Response Of Antioxidant System Research Articles

Response of photosynthetic characteristics and antioxidant system in the leaves of safflower to NaCl and NaHCO3.

Compared with NaCl, NaHCO3 caused more serious oxidative damage and photosynthesis inhibition in safflower by down-regulating the expression of related genes. Salt-alkali stress is one of the important factors that limit plant growth. NaCl and sodium bicarbonate (NaHCO3) are neutral and alkaline salts, respectively. This study investigated the physiological characteristics and molecular responses of safflower (Carthamus tinctorius L.) leaves treated with 200mmolL-1 of NaCl or NaHCO3. The plants treated with NaCl treatment were less effective at inhibiting the growth of safflower, but increased the content of malondialdehyde (MDA) in leaves. Meanwhile, safflower alleviated stress damage by increasing proline (Pro), soluble protein (SP), and soluble sugar (SS). Both fresh weight and dry weight of safflower was severely decreased when it was subjected to NaHCO3 stress, and there was a significant increase in the permeability of cell membranes and the contents of osmotic regulatory substances. An enrichment analysis of the differentially expressed genes (DEGs) using Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes identified significant enrichment of photosynthesis and pathways related to oxidative stress. Furthermore, a weighted gene co-expression network analysis (WGCNA) showed that the darkgreen module had the highest correlation with photosynthesis and oxidative stress traits. Large numbers of transcription factors, primarily from the MYB, GRAS, WRKY, and C2H2 families, were predicted from the genes within the darkgreen module. An analysis of physiological indicators and DEGs, it was found that under saline-alkali stress, genes related to chlorophyll synthesis enzymes were downregulated, while those related to degradation were upregulated, resulting in inhibited chlorophyll biosynthesis and decreased chlorophyll content. Additionally, NaCl and NaHCO3 stress downregulated the expression of genes related to the Calvin cycle, photosynthetic antenna proteins, and the activity of photosynthetic reaction centers to varying degrees, hindering the photosynthetic electron transfer process, suppressing photosynthesis, with NaHCO3 stress causing more pronounced adverse effects. In terms of oxidative stress, the level of reactive oxygen species (ROS) did not change significantly under the NaCl treatment, but the contents of hydrogen peroxide and the rate of production of superoxide anions increased significantly under NaHCO3 stress. In addition, treatment with NaCl upregulated the levels of expression of the key genes for superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), the ascorbate-glutathione cycle, and the thioredoxin-peroxiredoxin pathway, and increased the activity of these enzymes, thus, reducing oxidative damage. Similarly, NaHCO3 stress increased the activities of SOD, CAT, and POD and the content of ascorbic acid and initiated the glutathione-S-transferase pathway to remove excess ROS but suppressed the regeneration of glutathione and the activity of peroxiredoxin. Overall, both neutral and alkaline salts inhibited the photosynthetic process of safflower, although alkaline salt caused a higher level of stress than neutral salt. Safflower alleviated the oxidative damage induced by stress by regulating its antioxidant system.

Transcriptome analysis of antioxidant system response in Styrax tonkinensis seedlings under flood-drought abrupt alternation

BackgroundStyrax tonkinensis (Pierre) Craib ex Hartwich faces challenges in expanding in the south provinces of Yangtze River region due to climate extremes like flood-drought abrupt alternation (FDAA) caused by global warming. Low tolerance to waterlogging and drought restricts its growth in this area. To study its antioxidant system and molecular response related to the peroxisome pathway under FDAA, we conducted experiments on two-year-old seedlings, measuring growth indexes, reactive oxygen species content, antioxidant enzyme activity, and analyzing transcriptomes under FDAA and drought (DT) conditions.ResultsThe physiological results indicated a reduction in water content in roots, stems, and leaves under FDAA conditions. The most significant water loss, amounting to 15.53% was observed in the leaves. Also, ROS accumulation was predominantly observed in leaves rather than roots. Through transcriptome analysis, we assembled a total of 1,111,088 unigenes (with a total length of 1,111,628,179 bp). Generally, SOD1 and CAT genes in S. tonkinensis seedlings were up-regulated to scavenge ROS. Conversely, the MPV17 gene exhibited contrasting reaction with up-regulation in leaves and down-regulation in roots, leading to increased ROS accumulation in leaves. CHS and F3H were down-regulated, which did not play an essential role in scavenging ROS. Moreover, the down-regulation of PYL, CPK and CALM genes in leaves may not contribute to stomatal closure, thereby causing continuous water loss through transpiration. Whereas, the decreased root vigor during the waterlogging phase and up-regulated CPK and CALM in roots posed obstacles to water absorption by roots. Additionally, the DEGs related to energy metabolism, including LHCA and LHCB, were negatively regulated.ConclusionsThe ROS generation triggered by MPV17 genes was not the main reason for the eventual mortality of the plant. Instead, plant mortality may be attributed to water loss during the waterlogging phase, decreased root water uptake capacity, and continued water loss during the subsequent drought period. This study establishes a scientific foundation for comprehending the morphological, physiological, and molecular facts of S. tonkinensis under FDAA conditions.

Breathing Air and Living Underwater: Molecular Evolution of Genes Related to Antioxidant Response in Cetaceans and Pinnipeds.

Cetaceans and pinnipeds are lineages of mammals that have independently returned to the aquatic environment, acquiring varying degrees of dependence on it while sharing adaptations for underwater living. Here, we focused on one critical adaptation from both groups, their ability to withstand the ischemia and reperfusion experienced during apnea diving, which can lead to the production of reactive oxygen species (ROS) and subsequent oxidative damage. Previous studies have shown that cetaceans and pinnipeds possess efficient antioxidant enzymes that protect against ROS. In this study, we investigated the molecular evolution of key antioxidant enzyme genes (CAT, GPX3, GSR, PRDX1, PRDX3, and SOD1) and the ROS-producing gene XDH, in cetaceans and pinnipeds lineages. We used the ratio of non-synonymous (dN) to synonymous (dS) substitutions as a measure to identify signatures of adaptive molecular evolution in these genes within and between the two lineages. Additionally, we performed protein modeling and variant impact analyzes to assess the functional consequences of observed mutations. Our findings revealed distinct selective regimes between aquatic and terrestrial mammals in five of the examined genes, including divergences within cetacean and pinniped lineages, between ancestral and recent lineages and between crowns groups. We identified specific sites under positive selection unique to Cetacea and Pinnipedia, with one site showing evidence of convergent evolution in species known for their long and deep-diving capacities. Notably, many sites under adaptive selection exhibited radical changes in amino acid properties, with some being damaging mutations in human variations, but with no apparent detrimental impacts on aquatic mammals. In conclusion, our study provides insights into the adaptive changes that have occurred in the antioxidant systems of aquatic mammals throughout their evolutionary history. We observed both distinctive features within each group of Cetacea and Pinnipedia and instances of convergence. These findings highlight the dynamic nature of the antioxidant system in response to challenges of the aquatic environment and provide a foundation for further investigations into the molecular mechanisms underlying these adaptations.

Effect of an Ipomoea aquatica Floating Raft on the Water Quality, Antioxidant System, Non-Specific Immune Responses, and Microbial Diversity of Penaeus vannamei in an Aquaculture System

Pacific white shrimp (Penaeus vannamei) is one of the main shrimp species cultivated around the world. Despite its high yields and easy handling, water pollution from intensive shrimp cultivation remains a serious problem in China. In this study, a compound aquaculture model of P. vannamei and water spinach (Ipomoea aquatica) was used to investigate the effect of a water spinach floating raft on water quality, antioxidants, non-specific immune response, growth performance, and microbial diversity. The experimental design of this study consisted of two groups with three replicates for each, i.e., control group: aquatic monoculture (AM) system with only P. vannamei; treatment group: P. vannamei-I. aquatica raft aquaponics (AP) system with a 50% cover ratio with a water spinach floating raft. The experiment lasted for seven weeks. The results show that the concentrations of total phosphorus (TP), total nitrogen (TN), nitrate nitrogen (NO3−-N), ammonia nitrogen (NH4+-N), nitrite nitrogen (NO2−-N), and active phosphorus (AP) in the AM group were higher than those in the AP group at different sampling times. The water quality index of the AP group was better than that of the AM group, indicating that water spinach can remove the nutrients from aquaculture water bodies. The average daily gain and survival rate of shrimp in the AP group were higher than those in the AM group. The total antioxidant capacity (T-AOC), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), and acid phosphatase (ACP) in the AP group were better than those in the AM group. The Shannon–Wiener and Simpson indices of the gut, water, and sediment of the AP system were significantly higher than those in the AM system, which implied a higher abundance of microorganisms in the AP system. These results demonstrate that the application of a water spinach floating raft in aquaponics can not only improve the water quality, but also improve the growth performance, antioxidant system, and non-specific immune responses of Pacific white shrimp, while increasing the abundance of microorganisms in the aquaculture system and improving the ecological benefits in terms of the expenditure.

Interaction of water salinity and titanium dioxide nanoparticle (TiO2) exposure in the Pacific oyster, Crassostrea gigas: immune and antioxidant system responses

Titanium dioxide nanoparticles (TiO2) are released into the natural waters in different ways and cause toxicity to aquatic life. Although various studies have reported the toxicity of nanoparticles for aquatic animals, there is limited information regarding the effects of environmental factors, especially salinity, on their toxicity. Simultaneous effects of TiNPs and water salinity were studied in the Pacific oyster, Crassostrea gigas. Oysters were exposed to sub-lethal concentrations of TiNPs (low concentration: 50 µg/l, middle concentration: 500 µg/l, high concentration: 5000 µg/l) at different water salinities (Extremely low salinity: 5 g/l, low salinity: 15 g/l, middle salinity: 25 g/l, high salinity (normal salinity): 35 g/l) for 96 h. After nano-TiO2 exposure, the immune components in hemolymph (total hemocyte concentration [THC], phagocytosis), antioxidant enzyme activities in digestive gland (superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase), oxidation stress index (malondialdehyde) in gills and the expression of immune-related genes (Vav-3 protein, cofilin, Galectin 4, pro-Cathepsin L, Rho protein, Ficolin, LPS/-1,3-glucan protein, Lysozyme, Defensin) in hemocytes were measured. The THC, phagocytosis, antioxidant enzyme activities, and immune-related gene expressions mostly decreased at salinities of 5 and 15 g/l in response to 500–5000 µg/l nano-TiO2 compared to non-exposed oysters and 50 µg/l nano-TiO2 group. An increase in water salinity up to 35 g/l mitigated the depressing effects of the nano-TiO2 on the immune and antioxidant components of the oysters. Exposure of oysters to 500–5000 µg/l nano-TiO2-induced oxidative stress at salinities of 5 and 15, since malondialdehyde levels were higher in these treatments compared to control and those in 50 µg/l nano-TiO2 group. The increase of salinity up to 35 g/l ameliorated the TiO2-induced oxidative stress. The results of the present study showed that the toxic impacts of nano-TiO2 can be ameliorated in the Pacific oyster with increase in water salinity, as the immune components, antioxidant enzyme activities recovered and oxidative stress mitigated when the salinity increased up to 35 g/l.

Effects of exogenous glycine betaine on growth and development of tomato seedlings under cold stress.

Low temperature is a type of abiotic stress affecting the tomato (Solanum lycopersicum) growth. Understanding the mechanisms and utilization of exogenous substances underlying plant tolerance to cold stress would lay the foundation for improving temperature resilience in this important crop. Our study is aiming to investigate the effect of exogenous glycine betaine (GB) on tomato seedlings to increase tolerance to low temperatures. By treating tomato seedlings with exogenous GB under low temperature stress, we found that 30 mmol/L exogenous GB can significantly improve the cold tolerance of tomato seedlings. Exogenous GB can influence the enzyme activity of antioxidant defense system and ROS levels in tomato leaves. The seedlings with GB treatment presented higher Fv/Fm value and photochemical activity under cold stress compared with the control. Moreover, analysis of high-throughput plant phenotyping of tomato seedlings also supported that exogenous GB can protect the photosynthetic system of tomato seedlings under cold stress. In addition, we proved that exogenous GB significantly increased the content of endogenous abscisic acid (ABA) and decreased endogenous gibberellin (GA) levels, which protected tomatoes from low temperatures. Meanwhile, transcriptional analysis showed that GB regulated the expression of genes involved in antioxidant capacity, calcium signaling, photosynthesis activity, energy metabolism-related and low temperature pathway-related genes in tomato plants. In conclusion, our findings indicated that exogenous GB, as a cryoprotectant, can enhance plant tolerance to low temperature by improving the antioxidant system, photosynthetic system, hormone signaling, and cold response pathway and so on.

Impact of ozone therapy on mouse liver mitochondrial function and antioxidant system

Ozone therapy's efficacy might stem from the regulated and mild oxidative stress resulting from ozone's interactions with various biological elements. The present work aimed to characterize the hepatic mitochondrial response to ozone treatment and its relationship with the antioxidant system response. Two groups of mice were used: one control group and another injected intraperitoneally with an O3/O2 mixture (80 ml/kg) for 5 days. Mitochondrial respiration supported by different substrates was significantly inhibited, as well as complexes I and II/III, but not complex IV. The analysis of the electron transport chain complex activity showed significant inhibitions in complexes I and II/III but not in complex IV. These inhibitions can prevent mitochondrial reactive oxygen species (ROS) production. Additionally, there was a decline in glutathione content, unaccompanied by a rise in its oxidized form. The ozone-treated groups showed a significant increase in the activity of superoxide dismutase and glutathione peroxidase, while catalase and glutathione reductase experienced no significant alterations. Adenine nucleotides increased in the ozone group, but only the increase in adenosine diphosphate is significant, so the cell's energy charge is unaffected. This study shows that mitochondria may play a crucial role in ozone treatment. However, it also highlights the need for further studies to understand the molecular mechanism.

The crosstalk between photoperiod and early mild stress on juvenile oscar (Astronotus ocellatus) after acute stress.

Early mild stress (EMS) is like preparedness and might help fish deal with stress appropriately. This study investigated how EMS and photoperiod changes can impact growth, haematology, blood biochemistry, immunological response, antioxidant system, liver enzymes, and stress response of oscar (Astronotus ocellatus; 7.29 ± 0.96 g) before and after acute confinement stress (AC stress). Ten experimental treatments included five different photoperiods 8L16D (08:16 light to dark), 12L12D (12:12 light to dark), 16L8D (16:08 light to dark), 20L4D (20:04 light to dark), and 24L0D (24:00 light to dark), and these five photoperiod schedules were conducted in an EMS condition. After 9 weeks, no significant differences were found in growth parameters, survival rate, and body composition. At the end of the experiment and after AC stress, fish farmed in 24 light hours had the lowest haematocrit, white blood cells, total protein, blood performance, lysozyme, immunoglobulin M, complement C3, superoxide dismutase, and catalase. Fish that experienced EMS had significantly higher survival rates than those farmed in normal conditions (80.67% vs 61.33%). In conclusion, considering all measured parameters, 8-h light can be suggested as an optimum photoperiod for this fish species. Under 24L0D (no EMS) conditions, there were many negative effects apparent. In addition, a positive effect of EMS was evident in terms of survival after AC stress. AC stress decreased some health parameters under 24-h light treatment, while these results were not observed in EMS-exposed fish. Therefore, the EMS schedule can be a useful tool in preventing the negative effects of stress.

Biodegradation of chloroxylenol by an aerobic enrichment consortium and a newly identified Rhodococcus strain.

Chloroxylenol is a commonly used antimicrobial agent in antibacterial and disinfection products, which has been detected in various environments, such as wastewater treatment plants, rivers, seawater, and even drinking water, with concentrations ranging from ng/L to mg/L. However, the biodegradation of chloroxylenol received limited attention with only sporadic reports available so far. In this study, an efficient chloroxylenol-degrading consortium, which could degrade 20 mg/L chloroxylenol within two days, was obtained after five months of enrichment. Amplicon sequencing analysis revealed a decrease in the α-diversity (e.g., Shannon index and Inv_Simpson index) of the community during the domestication process. Microbial community dynamics were uncovered, with sequences affiliated to Achromobacter, Pseudomonas, and Rhodococcus identified as the most abundant taxonomic groups. From the consortium, five pure isolates were obtained; however, it was found that only one strain of Rhodococcus could degradechloroxylenol. Strain Rhodococcus sp. DMU2021 could degrade chloroxylenol efficiently under the conditions of temperature 30-40 °C, and neutral/alkaline conditions. Chloroxylenol was toxic to strain DMU2021 and triggered both enzymatic and non-enzymatic antioxidant systems in response. This study provides novel insights into the biodegradation process of chloroxylenol, as well as valuable bioresources for bioremediation.

Integrated Ca, Mg, Cu, and Zn supply upregulates leaf anatomy and metabolic adjustments in Eucalyptus seedlings

Adaptive responses to abiotic stresses such as soil acidity in Eucalyptus—the most widely planted broad-leaf forest genus globally—are poorly understood. This is particularly evident in physiological and anatomical disorders that inhibit plant development and wood quality. We aimed to explore how the supply of Ca and Mg through liming (lime), combined with Cu and Zn fertilization (CZF), influences physiological and anatomical responses during Eucalyptus grandis seedlings growth in tropical acid soil. Therefore, related parameters of leaf area and leaf anatomy, stomatal size, leaf gas exchange, antioxidant system, nutrient partitioning, and biomass allocation responses were monitored. Liming alone in Eucalyptus increased specific leaf area, stomatal density on the abaxial leaf surface, and Ca and Mg content. Also, Eucalyptus exposed only to CZF increased Cu and Zn content. Lime and CZF increased leaf blade and adaxial epidermal thickness, and improved the structural organization of the spongy mesophyll, promoting increased net CO2 assimilation, and stomatal conductance. Fertilization with Ca, Mg, Cu, and Zn positively affects plant nutrition, light utilization, photosynthetic rate, and antioxidant performance, improving growth. Our results indicate that lime and CZF induce adaptive responses in the physiological and anatomical adjustments of Eucalyptus plantation, thereby promoting biomass accumulation.

Effect of light intensity on nitrogen transformation, enzymatic activity, antioxidant system and transcriptional response of Chlorella pyrenoidosa during treating mariculture wastewater

The nitrogen transformation, enzymatic activity, antioxidant ability and transcriptional response of Chlorella pyrenoidosa (C. pyrenoidosa) treating mariculture wastewater were compared under different light intensities. The microalgal growth, chlorophyll synthesis and nitrogen removal ability of C. pyrenoidosa increased with the light intensity from 3000 to 7000 Lux, whereas they slightly decreased under 9000 and 11,000 Lux. The nitrogen metabolism enzymatic activities displayed obvious differences under different light intensities and affected the nitrogen transformation process. The reactive oxygen species (ROS) production increased with the increase of operational time, whereas it had distinct differences under different light intensities. The changes of antioxidant enzymatic activities were positively correlated with the ROS production. The transcriptional response of C. pyrenoidosa was in accordance with the variation of the photosynthesis, nitrogen assimilation and antioxidant system under different light intensities. This study provides theoretical basis and technical support to select suitable light intensity for algae treating mariculture wastewater.

Kaempferol mitigates reproductive dysfunctions induced by Naja nigricollis venom through antioxidant system and anti-inflammatory response in male rats

Naja nigricollis Venom (NnV) contains complex toxins that affects various vital systems functions after envenoming. The venom toxins have been reported to induce male reproductive disorders in envenomed rats. This present study explored the ameliorative potential of kaempferol on NnV-induced male reproductive toxicity. Fifty male wistar rats were sorted randomly into five groups (n = 10) for this study. Group 1 were noted as the control, while rats in groups 2 to 5 were injected with LD50 of NnV (1.0 mg/kg bw; i.p.). Group 2 was left untreated post envenomation while group 3 was treated with 0.2 ml of polyvalent antivenom. Groups 4 and 5 were treated with 4 and 8 mg/kg of kaempferol, respectively. NnV caused substantial reduction in concentrations of follicle stimulating hormone, testosterone and luteinizing hormone, while sperm motility, volume and counts significantly (p < 0.05) decreased in envenomed untreated rats. The venom enhanced malondialdehyde levels and substantially decreased glutathione levels, superoxide dismutase and glutathione peroxidase activities in the testes and epididymis of envenomed untreated rats. Additionally, epididymal and testicular myeloperoxidase activity and nitric oxide levels were elevated which substantiated severe morphological defects noticed in the reproductive organs. However, treatment of envenomed rats with kaempferol normalized the reproductive hormones with significant improvement on sperm functional parameters. Elevated inflammatory and oxidative stress biomarkers in testis and epididymis were suppressed post kaempferol treatment. Severe histopathological lesions in the epididymal and testicular tissues were ameliorated in the envenomed treated groups. Results highlights the significance of kaempferol in mitigating reproductive toxicity induced after snakebite envenoming.

Acute toxicity of cerium to neonatal Daphnia magna: Responses of antioxidant systems, influence of environmental factors and development of a biotic ligand model

The bioavailability of cerium (Ce) and its toxic effects on aquatic organisms are still unclear, which limits the toxicity prediction and pollution control for this element. Here, the acute toxicity of Ce to Daphnia magna neonates and the responses of the antioxidant system were investigated, and the quantitative relationships between the toxicity of Ce and environmental factors were determined. The 24 and 48 h EC50Ce-D values based on the dissolved concentration of Ce in Daphnia magna were 60.6 and 10.9 μM, respectively, and the EC50Ce3+ values were 23.4 and 3.73 μM, respectively. After Ce exposure at environmentally relevant concentrations (0.5–3.5 μM), significant increases in superoxide dismutase activity and malondialdehyde content were observed in Daphnia magna, while significant decreases in catalase activity and H2O2 content occurred. Low levels of Ce cause oxidative damage to Daphnia magna and adverse impacts on the antioxidant system; however, further molecular-based studies are needed. The addition of Ca2+ or Na+ reduced the acute toxicity of Ce to Daphnia magna. In contrast, Mg2+ (MgSO4) promoted Ce toxicity, which is a new finding related to the interaction effects between cations and rare earth elements on biological ligands; however, the effects of SO42+ could not be distinguished. Complexation with organic ligands could significantly reduce the toxicity of Ce to Daphnia magna; however, complexes of Ce with citric acid and malic acid might be bioavailable to Daphnia magna. In the absence of organic ligands and competing metals, the binding constant of Ce3+ to Daphnia magna at toxic concentrations was 5.83. The log K values for the competitive effects of Ca2+ and Na+ were 3.73 and 2.59, respectively, while the log K value for the protective effect of fulvic acid was 3.76. These results contribute to understanding the toxicity of Ce and will help predict the toxicity of Ce in freshwater.

Carnosol ameliorated cancer cachexia-associated myotube atrophy by targeting P5CS and its downstream pathways.

Introduction: Carnosol exhibited ameliorating effects on muscle atrophy of mice developed cancer cachexia in our previous research. Method: Here, the ameliorating effects of carnosol on the C2C12 myotube atrophy result from simulated cancer cachexia injury, the conditioned medium of the C26 tumor cells or the LLC tumor cells, were observed. To clarify the mechanisms of carnosol, the possible direct target proteins of carnosol were searched using DARTS (drug affinity responsive target stability) assay and then confirmed using CETSA (cellular thermal shift assay). Furthermore, proteomic analysis was used to search its possible indirect target proteins by comparing the protein expression profiles of C2C12 myotubes under treatment of C26 medium, with or without the presence of carnosol. The signal network between the direct and indirect target proteins of carnosol was then constructed. Results: Our results showed that, Delta-1-pyrroline-5-carboxylate synthase (P5CS) might be the direct target protein of carnosol in myotubes. The influence of carnosol on amino acid metabolism downstream of P5CS was confirmed. Carnosol could upregulate the expression of proteins related to glutathione metabolism, anti-oxidant system, and heat shock response. Knockdown of P5CS could also ameliorate myotube atrophy and further enhance the ameliorating effects of carnosol. Discussion: These results suggested that carnosol might ameliorate cancer cachexia-associated myotube atrophy by targeting P5CS and its downstream pathways.

The Multifaceted Roles of NRF2 in Cancer: Friend or Foe?

Physiological concentrations of reactive oxygen species (ROS) play vital roles in various normal cellular processes, whereas excessive ROS generation is central to disease pathogenesis. The nuclear factor erythroid 2-related factor 2 (NRF2) is a critical transcription factor that regulates the cellular antioxidant systems in response to oxidative stress by governing the expression of genes encoding antioxidant enzymes that shield cells from diverse oxidative alterations. NRF2 and its negative regulator Kelch-like ECH-associated protein 1 (KEAP1) have been the focus of numerous investigations in elucidating whether NRF2 suppresses tumor promotion or conversely exerts pro-oncogenic effects. NRF2 has been found to participate in various pathological processes, including dysregulated cell proliferation, metabolic remodeling, and resistance to apoptosis. Herein, this review article will examine the intriguing role of phase separation in activating the NRF2 transcriptional activity and explore the NRF2 dual impacts on tumor immunology, cancer stem cells, metastasis, and long non-coding RNAs (LncRNAs). Taken together, this review aims to discuss the NRF2 multifaceted roles in both cancer prevention and promotion while also addressing the advantages, disadvantages, and limitations associated with modulating NRF2 therapeutically in cancer treatment.

Defense responses of the green microalgae Chlorella vulgaris to the vanadium pentoxide nanoparticles

Although vanadium-based nanomaterials have found extensive use in industry, their influence on ecosystems and living organisms is not yet well investigated. In this study, hydrothermal methods were utilized for the synthesis of vanadium pentoxide nanoparticles (V2 O5 NPs). The gained NPs were characterized using XRD, FT-IR, EDS, DLS, SEM and TEM techniques. Subsequently, the toxic effects of V2 O5 NPs on the model green microalgae Chlorella vulgaris were evaluated. According to the obtained results, V2 O5 NPs caused a significant reduction in cell number and biomass production of algae in a dose and time dependent manner. Moreover, flow cytometric analysis confirmed a reduction in the quantity of living cells. Scanning electron microscopy showed plasmolysis and deformation of the cells after exposure to nanoparticles. The photosynthetic pigments and phenolics content exhibited a decrease in comparison with the control sample. Although, non-enzymatic antioxidant system in C. vulgaris displayed an average action, antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) showed a dose dependent increasing trend. These intercellular reactions designated the activation of the antioxidant defense system in response to the induced oxidative stress by V2 O5 NPs.

A proteomic study on gastric impairment in rats caused by microcystin-LR

Microcystins (MCs) are the most common cyanobacterial toxins. Epidemiological investigation showed that exposure to MCs can cause gastro-intestinal symptoms, gastroenteritis and gastric cancer. MCs can also accumulate in and cause histopathological damage to stomach. However, the exact mechanisms by which MCs cause gastric injury were unclear. In this study, Wistar rats were administrated 50, 75 or 100 μg microcystin-LR (MC-LR)/kg, body mass (bm) via tail vein, and histopathology, response of anti-oxidant system and the proteome of gastric tissues at 24 h after exposure were studied. Bleeding of fore-stomach and gastric corpus, inflammation and necrosis in gastric corpus and exfoliation of mucosal epithelial cells in gastric antrum were observed following acute MC-LR exposure. Compared with controls, activities of superoxide dismutase (SOD) were significantly greater in gastric tissues of exposed rats, while activities of catalase (CAT) were less in rats administrated 50 μg MC-LR/kg, bm, and concentrations of glutathione (GSH) and malondialdehyde (MDA) were greater in rats administrated 75 or 100 μg MC-LR/kg, bm. These results indicated that MC-LR could disrupt the anti-oxidant system and cause oxidative stress. The proteomic results revealed that MC-LR could affect expressions of proteins related to cytoskeleton, immune system, gastric functions, and some signaling pathways, including platelet activation, complement and coagulation cascades, and ferroptosis. Quantitative real-time PCR (qRT-PCR) analysis showed that transcriptions of genes for ferroptosis and gastric function were altered, which confirmed results of proteomics. Overall, this study illustrated that MC-LR could induce gastric dysfunction, and ferroptosis might be involved in MC-LR-induced gastric injury. This study provided novel insights into mechanisms of digestive diseases induced by MCs.

Fluoranthene biotreatment using prominent freshwater microalgae: physiological responses of microalgae and artificial neural network modeling of the bioremoval process

Due to the intensified industrial activities and other anthropogenic actions, contamination of polycyclic aromatic hydrocarbons (PAHs) has been growing at an alarming rate, turning in to a serious environmental concern. Bioremediation, as an eco-friendly and sustainable removal technology, can be used by organisms to reduce the resulting contaminations. In the present study, the ability of Tetradesmus obliquus to remove of fluoranthene (FLA) was evaluated. It was confirmed that FLA removal efficiency was managed by various environmental parameters and pH was found to be one of the most important influencial factors. The reusability of the algae in long-term repetitive operations confirmed the occurrence of biodegradation along with other natural attenuation and 10 intermediate compounds were identified in the FLA biodegradation pathway by GC-MS. As a result of physiological assays, induced antioxidant enzymes activities and augmentation of phenol and flavonoids contents, after the treatment of the microalgae by a high concentration of FLA, confirmed the ability of the microalgae to upregulate its antioxidant defense system in response to the toxic effects of FLA. An artificial neural network (ANN) model was then developed to predict FLA biodegradation efficiency and the appropriate predictive performance of ANN was confirmed by comparing the experimental FLA removal efficiency with its predicted amounts (R2 = 0.99).

Aqueous extract of the bark of Uncaria tomentosa, an amazonian medicinal plant, promotes gastroprotection and accelerates gastric healing in rats

Ethnopharmacological importanceUncaria tomentosa Willd. DC., is used in the Amazonian region of South America, wherein ethnic groups use the plant to treat diseases, including gastric disorders. However, despite its widespread popular use, this species has yet to be assessed for its anti-ulcer effects. Aim of the studyIn this study, we aimed to evaluate the in vivo gastroprotective and gastric healing activities of an aqueous extract of the bark of Uncaria tomentosa (AEUt) and sought to gain an understanding of the pharmacological mechanisms underlying these biological effects. Materials and methodsTo verify the gastroprotective properties rats were treated with AEUt (30, 60, or 120 mg/kg) prior to inducing gastric ulceration with ethanol or piroxicam. Additionally, the involvement of nitric oxide, non-protein sulfhydryl compounds (NP-SH), α-2 adrenergic receptors, and prostaglandins was investigated. Furthermore, a pylorus ligature model was employed to investigate the antisecretory activity of AEUt. The gastric healing effects of AEUt (60 mg/kg) were examined in rats in which ulceration had been induced with 80% acetic acid, whereas the quality of healing was evaluated in mice with interleukin-induced recurrent ulcers. We also evaluated the in vivo thickness of the gastric wall using ultrasonography. Moreover, the levels of reduced glutathione (GSH) and malondialdehyde (MDA) were evaluated in ulcerated mucosa, and we determined the activities of the enzymes myeloperoxidase (MPO), N-acetyl-β-D-glycosaminidase, superoxide dismutase, catalase, and glutathione S-transferase. In addition, we assessed the effects of AEUt on cell viability and subjected the AEUt to phytochemical analyses. ResultsAdministration of the AEUt (60 or 120 mg/kg) prevented ethanol- and piroxicam-induced ulceration, which was also confirmed histologically. Moreover, we observed that pre-treatment with NEM and indomethacin abolished the gastroprotective effects of AEUt, thereby indicating the involvement of NP-SH and prostaglandins in these protective effects. In addition, we found that the administration of AEUt had no appreciable effects on the volume, acidity, or peptic activity of gastric juice. Furthermore, the AEUt (60 mg/kg) accelerated the gastric healing of acetic acid-induced ulcers by 46.2% and ultrasonographic findings revealed a reduction in the gastric wall thickness in this group. The gastric healing effect of AEUt was also accompanied by a reduction in MPO activity. The AEUt (60 mg/kg) also minimized ulcer recurrence in mice exposed to IL-1β and was associated with the maintenance of GSH levels and a reduction in MDA contents. We deduce that the biological effects of AEUt could be associated with the activities of polyphenols and the alkaloids isomitraphylline and mitraphylline, identified as predominant constituents of the AEUt. Furthermore, we found no evidence to indicate that AEUt would have any cytotoxic effects. ConclusionCollectively, our findings provide compelling evidence indicating the therapeutic efficacy of U. tomentosa. Our data indicate that compounds in AEUt confer gastroprotection and that this preventive effect of AEUt was accompanied by gastric healing and a reduction in gastric ulcer recurrence. Moreover, we provide evidence to indicate that the gastroprotective and gastric healing effects involve the antioxidant system and anti-inflammatory responses that contribute to preserving the gastric mucosa.

Transcriptomic profiling of the response to excess iodide in Keap1 hypomorphic mice reveals new gene-environment interactions in thyroid homeostasis

Iodide plays a pivotal role in thyroid homeostasis due to its crucial involvement in thyroid hormone biosynthesis. Exposure to pharmacological doses of iodide elicits in the thyroid an autoregulatory response to preserve thyroid function, as well as an antioxidant response that is mediated by the Keap1/Nrf2 signaling pathway. The objective of the present study was to investigate the transcriptional response of the thyroid to excess iodide in a background of enhanced Nrf2 signaling. Keap1 knockdown (Keap1KD) mice that have activated Nrf2 signaling were exposed or not to excess iodide in their drinking water for seven days and compared to respective wild-type mice. RNA-sequencing of individual mouse thyroids identified distinct transcriptomic patterns in response to iodide, with Keap1KD mice showing an attenuated inflammatory response, altered thyroidal autoregulation, and enhanced cell growth/proliferative signaling, as confirmed also by Western blotting for key proteins involved in antioxidant, autoregulatory and proliferative responses. These findings underscore novel gene-environment interactions between the activation status of the Keap1/Nrf2 antioxidant response system and the dietary iodide intake, which may have implications not only for the goiter phenotype of Keap1KD mice but also for humans harboring genetic variations in KEAP1 or NFE2L2 or treated with Nrf2-modulating drugs.