 mediates efficient translation of selenoproteins essential for the cellular antioxidant response. Our findings uncover a role for tRNASec Um34 modification in oxidative stress resistance and highlight FTSJ1 as a potential therapeutic target specific for metastatic disease.

Lactobacillus reuteri or Lactobacillus rhamnosus GG intervention facilitates gut barrier function, decreases corticosterone and ameliorates social behavior in LPS-exposed offspring

Probiotic therapy with Lactobacillus reuteri and Lactobacillus rhamnosus (LGG) demonstrates potential as an adjunctive treatment for autism spectrum disorder (ASD). In a rat model of ASD induced by lipopolysaccharide (LPS) injection during pregnancy, we evaluated the effects of these probiotics on offspring. Administration of L. reuteri or LGG for three weeks post-birth improved social deficits and reduced anxiety in LPS-exposed rats. Additionally, probiotics significantly modified short-chain fatty acid profiles, increasing butyric acid levels and decreasing propionic acid levels. They also enhanced colonic barrier integrity by upregulating tight junction proteins, including ZO-1, Occludin, and Claudin4. RNA sequencing identified differential gene expression in pathways related to inflammation, the HPA axis, and reactive oxygen species metabolism, with NADPH oxidase 1 (NOX1) emerging as a crucial gene. Validation studies confirmed that Lactobacillus strains reduced inflammatory cytokines, inhibited corticosterone secretion, increased antioxidant levels, and suppressed the NF-κB/NOX1 pathway. In an H2O2-induced oxidative stress model using Caco-2 cells, pre-treatment with L. reuteri, LGG, or NF-κB inhibitors enhanced cellular antioxidants, inhibited NF-κB/NOX1 activation, and improved barrier function. Overall, L. reuteri and LGG administration improved social behavior, bolstered colonic barrier function, and mitigated HPA axis overactivation in LPS-exposed rats, while also alleviating oxidative stress in the colon and Caco-2 cells. These findings suggest that L. reuteri and LGG have substantial clinical potential for ASD treatment by targeting multiple pathophysiological mechanisms, including inflammation, HPA axis dysregulation, and oxidative stress, thereby presenting a promising adjunctive therapeutic strategy for enhancing social behavior and gut health in ASD.

Metabolic pathways regulated by strigolactones foliar spraying enhance osmoregulation and antioxidant defense in drought-prone soybean

BackgroundDrought stress is a significant abiotic stressor that hinders growth, development, and crop yield in soybeans. Strigolactones (SLs) positively regulate plant resistance to drought stress. However, the impact of foliar application of SLs having different concentrations on soybean growth and metabolic pathways related to osmoregulation remains unknown. Therefore, to clarify the impact of SLs on soybean root growth and cellular osmoregulation under drought stress, we initially identified optimal concentrations and assessed key leaf and root indices. Furthermore, we conducted transcriptomic and metabolic analyses to identify differential metabolites and up-regulated genes.ResultsThe results demonstrated that drought stress had a significant impact on soybean biomass, root length, root surface area, water content and photosynthetic parameters. However, when SLs were applied through foliar application at appropriate concentrations, the accumulation of ABA and soluble protein increased, which enhanced drought tolerance of soybean seedlings by regulating osmotic balance, protecting membrane integrity, photosynthesis and activating ROS scavenging system. This also led to an increase in soybean root length, lateral root number and root surface area. Furthermore, the effects of different concentrations of SLs on soybean leaves and roots were found to be time-sensitive. However, the application of 0.5 µM SLs had the greatest beneficial impact on soybean growth and root morphogenesis under drought stress. A total of 368 differential metabolites were screened in drought and drought plus SLs treatments. The up-regulated genes were mainly involved in nitrogen compound utilization, and the down-regulated metabolic pathways were mainly involved in maintaining cellular osmoregulation and antioxidant defenses.ConclusionsSLs enhance osmoregulation in soybean plants under drought stress by regulating key metabolic pathways including Arachidonic acid metabolism, Glycerophospholipid metabolism, Linoleic acid metabolism, and Flavone and flavonol biosynthesis. This study contributes to the theoretical understanding of improving soybean adaptability and survival in response to drought stress.

Lactic acid bacteria supplementation: A bioprotective approach to mitigating cadmium-induced toxicity and modulating gene expression in murine models

This study aimed to assess the effects of different strains of lactic acid bacteria, namely LeviLactobacillus brevis (AC10), Lacticaseibacillus rhamnosus (AC11), and Pediococcus acidilactici (AC15), on mice exposed to cadmium-induced oxidative stress. The study assessed weight gain, liver enzymes, antioxidant enzymes, immunoglobulin factors, lipid peroxidation, and gene expression in liver and brain of mice. The findings revealed that the AC10 and AC11 strains had a higher ability to absorb Cd as compared to AC15. The in vivo analysis demonstrated that the dietary dual supplementation of AC10 and AC11 resulted in significant (p < 0.05) improvements, including increased body weight and food intake, reduced cadmium tissue deposition, decreased lipid peroxidation, enhanced cellular antioxidant redox potential, suppressed inflammation genes in the liver and brain tissues, and improved morpho-characteristics of the jejunum in mice challenged by cadmium-induced toxicity. The multiple mechanisms of action, including heavy metal sequestration, antioxidant enhancement, and maintenance of intestinal integrity, highlight the potential of these probiotics’ intervention as a viable approach to counteract the deleterious effects of cadmium exposure.

Arsenic and Chromium Induced Toxicity on Zebrafish Kidney: Mixture Effects on Oxidative Stress and Involvement of Nrf2-Keap1-ARE, DNA Repair, and Intrinsic Apoptotic Pathways.

In polluted water, cooccurrences of two carcinogens, arsenic (As) and chromium (Cr), are extensively reported. Individual effects of these heavy metals have been reported in kidney of fishes, but underlying molecular mechanisms are not well established. There is no report on combined exposure of As and Cr in kidney. Thus, the present study investigated and compared individual and combined effects of As and Cr on zebrafish (Danio rerio) kidney treating at their environmentally relevant concentrations for 15, 30, and 60 days. Increased ROS levels, lipid peroxidation, GSH level, and decreased catalase activity implied oxidative stress in treated zebrafish kidney. Damage in histoarchitecture in treated groups was also noticed. The current study involved gene expression study of Nrf2, an important transcription factor of cellular stress responses along with its negative regulator Keap1 and downstream antioxidant genes nqo1 and ho1. Results indicated activation of Nrf2-Keap1 pathway after combined exposure. Expression pattern of ogg1, apex1, polb, and creb1 revealed the inhibition of base excision repair pathway in treatments. mRNA expression of tumor suppressor genes p53 and brca2 was also altered. Expressional alteration in bax, bcl2, caspase9, and caspase 3 indicated apoptosis (intrinsic pathway) induction, which was maximum in combined group. Inhibition of DNA repair and induction of apoptosis indicated that the activated antioxidant system was not enough to overcome the damage caused by As and Cr. Overall, this study revealed additive effects of As and Cr in zebrafish kidney after chronic exposure focusing cellular antioxidant and DNA damage responses.

Antioxidant Properties of Postbiotics: An Overview on the Analysis and Evaluation Methods.

Antioxidants found naturally in foods have a significant effect on preventing several human diseases. However, the use of synthetic antioxidants in studies has raised concerns about their potential link to liver disease and cancer. The findings show that postbiotics have the potential to act as a suitable alternative to chemical antioxidants in the food and pharmaceutical sectors. Postbiotics are bioactive compounds generated by probiotic bacteria as they ferment prebiotic fibers in the gut. These compounds can also be produced from a variety of substrates, including non-prebiotic carbohydrates such as starches and sugars, as well as proteins and organic acids, all of which probiotics utilize during the fermentation process. These are known for their antioxidant, antibacterial, anti-inflammatory, and anti-cancer properties that help improve human health. Various methodologies have been suggested to assess the antioxidant characteristics of postbiotics. While there are several techniques to evaluate the antioxidant properties of foods and their bioactive compounds, the absence of a convenient and uncomplicated method is remarkable. However, cell-based assays have become increasingly important as an intermediate method that bridges the gap between chemical experiments and in vivo research due to the limitations of in vitro and in vivo assays. This review highlights the necessity of transitioning towards more biologically relevant cell-based assays to effectively evaluate the antioxidant activity of postbiotics. These experiments are crucial for assessing the biological efficacy of dietary antioxidants. This review focuses on the latest applications of the Caco-2 cell line in the assessment of cellular antioxidant activity (CAA) and bioavailability. Understanding the impact of processing processes on the biological properties of postbiotic antioxidants can facilitate the development of new food and pharmaceutical products.

The Effect of Multilayer Nanoemulsion on the In Vitro Digestion and Antioxidant Activity of β-Carotene.

The objectives of this study were to design multilayer oil-in-water nanoemulsions using a layer-by-layer technique to enhance the stability of β-carotene and evaluate its effect on in vitro release and antioxidant activity. To prepare β-carotene-loaded multilayer nanoemulsions (NEs), a primary NE (PRI-NE) using Tween 20 was coated with chitosan (CS) for the secondary NE (SEC-CS), and with dextran sulfate (DS) and sodium alginate (SA) for the two types of tertiary NEs (TER-DS, TER-SA). The multilayer NEs ranged in particle size from 92 to 110 nm and exhibited high entrapment efficiency (92-99%). After incubation in a simulated gastrointestinal tract model, the release rate of free fatty acids decreased slightly after coating with CS, DS, and SA. The bioaccessibility of β-carotene was 7.02% for the PRI-NE, 7.96% for the SEC-CS, 10.88% for the TER-DS, and 10.25% for the TER-SA. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging abilities increased by 1.2 times for the multilayer NEs compared to the PRI-NE. In addition, the cellular antioxidant abilities improved by 1.8 times for the TER-DS (87.24%) compared to the PRI-NE (48.36%). Therefore, multilayer nanoemulsions are potentially valuable techniques to improve the stability, in vitro digestion, and antioxidant activity of β-carotene.

Proteomics Analysis on the Effects of Oxidative Stress and Antioxidants on Proteins Involved in Sterol Transport and Metabolism in Human Telomerase Transcriptase-Overexpressing-Retinal Pigment Epithelium Cells.

Age-related macular degeneration (AMD) is the most prevalent ocular disease in the elderly, resulting in blindness. Oxidative stress plays a role in retinal pigment epithelium (RPE) pathology observed in AMD. Tocopherols are potent antioxidants that prevent cellular oxidative damage and have been shown to upregulate the expression of cellular antioxidant proteins. Here, we determined whether oxidative stress and tocopherols, using either normal cellular conditions or conditions of sublethal cellular oxidative stress, alter the expression of proteins mediating sterol uptake, transport, and metabolism. Human telomerase transcriptase-overexpressing RPE cells (hTERT-RPE) were used to identify differential expression of proteins resulting from treatments. We utilized a proteomics strategy to identify protein expression changes in treated cells. After the identification and organization of data, we divided the identified proteins into groups related to biological function: cellular sterol uptake, sterol transport and sterol metabolism. Exposure of cells to conditions of oxidative stress and exposure to tocopherols led to similar protein expression changes within these three groups, suggesting that α-tocopherol (αT) and γ-tocopherol (γT) can regulate the expression of sterol uptake, transport and metabolic proteins in RPE cells. These data suggest that proteins involved in sterol transport and metabolism may be important for RPE adaptation to oxidative stress, and these proteins represent potential therapeutic targets.

Microalgal astaxanthin ameliorates cypermethrin-induced necroptosis and inflammation via targeting mitochondrial Ca2+ homeostasis and the ROS-NF-κB-RIPK3/MLKL axis in carp hepatocytes (Cyprinus carpio)

Cypermethrin is a toxic pesticide that has infiltrated water bodies due to its widespread use. This contamination has led to detrimental effects on the immune organs of aquatic species, including fish. The natural fat-soluble orange-red carotenoid, astaxanthin (MAT), derived from microalgae, possesses anti-inflammatory, antioxidant, and immunomodulatory properties. To elucidate the mechanism of CY induced damage to carp liver cells and assess the potential protective effects of MAT, we established a carp hepatocyte model exposed to CY and/or MAT. Hepatocytes from carp (Cyprinus carpio) were treated with either 8 μM CY or 60 μM MAT for 24 h. Upon exposure CY, a significant increase in reactive oxygen species (ROS) was observed alongside a diminution in the activities of key antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), suggesting an impairment of cellular antioxidant capacity. Subsequently, acridine orange/ethidium bromide (AO/EB) staining and flow cytometry analysis revealed that hepatocytes exposed to CY exhibited a higher incidence of necroptosis, associated with an elevated mitochondrial Ca2+ concentration, which contributed to cellular dysfunction. Furthermore, exposure to CY also activated the ROS-NF-κB-RIPK3/MLKL signaling pathway, increasing the levels of necroptosis-related regulatory factors (RIP1, RIP3, and MLKL) in hepatocytes and the expression of inflammatory genes (IL-6, IFN-γ, IL-4, IL-1β, and TNF-α), which led to immune dysfunction in hepatocytes. The immunotoxic effects induced by CY were mitigated by MAT treatment, suggesting its potential in alleviating the aforementioned changes caused by CY. Overall, the data suggested that MAT therapy could enhance hepatocyte defenses against CY-induced necroptosis and inflammatory responses by regulating mitochondrial Ca2+ homeostasis and inhibiting the ROS-NF-κB-RIPK3/MLKL signaling cascade. This study elucidated the potential benefits of employing MAT to protect farmed fish from agrobiological hazards during CY exposure, underscoring the practical applications of MAT in aquaculture.

Quercetin microgels alter gut metabolome and reverse oxidative damage invitro

Colonic delivery of quercetin using encapsulation techniques is an effective approach in maximizing quercetin efficacy against oxidative-stress related diseases such as inflammatory bowel disease. We hypothesized that colon-targeted delivery of quercetin with quercetin loaded alginate-chitosan microgels (ALQ) could alter colonic microbial metabolism regulating microbial metabolites production that may exert biological effects at the cellular level. To demonstrate this, ALQ were subjected to colonic fermentation using human fecal microbiota with empty microgels (AL) as control, and fermented fecal samples were collected at 0, 8, and 24 h. Short chain fatty acid analysis using gas chromatography showed that ALQ increased productions of acetic acid, while decreased isobutyric and isovaleric acid production. Semi-targeted metabolome scanning using Orbitrap mass spectrometer showed that the overall metabolome profile was remarkably different between AL and ALQ treatments at both 8 h and 24 h of fermentation. There were 9 metabolites at 8 h, and 54 metabolites at 24 h that were significantly regulated with more than 2-fold changes between AL and ALQ treatments. The metabolites included quercetin derived metabolites, amino acids and their derivatives, nucleotide derivatives, and organic acids. ALQ significantly modulated tyrosine metabolism, amino acids metabolic pathways, and the tricarboxylic acid cycle. These ALQ modulated metabolites in turn protected the Caco-2 cells from lipopolysaccharides induced injury, increased cellular antioxidant activities, and alleviated lipid oxidation induced by H2O2. Conclusively, ALQ could alter human fecal metabolome in vitro with significant shifts in key metabolites and exert antioxidant effects on cellular level, exhibiting potentials in colonic disease management.

Sensitization of Multidrug Resistant Cancer Cells to Doxorubicin Using Ebselen by Disturbing Cellular Redox Status.

Multidrug resistance (MDR) poses a significant problem in cancer treatment, often causing adverse effects during chemotherapy. Ebselen (Ebs), a synthetic organoselenium compound, affects cellular redox status in cancer cells. In the study, we observed that Ebs disrupted cellular redox balance and sensitized drug-resistant cells to doxorubicin (DOX) treatment. The combination of Ebs and DOX led to increased intracellular reactive oxygen species (ROS) levels and lipid peroxidation while decreasing the activity of thioredoxin reductase (TrxR) and cellular antioxidants in drug-resistant cells. Furthermore, this combination treatment demonstrated notable chemosensitizing effects by reducing cell viability and proliferation in MDR cells compared to DOX treatment alone. Additionally, the combination of Ebs and DOX induced DNA fragmentation and exhibited G2/M phase cell cycle arrest. Immunofluorescent analysis revealed that the Ebs and DOX combination upregulated the expression of p53 and p21, which activated the mitochondrial-dependent apoptotic pathway. The combination treatment also enhanced the upregulation of proapoptotic markers such as Bax, Caspase-3, -9, and cytochrome C, while downregulating the expression of the antiapoptotic marker Bcl-2. Therefore, the current discoveries suggest that Ebs could be employed as a drug candidate for reversing MDR in cancer cells by regulating cellular redox homeostasis.

Overview and Trends in Electrochemical Sensors, Biosensors and Cellular Antioxidant Assays for Oxidant and Antioxidant Determination in Food

Screening and quantifying antioxidants from food samples, their antioxidant activity, as well as the assessment of food oxidation is critical, not only for ensuring food quality and safety, but also to understand and relate these parameters to the shelf life, sensory attributes, and health aspects of food products. For this purpose, several methods have been developed and used for decades, which regardless of their effectiveness, present a certain number of drawbacks mainly related to extensive sample preparation and technical complexity, time requirement, and use of hazardous chemicals. Electrochemical sensors and biosensors are gaining popularity in food analysis due to their high sensitivity, specificity, rapid response times, and potential for miniaturisation and portability. Furthermore, other modern methods using whole living cells such as the cellular antioxidant activity assay, the antioxidant power 1 assay, and the catalase-like assays, may interpret more realistic antioxidant results rather than just reporting the ability of scavenging free radicals in isolated systems with extrapolation to the reality. This paper provides an overview on the electrochemical sensors, biosensors, and cellular antioxidant assays, and reviews the latest advancements and emerging trends in these techniques for determining oxidants and antioxidants in complex food matrices. The performances of different strategies are described for each of these approaches to provide insights into which extent these methods can be exploited in the field and inspire new research to fill the identifiable current gaps.

O-GlcNAcylation promotes malignancy and cisplatin resistance of lung cancer by stabilising NRF2.

The transcription factor NRF2 plays a significant role in regulating genes that protect cells from oxidative damage. O-GlcNAc modification, a type of posttranslational modification, is crucial for cellular response to stress. Although the involvement of both NRF2 and O-GlcNAc in maintaining cellular redox balance and promoting cancer malignancy has been demonstrated, the potential mechanisms remain elusive. The immunoblotting, luciferase reporter, ROS assay, co-immunoprecipitation, and immunofluorescence was used to detect the effects of global cellular O-GlcNAcylation on NRF2. Mass spectrometry was utilised to map the O-GlcNAcylation sites on NRF2, which was validated by site-specific mutagenesis and O-GlcNAc enzymatic labelling. Human lung cancer samples were employed to verify the association between O-GlcNAc and NRF2. Subsequently, the impact of NRF2 O-GlcNAcylation in lung cancer malignancy and cisplatin resistance were evaluated in vitro and in vivo. NRF2 is O-GlcNAcylated at Ser103 residue, which hinders its binding to KEAP1 and thus enhances its stability, nuclear localisation, and transcription activity. Oxidative stress and cisplatin can elevate the phosphorylation of OGT at Thr444 through the activation of AMPK kinase, leading to enhanced binding of OGT to NRF2 and subsequent elevation of NRF2 O-GlcNAcylation. Both in cellular and xenograft mouse models, O-GlcNAcylation of NRF2 at Ser103 promotes the malignancy of lung cancer. In human lung cancer tissue samples, there was a significant increase in global O-GlcNAcylation, and elevated levels of NRF2 and its O-GlcNAcylation compared to paired adjacent normal tissues. Chemotherapy promotes NRF2 O-GlcNAcylation, which in turn decreases cellular ROS levels and drives lung cancer cell survival. Our findings indicate that OGT O-GlcNAcylates NRF2 at Ser103, and this modification plays a role in cellular antioxidant, lung cancer malignancy, and cisplatin resistance.

YiMu-QingGong san alleviates lipopolysaccharide-induced endometritis in mice via inhibiting inflammation and oxidative stress through regulating macrophage polarization

Ethnopharmacological relevanceEndometritis is a common reproductive disease in dairy cattle after calving, characterized by persistent inflammation of the endometrium. YiMu-QingGong San (YMQGS), a patented Chinese medicine formulation, has demonstrated efficacy in the treatment of clinical endometritis in dairy cattle. However, the potential mechanisms by which YMQGS alleviates endometritis remain unclear. Aim of the studyThe objective of this study is to elucidate the underlying therapeutic mechanisms of YMQGS in the context of endometritis. Materials and methodsThe chemical components of YMQGS were analyzed using UHPLC/MS. The anti-inflammatory capabilities of YMQGS were assessed by inducing an inflammatory response in RAW264.7 cells with lipopolysaccharide (LPS). Moreover, a clinical model of endometritis was simulated via vaginal injection of LPS into the uterine horns to investigate the therapeutic mechanisms of YMQGS. ResultsYMQGS could downregulate the expression of inflammatory mediators (TNF-α, IL-6, IL-1β) by suppressing the activation of the TLRs/MyD88/TRAF6/NF-κB signaling pathway in RAW264.7 cells. Additionally, YMQGS facilitated the polarization of RAW264.7 cells towards M2-like macrophages (Mφs) while inhibiting M1-like Mφs polarization, thereby exerting anti-inflammatory effects. Further investigation revealed that YMQGS could diminish ROS production, augment cellular antioxidant capacity, preserve mitochondrial membrane potential, and reduce intracellular [Ca2+]i accumulation, thereby minimizing cellular damage. In the mouse model of endometritis, YMQGS similarly inhibited the activation of the NF-κB signaling pathway in uterine tissues and modulated Mφ polarization in the endometrium, leading to a decrease in the expression of inflammatory factors and subsidence of the inflammatory response in the endometrium. Histological staining results showed that YMQGS reduced endometrial fibrosis, increased the expression of endometrial ZO-1, Occludin and glycoprotein, protect the endometrial barrier function, and prevent the further development of endometritis. ConclusionCollectively, the present study confirms that YMQGS possesses notable anti-inflammatory and antioxidant properties. The suppression of the NF-κB signaling pathway and the modulation of Mφ polarization emerge as the pivotal mechanisms by which YMQGS alleviates endometritis.

Polyphenols from unconventional fruit by-products protect human epithelial intestinal cells from oxidative damage

Polyphenols from discards of unconventional fruits, namely guava (Psidium guajava L.), jerivá (Syagrus romanzoffiana), butiá (Butia catarinensis), and sea buckthorn (Hippophae rhamnoids L.) have shown in vitro capacity to ameliorate risk factors associated with chronic diseases. To verify their effects in models simulating human physiology, human colorectal adenocarcinoma (Caco-2) cells can be used to reproduce the small intestine's brush border. Therefore, differentiated Caco-2 cells were treated with phenolic extracts from guava processing discards and jerivá, butiá, and sea buckthorn seeds. Cells were assessed for cytotoxicity through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cellular antioxidant activity (CAA) by fluorescence decline of treated cells mixed with a free radical. Selected extract concentrations induced Caco-2 cytotoxicity mostly in the 100–150 μg/mL range. For CAA, extracts from guava, jerivá, and butiá by-products displayed a hormetic-like behavior, showing antioxidant effect at low concentrations while becoming prooxidants at higher concentrations. In some instances, restoration of the antioxidant effect followed, possibly due to cellular adaptative mechanisms. Sea buckthorn seeds extract showed the most consistent CAA response among all samples. Hence, polyphenols from fruit by-products showed antioxidant activity in Caco-2 cells, although future research should concentrate on assessing their absorption and evaluating their effects in other cell models.

Fractionated irradiation promotes radioresistance and decreases oxidative stress by increasing Nrf2 of ALDH-positive nasopharyngeal cancer stem cells

Radiotherapy is widely regarded as the primary therapeutic modality for nasopharyngeal cancer (NPC). Studies have shown that cancer cells with high resistance to radiation, known as radioresistant cancer cells, may cause residual illness, which in turn might contribute to the occurrence of cancer recurrence and metastasis. It has been shown that cancer stem-like cells (CSCs) exhibit resistance to radiation therapy. In the present study, fractionated doses of radiation-induced epithelial-mesenchymal transition (EMT) and ALDH+ CSCs phenotype of NPC tumor spheroids. Furthermore, it has been shown that cells with elevated ALDH activity have increased resistance to the effects of fractionated irradiation. Nuclear factor erythroid-2-related factor 2 (Nrf2) plays a pivotal role in regulating cellular antioxidant systems. A large body of evidence suggests that Nrf2 plays a significant role in the development of radioresistance in cancer. The authors’ research revealed that the application of fractionated irradiation resulted in a decline in Nrf2-dependent reactive oxygen species (ROS) levels, thereby mitigating DNA damage in ALDH+ stem-like NPC cells. In addition, immunofluorescence analysis revealed that subsequent to the process of fractionated irradiation of ALDH+ cells, activated Nrf2 was predominantly localized inside the nucleus. Immunofluorescent analysis also revealed that the presence of the nuclear Nrf2+/NQO1+/ALDH1+ axis might potentially serve as an indicator of poor prognosis and resistance to radiotherapy in patients with NPC. Thus, the authors’ findings strongly suggest that the radioresistance of ALDH-positive NPC CSCs to fractionated irradiation is regulated by nuclear Nrf2 accumulation. Nrf2 exerts its effects through the downstream effector NQO1/ALDH1, which depends on ROS attenuation.

Exogenous Reactive Oxygen Species Augments SMAD4 Expression And TGF-β Paradox in Human Breast Cancer

Background: The Transforming growth factor-β (TGF-β) functions to induce apoptosis, cell cycle arrest, and differentiation is central to sustaining tissue homeostasis and maintaining genomic stability. TGF-β normally, an effective tumor-suppressor that restricts the uncontrolled division of cells augments the development and progression of human malignancies when cytostatic activities of TGF-β are resisted by genetic and epigenetic events caused by tumorigenesis. This dichotomic nature of TGF-β during oncogenesis termed as “TGF-β Paradox,” persists to be the most crucial and puzzling query regarding its physio-pathological function and the role of cellular antioxidant status is highly interrelated which warrants more studies on the role of endogenous reactive oxygen species (ROS) in deciding epithelial-mesenchymal transition (EMT) process. The objective of the study was to check whether enhanced ROS augments the TGF-β pathway facilitating EMT. Methods: In vitro toxicity assay was performed to assess the appropriate concentration of hydrogen peroxide (H2O2) imparting oxidative stress. Comet assay and 8-OHdG (8-hydroxy-2’-deoxyguanosine) enzyme-linked immunosorbent assay (ELISA) were performed to check the extent of DNA damage and adduct production respectively. Mitogen-activated protein kinase (MAPK) p38 ELISA and mRNA gene expression analysis of TGF-β and SMAD were done to verify the effect of H2O2 on these signaling. Results: The objective of the study was to check whether enhanced ROS augments the TGF-β pathway facilitating EMT. Along with morphological alterations, a dose-dependent decrease in cell viability was seen at 300µM of H2O2 compared to 75µM. DCFDA labeling discovered the dose-dependent gradation of intracellular ROS generation and this was correlated to increased cellular DNA damage and DNA adduct production which was increased linearly with increasing H2O2 as evident with comet test and 8-OHdG ELISA. Significantly reduced MAPK p38 activity revealed by indirect ELISA analysis suggests lessened suppression of cell growth. Conclusions: The study establishes that higher intracellular ROS will facilitate the TGF-β paradox leading to epithelial mesenchymal transition which can adversely affect therapeutic strategies targeting EMT

Impacts of ocean acidification and hypoxia on cellular immunity, oxygen consumption and antioxidant status in Mediterranean mussel

There is growing recognition that the hypoxic regions of the ocean are also becoming more acidic due to increasing levels of global carbon dioxide emissions. The impact of water acidification on marine life is largely unknown, as most previous studies have not taken into account the effects of hypoxia, which may affect how organisms respond to low pH levels. In this study, we experimentally examined the consequences of water acidification in combination with normoxic or hypoxic conditions on cellular immune parameters in Mediterranean mussels. We measured total hemocyte counts in hemolymph, the cellular composition of hemolymph, phagocytosis, reactive oxygen species (ROS) production. General response of the organism was evaluated on the basis of the activity of antioxidant enzymes in the hepatopancreas, as well as respiratory rates over an 8-day exposure period. The mussels were exposed to low pH conditions (7.3), either under normoxic conditions (dissolved oxygen concentration of 8 mg/L) or hypoxic conditions (dissolved oxygen concentration of 2 mg/L). The parameters were assessed at days 1, 3, 6, and 8 of the experiment. Experimental acidification under normoxic conditions reduced THC and ROS production by hemocytes during later stages of exposure, but phagocytic activity (PA) only decreased at day 3 and then recovered. Combined acidification and hypoxia suppressed PA in hemocytes at the beginning of exposure, while hemocyte ROS production and THC decreased by the end of the experiment. The hemolymph cellular composition and activity of antioxidant enzymes were unaffected by acidified conditions under different oxygen regimes, but mussel respiratory rate (RR) decreased with a more significant reduction in oxygen consumption under hypoxia. Mussels showed a relatively high tolerance to acidification in combination with various dissolved oxygen levels, although prolonged acidification exposure led to increased detrimental effects on immunity and metabolism.