Oleanolic acid enhances tight junctions and ameliorates inflammation in Salmonella typhimurium-induced diarrhea in mice via the TLR4/NF-κB and MAPK pathway

Oleanolic acid-based therapeutics ameliorate rotenone-induced motor and depressive behaviors in parkinsonian male mice via controlling neuroinflammation and activating Nrf2-BDNF-dopaminergic signaling pathways

Parkinson's disease (PD) is often accompanied by depression, which may appear before motor signs. Oleanolic acid (OA), a pentacyclic triterpenoid substance, have many pharmacological properties. However, its efficacy in treating PD-related chronic unpredictable stress (CUS) is unknown. Our study used behavioral, biochemical, and immunohistochemical techniques to assess how OA affected PDrelated CUS. Rotenone (1 mg/kg i.p. for first 21 days) was used to induce Parkinsonism, and modest psychological & environmental stresses generated CUS (from day 22 to day 43) in animals. The study included daily i.p.administration of OA (5, 10, and 20 mg/kg) from day 1 to day 57 in male swiss albino mice. Animals were evaluated for behavioral, biochemical parameters, neurotransmitters, and immunohistochemical expression following the treatment. Results of the study revealed that treatment with OA at all doses alleviated the core symptoms of CUS linked to PD and improved motor and non-motor function. OA therapy significantly lowered IL-1β, TNF-α (p < 0.01, < 0.01, < 0.001), IL-6 (p < 0.05, < 0.01, < 0.001), oxidative stress (p < 0.05, < 0.01, < 0.01), and elevated norepinephrine (p < 0.05, < 0.01, < 0.01), dopamine, and serotonin (p < 0.05, < 0.01, < 0.001) levels. Moreover, OA therapy substantially reduced α-synuclein (p < 0.05, < 0.01, < 0.01) aggregation and increased BDNF (p < 0.05, < 0.01, < 0.001) & Nrf-2 (p < 0.05, < 0.01, < 0.01) levels, which boosts neuronal dopamine survival. The study's findings indicated that OA ameliorates depressive-like behavior persuaded by CUS in PD, decreases neuroinflammation, and improves neurotransmitter concentration via activating Nrf2-BDNF-dopaminergic pathway.

Oleanolic acid promotes liver regeneration after partial hepatectomy via regulating pregnane X receptor signaling pathway in mice

Liver regeneration after liver tumor resection or liver transplantation is crucial, the remaining liver frequently fails to regenerate in some patients. Oleanolic acid (OA), a pentacyclic triterpenoid compound which has been shown to protect against various liver diseases. However, the effect of OA on liver regeneration after partial hepatectomy (PHx) is still unclear. In this study, the results showed that OA (50 mg/kg, twice daily) treatment induced liver mass restoration and increased the liver-to-body weight ratio of mice following PHx. Meanwhile, OA promoted hepatocyte proliferation and increased the number of BrdU-, Ki67-and PCNA-positive cells. Furthermore, OA increased the nuclear accumulation of PXR and induced the expression of PXR downstream proteins such as CYP3A11, UGT1A1 and GSTM2 in mice, as well as in AML12 and HepRG cells. Luciferase reporter assay and nuclear localization of PXR further demonstrated the effect of OA on PXR activation in vitro. Molecular docking simulation showed that OA could interact with the PXR active sites. Moreover, OA inhibited the expression of FOXO1, RBL2 and CDKN1B, and increased the expression of PCNA, CCND1 and CCNE1 in vivo and in vitro. Silencing of Pxr further confirmed that OA-mediated upregulation of proliferation-related proteins depended on PXR. The current study illustrated that OA exhibited a significant promoting effect on liver regeneration following PHx, potentially through regulation of the PXR signaling pathway to accelerate liver recovery.

In vitro and in vivo anti-inflammatory properties of an active fucoidan fraction from Sargassum fusiforme and a fraction-based hydrogel

In a previous study, we separated an active fucoidan (JHCF4) from acid-processed Sargassum fusiforme, then analyzed and confirmed its structure. In the present study, we investigated the potential anti-inflammatory properties of JHCF4 and a JHCF4-based hydrogel in vitro and in vivo. JHCF4 reliably inhibited nitric oxide (NO) production in LPS-induced RAW 264.7 macrophages, with an IC50 of 22.35 μg/ml. Furthermore, JHCF4 attenuated the secretion of prostaglandin E2, tumor necrosis factor-α, interleukin (IL)-1β, and IL-6, indicating that JHCF4 regulates inflammatory reactions. In addition, JHCF4 downregulated iNOS and COX-2 and inhibited the activation of the MAPK pathway. According to further in vivo analyses, JHCF4 significantly reduced the generation of reactive oxygen species (ROS), NO production, and cell death in an LPS-induced zebrafish model, suggesting that JHCF4 exhibits anti-inflammatory effects. Additionally, a JHCF4-based hydrogel was developed, and its properties were evaluated. The hydrogel significantly decreased inflammatory and nociceptive responses in carrageenan (carr)-induced mouse paws by reducing the increase in paw thickness and decreasing neutrophil infiltration in the basal and subcutaneous layers of the toe epidermis. These results indicate that JHCF4 exhibits potential anti-inflammatory activity in vitro and in vivo and that JHCF4-based hydrogels have application prospects in the cosmetic and pharmaceutical fields.

Tannic acid alleviates ETEC K88-induced intestinal damage through regulating the p62-keap1-Nrf2 and TLR4-NF-κB-NLRP3 pathway in IPEC-J2 cells

BACKGROUND

Tannic acid (TA), a naturally occurring polyphenol, has shown diverse potential in preventing intestinal damage in piglet diarrhea induced by Enterotoxigenic Escherichia coli (ETEC) K88. However, the protective effect of TA on ETEC k88 infection-induced post-weaning diarrhea and its potential mechanism has not been well elucidated. Therefore, an animal trial was carried out to investigate the effects of dietary supplementation with TA on the intestinal diarrhea of weaned piglets challenged with ETEC K88. In addition, porcine intestinal epithelial cells were used as an in vitro model to explore the mechanism through which TA alleviates intestinal oxidative damage and inflammation.

RESULTS

The results indicated that TA supplementation (2 and 4 g kg-1 ) reduced diarrhea rate, enzyme activity (diamine oxidase [DAO] and Malondialdehyde [MAD]) and serum inflammatory cytokines concentration (TNF-α and IL-1β) (P < 0.05) compared to the Infection group (IG), group in vivo. In vitro, TA treatment effectively alleviated ETEC-induced cytotoxicity, increased the expression of ZO-1, occludin and claudin-1 at both mRNA and protein levels. Moreover, TA pre-treatment increased the activity of antioxidant enzymes (such as T-SOD) and decreased serum cytokine levels (TNF-α and IL-1β). Furthermore, TA increased cellular antioxidant capacity by activating the Nrf2 signaling pathway and decreased inflammatory response by down-regulating the expression of TLR4, MyD88, NF-kB and NLRP3.

CONCLUSION

The present study showed that TA reduced the diarrhea rate of weaned piglets by restoring the intestinal mucosal mechanical barrier function, alleviating oxidative stress and inflammation. The underlying mechanism was achieved by modulating the p62-keap1-Nrf2 and TLR4-NF-κB-NLRP3 pathway. © 2024 Society of Chemical Industry.

Oleanolic acid attenuates hydrogen peroxide-induced apoptosis of IPEC-J2 cells through suppressing c-Jun and MAPK pathway

Oleanolic acid (OA) is a natural triterpenoid with therapeutic potential for a multitude of diseases. However, the precise mechanism by which OA influences stress-induced apoptosis of intestinal epithelial cells remains elusive. Therefore, the effect of OA on intestinal diseases under stressful conditions and its possible mechanisms have been investigated. In a hydrogen peroxide (H2 O2 )-induced oxidative stress model, OA attenuated H2 O2 -induced apoptosis in a concentration-dependent manner. To investigate the underlying mechanisms, the gene expression profile of OA on IPEC-J2 cells was analyzed using an RNA sequencing system. Results from gene ontology and Kyoto encyclopedia of genes and genomes analysis confirmed that OA may mitigate the cytotoxic effects of H2 O2 by downregulating gene expression through the MAPK signaling pathway. Furthermore, Quantitative real-time polymerase chain reaction results validated the differentially expressed genes data. Western blot analysis further demonstrated that OA effectively suppressed the expression level of c-Jun protein induced by H2 O2 in IPEC-J2 cells. Collectively, our results indicate that OA pretreatment significantly attenuated H2 O2 -induced apoptosis in intestinal epithelial cells through suppressing c-Jun and MAPK pathway.

The Microbial Tryptophan Metabolite Contributes to the Remission of Salmonella typhimurium Infection in Mice

Salmonella enterica serovar Typhimurium (S. Tm) causes severe foodborne diseases. Interestingly, gut microbial tryptophan (Trp) metabolism plays a pivotal role in such infections by a yet unknown mechanism. This study aimed to explore the impact of Trp metabolism on S. Tm infection and the possible mechanisms involved. S. Tm-infected C57BL6/J mice were used to demonstrate the therapeutic benefits of the Bacillus velezensis JT3-1 (B. velezensis/JT3-1) strain or its cell-free supernatant in enhancing Trp metabolism. Targeted Trp metabolomic analyses indicated the predominance of indole-3-lactic acid (ILA), an indole derivative and ligand for aryl hydrocarbon receptor (AHR). Based on the 16S amplicon sequencing and correlation analysis of metabolites, we found that B. velezensis supported the relative abundance of Lactobacillus and Ligilactobacillus in mouse gut and showed positive correlations with ILA levels. Moreover, AHR and its downstream genes (especially IL-22) significantly increased in mouse colons after B. velezensis or cell-free supernatant treatment, suggesting the importance of AHR pathway activation. In addition, ILA was found to stimulate primary mouse macrophages to secrete IL-22, which was antagonized by CH-223191. Furthermore, ILA could protect mice from S. Tm infection by increasing IL-22 in Ahr+/- mice, but not in Ahr-/- mice. Finally, Trp-rich feeding showed amelioration of S. Tm infection in mice, and the effect depended on gut microbiota. Taken together, these results suggest that B. velezensis-associated ILA contributes to protecting mice against S. Tm infection by activating the AHR/IL-22 pathway. This study provides insights into the involvement of microbiota-derived Trp catabolites in protecting against Salmonella infection.

Therapeutic effects of Stemmoside C against Salmonella enterica serotype typhimurium infected BALB/c mice

Salmonella is a Gram-negative bacterium that causes gastrointestinal diseases in 20 to 40 million people globally. Stemmoside C is a steroidal glycoside isolated from Argel, although its antibacterial and antibiofilm properties have not been studied. The antibacterial activity of Stemmoside C against Salmonella enterica was revealed, where MIC of the compound was 16 μg/mL (0.15 µM). Biofilm-associated Stemmoside C treatment destroyed S. typhi cells and reduced viable S. typhi numbers below detectable levels. When compared to Stemmoside C or Ciprofluxacin-treated mice, infected BALB/c mice had a greater death rate and a larger bacterial blood burden. The protective effects of orally administered Stemmoside C at dose of 25 and 50 mg/kg b.wt. against bacterial infection was associated with reduction in the levels of inflammatory cytokines (IFN-γ, Il-1β, IL-2, IL-6, MPO, and TNF-α) and elevation of anti-inflammatory cytokine (IL-10 and IL-12) in serum. Where, Stemmoside C at dose of 50 mg/kg b.wt. regulated the levels almost as normal control group and demonstrated apparently normal intestinal sections. It also resulted in a decrease in the number of viable S. typhi retrieved from feces. Stemmoside C is a promising drug for the treatment or prevention of S. typhimurium infection.

Eugenol alleviates Salmonella Typhimurium-infected cecal injury by modulating cecal flora and tight junctions accompanied by suppressing inflammation

BACKGROUND

Salmonella enterica serovar Typhimurium (ST) mainly exists in poultry and poultry related products, which are common sources of human salmonellosis. So, ST is an important zoonotic pathogen that threatens public health and safety. Eugenol has been noted for its antibacterial and anti-inflammatory properties, and it is expected to develop into an antibacterial therapy in vivo.

METHODS

Herein, the effects of eugenol against ST infection in terms of intestinal flora, cecal tight junction, and cecal inflammation in broilers was evaluated in this study.

RESULTS

The results showed that oral eugenol pretreatment obviously relieved the histopathological changes and ultrastructural injury of cecum caused by ST infection. Further analysis found that eugenol lessened the number of ST in the cecum, restrained Proteobacteria and Ruminococcus, and kept the ratio of Firmicutes to Bacteroidetes (F/B), improved the relative abundance of Alistipes compared to the infection control. Moreover, eugenol sustained the expression of ZO-1, claudin-1, and occluding tight junction proteins, reduced the mRNA levels of myeloid differentiation factor 88 (MyD88), toll-like receptor-4 (TLR4) and inducible nitric oxide synthesis (iNOS), suppressed the phosphorylation of p65 and IκBα in the NF-κB signaling pathway, as well as the mRNA levels of TNF-α, IL-1β, IL-2, and IL-18 in the cecum tissue.

CONCLUSION

Taken together, eugenol could protect broilers against ST infection via maintaining intestinal flora, tight junctions involved in mucosal barrier function, then accordingly limiting the excessive inflammation, finally contributed to improving relative weight gains and survival rates of broilers.

Exopolysaccharides of Lactobacillus rhamnosus GG ameliorate Salmonella typhimurium-induced intestinal inflammation via the TLR4/NF-κB/MAPK pathway

BACKGROUND

Salmonella typhimurium (S.T), as an important foodborne bacterial pathogen, can cause diarrhea and gastroenteritis in humans and animals. Numerous studies have confirmed that exopolysaccharides (EPSs) have various biological functions, but the mechanism through which EPSs improve the immunity of animals against the invasion of pathogenic bacteria is unclear. Here, we explored the protective effect of EPSs of Lactobacillus rhamnosus GG (LGG) on the S.T-infected intestine.

METHODS

Mice received adequate food and drinking water for one week before the start of the experiment. After 7 d of prefeeding, 2×10⁸ CFU/mL S.T solution and an equivalent volume of saline (control group) were given orally for 1 d. On the fourth day, the mice were treated with 0.5 mg/mL EPSs, 1.0 mg/mL EPSs, 2.0 mg/mL EPSs, or 2.0 mg/mL penicillin for 7 d. Finally, the body and relative organ weight, histological staining, and the levels of antioxidant enzyme activity and inflammatory cytokines were determined.

RESULTS

The S.T-infected mice exhibited symptoms of decreased appetite, somnolence, diarrhea and flagging spirit. Treatment with EPSs and penicillin improved the weight loss of the mice, and the high dose of EPSs showed the best therapeutic effect. EPSs significantly ameliorated S.T-induced ileal injury in mice. High-dose EPSs were more effective than penicillin for alleviating ileal oxidative damage induced by S.T. The mRNA levels of inflammatory cytokines in the ileum of mice showed that the regulatory effects of EPSs on inflammatory cytokines were better than those of penicillin. EPSs could inhibit the expression and activation of key proteins of the TLR4/NF-κB/MAPK pathway and thereby suppress the level of S.T-induced ileal inflammation.

CONCLUSIONS

EPSs attenuate S.T-induced immune responses by inhibiting the expression of key proteins in the TLR4/NF-κB/MAPK signaling pathway. Moreover, EPSs could promote bacterial aggregation into clusters, which may be a potential strategy for reducing the bacterial invasion of intestinal epithelial cells.

Mechanistic insights of Cucumis melo L. seeds for gastrointestinal muscle spasms through calcium signaling pathway-related gene regulation networks in WGCNA and in vitro, in vivo studies

BACKGROUND

In addition to the nutritional benefits of Cucumis melo L., herbalists in Pakistan and India employ seeds to treat various ailments. This study aimed to determine the regulatory role of C. melo seeds in calcium-mediated smooth muscle contraction.

METHODS

We identified and quantified the phytochemicals of C. melo with LC ESI-MS/MS and HPLC, then conducted in vitro and in vivo tests to confirm the involvement in smooth muscle relaxation. Then, diarrhea-predominant irritable bowel syndrome gene datasets from NCBI GEO were acquired, DEGs and WGCNA followed by functional enrichment analysis. Next, molecular docking of key genes was performed.

RESULTS

The quantification of C. melo seeds revealed concentrations of rutin, kaempferol, and quercetin were 702.38 μg/g, 686.29 μg/g, and 658.41 μg/g, respectively. In vitro experiments revealed that C. melo seeds had a dose-dependent relaxant effect for potassium chloride (80 mM)-induced spastic contraction and exhibited calcium antagonistic response in calcium dose-response curves. In in vivo studies, Cm.EtOH exhibited antidiarrheal, antiperistaltic, and antisecretory effects. The functional enrichment of WGCNA and DEGs IBS-associated pathogenic genes, including those involved in calcium-mediated signaling, MAPK cascade, and inflammatory responses. MAPK1 and PIK3CG were identified as key genes with greater binding affinity with rutin, quercitrin, and kaempferol in molecular docking.

CONCLUSIONS

The bronchodilator and antidiarrheal effects of C. melo were produced by altering the regulatory genes of calcium-mediated smooth contraction.

The Impact of Za'atar Antioxidant Compounds on the Gut Microbiota and Gastrointestinal Disorders: Insights for Future Clinical Applications

Since the gut microbiota plays a pivotal role in host homeostasis and energy balance, changes in its composition can be associated with disease states through the promotion of immune-mediated inflammatory disorders and increasing intestinal permeability, ultimately leading to the impairment of intestinal barrier function. Za'atar is one of the most popular plant-based foods in the Eastern Mediterranean region. Za'atar is a mixture of different plant leaves, fruits, and seeds and contains hundreds of antioxidant compounds, especially polyphenols, and fiber, with pre-clinical and clinical evidence suggesting health-promoting effects in cardiovascular and metabolic disease. Za'atar compounds have also been studied from a gastrointestinal perspective, concerning both gut microbiota and gastrointestinal diseases. Antioxidants such as Za'atar polyphenols may provide beneficial effects in the complex interplay between the diet, gut microbiota, and intestinal permeability. To our knowledge, no studies have reported the effects of the whole Za'atar mixture, however, based on the pre-clinical studies published on components and single compounds found in Za'atar, we provide a clinical overview of the possible effects on the gastrointestinal tract, focusing mainly on carvacrol, rosmarinic acid, gallic acid, and other polyphenols. We also cover the potential clinical applications of Za'atar mixture as a possible nutraceutical in disorders involving the gastrointestinal tract.

Asiatic acid and andrographolide reduce hippocampal injury through suppressing neuroinflammation caused by Salmonella typhimurium infection

Damage caused by Salmonella is not only limited to the gastrointestinal tract, but also occurs in the central nervous system (CNS). The aim of this study was to explore the protective effects of asiatic acid (AA) and andrographolide (AD) on the CNS through simulating common infection in mice by oral administration of Salmonella typhimurium (S. typhimurium). The results showed that the neurons in the hippocampus of mice were damaged after S. typhimurium invaded CNS in mice, and the inflammation was increased, which was manifested by the increased expression of inflammatory factors interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, interferon (IFN)-γ and IL-12b and the activation of NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasomes. The damage and inflammatory response of mouse hippocampal neurons were effectively reduced by AA or AD pretreatment. Furthermore, we observed the significant activation of microglia after S. typhimurium infection. AA and AD attenuated S. typhimurium -induced hippocampal injury by reducing the inflammatory response on microglia. The findings suggest that the AA and AD protect CNS from injury caused by S. typhimurium infection through inhibiting over expression of multiple neuroinflammatory mediators and NLRP3 inflammasome in mice.

Pueraria lobata polysaccharides alleviate neonatal calf diarrhea by modulating gut microbiota and metabolites

Introduction

Neonatal calf diarrhea (NCD) is still one of the most critical diseases in calf rearing. Studies have shown that Pueraria lobata polysaccharides (PLP) have intense antioxidant and immunomodulatory activity and modulate gut microbiota. This randomized clinical trial aimed to determine the effect of PLP on the neonatal calf with diarrhea.

Methods

In this study, we recorded the fecal score of experimental calves, and calves with fecal scores ≥ 2 were determined as diarrhea and assessed their serum concentrations of inflammatory cytokines and oxidative damage-related indices. Fecal microbiota and metabolomics of diarrheal calves were further investigated.

Results

Results showed that treatment with PLP decreased the fecal score of diarrheal calves, serum concentrations of IL-1β, TNF-γ, and malondialdehyde, and also elevated the level of superoxide dismutase. In addition, PLP treatment altered the gut microbiota, significantly increased the relative abundances of beneficial bacteria, including the phyla Bacteroidetes and Actinobacteria, the genus Collinsella, Megamonas, and Bifidobacterium; decreased the relative abundances of pathogenetic or diarrhea related bacteria, such as Proteobacteria, Fusobacteria, Clostridium_sensu_stricto_1, and Escherichia_Shigella. Moreover, PLP can increase the fecal concentrations of isobutyric acid, propionic acid, and pantothenate; lower the levels of PC [18:0/18:1(9Z)], arachidonic acid, and docosahexaenoic acid.

Discussion

Thus, the results suggested that the PLP may perform the therapeutic activity via alleviating intestinal inflammation and regulating gut microbiota, avoiding further dysbiosis to restore the metabolism of gut microbiota, and finally promoting the recovery of diarrhea. The change further mitigated intestinal inflammation and oxidative damage in diarrheal calves. This indicated that PLP might be a promising treatment to attenuate diarrhea in neonatal calves.

Potential pharmacological mechanisms of four active compounds of Macleaya cordata extract against enteritis based on network pharmacology and molecular docking technology

Background: Macleaya cordata extract (MCE) is effective in the treatment of enteritis, but its mechanism has not been fully elucidated. Therefore, this study combined network pharmacology and molecular docking technologies to investigate the potential pharmacological mechanism of MCE in the treatment of enteritis. Methods: The information of active compounds in MCE was accessed through the literature. Furthermore, PubChem, PharmMapper, UniProt, and GeneCards databases were used to analyze the targets of MCE and enteritis. The intersection of drug and disease targets was imported into the STRING database, and the analysis results were imported into Cytoscape 3.7.1 software to construct a protein-protein interaction (PPI) network and to screen core targets. The Metascape database was used for conducting Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. AutoDock Tools software was used for the molecular docking of active compounds with the core targets. Results: MCE has four active compounds, namely, sanguinarine, chelerythrine, protopine, and allocryptopine, and a total of 269 targets after de-duplication. Furthermore, a total of 1,237 targets were associated with enteritis, 70 of which were obtained by aiding the drug-disease intersection with the aforementioned four active compound targets of MCE. Five core targets including mitogen-activated protein kinase 1 (MAPK1) and AKT serine/threonine kinase 1 (AKT1) were obtained using the PPI network, which are considered the potential targets for the four active compounds of MCE in the treatment of enteritis. The GO enrichment analysis involved 749 biological processes, 47 cellular components, and 64 molecular functions. The KEGG pathway enrichment analysis revealed 142 pathways involved in the treatment of enteritis by the four active compounds of MCE, among which PI3K-Akt and MAPK signaling pathways were the most important pathways. The results of molecular docking showed that the four active compounds demonstrated good binding properties at the five core targets. Conclusion: The pharmacological effects of the four active compounds of MCE in the treatment of enteritis involve acting on signaling pathways such as PI3K-Akt and MAPK through key targets such as AKT1 and MAPK1, thus providing new indications for further research to verify its mechanisms.

Exploration of In Vivo and In Vitro Biological Effects of Sonneratia caseolaris (L.) Fruits Supported by Molecular Docking and ADMET Study

Sonneratia caseolaris (L.) is a common mangrove plant which has significant medicinal value in traditional medicine. Ethanol extract from the fruits of S. caseolaris (SCE) was used in this project to explore its different pharmacological effects considering its traditional usage. In the castor oil-induced diarrheal method, SCE significantly lengthened the latency of the first defecation period up to 95.8 and 119.4 min as well as lowering stool count by 43.3% and 64.4% at the doses of 250 and 500 mg/kg, respectively. In evaluating the neuropharmacological effect using the open-field model, a significant central nervous system (CNS) depressant nature was observed after a reduction in the no. of squares crossed by mice at various time intervals. In evaluating the blood coagulation effect, SCE significantly reduced blood clotting time at 5.86, 5.52, and 5.01 min at 25, 50, and 100 mg/ml doses, respectively. In the assessment of the anthelmintic effect, SCE significantly killed Paramphistomum cervi (P. cervi) where the death times of the nematodes were 40.3, 36.8, and 29.9 min at 12.5, 25, and 50 mg/ml doses, respectively. The extract showed a very poor cytotoxic effect in brine shrimp lethality bioassay. In molecular docking analysis, maslinic acid, oleanolic acid, luteolin, luteolin 7-O-β-glucoside, myricetin, ellagic acid, and R-nyasol showed the best binding affinities with the selected proteins which might be the credible reasons for eliciting pharmacological responses. Among these seven compounds, only luteolin 7-O-β-glucoside had two violations in Lipinski's rule of five.

Exploration of the mechanisms underlying the beneficial effect of Luo Tong formula on retinal function in diabetic rats via the "gut microbiota-inflammation-retina" axis

BACKGROUND

Diabetic retinopathy (DR) is a common microvascular complication of diabetes. Luo Tong formula (LTF), a classical traditional Chinese medicine (TCM) prescription, consists of four plants that have been widely and effectively used to treat DR. Previous work in our laboratory has confirmed that LTF can effectively ameliorate DR. However, the potential mechanism underlying the therapeutic effect of LTF on DR has not been fully elucidated. To explore the potential mechanism of action through which LTF prevents and alleviates DR from an inflammation and gut microbiota perspective.

MATERIALS AND METHODS

Metabolite profiling of LTF was performed using liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). Type 1 diabetes was induced in male Sprague Dawley (SD) rats via tail vein injection of 45 mg/kg streptozotocin. Next, 100 SD rats were randomly divided into four groups, normal control; diabetic control; diabetic + insulin + calcium dobesilate; and diabetic + insulin + LTF. After 12 weeks of treatment, glucose metabolism, fundus oculi, blood-retinal barrier permeability, retinal thickness, microvascular damage, as well as cell junction expression in retinas were measured and the changes observed in different groups were compared. Finally, the alteration in gut microbiota and inflammatory cytokine expression in serum and tissues were monitored, and their correlation was analyzed.

RESULTS

A total of 1024 valid peaks were obtained for LTF using GC-MS. The HbA1c and fasting blood glucose (FBG) levels in the LTF group were slightly decreased. LTF exerted protective effects on fundus oculi and the retina structure to different degrees. LTF attenuated systemic and local retinal inflammation by significantly decreasing the levels of seven pro-inflammatory cytokines, including ICAM-1, IL-6, IL-8, MCP-1, VCAM-1, VEGF, and IL-1β. LTF restored the intestinal microbiota of diabetic rats to levels that were similar to those of normal rats. Further analysis revealed that Enterobacteriales, Prevotellaceae, Enterobacteriaceae, Bacteroides, and Klebsiella were significantly and positively correlated with the inflammatory factors in DR after LTF treatment.

CONCLUSIONS

Our results revealed the mechanisms underlying the preventive effects of LTF on DR development and progression. LTF inhibited pathological changes in retinal histopathology, cell composition, and cell junction proteins while effectively ameliorating systemic and local retinal inflammation via regulating pivotal gut microbiota.

Antioxidant and anti-inflammation effects of dietary phytochemicals: The Nrf2/NF-κB signalling pathway and upstream factors of Nrf2

Oxidative stress (OS) is created by an imbalance between reactive oxygen species and antioxidant levels. OS promotes inflammation and is associated with many diseases, such as neurodegenerative disorders, diabetes, and cardiovascular disease. Nrf2 and NF-κB are critical in the cellular defence against OS and the regulators of inflammatory responses, respectively. Recent studies revealed that the Nrf2 signalling pathway interacts with the NF-κB signalling pathway in OS. More importantly, many natural compounds have long been recognized to ameliorate OS and inflammation via the Nrf2 and/or NF-κB signalling pathway. Thus, we briefly overview the potential crosstalk between Nrf2 and NF-κB and the upstream regulators of Nrf2 and review the literature on the antioxidant and anti-inflammatory effects of dietary phytochemicals (DPs) that can activate these defence systems. The aim is to provide evidence for the development of DPs into functional food for the regulation of the Nrf2/NF-κB signalling pathway by upstream regulators of Nrf2.

Different Structures of Arabinoxylan Hydrolysates Alleviated Caco-2 Cell Barrier Damage by Regulating the TLRs/MyD88/NF-κB Pathway

Arabinoxylan (AX) has been associated with alleviating intestinal barrier damage, and different structures of AX give rise to different effects on the intestinal barrier. This study investigated the main structural characteristics of AX, whose functional properties are attributed to alleviating intestinal barrier damage, and clarified their underlying mechanisms. An in vitro Caco-2 cell model was established to investigate the intestinal barrier effects of AX with various degrees of substitution (Ds) and molecular weight (Mw), with an added MyD88 inhibitor to verify the signaling pathways. Arabinoxylan treated with endo-1,4-β-xylanase (AXX) with higher Ds and Mw showed stronger physiological activity, which might be correlated with the uronic acid and bound ferulic acid contents in AXX. Moreover, AXX alleviated the intestinal barrier damage by upregulating the transepithelial electrical resistance (TER) and alleviating the decrease of claudin-1 (p < 0.05). AXX regulated the expression of inflammatory factors IL-2, TNF-α, IL-6 and IL-10 (p < 0.05). In addition, AXX reduced the intestinal barrier damage induced via inhibiting the TLRs/MyD88/NF-κB pathway and activating the TLRs/PKC pathway. Thus, AX with higher Ds and Mw might be better in alleviating intestinal barrier damage, and MyD88 might be the key point of AXX to identify these signaling pathways.

Chloroform extracts of Atractylodes chinensis inhibit the adhesion and invasion of Salmonella typhimurium

There are 27 million cases of Salmonella Typhimurium (STM) reported worldwide annually, which have resulted in 217,000 deaths to date. Thus, there is an urgent requirement to develop novel antibacterial agents to target the multidrug-resistant strains of STM. We evaluated the inhibitory effect of the chloroform extracts of Atractylodes chinensis (Ac-CE) on the virulence of STM in vitro and develop it as a potential antibacterial agent. First, we determined the in vitro effects of Ac-CE on STM biofilm formation, and swimming, swarming, and adhesion to mucin. Further, we evaluated the effect of Ac-CE on the adhesion and invasion of STM at the gene level. Lastly, we evaluated the inhibitory effect of Ac-CE on STM infectivity at the cellular level. Ac-CE could attenuate both the adhesion and invasion abilities of STM in vitro. At the gene level, it could inhibit the expression of flagella, pilus, biofilm, SPI-1, and SPI-2 genes, which are related to the adhesion and invasion ability of STM in cells. Ac-CE significantly downregulated the expression of inflammatory cytokines and the TLR4/MyD88/NF-κB pathway in an STM infection cell model. It also significantly recovered the expression of intestinal barrier-related genes and proteins in intestinal cells that are damaged during STM infection. Ac-CE is effective as an antivirulence agent in alleviating STM infection. Although the main components of Ac-CE were analyzed.We have not demonstrated the antivirulence effect of the active ingredients in Ac-CE. And the antivirulence effect of Ac-CE and its active ingredients warrant further in vivo studies.

Gut microbiota dysbiosis: The potential mechanisms by which alcohol disrupts gut and brain functions

Alcohol use disorder (AUD) is a high-risk psychiatric disorder and a key cause of death and disability in individuals. In the development of AUD, there is a connection known as the microbiota-gut-brain axis, where alcohol use disrupts the gut barrier, resulting in changes in intestinal permeability as well as the gut microbiota composition, which in turn impairs brain function and worsens the patient’s mental status and gut activity. Potential mechanisms are explored by which alcohol alters gut and brain function through the effects of the gut microbiota and their metabolites on immune and inflammatory pathways. Alcohol and microbiota dysregulation regulating neurotransmitter release, including DA, 5-HT, and GABA, are also discussed. Thus, based on the above discussion, it is possible to speculate on the gut microbiota as an underlying target for the treatment of diseases associated with alcohol addiction. This review will focus more on how alcohol and gut microbiota affect the structure and function of the gut and brain, specific changes in the composition of the gut microbiota, and some measures to mitigate the changes caused by alcohol exposure. This leads to a potential intervention for alcohol addiction through fecal microbiota transplantation, which could normalize the disruption of gut microbiota after AUD.

Recent Advances Regarding the Molecular Mechanisms of Triterpenic Acids: A Review (Part I)

Triterpenic acids are phytocompounds with a widespread range of biological activities that have been the subject of numerous in vitro and in vivo studies. However, their underlying mechanisms of action in various pathologies are not completely elucidated. The current review aims to summarize the most recent literature, published in the last five years, regarding the mechanism of action of three triterpenic acids (asiatic acid, oleanolic acid, and ursolic acid), corelated with different biological activities such as anticancer, anti-inflammatory, antidiabetic, cardioprotective, neuroprotective, hepatoprotective, and antimicrobial. All three discussed compounds share several mechanisms of action, such as the targeted modulation of the PI3K/AKT, Nrf2, NF-kB, EMT, and JAK/STAT3 signaling pathways, while other mechanisms that proved to only be specific for a part of the triterpenic acids discussed, such as the modulation of Notch, Hippo, and MALAT1/miR-206/PTGS1 signaling pathway, were highlighted as well. This paper stands as the first part in our literature study on the topic, which will be followed by a second part focusing on other triterpenic acids of therapeutic value.

Microbiome function underpins the efficacy of a fiber-supplemented dietary intervention in dogs with chronic large bowel diarrhea

Background

Chronic large bowel diarrhea is a common occurrence in pet dogs. While nutritional intervention is considered the primary therapy, the metabolic and gut microfloral effects of fiber and polyphenol-enriched therapeutic foods are poorly understood.

Methods

This prospective clinical study enrolled 31 adult dogs from private veterinary practices with chronic, active large bowel diarrhea. Enrolled dogs received a complete and balanced dry therapeutic food containing a proprietary fiber bundle for 56 days. Metagenomic and metabolomic profiling were performed on fecal samples at Days 1, 2, 3, 14, 28, and 56; metabolomic analysis was conducted on serum samples taken at Days 1, 2, 3, 28, and 56.

Results

The dietary intervention improved clinical signs and had a clear effect on the gut microfloral metabolic output of canines with chronic diarrhea, shifting gut metabolism from a predominantly proteolytic to saccharolytic fermentative state. Microbial metabolism of tryptophan to beneficial indole postbiotics and the conversion of plant-derived phenolics into bioavailable postbiotics were observed. The intervention altered the endocannabinoid, polyunsaturated fatty acid, and sphingolipid profiles, suggesting a modulation in gastrointestinal inflammation. Changes in membrane phospholipid and collagen signatures were indicative of improved gut function and possible alleviation of the pathophysiology related to chronic diarrhea.

Conclusions

In dogs with chronic diarrhea, feeding specific dietary fibers increased gut saccharolysis and bioavailable phenolic and indole-related compounds, while suppressing putrefaction. These changes were associated with improved markers of gut inflammation and stool quality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03315-3.

Dietary Aronia melanocarpa Pomace Supplementation Enhances the Expression of ZO-1 and Occludin and Promotes Intestinal Development in Pigs

A fruit juice production byproduct, Aronia melanocarpa pomace (AMP) is rich in natural polyphenol antioxidant components. The objectives of this study were to study the effects of dietary AMP supplementation on the feeding outcome and intestinal barrier function of pigs. In total, 27 growing pigs (Duroc × Landrace × Yorkshire, ~60 days, average weight of 27.77 ± 2.87 kg, males and females included at random) were randomly allotted to 3 treatment groups, with 3 repetitions per group and 3 pigs per repetition. At the experiment completion, 2 pigs (close to the average body weight of all experimental pigs) per replicate were slaughtered. The control group (CON group) was fed a basic diet, and the experimental groups were fed 4% (4% AMP group) and 8% (8% AMP group) AMP in the basic diet. These pigs were prefed for 3 days, and the formal experiments were performed for 7 weeks. The results showed that compared with the CON diet, the 4% AMP supplementation significantly increased the average daily gain of pigs (P < 0.05). Regarding intestinal development, 4% AMP significantly increased the jejunal villus height/crypt depth ratio (P < 0.05), and different AMP levels had no significant effect on the pig cecum morphology. Different AMP levels significantly decreased the relative abundance of Proteobacteria (P < 0.05). Regarding other microbial genera, 4% AMP supplementation significantly increased the levels of Lachnospira, Solobacterium, Romboutsia and other beneficial microorganisms (P < 0.05). Different AMP levels significantly decreased the relative abundances of the opportunistic pathogens Escherichia-Shigella and Pseudoscardovia (P < 0.05) and increased the contents of acetic acid and butyric acid in the pig cecal contents (P < 0.05). Compared with the CON treatment, 4% AMP supplementation significantly downregulated the jejunal gene expression of porcine proinflammatory factors (IL-1β, IL-6, IL-8 and TNF-α) and significantly upregulated the jejunal gene expression of ZO-1, Occludin and Claudin-1 (P < 0.05). In conclusion, 4% AMP supplementation in feed is beneficial to overall pig health and growth.

Modulation of Gut Microbiota Combined with Upregulation of Intestinal Tight Junction Explains Anti-Inflammatory Effect of Corylin on Colitis-Associated Cancer in Mice

Inflammatory bowel disease (IBD) involves chronic inflammation, loss of epithelial integrity, and gastrointestinal microbiota dysbiosis, resulting in the development of a colon cancer known as colitis-associated colorectal cancer (CAC). In this study, we evaluated the effects of corylin in a mouse model of dextran sodium sulfate (DSS)-induced colitis. The results showed corylin could improved the survival rate and colon length, maintained body weight, and ameliorated the inflammatory response in the colon. Then, we further identified the possible antitumor effects after 30-day treatment of corylin on an azoxymethane (AOM)/DSS-induced CAC mouse model. Biomarkers associated with inflammation, the colon tissue barrier, macrophage polarization (CD11c, CCR7, CD163, and CD206), and microbiota dysbiosis were monitored in the AOM/DSS group versus corylin groups. Corylin downregulated pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1β, and IL-6) mRNA expression and inflammatory signaling-associated markers (TLR4, MyD88, AP-1, CD11b, and F4/80). In addition, a colon barrier experiment revealed that epithelial cell proliferation of the mucus layer (Lgr5, Cyclin D1, and Olfm4) was downregulated and tight junction proteins (claudin-1 and ZO-1) were upregulated. Furthermore, the Firmicutes/Bacteroidetes ratio changed with corylin intervention, and the microbial diversity and community richness of the AOM/DSS mice were improved by corylin. The comparative analysis of gut microbiota revealed that Bacteroidetes, Patescibacteria, Candidatus Saccharimonas, Erysipelatoclostridium, and Enterorhabdus were significantly increased but Firmicutes, Turicibacter, Romboutsia, and Blautia decreased after corylin treatment. Altogether, corylin administration showed cancer-ameliorating effects by reducing the risk of colitis-associated colon cancer via regulation of inflammation, carcinogenesis, and compositional change of gut microbiota. Therefore, corylin could be a novel, potential health-protective, natural agent against CAC.

The protective effect and potential mechanisms of eugenol against Salmonella in vivo and in vitro

Salmonella enterica serovar Typhimurium (S. Typhimurium) continues to be a serious concern to the poultry industry as a bacterial foodborne zoonosis, which generally results in intestinal inflammation and barrier dysfunction or even death. Eugenol is a phenolic compound with various pharmacological activities involved antioxidant, anti-inflammatory, and antibacterial effects, which is expected to be an effective nonantibiotic therapy. The purpose of this study was to explore the protective effects of eugenol in the cellular and broiler models of S. Typhimurium infection and the possible underlying mechanisms. The results of animal infection showed that eugenol treatments enhanced the relative weight gains and survival rates of broilers with a reduction of the organ bacterial load and intestinal ultrastructural injury. Moreover, eugenol significantly inhibited the mRNA levels of myeloid differentiation factor 88 (MyD88) and toll-like receptor-4 (TLR4), then declined the phosphorylation of p65 and IκBα of NF-κB pathway and the expressions of inflammatory factors (TNF-α, IL-1β, IL-2, and IL-18) in duodenum tissues, while maintained the expressions of intestinal tight junction proteins (ZO-1, claudin-1, occludin). Further experiments in vitro revealed that eugenol markedly inhibited the adhesion and invasion of S. Typhimurium to RAW264.7 or IEC-6 cells, then reduce bacterial multiplication in IEC-6 or DF-1 cells. In conclusion, eugenol could defend broilers from S. Typhimurium infection by stabilizing the intestinal mucosal barrier and relieving inflammatory response, as well as inhibiting bacterial adhesion and invasion to cells.

Oleanolic acid reshapes the gut microbiota and alters immune-related gene expression of intestinal epithelial cells

BACKGROUND

Oleanolic acid (OA) is a pentacyclic triterpenoid compound that is present at high levels in olive oil and has several promising pharmacological effects, such as liver protection and anti-inflammatory, antioxidant, and anticancer effects. The purpose of the present study was to assess whether OA treatment affects gut health compared to a control condition, including gut microbiota and intestinal epithelial immunity.

RESULTS

Illumina MiSeq sequencing (16S rRNA gene) was used to investigate the effect of OA on the microbial community of the intestinal tract, while Illumina HiSeq (RNA-seq) technology was used to investigate the regulatory effect of OA on gene expression in intestinal epithelial cells, which allowed for a comprehensive analysis of the effects of OA on intestinal health. The results showed that the consumption of OA initially controlled weight gain in mice and altered the composition of the gut microbiota. At the phylum level, OA significantly increased the relative abundances of cecum Firmicutes but decreased the abundance of Actinobacteria, and at the genus level it increased the relative abundance of potentially beneficial bacteria such as Oscillibacter and Ruminiclostridium 9. Oleanolic acid treatment also altered the expression of 12 genes involved in the Kyoto Encyclopedia of Genes and Genomes（KEGG）pathways of complement and coagulation cascades, hematopoietic cell lineage, and leukocyte transendothelial migration in intestinal epithelial cells to improve gut immunity.

CONCLUSION

Intake of OA can contribute beneficial effects by optimizing gut microbiota and altering the immune function of intestinal epithelial cells, potentially to improve intestinal health status. © 2021 Society of Chemical Industry.

Dietary ferulic acid and vanillic acid on inflammation, gut barrier function and growth performance in lipopolysaccharide-challenged piglets

Ferulic acid (FA) and vanillic acid (VA) are considered as major phenolic metabolites of cyanidin 3-glucoside, a polyphenol that widely exists in plants that possess a protective effect against oxidative stress and inflammation in our previous study. This study aimed to investigate the effect of FA and VA on inflammation, gut barrier function, and growth performance in a weaned piglet model challenged with lipopolysaccharide (LPS). Thirty-six piglets (PIC 337 × C48, 28 d of age) were randomly allocated into 3 treatments with 6 replicate pens (2 piglets per pen). They were fed with a basal diet or a diet containing 4,000 mg/kg of FA or VA. Dietary supplementation of VA significantly increased average daily gain (ADG) (P < 0.05). Both FA and VA decreased serum levels of thiobarbituric acid reactive substances (TBARS), interlukin (IL)-1β, IL-2, IL-6, and tumor necrosis factor (TNF)-α (P < 0.05), and enhanced the expression of tight junction protein oclaudin (P < 0.05). Analysis of gut microbiota indicated that both FA and VA increased the Firmicutes/Bacteroidetes ratio alongside reducing the relative abundance of the Prevotellaceae family including Prevotella 9 and Prevotella 2 genera, but enriched the Lachoiraceaea family including the Lachnospiraceae FCS020 group (P < 0.05). Moreover, VA reduced the relative abundance of Prevotella 7 and Prevotella 1 but enriched Lachnospira, Eubacterium eligens group, and Eubacterium xylanophilum group (P < 0.05), while FA showed a limited effect on these genera. The results demonstrated that both VA and FA could alleviate inflammation and oxidative stress, but only VA has a significant positive effect on the growth performance of LPS-challenged piglets potentially through modulating gut microbiota.

Lactiplantibacillus plantarum 1201 Inhibits Intestinal Infection of Salmonella enterica subsp. enterica Serovar Typhimurium Strain ATCC 13311 in Mice with High-Fat Diet

Salmonella Typhimurium is widely distributed in food. It can colonise the gastrointestinal tract after ingestion, causing lamina propria edema, inflammatory cell infiltration, and mucosal epithelial decomposition. A high-fat diet (HFD) can induce an inflammatory response, but whether HFD can increase the infection level of S. Typhimurium is unknown. We established a model of Salmonella enterica subsp. enterica serovar Typhimurium strain ATCC 13311 ATCC 13311 infection in healthy adult mice with a maintenance diet (MD) or HFD to explore the effect of Lactiplantibacillus plantarum 1201 intervention on S. Typhimurium ATCC 13311 colonization and its protective effects on mice. HFD exacerbated the infection of S. Typhimurium ATCC 13311, while the intervention of L. plantarum 1201 effectively mitigated this process. L. plantarum 1201 can reduce the colonies of S. ATCC 13311 in the intestines and tissues; and reduce intestinal inflammation by down-regulating the level of TLR4/NF-κB pathway related proteins in serum and the expression of related inflammatory factors in the colon and jejunum. Since L. plantarum 1201 can inhibit the colonization of S. Typhimurium ATCC 13311 and relieve inflammation in HFD, current research may support the use of L. plantarum 1201 to prevent S. Typhimurium infection.

Mechanistic insight into immunomodulatory effects of food-functioned plant secondary metabolites

Medicinally important plant-foods offer a balanced immune function, which is essential for protecting the body against antigenic invasion, mainly by microorganisms. Immunomodulators play pivotal roles in supporting immune function either suppressing or stimulating the immune system's response to invading pathogens. Among different immunomodulators, plant-based secondary metabolites have emerged as high potential not only for immune defense but also for cellular immunoresponsiveness. These natural immunomodulators can be developed into safer alternatives to the clinically used immunosuppressants and immunostimulant cytotoxic drugs which possess serious side effects. Many plants of different species have been reported to possess strong immunomodulating properties. The immunomodulatory effects of plant extracts and their bioactive metabolites have been suggested due to their diverse mechanisms of modulation of the complex immune system and their multifarious molecular targets. Phytochemicals such as alkaloids, flavonoids, terpenoids, carbohydrates and polyphenols have been reported as responsible for the immunomodulatory effects of several medicinal plants. This review illustrates the potent immunomodulatory effects of 65 plant secondary metabolites, including dietary compounds and their underlying mechanisms of action on cellular and humoral immune functions in in vitro and in vivo studies. The clinical potential of some of the compounds to be used for various immune-related disorders is highlighted.

Oleanolic Acid Alleviates Atopic Dermatitis-like Responses In Vivo and In Vitro

Oleanolic acid (OA) is a pentacyclic triterpenoid, abundantly found in plants of the Oleaceae family, and is well known for its beneficial pharmacological activities. Previously, we reported the inhibitory effect of OA on mast cell-mediated allergic inflammation. In this study, we investigated the effects of OA on atopic dermatitis (AD)-like skin lesions and its underlying mechanism of action. We evaluated the inhibitory effect of OA on AD-like responses and the possible mechanisms using a 1-chloro-2,4-dinitrochlorobenzene (DNCB)-induced AD animal model and tumor necrosis factor (TNF)-α/interferon (IFN)-γ-stimulated HaCaT keratinocytes. We found that OA has anti-atopic effects, including histological alterations, on DNCB-induced AD-like lesions in mice. Moreover, it suppressed the expression of Th2 type cytokines and chemokines in the AD mouse model and TNF-α/IFN-γ-induced HaCaT keratinocytes by blocking the activation of serine-threonine kinase Akt, nuclear factor-κB, and the signal transducer and activator of transcription 1. The results demonstrate that OA inhibits AD-like symptoms and regulates the inflammatory mediators; therefore, it may be used as an effective and attractive therapeutic agent for allergic disorders, such as AD. Moreover, the findings of this study provide novel insights into the potential pharmacological targets of OA for treating AD.

FAT1 and PTPN14 Regulate the Malignant Progression and Chemotherapy Resistance of Esophageal Cancer through the Hippo Signaling Pathway

Background

Esophageal cancer (EC) is a common malignant tumor, which brings heavy economic burden to patients and society. Therefore, it is important to understand the molecular mechanism of recurrence, metastasis, and drug resistance of esophageal cancer.

Methods

Human esophageal cancer cell line TE13 (poorly differentiated squamous cell carcinoma) and normal human esophageal epithelial cell line het-1a were selected for aseptic culture. At the same time, 6 bottles of TE13 cell line were inoculated in logarithmic phase. Cell apoptosis was analyzed by flow cytometry (FCM). Cell clone formation assay was used to analyze the proliferation. Fibronectin-coated dishes were used to detect the characteristics of cell adhesion to extracellular matrix. The Transwell method was used to detect the cell invasion ability. Western blot was used to analyze the expression of Yap1, PTPN14, FAT1, and Myc.

Results

Results showed that FAT1 and PTPN14 were downregulated, while Yap1 was upregulated in esophageal cancer tissues. FAT1 inhibited the proliferation, adhesion, and invasion of human esophageal cancer cell lines, which might be associated with the upregulation of PTPN14 and the inhibition of Yap1 and Myc.

Conclusion

The results suggested that PTPN14 and FAT1 could regulate malignant progression and chemotherapy resistance of esophageal cancer based on the Hippo signaling pathway.

Shenjinhuoxue Mixture Attenuates Inflammation, Pain, and Cartilage Degeneration by Inhibiting TLR-4 and NF-κB Activation in Rats with Osteoarthritis: A Synergistic Combination of Multitarget Active Phytochemicals

Osteoarthritis (OA), a highly prevalent chronic joint disease, involves a complex network of inflammatory mediators that not only triggers pain and cartilage degeneration but also accelerates disease progression. Traditional Chinese medicinal shenjinhuoxue mixture (SHM) shows anti-inflammatory and analgesic effects against OA with remarkable clinical efficacy. This study explored the mechanism underlying anti-OA properties of SHM and evaluated its efficacy and safety via in vivo experiments. Through network pharmacology and published literature, we identified the key active phytochemicals in SHM, including β-sitosterol, oleanolic acid, licochalcone A, quercetin, isorhamnetin, kaempferol, morusin, lupeol, and pinocembrin; the pivotal targets of which are TLR-4 and NF-κB, eliciting anti-OA activity. These phytochemicals can enter the active pockets of TLR-4 and NF-κB with docking score ≤ -3.86 kcal/mol, as shown in molecular docking models. By using surface plasmon resonance assay, licochalcone A and oleanolic acid were found to have good TLR-4-binding affinity. In OA rats, oral SHM at mid and high doses (8.72 g/kg and 26.2 g/kg) over 6 weeks significantly alleviated mechanical and thermal hyperalgesia (P < 0.0001). Accordingly, the expression of inflammatory mediators (TLR-4, interleukin (IL-) 1 receptor-associated kinase 1 (IRAK1), NF-κB-p65, tumor necrosis factor (TNF-) α, IL-6, and IL-1β), receptor activator of the NF-κB ligand (RANKL), and transient receptor potential vanilloid 1 (TRPV1) in the synovial and cartilage tissue of OA rats was significantly decreased (P < 0.05). Moreover, pathological observation illustrated amelioration of cartilage degeneration and joint injury. In chronic toxicity experiment of rats, SHM at 60 mg/kg demonstrated the safety. SHM had an anti-inflammatory effect through a synergistic combination of active phytochemicals to attenuate pain and cartilage degeneration by inhibiting TLR-4 and NF-κB activation. This study provided the experimental foundation for the development of SHM into a more effective dosage form or new drugs for OA treatment.

Plant Polyphenols: Potential Antidotes for Lead Exposure

Lead is one of the most common heavy metal elements and has high biological toxicity. Long-term lead exposure will induce the contamination of animal feed, water, and food, which can cause chronic lead poisoning including nephrotoxicity, hepatotoxicity, neurotoxicity, and reproductive toxicity in humans and animals. In the past few decades, lead has caused widespread concern because of its significant threat to health. A large number of in vitro and animal experiments have shown that oxidative stress plays a key role in lead toxicity, and endoplasmic reticulum (ER) stress and the mitochondrial apoptosis pathway can also be induced by lead toxicity. Therefore, plant polyphenols have attracted attention, with their advantages of being natural antioxidants and having low toxicity. Plant polyphenols can resist lead toxicity by chelating lead with their special chemical molecular structure. In addition, scavenging active oxygen and improving the level of antioxidant enzymes, anti-inflammatory, and anti-apoptosis are also the key to relieving lead poisoning by plant polyphenols. Various plant polyphenols have been suggested to be useful in alleviating lead toxicity in animals and humans and are believed to have good application prospects.

Oleanolic Acid-Enriched Olive Oil Alleviates the Interleukin-6 Overproduction Induced by Postprandial Triglyceride-Rich Lipoproteins in THP-1 Macrophages

Oleanolic acid (OA), a triterpene that is highly present in olive leaves, has been proposed as a component of functional foods for the prevention of metabolic syndrome, due to its anti-inflammatory activity. We analyzed the effects of OA on inflammatory parameters and signaling proteins in LPS-stimulated THP-1 macrophages. Thus, THP-1 macrophages were incubated with LPS for 48 h after pretreatment with OA at different concentrations. Pretreatment with OA was significantly effective in attenuating IL-6 and TNF-α overproduction induced by LPS in macrophages, and also improved the levels of AMPK-α. We also evaluated the effects of human triglyceride-rich lipoproteins (TRLs) derived from individuals consuming an OA-enriched functional olive oil. For this purpose, TRLs were isolated from healthy adolescents before, 2 and 5 h postprandially after the intake of a meal containing the functional olive oil or common olive oil, and were incubated with THP-1 macrophages. THP-1 macrophages incubated with TRLs isolated at 2 h after the consumption of the OA-enriched olive oil showed significant lower levels of IL-6 compared to the TRLs derived from olive oil. Our results suggest that OA might have potential to be used as a lipid-based formulation in functional olive oils to prevent inflammatory processes underlying metabolic syndrome in adolescents.

Lactobacillus johnsonii L531 Alleviates the Damage Caused by Salmonella Typhimurium via Inhibiting TLR4, NF-κB, and NLRP3 Inflammasome Signaling Pathways

Salmonella Typhimurium (S. Typhimurium) is an aggressive zoonotic pathogen that causes enteritis and diarrhea. Antibiotic therapy is still the primary method at present. However, the increasing emergence of multi-drug resistant bacteria weakens the therapeutic efficacy of antibiotics. Probiotics have been widely studied as an alternative antibiotic therapy. In this study, we established an IPEC-J2 cell model of S. Typhimurium infection, aiming to determine the protective effect of Lactobacillus johnsonii L531 (L. johnsonii L531) on S. Typhimurium infection. As our data showed, S. Typhimurium infection resulted in a robust inflammatory response demonstrated by promoted protein levels of the inflammatory-related pathway (TLR4, MyD88, p-IκBα, and p-p65), increased cytokine levels of IL-6, IL-1β, IL-18, and TNF-α, and activated the NLRP3 inflammasome via promoting its assembly. However, L. johnsonii L531 pre-incubation inhibited the activation of the above inflammatory signaling pathways and reduced the expression levels of pro-inflammatory cytokines. In addition, L. johnsonii L531 alleviated the damage of S. Typhimurium to tight junctions ZO-1, Occludin, and Claudin-1. In summary, our findings suggested that L. johnsonii L531 alleviated S. Typhimurium-induced tight junction injury by inhibiting the TLR4/NF-κB/NLRP3 inflammasome signaling pathway.

Protective effect of Bifidobacterium bifidum FSDJN7O5 and Bifidobacterium breve FHNFQ23M3 on diarrhea caused by enterotoxigenic Escherichia coli

Enterotoxigenic Escherichia coli (ETEC) is the main bacterial cause of diarrhea among children in developing countries and of traveler's diarrhea. In this study, a mouse model was used to evaluate the effect of Bifidobacterium on alleviating diarrhea caused by ETEC. The results showed that B. breve FHNFQ23M3 and B. bifidum FSDJN7O5 could relieve the symptoms of diarrhea. Both strains significantly reduced the stool water content, restored the villi structure in the jejunum and ameliorated the fecal short-chain fatty acid (SCFA) content. In addition, B. breve FHNFQ23M3 restored body weight to the level before ETEC challenge and significantly reduced interferon-γ (IFN-γ), while B. bifidum FSDJN7O5 significantly improved interleukin (IL)-10. Furthermore, all the Bifidobacterium strains used in this study could significantly downregulate tumor necrosis factor-α (TNF-α) and restore the unbalanced gut microbiota, which had a high content of pathogenic Escherichia-Shigella and low content of Blautia and Clostridium innocuum groups due to ETEC. All the results proved that Bifidobacterium could be a potential probiotic for alleviating diarrhea from ETEC infection.

The in vitro and in vivo study of oleanolic acid indole derivatives as novel anti-inflammatory agents: Synthesis, biological evaluation, and mechanistic analysis

Oleanolic acid (OA) is a well-known natural product possessing many important pharmacological activities; however, its weak bioactivities significantly restrict the potential application in drug development. The structural modification of oleanolic acid is an effective mean to enhance its bioactivity with lower toxicity but it is challenging. In the present study, we systematically synthesized a series of new 11-oxooleanolic acid derivatives and evaluated their anti-inflammatory activities with a LPS induced BV2 cells inflammation model and a 12-O-tetradecanoyl phorbol-13-acetate (TPA) induced ear inflammation mice model. It was found that compounds 8 and 9 show more potent anti-inflammatory effects than OA and exhibit a low cytotoxicity. The possible mechanism of action was also investigated. The in vitro and in vivo results revealed that these two new 11-oxooleanolic acid derivatives may exert anti-inflammatory activities through the inhibition of NO, pro-inflammatory cytokines and chemokines (IL-1β, IL-6, IL-12, TNF-α, MCP-1 and MIP-1α) and upregulation of anti-inflammatory cytokines (IL-10), which may be caused by inhibiting the activation of NF-κB, MAPKs and PI3K/Akt related inflammatory signaling pathways and the activation of Nrf2/HO-1 signaling pathway. The results suggest that these two 11-oxooleanolic acid derivatives may be potential candidates for further anti-inflammatory drug development and our study demonstrated an important and practical strategy for drug discovery through the rational modification of natural products.

Genistein Inhibits Colonic Goblet Cell Loss and Colorectal Inflammation Induced by Salmonella Typhimurium Infection

SCOPE

Salmonella is the main food-borne pathogen, which can infect intestinal epithelial cells and causes colitis. Genistein has a variety of biological activities that alleviates colitis induced by sodium dextran sulfate in a variety of ways, but its protective effects on colitis caused by pathogenic bacteria are still unknown.

METHODS AND RESULTS

This study explores the protective effect of genistein in reducing colitis caused by Salmonella infection. Salmonella causes colon inflammation through activating cyclooxygenase-2/prostaglandin E2, and genistein inhibits colitis caused by Salmonella typhimurium infection. Salmonella infection increases colonic mucosal damage, proliferating cells, and goblet cell loss, while the administration of genistein solves these pathological changes. In addition, it is further proved that Salmonella causes severe colitis related to goblet cell loss and activates the host crypt stem cells to repair the damaged epithelium. Salmonella infection inhibites the host mammalian target of rapamycin, activates light chain 3 II pathways to induce autophagy to eliminate pathogenic bacteria. Genistein increases Lactobacillus in feces and reduces Salmonella colonization to inhibit colitis induces by Salmonella infection.

CONCLUSION

This study demonstrates genistein alleviated colitis and inhibites the goblet cell loss causes by Salmonella infection through regulating the gut bacteria and intestinal stem cell development.

Efficient In Vitro and In Vivo Anti-Inflammatory Activity of a Diamine-PEGylated Oleanolic Acid Derivative

Recent evidence has shown that inflammation can contribute to all tumorigenic states. We have investigated the anti-inflammatory effects of a diamine-PEGylated derivative of oleanolic acid (OADP), in vitro and in vivo with inflammation models. In addition, we have determined the sub-cytotoxic concentrations for anti-inflammatory assays of OADP in RAW 264.7 cells. The inflammatory process began with incubation with lipopolysaccharide (LPS). Nitric oxide production levels were also determined, exceeding 75% inhibition of NO for a concentration of 1 µg/mL of OADP. Cell-cycle analysis showed a reversal of the arrest in the G0/G1 phase in LPS-stimulated RAW 264.7 cells. Furthermore, through Western blot analysis, we have determined the probable molecular mechanism activated by OADP; the inhibition of the expression of cytokines such as TNF-α, IL-1β, iNOS, and COX-2; and the blocking of p-IκBα production in LPS-stimulated RAW 264.7 cells. Finally, we have analyzed the anti-inflammatory action of OADP in a mouse acute ear edema, in male BL/6J mice treated with OADP and tetradecanoyl phorbol acetate (TPA). Treatment with OADP induced greater suppression of edema and decreased the ear thickness 14% more than diclofenac. The development of new derivatives such as OADP with powerful anti-inflammatory effects could represent an effective therapeutic strategy against inflammation and tumorigenic processes.

Oleanolic Acid Targets the Gut-Liver Axis to Alleviate Metabolic Disorders and Hepatic Steatosis

This study investigated the effects of oleanolic acid (OA) on hepatic lipid metabolism and gut-liver axis homeostasis in an obesity-related non-alcoholic fatty liver disease (NAFLD) nutritional animal model and explored possible molecular mechanisms behind its effects. The results revealed that OA ameliorated the development of metabolic disorders, insulin resistance, and hepatic steatosis in obese rats. Meanwhile, OA restored high-fat-diet (HFD)-induced intestinal barrier dysfunction and endotoxin-mediated induction of toll-like-receptor-4-related pathways, subsequently inhibiting endotoxemia and systemic inflammation and balancing the homeostasis of the gut-liver axis. OA also reshaped the composition of the gut microbiota of HFD-fed rats by reducing the Firmicutes/Bacteroidetes ratio and increasing the abundance of butyrate-producing bacteria. Our results support the applicability of OA as a treatment for obesity-related NAFLD through its anti-inflammatory, antioxidant, and prebiotic integration responses mediated by the gut-liver axis.

Phenyl lactic acid alleviates Samonella Typhimurium-induced colitis via regulating microbiota composition, SCFA production and inflammatory responses

Colitis caused by non-typhoidal Salmonella (NST) infection is increasingly serious and widespread, so new effective treatment strategies with little or no side-effects are urgently needed. Our previous research found that phenyl lactic acid (PLA) derived from Lactobacillus plantarum ZJ316 can effectively inhibit Salmonella enterica Typhimurium (S. Typhimurium). In this study, we further investigated the protective effects of this PLA against S. Typhimurium-induced colitis in mice. An infection model was established using female C57BL/6J mice by oral administration of 109 CFU mL-1 of S. Typhimurium, and PLA was supplied for 10 days after infection. In colitic mice, PLA administration reduced the disease activity index, prevented the colon shortening and spleen enlargement, decreased liver enzyme (AST and ALT) activities, and alleviated the colonic tissue damage. RT-qPCR analysis showed that PLA significantly down-regulated the levels of NF-κB, TLR4 and pro-inflammatory cytokines (IFN-γ, IL-1β and TNF-α), but stimulated the mRNA expression of the anti-inflammatory cytokine IL-10. Changes in intestinal microecology were analyzed by 16S rRNA sequencing. PLA modulated colonic microbiota dysbiosis by increasing the abundance of Lactobacillus, Butyricicoccus and Roseburia, and reducing Salmonella and Alloprevotella at the genus level. In addition, PLA significantly increased the concentrations of short-chain fatty acids (SCFAs) in the colon, especially propionic acid and butyric acid. These findings revealed that PLA has potential benefits on alleviating S. Typhimurium-induced colitis mainly through intestinal microbiota regulation and inflammation elimination, providing a new perspective for the NTS infection treatment strategy.

Triterpene Acids from Mesona procumbens Exert Anti-inflammatory Effects on LPS-Stimulated Murine Macrophages by Regulating the MAPK Signaling Pathway

Five new triterpene acids, mesonaic acids A-C (1-3), 2α,3α,19α-trihydroxy-24-nor-4(23),12-oleanadien-28-oic acid (4), and 3α,19α,22α-trihydroxy-2-oxo-12-ursen-28-oic acid (5), and 10 known triterpene acid compounds (6-15) were isolated from a methanolic extract of Mesona procumbens. Triterpenes 1-3 possess unusual hexacyclic skeletons with a 13α,27-cyclopropane ring. Regarding their anti-inflammatory activity, compounds 1-3, 6, and 7 inhibited NO production with EC₅₀ values lower than 15 μM, which were better than that of the positive control quercetin. Compounds 1-3, 6, and 7 markedly decreased levels of the inducible iNOS and COX-2 proteins in macrophages by inhibiting the activation of NF-κB through interference with the MAPK signaling pathway. Based on these data, compounds 1-3, 6, and 7 have great potential as NO inhibitors.

Effects of acid, alkaline, cold, and heat environmental stresses on the antibiotic resistance of the Salmonella enterica serovar Typhimurium

Antibiotic resistance in Salmonella enterica serovar Typhimurium (S. ser. Typhimurium) has become a critical safety hazard in food. Sublethal environmental stresses can influence resistance in Salmonella during food processing. This study simulated environmental stresses in food processing. The antibiotic resistance of three strains of S. ser. Typhimurium (the ATCC 14028 strain and two wild-type isolates from chicken and pork product processing) was evaluated under different pH levels (5.0, 5.5, 6.0, 8.0, and 9.0). Also, dynamic changes in resistance with treatment duration under cold (4 °C, -20 °C) and heat (55 °C) treatment were studied. The results showed that acid and alkaline stresses reduced the resistance of S. ser. Typhimurium to eight antibiotics; meanwhile, the resistance of meropenem (MERO) increased. The minimal inhibitory concentration (MIC) of MERO was increased 16- to 64-fold. With acid or alkaline stress, the extracellular ATP content increased, and the scanning electron microscopy (SEM) result clearly revealed the appearance of wrinkles and holes on the outer membrane of Salmonella. These observations imply changes in membrane permeability, which may decrease the antibiotic resistance of Salmonella. Cold or heat stress increased the resistance of S. ser. Typhimurium to tetracycline, cefotaxime, ceftazidime, nalidixic acid, azithromycin, and ampicillin; the MIC increased 2- to 4-fold. The antibiotic resistance only changed when cold and heat stresses occurred over a certain period of time and remained unchanged when the stress persisted. This study reports on the ability of S. ser. Typhimurium to develop antibiotic resistance after environmental stresses. It can provide valuable information for meat processing to improve interventions and risk management.

MiMeNet: Exploring microbiome-metabolome relationships using neural networks

The advance in microbiome and metabolome studies has generated rich omics data revealing the involvement of the microbial community in host disease pathogenesis through interactions with their host at a metabolic level. However, the computational tools to uncover these relationships are just emerging. Here, we present MiMeNet, a neural network framework for modeling microbe-metabolite relationships. Using ten iterations of 10-fold cross-validation on three paired microbiome-metabolome datasets, we show that MiMeNet more accurately predicts metabolite abundances (mean Spearman correlation coefficients increase from 0.108 to 0.309, 0.276 to 0.457, and -0.272 to 0.264) and identifies more well-predicted metabolites (increase in the number of well-predicted metabolites from 198 to 366, 104 to 143, and 4 to 29) compared to state-of-art linear models for individual metabolite predictions. Additionally, we demonstrate that MiMeNet can group microbes and metabolites with similar interaction patterns and functions to illuminate the underlying structure of the microbe-metabolite interaction network, which could potentially shed light on uncharacterized metabolites through “Guilt by Association”. Our results demonstrated that MiMeNet is a powerful tool to provide insights into the causes of metabolic dysregulation in disease, facilitating future hypothesis generation at the interface of the microbiome and metabolomics.

The microbiome has shown to functionally interact with its host or environment at a metabolic level, however the exact nature of these interactions is not well understood. In addition, metabolic dysregulation caused by the microbiome is believed to contribute to the development of diseases such as inflammatory bowel disease, diabetes mellitus, and obesity. In this manuscript, we introduce a computational framework to integrate microbiome and metabolome data to uncover microbe-metabolite interactions in a data-driven manner. Our model uses neural networks to predict metabolite abundances from microbe abundances. The trained models are then used to derive microbe-metabolite feature scores, which are used for clustering microbes and metabolites into functional modules. These module-based interactions are useful in generating biological insights and facilitating hypothesis generation for the investigation of their roles in various metabolic diseases. The software of our model is made freely available to interested researchers.

Shenling Baizhu Powder Inhibits RV-SA11-Induced Inflammation and Rotavirus Enteritis via TLR4/MyD88/NF-κB Signaling Pathway

Rotavirus enteritis (RVE) is a common acute intestinal infectious disease caused by rotavirus infection. It is an important cause of death in children younger than 5 years worldwide. Shenling baizhu powder (SBP), a classic traditional Chinese formulation, is one of the most popularly prescribed medicines for digestive diseases. Clinical studies have revealed the protective effects of SBP on RVE. However, the potential mechanism is still unclear. In this study, we aimed to evaluate the anti-rotavirus effect of SBP and its mechanism, focusing on the TLR4/MyD88/NF-κB signaling pathway. Our results demonstrated that, based on the inhibition of the virus-induced cytopathic effect in Caco-2 cells, the concentration for 50% of maximal effect (EC₅₀) and selectivity index (SI) of SBP for RV-SA11 in the serum were 5.911% and 11.63, respectively. A total of 219 active compounds with oral bioavailability ≥30% and drug-likeness ≥ 0.18 were selected from the 10 ingredients present in the formulation of SBP, which acted on 471 potential targets. A total of 226 target genes of RVE were obtained from the GeneCards database. The protein-protein interaction (PPI) network showed that there was a close interaction between 44 common targets of SBP and RVE. The results of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that SBP acted on RVE through various inflammatory pathways and the intestinal immune network. Subsequently, we investigated the effect of SBP on TLR4/MyD88/NF-κB signaling pathway in vitro. After infection with RV- SA11, the expression of TLR4, MyD88, and NF-κB mRNA and protein increased significantly, which could be abolished by SBP treatment. In addition, the IL-1β, TNF-α, IL-6, and IFN-β levels increased markedly in Caco-2 cells infected with RV-SV11. Treatment with SBP partly reversed the changes of IL-1β, TNF-α, and IL-6, while further increased the level of IFN-β. In conclusion, our study revealed that SBP can significantly inhibit rotavirus replication and proliferation in vitro. The antiviral effect may be related to the regulation of the TLR4/MyD88/NF-κB signaling pathway, followed by the down regulation of inflammatory cytokines and up regulation of IFN-β induced by rotavirus.

Aquaporin: targets for dietary nutrients to regulate intestinal health

Aquaporins (AQP) are a class of water channel membrane proteins that are widely expressed in the gut. The biological functions of aquaporins, which regulate the absorption and secretion of water molecules and small solutes, maintain the stable state of the intestine, regulate cell proliferation and migration, participate in the process of intestinal inflammation, and mediate tumorigenesis, demonstrate the physiological significance of these channels in intestinal health. The pathology of many intestinal diseases is associated with changes in the location and expression of aquaporins, such as intestinal infection, which can change the expression and distribution of AQPs in intestinal tissues/cells by affecting cytokines and chemokines. This can lead to various intestinal diseases such as diarrhoea, which also suggests the importance of aquaporins in the prevention and treatment of intestinal diseases. This review summarizes the relationship between aquaporins and intestinal physiology and diseases and focuses on drugs (such as plant extracts) or diets that can regulate intestinal health by regulating aquaporins. It provides a basis for establishing aquaporins as biomarkers and therapeutic targets for intestinal health.