ROS/ER stress contributes to trimethyltin chloride-mediated hepatotoxicity; Tea polyphenols alleviate apoptosis and immunosuppression

Targeting mitochondria with natural polyphenols for treating Neurodegenerative Diseases: a comprehensive scoping review from oxidative stress perspective

Neurodegenerative diseases are a class of conditions with widespread detrimental impacts, currently lacking effective therapeutic drugs. Recent studies have identified mitochondrial dysfunction and the resultant oxidative stress as crucial contributors to the pathogenesis of neurodegenerative diseases. Polyphenols, naturally occurring compounds with inherent antioxidant properties, have demonstrated the potential to target mitochondria and mitigate oxidative stress. This therapeutic potential has garnered significant attention in recent years. Investigating the mitochondrial targeting capacity of polyphenols, their role in functional regulation, and their ability to modulate oxidative stress, along with exploring novel technologies and strategies for modifying polyphenol compounds and their formulations, holds promise for providing new avenues for the treatment of neurodegenerative diseases.

Myricetin alleviates learning and memory deficits in trimethyltin Alzheimer's phenotype via attenuating hippocampal endoplasmic reticulum stress and regulating inflammation and oxidative stress

Trimethyltin hydrochloride (TMT) induces hippocampal neurodegeneration and learning and memory impairments, providing a useful experimental model for Alzheimer's disease (AD) research. This study aimed to explore the neuroprotective effects of myricetin, a naturally occurring flavonoid with antioxidant and anti-inflammatory properties, against TMT-induced hippocampal damage and elucidate some of its underlying molecular mechanisms. Male NMRI mice (n = 32) were divided into four experimental groups: control, control + myricetin, TMT, and TMT + myricetin. Neurodegeneration was induced by intraperitoneal TMT injection (2.8 mg/kg), followed by daily oral administration of myricetin (25 mg/kg) for 21 days. Learning and memory-related function was assessed using passive avoidance, novel object recognition, and Y-maze tests. After behavioral tasks, hippocampal levels of oxidative stress parameters (glutathione (GSH), superoxide dismutase (SOD), catalase, malondialdehyde (MDA)), inflammatory markers (tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10)), and endoplasmic reticulum stress pathway proteins (GRP78, PERK, IRE1α, and CHOP) were evaluated. Histological examinations included Nissl staining to quantify neuronal degeneration in CA1 and dentate gyrus regions, as well as glial fibrillary acidic protein (GFAP) immunohistochemistry. Myricetin treatment attenuated TMT-induced learning and memory impairments and neuronal loss in the CA1 and dentate gyrus subfields. It significantly enhanced hippocampal levels of GSH, SOD and catalase activities, and IL-10 while reducing levels of MDA, TNF-α, and GFAP immunoreactivity. Moreover, myricetin alleviated the TMT-induced elevation of GRP78, PERK, IRE1α, and CHOP. These findings suggest that myricetin holds promise as a therapeutic candidate for AD and other neurodegenerative disorders by counteracting oxidative stress, suppressing neuroinflammation, and modulating endoplasmic reticulum stress pathways.

Tea Polyphenol Protects the Immune Barrier and Inhibits TLR2/NF-κB/MLCK Signal Activation to Prevent Inflammatory Injury in the Intestines of Common Carp (Cyprinus carpio L.)

Tea polyphenol (TP) is a kind of natural macromolecular compound present in tea extract with rich biological potential. The purpose of this study was to explore the protective effect of TP on the intestinal immune barrier and the related mechanisms of TP alleviating intestinal injury. Models of common carp (Cyprinus carpio L.) and primary intestinal epithelial cells treated with TP and lipopolysaccharide (LPS) were established. The qPCR and ELISA results showed that TP increased the levels of lysozyme (LZ), alkaline phosphatase (ALP), complement component 3 (C3), complement component 4 (C4), immunoglobulin T (IgT), immunoglobulin D (IgD), and immunoglobulin M (IgM) to activate intestinal immune ability. Molecular docking indicated that TP had a strong interaction with TLR2. Meanwhile, TP alleviated LPS-induced intestinal inflammatory damage as evidenced by reducing the mRNA levels of TNF-α, IL-6, IL-1β, TLR2, MyD88, P65, and IκBα, which were consistent with those of ELISA and Western blotting results. Moreover, the qPCR and Western blotting results revealed TP promoted the levels of tight junction-related proteins (claudins, occludin, and ZOs) and inhibited the phosphorylation of MLC, which showed the opposite trend after LPS treatment. In summary, the present study indicated that TP improved immune ability and inhibited the activation of the TLR2/NF-κB/MLCK pathway to attenuate LPS-induced inflammatory injury in the intestines of common carp.

Exposure to Trimethyltin Chloride Induces Pyroptosis and Immune Dysfunction in Grass Carp CIK Cells by Activating the NF-κB Pathway Through Oxidative Stress

Trimethyltin chloride (TMT) is a highly toxic organotin pollutant frequently found in aquatic environments, posing a significant threat to the ecological system. The kidney plays a vital role in the body's detoxification processes, and TMT present in the environment tends to accumulate in the kidneys. However, it remained unclear whether exposure to different doses of TMT could induce pyroptosis and immune dysfunction in grass carp kidney cells (CIK cells). For this purpose, after assessing the half-maximal inhibitory concentration (IC50) of TMT on CIK cells, we established a model for exposure of CIK cells at varying concentrations of TMT. CIK cells were treated with various doses of TMT (2.5, 5, 10 μM) for 24 h. Oxidative stress levels were measured using kits and fluorescence methods, whereas the expression of related genes was verified through western blot and quantitative real-time PCR (qRT-PCR). The results indicated that TMT exposure led to oxidative stress, with increased levels of ROS, H2O2, MDA, and GSH, and inhibited activities of T-AOC, SOD, and CAT. It activated the NF-κB pathway, leading to the upregulation of NF-κB p65, NF-κB p50, GSDMD, NLRP3, ASC, and Caspase-1. Furthermore, TMT exposure also resulted in increased expression of cytokines (IL-18, IL-6, IL-2, IL-1β, and TNF-α) and decreased expression of antimicrobial peptides (LEAP2, HEPC, and β-defensin). In summary, exposure to TMT induces dose-dependent oxidative stress that activates the NF-κB pathway, leading to pyroptosis and immune dysfunction in grass carp CIK cells.

Trimethyltin chloride induces oxidative damage and apoptosis in chicken liver

Trimethyltin chloride (TMT) is widespread in the environment and is harmful to both humans and animals. In order to investigate the toxicity mechanism of TMT exposure on chicken liver, We established an in vivo experimental model by giving chickens oral administration of different concentrations of TMT dilution solution and vitro experiments of treating leghorn male hepatoma (LMH) cells for 12 h. The results showed that Albumin (ALB), total protein (TP) and alanine aminotransferase (ALT) in the blood of TMT-treated chickens, as well as ALT and aspartate aminotransferase (AST) in the liver, were dose-dependently increased, and different degrees of necrosis of hepatocytes were observed in histology. Meanwhile, TMT exposure led to a significant decrease in glutathione (GSH) content in chicken liver tissues and LMH cells, what's more a significant increase in malondialdehyde (MDA) content in cell supernatants. The expression of apoptosis-related genes Caspase8, Caspase3 and Caspase9 were increased in chicken liver tissues and LMH cells after treated by TMT, and an increased in the percentage of late apoptosis in LMH cells. This suggests that TMT can cause oxidative stress and apoptosis in chicken livers and cells, resulting in liver injury.

Ferulic acid alleviates avermectin induced renal injury in carp by inhibiting inflammation, oxidative stress and apoptosis

Avamectin (AVM), a macrolide antibiotic, is widely used in fisheries, agriculture, and animal husbandry, however, its irrational use poses a great danger to aquatic organisms. Ferulic acid (FA) is a natural chemical found in the cell walls of plants. It absorbs free radicals from the surrounding environment and acts as an antioxidant. However, the protective effect of FA against kidney injury caused by AVM has not been demonstrated. In this study, 60 carp were divided into the control group, AVM group (2.404 μg/L), FA+AVM group and FA group (400 mg/kg). Pathological examination, quantitative real-time PCR (qPCR), reactive oxygen species (ROS) and western blot were used to evaluate the preventive effect of FA on renal tissue injury after AVM exposure. Histological findings indicated that FA significantly reduced the swelling and infiltration of inflammatory cells in the kidney tissues of carp triggered by AVM. Dihydroethidium (DHE) fluorescent probe assay showed that FA inhibited the accumulation of kidney ROS. Biochemical results showed that FA significantly increased glutathione (GSH) content, total antioxidant capacity (T-AOC) and catalase (CAT) activity, and decreased intracellular malondialdehyde (MDA) content. In addition, western blot results revealed that the protein expression levels of Nrf2 and p-NF-κBp65 in the carp kidney were inhibited by AVM, but reversed by the FA. The qPCR results exhibited that FA significantly increased the mRNA levels of tgf-β1 and il-10, while significantly down-regulated the gene expression levels of tnf-α, il-6 and il-1β. These data suggest that FA can reduce oxidative stress and renal tissue inflammation induced by AVM. At the same time, FA inhibited the apoptosis of renal cells induced by AVM by decreasing the transcription level and protein expression level of Bax, and increasing the transcription level and protein expression level of Bcl2, PI3K and AKT. This study provides preliminary evidence for the theory that FA reduces the level of oxidative stress, inflammation response and kidney tissue damage caused by apoptosis in carp, providing a theoretical basis for the prevention and treatment of the AVM.

Effects of atrazine and curcumin exposure on TCMK-1 cells: Oxidative damage, pyroptosis and cell cycle arrest

Atrazine (ATR), a commonly used herbicide, is highly bioaccumulative and toxic, posing a threat to a wide range of organisms. Curcumin has strong antioxidant properties. However, it is unclear whether curcumin counteracts cellular pyroptosis as well as cell cycle arrest induced by ATR exposure. Therefore, we conducted a study using TCMK-1 cells and established cell models by adding 139 μmol/L ATR and 20 μmol/L curcumin. The results showed that ATR exposure produced excessive reactive oxygen species (ROS), reduced activities of enzymes such as GSH-PX, SOD and Total Antioxidant Capacity, markedly increased the content of H2O2, disrupted the antioxidant system, activated Caspase-1, and the expression levels of the pyroptosis-related genes NLRP3, GSDMD, ASC, Caspase-1, IL-1β and IL-18 were increased. The simultaneous excess of ROS led to DNA damage, activation of P53 led to elevated expression levels of P53 and P21, as a consequence, the expression levels of cyclinE, CDK2 and CDK4 were reduced. These results suggest that Cur can modulate ATR exposure-induced pyroptosis as well as cell cycle arrest in TCMK-1 cells by governing oxidative stress.

Environment-relevant concentrations of cadmium induces necroptosis and inflammation; baicalein maintains gill homeostasis through suppressing ROS/ER stress signaling in common carps (Cyprinus carpio L.)

Cadmium (Cd) is a major contaminant in natural environments and exerts adverse effects on aquatic biota at low concentrations. Gill is as vital respiratory organ and may cause pollutants to enter fish during gas exchange. Baicalein (BAI), as a kind of flavonoids, possess antioxidant properties through inactivating free radicals. To confirm the potential effects and approaches of BAI addition in maintaining the gill stability, 90 common carps (Cyprinus carpio L.) were selected and randomly divided into water environment exposure group (0.22 mg/L Cd) and/or feed added with 0.10 g/kg BAI for 30 days. The analysis of ion content in serum showed that Cd exposure disturbed ion homeostasis, and BAI could reduce serum Cd concentration. The histopathological results of gills showed that Cd exposure caused gill tissue lesions and structural damage, and BAI feeding effectively alleviated this damage. In addition, BAI could enhance antioxidant activity and activate Nrf2/HO-1 axis, thereby reducing oxidative stress and endoplasmic reticulum (ER) stress. Moreover, BAI lightened cytokine imbalance, inflammatory response, and necroptosis. Overall, the results indicated that BAI feeding could maintain gill homeostasis against Cd poisoning via the ROS/ER stress signaling. This trial revealed the properties of BAI resistance to metal Cd in aquaculture and partially elucidated its mechanism.

SeMet alleviates LPS-induced eggshell gland necroptosis mediated inflammation by regulating the Keap1/Nrf2/HO-1 pathway

Exposure to lipopolysaccharide (LPS) can lead to inflammation in a variety of tissues and organs. Selenium (Se) plays a crucial role in mitigating inflammatory damage. Compared with inorganic selenium, organic selenium, such as selenomethionine (SeMet), has the advantages of a higher absorption rate and lower toxicity in animals. This study examined the protective effects of SeMet on eggshell gland tissue damage caused by LPS. Hy-Line Brown laying hens were chosen as the experimental animals and were randomly assigned to four groups: control group (C), lipopolysaccharide group (LPS), SeMet group (Se), and SeMet + lipopolysaccharide group (Se + LPS). H&E staining and transmission electron microscope were performed to observe the pathological changes of eggshell glands, oxidative stress related indicators were measured using relevant kits, qRT‒PCR and western blotting were used to evaluate the mRNA and protein levels of the Nrf2 pathway, necroptosis, and inflammation related indicators. The results showed that LPS treatment increased the content of malondialdehyde (MDA), decreased the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX), and decreased the content of glutathione (GSH). LPS increased the levels of Keap1, RIPK1, RIPK3, MLKL, TNF-α, COX-2, and NF-κB, while decreasing the levels of HO-1, NQO1, Nrf2, and Caspase-8. However, SeMet treatment effectively reversed the changes of the above indicators, indicating that SeMet alleviates eggshell gland cell necroptosis-mediated inflammation induced by LPS via regulating the Keap1/Nrf2/HO-1 pathway. This study elucidated the mechanism by which SeMet alleviates LPS-induced eggshell gland tissue damage in Hy-Line Brown laying hens and provided a new direction for expanding the application of SeMet in the feeding and production of laying hens.

Trimethyltin chloride induces apoptosis and DNA damage via ROS/NF-κB in grass carp liver cells causing immune dysfunction

Trimethyltin chloride (TMT), a common component in fungicides and plastic stabilizers, presents environmental risks, particularly to fish farming. The precise toxicological mechanisms of TMT in L8824 grass carp liver cells remain undefined. Our study investigates TMT's effects on these cells, focusing on its potential to induce hepatotoxicity via oxidative stress and NF-κB pathway activation. First, we selected 0, 3, 6, and 12 μM as the challenge doses, according to the inhibitory concentration of 50% (IC50) of TMT. Our results demonstrate that TMT decreases cell viability dose-dependently and triggers oxidative stress, as evidenced by increased ROS staining and MDA content. Concurrently, it inhibited the antioxidant activities of T-AOC, T-SOD, CAT, and GSH. The activation of the NF-κB pathway was confirmed by gene expression changes. Furthermore, we observed an increase in cell apoptosis rate by AO/EB staining and cell flow cytometry, and the downregulation of Bcl-2 and the upregulation of Bax, Cytc, Caspase-9, and casp3 verified that TMT passed through the BCL2/BAX/casp3 pathway induces apoptosis. DNA damage was validated by the comet assay and γH2AX gene overexpression. Lastly, our data showed increased expression of TNF-α, IL-1β, IL-6, and INF-γ and decreased antimicrobial peptides, validating immune dysfunction. In conclusion, our findings establish that TMT induces apoptosis and DNA damage via ROS/NF-κB in grass carp liver cells, causing immune dysfunction. This study provides novel insights into the toxicology research of TMT and sheds light on the immunological effects of TMT toxicity, enriching our understanding of the immunotoxicity of TMT on aquatic organisms and contributing to the protection of ecosystems.

Ferulic acid alleviates carp brain damage and growth inhibition caused by avermectin by modulating the Nrf2/Keap1 and NF-κB signaling pathways

The increasing concern over environmental pollution caused by the pesticide avermectin used in aquaculture has attracted significant attention. The use of avermectin, a neurotoxic pesticide, in aquatic environments leads to toxic effects on non-target organisms, particularly causing harm to fish. The phenolic compound ferulic acid possesses excellent anti-inflammatory and antioxidant capabilities. This study was conducted by establishing a chronic exposure experiment to avermectin, proposes the use of ferulic acid as a dietary additive to protect the carp brain from damage caused by exposure to avermectin. Furthermore, it investigates the anti-inflammatory and antioxidant effects of ferulic acid in the carp brain under chronic exposure to avermectin. The experimental results demonstrate that ferulic acid can alleviate brain tissue inflammation and oxidative stress by modulating the Nrf2/Keap1 and NF-κB signaling pathways. It protects the carp brain from chronic avermectin-induced damage, preserves the integrity of the carp blood-brain barrier, enhances the levels of feeding factors, and thereby alleviates carp growth inhibition. These findings provide new therapeutic strategies and a theoretical foundation for the sustainable development of carp aquaculture.

Co-exposure of avermectin and imidacloprid induces DNA damage, pyroptosis, and immune dysfunction in epithelioma papulosum cyprini cells via ROS-mediated Keap1/Nrf2/TXNIP axis

Pesticide mixtures can reduce pest resistance, however, their overuse severely threatens aquatic animal survival and public health. Avermectin (AVM) and imidacloprid (IMI) are potent insecticides often employed in agriculture. By inducing oxidative stress, these chemicals can induce cell death. Here, we evaluated the combined toxicity of AVM and IMI on EPC cells based on the concept of toxicity units (TU). We established EPC cell models exposed to AVM and IMI alone and in combination. The results showed that AVM and IMI had additive effects on the toxicity of EPC cells. Meanwhile, the co-exposure of AVM and IMI exacerbated oxidative stress and induced excessive production of reactive oxygen species (ROS), triggered Keap1/Nrf2/TXNIP axis, caused DNA damage and increased the expression of genes related to pyroptosis. In addition, co-exposure to AVM and IMI caused immunosuppression of EPC cells. The ROS inhibitor N-Acetyl-l-cysteine (NAC) can dramatically reverse these alterations brought on by AVM and IMI co-exposure. The findings above conclude that co-exposure to AVM and IMI causes DNA damage, pyroptosis, and immunosuppression in EPC cells through the ROS-mediated Keap1/Nrf2/TXNIP pathway. This study revealed the joint toxicity of AVM and IMI on EPC cells, and reminded people to consider its impact on aquatic animals when using pesticide mixtures.

Using proteomics, q-PCR and biochemical methods complementing as a multiapproach to elicit the crucial responses of zebrafish liver exposed to neonicotinoid pesticide

Pesticides enter the environment through runoff and leaching and this raises public concern about effects on non-target organisms. Imidacloprid (IMI) a synthetic pesticide, has an unstable half-life, metabolized in minutes to weeks in the water. To evaluate the effects of IMI on the zebrafish liver, we conducted proteomic, molecular and biochemical analysis in a multi-level approach, to highlight the complementary features regarding the results of each method. Adult zebrafish were exposed to 60 mg/L IMI for 48 h and were evaluated using nLC-MS/MS for proteins, q-PCR analysis for expression of cat, gpx, pxr, ache, along with CAT and AChE enzyme activities and GSH and MDA assays. Based on proteomics, the regulation of antioxidant and immune responses, as well as gene transcription were significant processes affected. Apoptosis and ER stress pathways were upregulated and there was a down-regulation of cat and gpx genes. There was also elevated CAT activity and GSH and decreased MDA. Additionally, elevated AChE activity and up regulation of ache expression was observed. The multi-approach results included regulators of antioxidant, xenobiotic response and neuro-protective related proteins (genes and enzymes), which overall reflected harmful effects of IMI. Consequently, this study highlights the effects of IMI on zebrafish liver and reveals new potential biomarkers. In this respect, evaluated outcomes reveal the complementary features emphasizing the importance of studying chemicals using several methods. Our study provides deeper insights for future work in ecotoxicological studies regarding IMI and contribute to existing toxicity literature.

Baicalin suppressed necroptosis and inflammation against chlorpyrifos toxicity; involving in ER stress and oxidative stress in carp gills

Chlorpyrifos (CPF) has caused large-scale pollution worldwide and posed a threat to non-target organisms. Baicalein (BAI) is a flavonoid extract with anti-oxidant and anti-inflammatory activities. The gills are the mucosal immune organ and the first physical barrier of fish. However, it is not clear whether BAI counteracts organophosphorus pesticide CPF exposure-caused gill damage. Therefore, we established the CPF exposure and BAI intervention models by adding 23.2 μg/L CPF in water and/or 0.15 g/kg BAI in feed for 30 days. The results showed that CPF exposure could cause gill histopathology lesions. Moreover, CPF exposure led to endoplasmic reticulum (ER) stress, caused oxidative stress and Nrf2 pathway activation, and triggered NF-κB-mediated inflammation reaction and necroptosis in carp gills. BAI adding effectively relieved the pathological changes, and lighten inflammation and necroptosis involving in the elF2α/ATF4 and ATF6 pathways through binding to GRP78 protein. Moreover, BAI could ease oxidative stress, but did not affect Nrf2 pathway in carp gills under CPF exposure. These results suggested that BAI feeding could alleviate necroptosis and inflammation against chlorpyrifos toxicity through elF2α/ATF4 and ATF6 axis. The results partially explained the poisoning effect of CPF, and showed BAI could be act as an antidote for organophosphorus pesticides.

Protective effect of quercetin on avermectin induced splenic toxicity in carp: Resistance to inflammatory response and oxidative damage

Avermectin pollution is an important problem that cannot be ignored in aquatic system in recent years. It has brought great trouble to freshwater aquaculture, especially fishery aquaculture. Plant-derived quercetin has anti-inflammatory and antioxidant properties and is widely used as a dietary additive, but its protective effect on immune damage induced by avermectin in freshwater carp remains unclear. This study evaluated the role of dietary additive quercetin supplementation in chronic avermectin exposure of carp spleen. Sixty carp were divided into 4 groups (n = 15/ group), including control group, avermectin treatment group, quercetin treatment group, quercetin and avermectin co-treatment group. Carp were exposed to a 1/10 96 h LC₅₀ dose of avermectin for 30 d and fed a carp diet containing 400 mg/kg quercetin twice a day (3% body weigh/ carp). The results showed that chronic avermectin exposure caused the loose parenchymal structure of carp spleen tissue and the increase of inflammatory cells, accompanied by increased transcription levels of pro-inflammatory il-1β, il-6, tnf-α and decreased levels of anti-inflammatory factors il-10 and tgf-β1, ROS accumulation in spleen tissue. MDA content increased and T-AOC, CAT and GSH levels decreased. Quercetin down-regulates the NF-κB pathway by inhibiting the expression of iNOS and activating p38 MAPK, blocking the transcription of inflammatory factors, and alleviating the inflammation of carp spleen caused by chronic avermectin exposure. In addition, quercetin inhibits the over-activation of Nrf2/Keap-1 signaling axis, blocks ROS accumulation, and restores the spleen REDOX homeostasis. In conclusion, quercetin, as a dietary additive for carp feed, can effectively improve the immune damage caused by avermectin pollution in aquatic environment, resist spleen inflammation and oxidative stress, and provide a theoretical basis for clinical development of freshwater carp feed.