Intestinal Oxidative Stress Research Articles

Corilagin alleviates intestinal ischemia/reperfusion injury by relieving oxidative stress and apoptosis via AMPK/Sirt1-autophagy pathway.

Intestinal ischemia/reperfusion (II/R) injury is a common pathological process with high clinical morbidity and mortality. Autophagy plays an important role in the pathological development of II/R. Corilagin (CA) is a natural ellagitannin with various pharmacological effects such as autophagy regulation, antioxidant, and antiapoptosis. However, whether CA alleviates II/R injury is still unclear. In this study, we had found that CA significantly attenuated II/R induced intestinal tissue pathological damage, oxidative stress, and cell apoptosis in rats. Further studies showed that CA significantly promoted AMPK phosphorylation and sirt1 expression, and thus activated autophagy by upregulating protein expression of autophagy-related proteins Beclin1 and LC3II and promoting SQSTM1/P62 degradation both in vivo and in vitro. Inhibition of AMPK phosphorylation by its inhibitor compound C(CC) significantly abolished CA-mediated autophagy activation and the relievable effects on oxidative stress and apoptosis in vitro, suggesting the excellent protective activity of CA against II/R injury via AMPK/Sirt1-autophagy pathway. These findings confirmed the potent effects of CA against II/R injury, and provided novel insights into the mechanisms of the compound as a potential candidate for the treatment of II/R.

Efficiently Inhibiting Systemic Inflammatory Cascades by Fullerenes for Retarding HFD-Fueled Atherosclerosis.

Atherosclerosis accounts for major mortality of cardiac-cerebral vascular diseases worldwide. Pathologically, persistent inflammation dominates the progression of atherosclerosis, which can be accelerated by a high-fat diet (HFD), possibly through triggering local intestinal oxidative stress and ensuing gut barrier dysfunction. Current pharmacotherapy has been disappointing, ascribed to limited therapeutic efficacy and undesirable side effects. Hence it is compelling to explore novel efficient anti-atherosclerotic drugs with minimal toxicity. Herein, two fullerene-based therapies with exceptional antioxidant capacity, in the form of water-soluble injectable fullerene nanoparticles (IFNPs) and oral fullerene tablets (OFTs), are demonstrated to retard HFD-fueled atherosclerosis in ApoE-/- mice with favorable biosafety. Especially, OFTs afford robust anti-atherosclerotic therapeutic even against advanced plaques, besides stabilizing plaques with less lipid deposition and improved collagen expression. Specifically, it is identified that OFTs can ameliorate HFD-induced dysregulated intestinal redox homeostasis and restore gut barrier integrity, thereby restraining the translocation of luminal lipopolysaccharide (LPS) into the bloodstream. Furthermore, significantly reduced circulating LPS after OFTs treatment contributes to down-regulated LPS/TLR4/NF-κB signaling in aortic focal, which further mitigates local inflammation and disease development. Overall, this study confirms the universal anti-atherosclerotic effect of fullerenes and provides a novel therapeutic mechanism via modulating intestinal barrier to attenuate atherosclerosis.

The Interaction between Oxidative Stress Biomarkers and Gut Microbiota in the Antioxidant Effects of Extracts from Sonchus brachyotus DC. in Oxazolone-Induced Intestinal Oxidative Stress in Adult Zebrafish.

Oxidative stress is a phenomenon caused by an imbalance between the production and accumulation of reactive oxygen species in cells and tissues that eventually leads to the production of various diseases. Here, we investigated the antioxidant effects of the extract from Sonchus brachyotus DC. (SBE) based on the 0.2% oxazolone-induced intestinal oxidative stress model of zebrafish. Compared to the model group, the treatment group alleviated oxazolone-induced intestinal tissue damage and reduced the contents of malondialdehyde, reactive oxygen species, IL-1β, and TNF-α and then increased the contents of superoxide dismutase, glutathione peroxidase, and IL-10. The 16s rDNA gene sequencing findings demonstrated that SBE could increase the relative abundance of Fusobacteriota, Actinobacteriota, and Firmicutes and decrease the relative abundance of Proteobacteria. Based on the correlation analysis between the oxidative stress biomarkers and intestinal flora, we found that the trends of oxidative stress biomarkers were significantly correlated with intestinal microorganisms, especially at the genus level. The correlations of MDA, IL-1β, and TNF-α were significantly negative with Shewanella, while SOD, GSH-Px, and IL-10 were significantly positive with Cetobacterium, Gemmobacter, and Flavobacterium. Consequently, we concluded that the antioxidant effect of SBE was realized through the interaction between oxidative stress biomarkers and gut microbiota.

Monoammonium glycyrrhizinate improves antioxidant capacity of calf intestinal epithelial cells exposed to heat stress in vitro.

Dairy calves are highly susceptible to the negative effects of heat stress, which can cause organ hypoxia after blood redistribution, damage the intestinal barrier, and trigger intestinal oxidative stress. This study aimed to investigate the antioxidant effects of monoammonium glycyrrhizinate (MAG) on calf small intestinal epithelial cells under heat stress in vitro. Small intestinal epithelial cells were isolated from a 1-d-old healthy calf and purified by differential enzymatic detachment. The purified cells were divided into seven groups. The control group was cultured with DMEM/F-12 at 37 °C for 6 h, and the treatment groups were cultured with 0, 0.1, 0.25, 0.5, 1, or 5 μg/mL MAG at 42 °C for 6 h. Heat stress causes oxidative damage to cells. Adding MAG to the medium can significantly improve cell activity and reduce cellular oxidative stress. MAG significantly increased the total antioxidant capacity and superoxide dismutase activity caused by heat stress, and significantly decreased malondialdehyde and nitric oxide levels. The MAG treatment also reduced lactate dehydrogenase release, increased mitochondrial membrane potential, and decreased apoptosis under heat stress. MAG also upregulated the expression of the antioxidant-related genes, Nrf2 and GSTT1, in heat-stressed intestinal epithelial cells and significantly downregulated the expression of the heat shock response-related proteins, MAPK, HSP70, HSP90, and HSP27. From the above results, we conclude that 0.25 μg/mL MAG improves the capability of the antioxidant system in small intestinal epithelial cells to eliminate reactive oxygen species by activating antioxidant pathways, improving the oxidant/antioxidant balance, lowering excessive heat shock responses, and reducing intestinal oxidative stress.

Efficacy of zinc glycinate reducing zinc oxide on intestinal health and growth of nursery pigs challenged with F18+ Escherichia coli.

The objective of this study was to investigate effects of zinc glycinate (ZnGly) supplementation reducing zinc oxide (ZnO) in feeds on intestinal health and growth of nursery pigs challenged with F18+Escherichia coli (E. coli). In total, 72 nursery pigs (BW 6.5 ± 0.5 kg) were allotted in a randomized complete block design to nine treatments: (1) NC: no challenge/no supplement; (2) PC: E. coli challenge/no-supplement; (3) E. coli challenge/ZnO at 2,500 mg/kg; (4, 5, and 6) E. coli challenge/ZnGly at 400, 800, and 1,200 mg/kg; and (7, 8, and 9) E. coli challenge/ZnGly at 400 mg/kg and ZnO at 700, 1,400, and 2,357 mg/kg. Pigs were fed for 28 d based on two phases (phase 1: 14 d and phase 2: 14 d). On day 7, challenged groups were orally inoculated with F18+E. coli at 6 × 109 CFU/mL whereas NC received saline solution. The PC showed reduced ADG (P = 0.076) and G:F (P = 0.055) during phase 1 and increased fecal score (P < 0.05) during the first week of postchallenge when compared with NC, whereas supplementation of ZnGly from 0 to 1,200 mg/kg linearly increased (P = 0.092) G:F and decreased (P < 0.05) the fecal score of the pigs challenged with F18+E. coli. Supplementation of ZnGly from 0 to 1,200 mg/kg had quadratic effects on TNF-α (P = 0.065; minimum 1.13 pg/mg at 850 mg/kg ZnGly), IL-8 (P = 0.093; minimum 0.53 ng/mg at 494 mg/kg), and protein carbonyl (P = 0.054; minimum 2.30 pg/mg at 675 mg/kg) and linearly increased mRNA expressions of ZIP4 (P = 0.057) and ZnT5 (P = 0.075) in the jejunum of the pigs. Supplementation of ZnGly from 0 to 1,200 mg/kg linearly increased (P < 0.05) the relative abundance of Actinobacteria and had quadratic effects on Cyanobacteria (minimum 0.67% at 625 mg/kg ZnO) and Proteobacteria (maximum 45.6 g/d at 735 mg/kg) at the phylum level, with linearly decreased (P < 0.05) Enterobacteriaceae at the family level in the jejunal mucosa-associated microbiota of the pigs. There was no difference in growth performance during the overall period, although pigs fed with ZnO at 2,500 mg/kg had greater (P < 0.05) ADG than pigs fed with ZnGly at 400 mg/kg during the first week of the post challenge period. In conclusion, ZnGly could be an alternative to the pharmaceutical use of ZnO without negatively affecting the growth of nursery pigs by enhancing intestinal Zn absorption, reducing intestinal inflammation and oxidative stress, and providing positive changes in jejunal mucosa-associated microbiota.

Selenium-enriched peptides identified from selenium-enriched soybean protein hydrolysate: protective effects against heat damage in Caco-2 cells.

Our previous study evaluated the antioxidant and anti-inflammatory activities of selenium-enriched soybean peptides (SePPs) in vivo. In this study, we purified SePPs via gel filtration chromatography and obtained five fractions (F1, F2, F3, F4 and F5), among which F3 displayed the highest antioxidant and anti-inflammatory activities. Nineteen selenium-enriched peptides were identified in F3 by mass spectrometry. Two selenium-enriched peptides with sequences ESeCQIQKL (Sep-1) and SELRSPKSeC (Sep-2) were selected for synthesis based on their score and the number of hydrophobic amino acids, acidic and basic amino acids. Both Sep-1 and Sep-2 exhibited preventive effects on the heat stress-induced impairment of intestinal epithelial cell integrity, oxidative stress and inflammatory responses in a Caco-2 cell model. Pretreatment of the cells with Sep-1 or Sep-2 for 24 h reduced intracellular reactive oxygen species (ROS) generation, prevented the disruption of tight junction (TJ) proteins, and decreased paracellular permeability. Western blot results showed that Sep-1 and Sep-2 could improve the abnormal expressions of Nrf2, Keap1, NLRP3, caspase-1 and ASC/TMS1, thereby enhancing the glutathione (GSH) redox system and reducing IL-1β and IL-18 concentrations. Sep-1 activated the Nrf2-Keap1 signaling pathway significantly more than Sep-2. Molecular docking results indicated that Sep-1 and Sep-2 are both bound to Keap1 and NLRP3 in the form of hydrogen bonds, hydrophobic interactions and salt bridges, which interferes with Nrf2 and NLRP3 signaling. Molecular dynamics simulations suggested that more hydrogen bonds were formed during the resultant process of Sep-1 with Keap1, and the compactness and stability of the complex structure were better than those of Sep-2. These findings confirm the value of both Sep-1 and Sep-2 in the development of dietary supplements as potential alternatives for heat damage and related disease prevention.

Study on Lactiplantibacillus plantarum R6-3 from Sayram Ketteki to prevent chronic unpredictable mild stress-induced depression in mice through the microbiota-gut-brain axis.

The prevention, mitigation and treatment of depression has become a global issue that needs to be solved urgently. Sayram Ketteki, a traditional natural fermented yoghurt from the region with the world's fourth highest life expectancy, has been known as the "longevity secret", whose longevity and anti-depression factors are speculated to come from its rich microorganisms. Therefore, for the first time, we systematically studied in depth the microbes of Sayram Ketteki, screened a new edible probiotic strain, Lactiplantibacillus plantarum R6-3, and explored its anti-depression effect in chronic unpredictable mild stress (CUMS)-induced depression in mice. It is encouraging that L. plantarum R6-3 was significantly superior to the classic anti-depressant drug, fluoxetine, in the performance of promoting sucrose preference test (SPT) behavior by 18% (p < 0.001), lowering the serum CORT content by 5.6% (p < 0.05), accelerating the brain-derived neurotrophic factor (BDNF) level by 5.9% (p < 0.01), increasing the serum IL-10 concentration by 2.3% (p < 0.05), up-regulating the expression of BDNF and phosphorylated-ERK by 74% (p < 0.01) and 45% (p < 0.001), respectively, and facilitating the secretion of fecal short-chain fatty acids (SCFAs), including n-butyric, n-valeric, and isovaleric acid by 47% (p < 0.01), 42% (p < 0.05) and 38% (p < 0.05), respectively. Through the microbiota-gut-brain axis, L. plantarum R6-3 promoted the secretion of intestinal SCFAs through regulation of the composition and function of the gut microbiota, and activated the production of the monoamine neurotransmitter, renewed the level of brain neurotrophic factor, and suppressed the hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis by adjusting the hippocampal BDNF/TrkB/ERK/CREB signaling pathway, thereby improving the immune and oxidative stress status, protecting hippocampal tissue from damage, maintaining a healthy weight and preventing CUMS-induced depressive behavior in mice. It has great prospects for the development of natural functional foods, the prevention and treatment of depression and in innovative microecological preparations.

Time-Related Evidence of Intestinal Oxidative Stress in Obstructive Jaundice-Induced Rats

Introduction: Obstructive jaundice is known to affect intestinal permeability and facilitate bacterial translocation through related mechanisms. This study was conducted to evaluate the alterations concerning blood biochemistry and levels of several markers of oxidative stress (OS) in blood and intestinal mucosa caused by obstructive jaundice and how these fluctuate over time, in order to further explore the possibility of intervening in the OS path in future experiments. Methods: A total of 54 albino Wistar rats were randomly divided into three groups (control, sham operated, and bile duct ligation) and sacrificed at specific time intervals (12 h and 2, 7, and 14 days). The intestinal barrier function was evaluated by measuring endotoxin levels in portal, aortic, and peripheral blood. Also, basic biochemical parameters were simultaneously measured in peripheral blood. Tissue samples collected from the terminal ileum were homogenized for determining the OS markers, lipid peroxidation, and protein-free radical-induced oxidation. Results: We designed this experiment to examine the alterations in enteric mucosa primarily in relation to OS in a period of 14 days. During this time period, we investigated in specific time intervals not only OS fluctuations but also other liver function parameters, as well as CRP and endotoxin levels. The alterations were monitored in relation to time after bile duct ligation. Conclusion: Bile duct ligation in rats causes OS versus post-ligation time progression of the common bile duct. OS was increased by ∼50% compared to control/sham and peaked at 7 days and at least up to 14 days post-ligation. This phenomenon was accompanied with a deranging of liver function after ligation, as anticipated, but not in all measured parameters; biochemical and endotoxin levels followed the same pattern.

Ulcerative colitis alleviation of colon-specific delivered rhamnolipid/fullerene nanocomposites via dual modulation in oxidative stress and intestinal microbiome.

As a typical inflammatory bowel disease (IBD), ulcerative colitis (UC) has become prevalent worldwide in recent years. Though several materials have been proved to be effective in reducing intestinal oxidative stress to alleviate UC symptoms, dependence on high doses of exogenous drugs amplifies their safety risk for patients. To address this challenge, an oral therapy based on colon-targeting delivery of low-dose rhamnolipid (RL)/fullerene (C60) nanocomposites has been reported. With high biocompatibility being verified, RL/C60 largely mitigated the inflammation of mice with colitis shortly after its oral administration. Not only this, but also the intestinal microbiome of diseased mice was remarkably restored to the near-healthy level by our composites. Specifically, RL/C60 significantly promoted the colonization of intestinal probiotics and suppressed the biofilm formation of pathogenic bacteria, which is beneficial for reshaping the intestinal barrier. A close relationship of cytokines and oxidoreductases levels with gut flora further revealed that a change in RL/C60-induced intestinal microecology effectively improved the organismal immune system, which can be considered important for long-time recovery from UC.

Glutathione Protects against Paraquat-Induced Oxidative Stress by Regulating Intestinal Barrier, Antioxidant Capacity, and CAR Signaling Pathway in Weaned Piglets.

Endogenous glutathione (GSH) effectively regulates redox homeostasis in the body. This study aimed to investigate the regulatory mechanism of different dietary levels of GSH supplementation on the intestinal barrier and antioxidant function in a paraquat-induced stress-weaned piglet model. Our results showed that dietary 0.06% GSH supplementation improved the growth performance of weaned piglets under normal and stressful conditions to some degree and decreased the diarrhea rate throughout. Exogenous GSH improved paraquat-induced changes in intestinal morphology, organelle, and permeability and reduced intestinal epithelial cell apoptosis. Moreover, GSH treatment alleviated intestinal oxidative stress damage by upregulating antioxidant (GPX4, CnZnSOD, GCLC, and GCLM) and anti-inflammatory (IL-10) gene expression and downregulating inflammatory cytokines (IFN-γ and IL-12) gene expression. Furthermore, GSH significantly reduced the expression levels of constitutive androstane receptor (CAR), RXRα, HSP90, PP2Ac, CYP2B22, and CYP3A29, and increased the expression levels of GSTA1 and GSTA2 in the jejunum and ileum of paraquat-induced piglets. We conclude that exogenous GSH protects against oxidative stress damage by regulating the intestinal barrier, antioxidant capacity, and CAR signaling pathway.

Knockdown of PHLDA1 Alleviates Necrotizing Enterocolitis by Inhibiting NLRP3 Inflammasome Activation and Pyroptosis Through Enhancing Nrf2 Signaling

ABSTRACT Objective Pleckstrin homology-like domain family A member 1 (PHLDA1) is involved in the progression of intestine-related diseases, but its role and related mechanisms in Necrotizing enterocolitis (NEC) are unclear. The aim of this study was to better understand the function of PHLDA1 in NEC and the underlying mechanisms. Methods A neonatal mouse model of NEC was established by hypoxic hypothermia, and sh-PHLDA1 was transfected into mice to observe the mortality of each group within 4 days. The levels of IL-1β, IL-6, IL-18 and TNF-α were measured by PCR and ELISA. ROS, MDA, SOD, and GSH-Px levels were detected by Dihydroethidium (DHE) method and kit; expression of pyroptosis-related factors including NLRP3, ASC, cleaved-caspase1, GSDMD-N, IL-1β, IL-18, and Nrf2 were detected by western-blot; mechanistically, the effects of transfection of sh-PHLDA1 and ML385 (Nrf2 inhibitor) were investigated, and the expression of pyroptosis-related factors was detected again. Results PHLDA1 was highly expressed in the intestinal tissues of NEC mice, and transfection of sh-PHLDA1 improved the survival rate, alleviated intestinal lesions, improved intestinal inflammation, oxidative stress and cellular scorching in NEC. In addition, sh-PHLDA1 was able to inhibit NLRP3 activation and pyroptosis by activating Nrf2. Conclusion Knockdown of PHLDA1 attenuated necrotizing small intestinal colitis by enhancing Nrf2 expression to inhibit NLRP3 inflammasome activation and pyroptosis.

Luteolin Attenuates APEC-Induced Oxidative Stress and Inflammation via Inhibiting the HMGB1/TLR4/NF-κB Signal Axis in the Ileum of Chicks

Avian pathogenic E. coli (APEC) is typically the cause of avian colibacillosis, which can result in oxidative stress, inflammation, and intestinal damage (APEC). Luteolin, in the form of glycosylation flavone, has potent anti-inflammatory and anti-oxidative properties. However, its effects on APEC-induced intestinal oxidative stress and NF-κB-mediated inflammation in chicks remains poorly understood. After hatching, one-day-old chicks were stochastically assigned to four groups: a control group (basic diet), an E. coli group (basic diet) and L10 and L20 groups (with a dry matter of luteolin diet 10 mg/kg and 20 mg/kg, respectively), with fifteen chicks in each group and one repeat per group. They were pretreated for thirteen days. The body weight, mortality, histopathological changes in the ileum, antioxidant status, and the mRNA and protein-expression levels of factors associated with the HMGB1/TLR4/NF-κB signal axis of the chicks were measured. The results showed that luteolin treatment decreased the mRNA and protein-expression level of the related factors of HMGB1/TLR4/NF-κB signal axis in the ileum, reduced inflammation, increased antioxidant enzyme activity, and reduced intestinal injury. Collectively, luteolin alleviated APEC-induced intestinal damage by means of hindering the HMGB1/TLR4/NF-κB signal axis, which suggests that luteolin could be a good method for the prevention and treatment of avian colibacillosis.

Ginsenoside Rk1 attenuates radiation-induced intestinal injury through the PI3K/AKT/mTOR pathway

Radiation-induced intestinal injury (RIII) frequently occurs during radiotherapy; however, methods for treating RIII are limited. Ginsenoside Rk1 (RK1) is a substance that is derived from ginseng, and it has several biological activities, such as antiapoptotic, antioxidant and anticancer activities. The present study was designed to investigate the potential protective effect of Rk1 on RIII and the potential mechanisms. The results showed that RK1 treatment significantly improved the survival rate of the irradiated rats and markedly ameliorated the structural injury of the intestinal mucosa observed by histology. Treatment with RK1 significantly alleviated radiation-induced intestinal epithelial cell oxidative stress apoptosis. Moreover, RNA-Seq identified 388 differentially expressed genes (DEGs) and showed that the PI3K-AKT pathway might be a key signaling pathway by which RK1 exerts its therapeutic effects on RIII. The western blotting results showed that the p-PI3K, p-AKT and p-mTOR expression levels, which were increased by radiation, were markedly inhibited by Rk1, and these effects were reversed by IGF-1. The present study demonstrates that Rk1 can alleviate RIII and that the mechanism underlying the antiapoptotic effects of RK1 may involve the suppression of the PI3K/Akt/mTOR pathway. This study provides a promising therapeutic agent for RIII.

Flos Puerariae-Semen Hoveniae medicinal pair extract ameliorates DSS-induced inflammatory bowel disease through regulating MAPK signaling and modulating gut microbiota composition.

Background: Inflammatory bowel disease (IBD) is a global gastrointestinal disease characterized by relapsing and remitting inflammatory conditions. Flos Puerariae (the flower of Pueraria lobata [Willd.] Ohwi and P. thomsonii Benth.) and Hovenia dulcis Thunb. (Rhamnaceae) are traditional Chinese medicines. This medicinal pair has been used to treat various diseases due to its excellent anti-oxidant and anti-inflammatory activity. However, the effects of extracts from these plants on dextran sulfate sodium (DSS)-induced colitis have not been investigated; further study is needed to improve the understanding of their mechanisms of action and potential applications. Methods: The chemical constitution of extracts from Flos Puerariae and Semen Hoveniae (PHE) was analyzed using UPLC-LTQ-Orbitrap-MS/MS. The protective effects of PHE on mice with DSS-induced colitis were evaluated through assessment of body weight loss, disease activity index (DAI) score, colon length shortening, and pathological changes. The levels of inflammatory cytokines were determined by ELISA and RT-qPCR. Biomarkers of oxidative stress (ROS, CAT, SOD, MDA, and T-AOC) were analyzed using biochemical kits. The expression of MAPK proteins was determined by Western blotting analysis. Gut microbiota were analyzed via 16S rRNA sequencing. Results: Chemical composition analysis indicated that PHE contains various bioactive compounds, including puerarin, kakkalide, tectoridin, and genistin. The findings from this study suggest that PHE could effectively modulate histopathological score, inflammatory cell infiltration, and inflammatory factor secretion. Notably, PHE ameliorated oxidative stress by inhibiting activation of the MAPK pathway, leading to decreased inflammatory mediators and restored antioxidant enzyme activity. Furthermore, PHE treatment regulated the composition of the gut microbiota by increasing the abundance of benign bacteria, such as Akkermansia, and reducing the abundance of harmful bacteria, such as Proteobacteria. Conclusion: The findings from this study demonstrate the mechanism underlying the amelioration of DSS-induced intestinal oxidative stress by PHE and its positive impact on the restoration of the composition of gut microbiota.

Long-term exposure to tire-derived 6-PPD quinone causes intestinal toxicity by affecting functional state of intestinal barrier in Caenorhabditis elegans

2-((4-Methylpentan-2-yl)amino)-5-(phenylamino)cyclohexa-2,5-diene-1,4-dione (6-PPDQ) is the ozonation product of 6-PPD, a commonly used tire preservative. Although the 6-PPDQ has been frequently detected in different environmental ecosystems, its long-term effects on organisms remain still largely unknown. We here used Caenorhabditis elegans as an experimental animal to investigate the toxic effect of prolonged exposure to 6-PPDQ (0.1–100 μg/L). After the exposure, we found that 100 μg/L 6-PPDQ caused the lethality. We further selected concentrations of 0.1–10 μg/L to examine the possible intestinal toxicity induced by 6-PPDQ. Although 0.1–10 μg/L 6-PPDQ could not influence intestinal morphology, the intestinal permeability was significantly enhanced by 1–10 μg/L 6-PPDQ as indicated by erioglaucine disodium staining. In addition, the expression of intestinal fatty acid transporter ACS-22 governing functional state of intestinal barrier was decreased by exposure to 1–10 μg/L 6-PPDQ. Meanwhile, intestinal reactive oxygen species (ROS) production was induced by 0.1–10 μg/L 6-PPDQ and lipofuscin accumulation reflected by intestinal autofluorescence was activated by 1–10 μg/L 6-PPDQ. Accompanied with activation of intestinal oxidative stress, expressions of some anti-oxidation related genes (ctl-2, sod-2, sod-3, and sod-4) were significantly increased by 0.1–10 μg/L 6-PPDQ. Moreover, intestinal RNAi of acs-22 strengthened the susceptibility of nematodes to intestinal toxicity of 6-PPDQ. Therefore, considering that the environmentally relevant concentrations of 6-PPDQ were ≤10 μg/L, our data suggested that long-term exposure to 6-PPDQ at environmentally relevant concentrations potentially results in intestinal toxicity by disrupting functional state of intestinal barrier in organisms.

Dietary ellagic acid supplementation attenuates intestinal damage and oxidative stress by regulating gut microbiota in weanling piglets

Intestinal oxidative stress triggers gut microbiota dysbiosis, which is involved in the etiology of post-weaning diarrhea and enteric infections. Ellagic acid (EA) can potentially serve as an antioxidant supplement to facilitate weaning transition by improving intestinal oxidative stress and gut microbiota dysbiosis. Therefore, we aimed to investigate the effects of dietary EA supplementation on the attenuation of intestinal damage, oxidative stress, and dysbiosis of gut microbiota in weanling piglets. A total of 126 piglets were randomly assigned into 3 groups and treated with a basal diet and 2mL saline orally (Ctrl group), or the basal diet supplemented with 0.1% EA and 2mL saline orally (EA group), or the basal diet and 2mL fecal microbiota suspension from the EA group orally (FEA group), respectively, for 14d. Compared with the Ctrl group, EA group improved growth performance by increasing average daily feed intake and average daily weight gain (P<0.05) and decreasing fecal scores (P<0.05). EA group also alleviated intestinal damage by increasing the tight junction protein occludin (P<0.05), villus height, and villus height-to-crypt depth ratio (P<0.05), while decreasing intestinal epithelial apoptosis (P<0.05). Additionally, EA group enhanced the jejunum antioxidant capacity by increasing the total antioxidant capacity (P<0.01), catalase (P<0.05), and glutathione/oxidized glutathione (P<0.05), but decreased the oxidative metabolite malondialdehyde (P<0.05) compared to the Ctrl group. Compared with the Ctrl group, EA and FEA groups increased alpha diversity (P<0.05), enriched beneficial bacteria (Ruminococcaceae and Clostridium ramosum), and increased metabolites short-chain fatty acids (P<0.05). Correspondingly, FEA group gained effects comparable to those of EA group on growth performance, intestinal damage, and intestinal antioxidant capacity. In addition, the relative abundance of bacteria shifted in EA and FEA groups was significantly related to the examined indices (P<0.05). Overall, dietary EA supplementation could improve growth performance and attenuate intestinal damage and oxidative stress by regulating the gut microbiota in weanling piglets.

Amelioration of ammonia-induced intestinal oxidative stress by dietary Clostridium butyricum in giant freshwater prawn (Macrobrachium rosenbergii)

The use of Clostridium butyricum in crustacean aquaculture for anti-abiotic stress is yet unknown. Feeds were formulated containing 0, 125, 250, 500, and 1000 mg/kg Clostridium butyricum (2 × 107 CFU/g), respectively. The giant freshwater prawns (Macrobrachium rosenbergii) were fed for 8 weeks in triplicate. The results showed that C. butyricum-supplemented groups improved growth performance significantly with the optimum level at 610 mg/kg. Ammonia stress reduced hemolymph glucose, total protein, total cholesterol, and triglyceride concentrations while dietary C. butyricum significantly increased hemolymph glucose and total protein levels after the ammonia challenge. Ammonia stress increased inducible nitric oxide synthase (iNOS) and nitric oxide (NO) levels, and the treatments supplemented with C. butyricum had considerably enhanced levels of iNOS and NO after stress. Treatment with C. butyricum increased the level of superoxide dismutase (SOD), and decreased the level of malondialdehyde (MDA) and superoxide anion, with the 125 mg/kg treated groups having the extreme value. Furthermore, C. butyricum-treated groups reduced the expression of HSPs after ammonia stress while the ammonia stress induced the expression of HSP60, HSP70, and HSP90. Dietary C. butyricum elevated the expression of peroxiredoxin-5 and toll in response to ammonia stress. The results indicate that dietary supplementation with 125–500 mg/kg of C. butyricum (2 × 107 CFU/g) improved biochemical and antioxidant features as well as intestinal immunity of M. rosenbergii under ammonia challenge by activating the toll signal pathway.

Identification of Phytogenic Compounds with Antioxidant Action That Protect Porcine Intestinal Epithelial Cells from Hydrogen Peroxide Induced Oxidative Damage.

Oxidative stress contributes to intestinal dysfunction. Plant extracts can have antioxidant action; however, the specific phytogenic active ingredients and their potential mechanisms are not well known. We screened 845 phytogenic compounds using a porcine epithelial cell (IPEC-J2) oxidative stress model to identify oxidative-stress-alleviating compounds. Calycosin and deoxyshikonin were evaluated for their ability to alleviate H2O2-induced oxidative stress by measuring their effects on malondialdehyde (MDA) accumulation, reactive oxygen species (ROS) generation, apoptosis, mitochondrial membrane potential (MMP), and antioxidant defense. Nrf2 pathway activation and the effect of Nrf2 knockdown on the antioxidative effects of hit compounds were investigated. Calycosin protected IPEC-J2 cells against H2O2-induced oxidative damage, likely by improving the cellular redox state and upregulating antioxidant defense via the Nrf2-Keap1 pathway. Deoxyshikonin alleviated the H2O2-induced decrease in cell viability, ROS production, and MMP reduction, but had no significant effect on MDA accumulation and apoptosis. Nrf2 knockdown did not weaken the effect of deoxyshikonin in improving cell viability, but it weakened its effect in suppressing ROS production. These results indicate that the mechanisms of action of natural compounds differ. The newly identified phytogenic compounds can be developed as novel antioxidant agents to alleviate intestinal oxidative stress in animals.

Five Natural Active Ingredients Achieve Anti-fatigue Function by Synergistic Antioxidation and Regulating the Structure of Intestinal Flora

In this study, the synergistic anti-fatigue effects of five natural active ingredients (anthocyanin, tea polyphenol, Lycium barbarum polysaccharide, ginsenoside, salidroside) and their effects on intestinal flora in mice were investigated. Synergistic antioxidant in vitro showed that when ginsenoside: Lycium barbarum polysaccharide: salidroside = 2:1:6 (4 mg/mL), the maximum experimental scavenging capacity (ESC) of the system was 124.73±5.32 μmol Trolox/L, the synergistic effect (SE) was 2.75. Natural active ingredients of different concentrations and formulations were orally administered to mice. The results showed that compared with control group, the group H (Ginsenoside/Lycium barbarum polysaccharide/Salidroside (2/1/6) 200 mg kg-1 d-1) can significantly increase the exhausting swimming time, decreasing the content of blood lactic acid (BLA), serum urea nitrogen (BUN), and malondialdehyde (MDA), which were accompanied by a corresponding increase in liver superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), liver glycogen content (LG) (p 0.05). The relative abundances of Verrucomicrobiota and Rokubacteria in group H were significantly decreased (p Acidobacteria, Parasutterella and Deferribacteres were significantly increased (p < 0.05). These data suggest that ginsenoside, Lycium barbarum polysaccharide, and salidroside achieve synergistic anti-fatigue effects by regulating intestinal flora and oxidative stress.

Effects of Dietary Coated Lysozyme on the Growth Performance, Antioxidant Activity, Immunity and Gut Health of Weaned Piglets.

The purpose of this study was to evaluate the effects of dietary coated lysozyme on growth performance, serum biochemical indexes, antioxidant activity, digestive enzyme activity, intestinal permeability, and the cecal microbiota in weaned piglets. In total, 144 weaned Large White × Landrace piglets were divided into six treatment groups, with 3 replicates and 8 piglets per replicate: CN, a basal diet; CL-L, CL-M, and CL-H, basal diet supplemented with 100, 150, 500 mg/kg coated lysozyme; UL, basal diet supplemented with 150 mg/kg lysozyme; and Abs, basal diet supplemented with 150 mg/kg guitaromycin for 6 weeks. Compared with the CN and UL diets, dietary CL-H inclusion increased the average daily gain (ADG) and decreased the feed/gain (F/G) ratio of piglets (p &lt; 0.05). The addition of 500 mg/kg coated lysozyme to the diet significantly increased the total protein (TP) and globulin (Glob) plasma levels of weaned piglets (p &lt; 0.05). Supplementation with 500 mg/kg coated lysozyme significantly increased the serum IgM concentration and increased lipase activity in the duodenum (p &lt; 0.05). The addition of coated lysozyme and lysozyme significantly decreased the malondialdehyde (MDA) content, while the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) levels all increased (p &lt; 0.05). High-throughput sequencing results showed that CL-H treatment effectively improved the intestinal microbiome. The relative abundance of Terrisporobacter in the CL-H and CL-M groups was significantly lower than that in the other groups (p &lt; 0.05). LEfSe analysis results showed that the relative abundance of Coprococcus_3 was higher in the CL-M treatment group. The marker species added to the CL-H treatment group was Anaerofilum. In summary, as a potential substitute for feed antibiotics, lysozyme is directly used as a dietary additive, which is inefficient. Therefore, we used palm oil as the main coating material to coat lysozyme. Lysozyme after coating can more effectively improve the growth performance of piglets by improving the intestinal flora, improving the activity of digestive enzymes, reducing the damage to intestinal permeability and oxidative stress in piglets caused by weaning stress, and improving the immunity of piglets.