Cardamonin, a natural flavone, alleviates inflammatory bowel disease by the inhibition of NLRP3 inflammasome activation via an AhR/Nrf2/NQO1 pathway

Potential interventions and interactions of bioactive polyphenols and functional polysaccharides to alleviate inflammatory bowel disease - A review

Inflammatory bowel disease is a multifaceted condition that is influenced by nutritional, microbial, environmental, genetic, psychological, and immunological factors. Polyphenols and polysaccharides have gained recognition for their therapeutic potential. This review emphasizes the biological effects of polyphenols and polysaccharides, and explores their antioxidant, anti-inflammatory, and microbiome-modulating properties in the management of inflammatory bowel disease (IBD). However, polyphenols encounter challenges, such as low stability and low bioavailability in the colon during IBD treatment. Hence, polysaccharide-based encapsulation is a promising solution to achieve targeted delivery, improved bioavailability, reduced toxicity, and enhanced stability. This review also discusses the significance of covalent and non-covalent interactions, and simple and complex encapsulation between polyphenols and polysaccharides. The administration of these compounds in appropriate quantities has proven beneficial in preventing the development of Crohn's disease and ulcerative colitis, ultimately leading to the management of IBD. The use of polyphenols and polysaccharides has been found to reduce histological scores and colon injury associated with IBD, increase the abundance of beneficial microbes, inhibit the development of colitis-associated cancer, promote the production of microbial end-products, such as short-chain fatty acids (SCFAs), and improve anti-inflammatory properties. Despite the combined effects of polyphenols and polysaccharides observed in both in vitro and in vivo studies, further human clinical trials are needed to comprehend their effectiveness on inflammatory bowel disease.

Kynurenine Attenuates Ulcerative Colitis Mediated by the Aryl Hydrocarbon Receptor

The higher prevalence of ulcerative colitis (UC) and the side effects of its therapeutic agents contribute to finding novel treatments. This study aimed to investigate whether kynurenine (KYN), a tryptophan metabolite, has the possibility of alleviating UC and further clarifying the underlying mechanism. The effect of KYN on treating UC was evaluated by intestinal pathology, inflammatory cytokines, and tight-junction proteins in colitis mice and LPS-stimulated Caco-2 cells. Our results revealed that KYN relieved pathological symptoms of UC, improved intestinal barrier function, enhanced AhR expression, and inhibited NF-κB signaling pathway activation in the colon of colitis mice. Moreover, the improved intestinal barrier function, the decreased inflammasome production, and the inhibited activation of the NF-κB signaling pathway by KYN were dependent on AhR in Caco-2 cells. KYN could trigger AhR activation, inactivate the NF-κB signaling pathway, and inhibit NLRP3 inflammasome production, thus alleviating intestinal epithelial barrier dysfunction and reducing intestinal inflammation. In conclusion, the present study reveals that KYN ameliorates UC by improving the intestinal epithelial barrier and activating the AhR-NF-κB-NLRP3 signaling pathway, and it can be a promising therapeutic agent and dietary supplement for alleviating UC.

Cardamonin attenuates iron overload-induced osteoblast oxidative stress through the HIF-1α/ROS pathway

BACKGROUND

Osteoporosis(OP) is a bone disease under research. Iron overload is a significant risk factor. Iron balance is crucial for bone metabolism and biochemical processes. When there is an excess of iron in the body, it tends to produce reactive oxygen species (ROS) which can cause oxidative damage to cells. The flavonoid compound, Cardamonin (CAR), possesses potent anti-inflammatory and anti-iron overload properties that can be beneficial in mitigating the risk of OP.

PURPOSE

This study investigates the potential therapeutic interventions and underlying mechanisms of CAR for treating OP in individuals with iron overload.

METHODS

The model of iron-overloaded mice was established by intraperitoneally injecting iron dextran(ID) into the mice. OP severity was evaluated with micro-CT and Hematoxylin-Eosin (HE) staining in vivo. In vitro, the iron-overloaded osteoblast model was induced by ferric ammonium citrate. Cell counting kit 8 assay to evaluate cell viability, Annexin V-FITC/PI assay to detect cell apoptosis. A range of cellular markers were detected, including the variation in mitochondrial membrane potential (MMP), levels of malondialdehyde (MDA), ROS, and lipid hydroperoxide (LPO).

RESULTS

CAR can reverse bone loss in iron overload-induced OP mouse models in vivo. CAR attenuates the impairment of iron overload on the activity and apoptosis of MC3T3-E1 cells as well as the accumulation of ROS and LPO activation via HIF-1α/ROS pathways.

CONCLUSION

CAR downregulating HIF-1α pathways prevents inhibition of iron overload-induced osteoblasts dysfunctional by attenuating ROS accumulation, reducing oxidative stress, promotes bone formation, and alleviates OP.

Aegeline attenuates TNBS-induced colitis by suppressing the NFƙB-mediated NLRP3 inflammasome pathway in mice

A chronic inflammatory condition of the intestine, ulcerative colitis (UC), is challenging to successfully manage once diagnosed. Currently, available medical therapies for UC exhibit minimal efficacy with unacceptable side effects, while inventive biological agents are expensive and yet not well accepted by patients. Discovering more effective and safer treatments to treat UC is therefore essential. One of the primary alkaloids found in Aegle marmelos, aegeline, has anti-inflammatory and antioxidant properties as well as being able to suppress several pro-inflammatory cytokines responsible for inflammation. The study aimed to investigate the effectiveness of aegeline in alleviating 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis through the NFƙB-mediated NLRP3 inflammasome pathway. Mice were randomly allocated into six groups, Normal control (NC), Model control (MC-TNBS, 2,4,6-trinitrobenzene sulfonic acid), STD (TNBS + sulfasalazine 100 mg/kg), AG1, AG2, and AG3 (TNBS + aegeline 5, 10, 20 mg/kg) respectively. Physical parameters such as a change in body weight, stool consistency, rectal bleeding, colon length, myeloperoxidase (MPO) levels and nitric oxide (NO) levels, and disease activity index (DAI) were assessed and supporting gene expression studies of various pro-inflammatory cytokines and enzymes were evaluated and histopathological changes observed. Administration of aegeline (10, 20 mg/kg) was found to be effective in colon protection by lowering the disease activity score and myeloperoxidase level and improving other physical parameters. Aegeline in high dose significantly downregulated the gene expression of NFƙB, iNOS, COX-2, NLRP3, IL-1β, and IL-18, conferring great anti-inflammatory potential. Suggestive of the findings, aegeline reduced the damage to the colon by downregulating transcriptional genes and enzymes leading to inflammation and mitigated TNBS-induced colitis probably through the NFƙB-mediated NLRP3 inflammasome pathway.

Ameliorative effect of nodakenin in combating TNBS-induced ulcerative colitis by suppressing NFƙB-mediated NLRP3 inflammasome pathway

Ulcerative colitis (UC) is an enduring and complex inflammatory bowel disease that is clinically prevalent, progressive, and debilitating. As of now, the few effective medical treatments for UC have unacceptably high side effects. It is crucial to find safer and more effective UC treatments. Nodakenin possesses anti-inflammatory and antioxidant activity by suppressing several pro-inflammatory mediators. In the present study, we aimed to evaluate the colonoprotective effect of nodakenin in combating colitis through the NFƙB-mediated NLRP3 inflammasome pathway. In mice, UC was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). Nodakenin (10, 20, and 40 mg/kg) was introduced intragastrically, and disease activity index (DAI) score was calculated. Malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD), nitric oxide (NO) levels, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) concentration were evaluated in colon homogenate. Colon samples were used for histopathological investigation and mRNA expression studies involving nuclear factor kappa B (NFƙB), cyclooxygenase-2 (COX-2), inducible nitric oxide (iNOS), nucleotide-binding receptor domain 3 (NLRP3), interleukin-1β (IL-1β), and interleukin-18 (IL-18). Nodakenin treatment was found effective in lowering the DAI score, histological score, MPO, MDA, and NO levels while elevating SOD levels as compared to the model control group, showcasing its anti-inflammatory and antioxidant properties. Nodakenin (40 mg/kg) significantly downregulated the expression of TNF-α, IL-6, NFƙB (1.24-fold), iNOS (1.2-fold), COX-2 (1.98-fold), NLRP3 (1.78-fold), IL-1β (1.29-fold), and IL-18 (1.17-fold) conferring its great anti-inflammatory potential in combating colitis. Taking together, nodakenin presumably alleviated TNBS-induced colitis by NFƙB-mediated NLRP3 inflammasome pathway and reduced colon damage by downregulating various transcriptional genes and pro-inflammatory mediators.

Icariin mitigates anxiety-like behaviors induced by hemorrhagic shock and resuscitation via inhibiting of astrocytic activation

BACKGROUND

Abnormal activation of astrocytes in the amygdala contributes to anxiety after hemorrhagic shock and resuscitation (HSR). Nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB)-associated epigenetic reprogramming of astrocytic activation is crucial to anxiety. A bioactive monomer derived from Epimedium icariin (ICA) has been reported to modulate NF-κB signaling and astrocytic activation.

PURPOSE

The present study aimed to investigate the effects of ICA on post-HSR anxiety disorders and its potential mechanism of action.

METHODS

We first induced HSR in mice through a bleeding and re-transfusion model and selectively inhibited and activated astrocytes in the amygdala using chemogenetics. Then, ICA (40 mg/kg) was administered by oral gavage once daily for 21 days. Behavioral, electrophysiological, and pathological changes were assessed after HSR using the light-dark transition test, elevated plus maze, recording of local field potential (LFP), and immunofluorescence assays.

RESULTS

Exposure to HSR reduced the duration of the light chamber and attenuated open-arm entries. Moreover, HSR exposure increased the theta oscillation power in the amygdala and upregulated NF-κB p65, H3K27ac, and H3K4me3 expression. Contrarily, chemogenetic inhibition of astrocytes significantly reversed these changes. Chemogenetic inhibition in astrocytes was simulated by ICA, but chemogenetic activation of astrocytes blocked the neuroprotective effects of ICA.

CONCLUSION

ICA mitigated anxiety-like behaviors induced by HSR in mice via inhibiting astrocytic activation, which is possibly associated with NF-κB-induced epigenetic reprogramming.

Indoxyl Sulfate-Induced Macrophage Toxicity and Therapeutic Strategies in Uremic Atherosclerosis

Cardiovascular disease (CVD) frequently occurs in patients with chronic kidney disease (CKD), particularly those undergoing dialysis. The mechanisms behind this may be related to traditional risk factors and CKD-specific factors that accelerate atherosclerosis and vascular calcification in CKD patients. The accumulation of uremic toxins is a significant factor in CKD-related systemic disorders. Basic research suggests that indoxyl sulfate (IS), a small protein-bound uremic toxin, is associated with macrophage dysfunctions, including increased oxidative stress, exacerbation of chronic inflammation, and abnormalities in lipid metabolism. Strategies to mitigate the toxicity of IS include optimizing gut microbiota, intervening against the abnormality of intracellular signal transduction, and using blood purification therapy with higher efficiency. Further research is needed to examine whether lowering protein-bound uremic toxins through intervention leads to a reduction in CVD in patients with CKD.

NLRP3 Inflammasome Inhibitors for Antiepileptogenic Drug Discovery and Development

Epilepsy is one of the most prevalent and serious brain disorders and affects over 70 million people globally. Antiseizure medications (ASMs) relieve symptoms and prevent the occurrence of future seizures in epileptic patients but have a limited effect on epileptogenesis. Addressing the multifaceted nature of epileptogenesis and its association with the Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-mediated neuroinflammation requires a comprehensive understanding of the underlying mechanisms of these medications for the development of targeted therapeutic strategies beyond conventional antiseizure treatments. Several types of NLRP3 inhibitors have been developed and their effect has been validated both in in vitro and in vivo models of epileptogenesis. In this review, we discuss the advances in understanding the regulatory mechanisms of NLRP3 activation as well as progress made, and challenges faced in the development of NLRP3 inhibitors for the treatment of epilepsy.

Upregulation of Nrf2 signaling: A key molecular mechanism of Baicalin's neuroprotective action against diabetes-induced cognitive impairment

BACKGROUND AND AIM

Diabetes-associated cognitive impairment (DCI) is a prevalent complication of diabetes. However, there is a lack of viable strategies for preventing and treating DCI. This study aims to explore the efficacy of baicalin (Bai) in attenuating DCI and elucidating the underlying mechanisms.

EXPERIMENTAL PROCEDURE

GK rats fed a high-fat and high-glucose diet were utilized to investigate the therapeutic potential of Bai. Cognitive function was assessed using the Morris water maze and novel object recognition tests. To gain insight into the molecular mechanisms underlying Bai's neuro-protective effects, co-cultured BV2/HT22 cells were established under high-glucose (HG) stimulation. The modes of action of Bai were subsequently confirmed in vivo using the DCI model in db/db mice.

KEY RESULTS

Bai restored cognitive and spatial memory and attenuated neuron loss, along with reducing expressions of Aβ and phosphorylated Tau protein in diabetic GK rats. At the cellular level, Bai exhibited potent antioxidant and anti-inflammatory effects against HG stimulation. These effects were associated with the upregulation of Nrf2 and supressed Keap1 levels. Consistent with these in vitro findings, similar mechanisms were observed in db/db mice. The significant neuroprotective effects of Bai were abolished when co-administered with ATRA, a Nrf2 blocker, in db/db mice, confirming that KEAP1-Nrf2 signaling pathway was responsible for the observed effect.

CONCLUSIONS AND IMPLICATIONS

Bai demonstrates a great therapeutic potential for attenuating DCI. The antioxidant defense and anti-inflammatory actions of Bai were mediated through the KEAP1-Nrf2 axis. These findings advance our understanding of potential treatment approaches for DCI, a common complication associated with diabetes.

Animal models of inflammatory bowel disease: category and evaluation indexes

Inflammatory bowel disease (IBD) research often relies on animal models to study the etiology, pathophysiology, and management of IBD. Among these models, rats and mice are frequently employed due to their practicality and genetic manipulability. However, for studies aiming to closely mimic human pathology, non-human primates such as monkeys and dogs offer valuable physiological parallels. Guinea pigs, while less commonly used, present unique advantages for investigating the intricate interplay between neurological and immunological factors in IBD. Additionally, New Zealand rabbits excel in endoscopic biopsy techniques, providing insights into mucosal inflammation and healing processes. Pigs, with their physiological similarities to humans, serve as ideal models for exploring the complex relationships between nutrition, metabolism, and immunity in IBD. Beyond mammals, non-mammalian organisms including zebrafish, Drosophila melanogaster, and nematodes offer specialized insights into specific aspects of IBD pathology, highlighting the diverse array of model systems available for advancing our understanding of this multifaceted disease. In this review, we conduct a thorough analysis of various animal models employed in IBD research, detailing their applications and essential experimental parameters. These include clinical observation, Disease Activity Index score, pathological assessment, intestinal barrier integrity, fibrosis, inflammatory markers, intestinal microbiome, and other critical parameters that are crucial for evaluating modeling success and drug efficacy in experimental mammalian studies. Overall, this review will serve as a valuable resource for researchers in the field of IBD, offering insights into the diverse array of animal models available and their respective applications in studying IBD.

A review of chemotherapeutic drugs-induced arrhythmia and potential intervention with traditional Chinese medicines

Significant advances in chemotherapy drugs have reduced mortality in patients with malignant tumors. However, chemotherapy-related cardiotoxicity increases the morbidity and mortality of patients, and has become the second leading cause of death after tumor recurrence, which has received more and more attention in recent years. Arrhythmia is one of the common types of chemotherapy-induced cardiotoxicity, and has become a new risk related to chemotherapy treatment, which seriously affects the therapeutic outcome in patients. Traditional Chinese medicine has experienced thousands of years of clinical practice in China, and has accumulated a wealth of medical theories and treatment formulas, which has unique advantages in the prevention and treatment of malignant diseases. Traditional Chinese medicine may reduce the arrhythmic toxicity caused by chemotherapy without affecting the anti-cancer effect. This paper mainly discussed the types and pathogenesis of secondary chemotherapeutic drug-induced arrhythmia (CDIA), and summarized the studies on Chinese medicine compounds, Chinese medicine Combination Formula and Chinese medicine injection that may be beneficial in intervention with secondary CDIA including atrial fibrillation, ventricular arrhythmia and sinus bradycardia, in order to provide reference for clinical prevention and treatment of chemotherapy-induced arrhythmias.

AhR Activation Ameliorates Intestinal Barrier Damage in Immunostressed Piglets by Regulating Intestinal Flora and Its Metabolism

The primary factor leading to elevated rates of diarrhea and decreased performance in piglets is immunological stress. The regulation of immune stress through the intestinal flora is a crucial mechanism to consider. In total, 30 weaned piglets were randomly allocated to five groups: the basal diet group (Control), basal diet + lipopolysaccharides group (LPS), basal diet + 250 μg/kg 6-Formylindolo [3,2-b] carbazole + LPS group (FICZ), basal diet + 3mg/kg Cardamonin + LPS group (LCDN), and basal diet + 6mg/kg Cardamonin + LPS group (HCDN/CDN). The results showed that compared with those of the LPS group, the expression of tight junction proteins (occludin; claudin-1) in the FICZ group was significantly increased, and the mRNA levels of IL-1β and TNF-α were significantly reduced (p < 0.05). HCDN treatment had a better effect on LPS-induced intestinal barrier damage in this group than it did in the LCDN group. HCDN treatment leads to a higher villus height (VH), a higher ratio of villi height to crypt depth (V/C), higher tight junction proteins (ZO-1; occludin), and higher short-chain fatty acids (SCFAs). In addition, correlation analyses showed that Succinivibrio was positively correlated with several SCFAs and negatively correlated with prostaglandin-related derivatives in the FICZ group and CDN group (p < 0.05). In summary, Cardamonin alleviates intestinal mucosal barrier damage and inflammatory responses by regulating the intestinal microbiota and its metabolism.

Natural compounds target programmed cell death (PCD) signaling mechanism to treat ulcerative colitis: a review

Ulcerative colitis (UC) is a nonspecific inflammatory bowel disease characterized by abdominal pain, bloody diarrhea, weight loss, and colon shortening. However, UC is difficult to cure due to its high drug resistance rate and easy recurrence. Moreover, long-term inflammation and increased disease severity can lead to the development of colon cancer in some patients. Programmed cell death (PCD) is a gene-regulated cell death process that includes apoptosis, autophagy, necroptosis, ferroptosis, and pyroptosis. PCD plays a crucial role in maintaining body homeostasis and the development of organs and tissues. Abnormal PCD signaling is observed in the pathological process of UC, such as activating the apoptosis signaling pathway to promote the progression of UC. Targeting PCD may be a therapeutic strategy, and natural compounds have shown great potential in modulating key targets of PCD to treat UC. For instance, baicalin can regulate cell apoptosis to alleviate inflammatory infiltration and pathological damage. This review focuses on the specific expression of PCD and its interaction with multiple signaling pathways, such as NF-κB, Nrf2, MAPK, JAK/STAT, PI3K/AKT, NLRP3, GPX4, Bcl-2, etc., to elucidate the role of natural compounds in targeting PCD for the treatment of UC. This review used (ulcerative colitis) (programmed cell death) and (natural products) as keywords to search the related studies in PubMed and the Web of Science, and CNKI database of the past 10 years. This work retrieved 72 studies (65 from the past 5 years and 7 from the past 10 years), which aims to provide new treatment strategies for UC patients and serves as a foundation for the development of new drugs.

VSIG4 ameliorates intestinal inflammation through inhibiting macrophages NLRP3 inflammasome and pyroptosis

Inflammatory bowel disease (IBD) is one of the most common diseases in the digestive system related to aberrant inflammation. V-set and immunoglobulin domain-containing 4 (VSIG4), a type I transmembrane receptor exclusively expressed in a subset of tissue-resident macrophages, has been reported to exert anti-inflammatory activity in immune-related diseases, which has been not explored in IBD yet. This study aims to explore the role and the potential mechanism of VSIG4 in IBD. Clinical samples were obtained from IBD patients and were examined by immunohistochemical staining. THP-1 cells were differentiated into macrophages, and then stimulated with IL-4 plus IL-13 or LPS to induce pro-inflammatory (M1) or anti-inflammatory (M2) phenotype. Cell transfection was conducted to overexpress VSIG4. Western blot and immunofluorescence assays were performed to assess NLRP3 inflammasome- and pyroptosis-related proteins. Cytokines were measured using ELISA. A cell co-culture model of Caco-2 cells and VSIG4-mediated macrophages were established. Cell viability and apoptosis was examined by CCK-8 and flow cytometry assays, respectively. VSIG4 was downregulated in IBD and was negatively correlated with NLRP3 inflammasome. M1 macrophages exhibited higher levels of NLRP3 inflammasome, pyroptosis and inflammatory response than M2 macrophages, while VSIG4 overexpression efficiently reversed these changes in M1 macrophages. In addition, VSIG4 overexpression partly abolished M1 macrophages-induced cell viability loss, inflammatory response, apoptosis and pyroptosis in Caco-2 cells. Collectively, VSIG4 might alleviate intestinal inflammation through regulating M1/M2 macrophages, providing novel insights for the treatment of human IBD.

Targeting NLRP3 Inflammasome: Structure, Function, and Inhibitors

Inflammasomes are multimeric protein complexes that can detect various physiological stimuli and danger signals. As a result, they perform a crucial function in the innate immune response. The NLRP3 inflammasome, as a vital constituent of the inflammasome family, is significant in defending against pathogen invasion and preserving cellhomeostasis. NLRP3 inflammasome dysregulation is connected to various pathological conditions, including inflammatory diseases, cancer, and cardiovascular and neurodegenerative diseases. This profile makes NLRP3 an applicable target for treating related diseases, and therefore, there are rising NLRP3 inhibitors disclosed for therapy. Herein, we summarized the updated advances in the structure, function, and inhibitors of NLRP3 inflammasome. Moreover, we aimed to provide an overview of the existing products and future directions for drug research and development.

Hippo pathway in intestinal diseases: focusing on ferroptosis

The incidence of intestinal diseases, such as inflammatory bowel disease, gastric cancer, and colorectal cancer, has steadily increased over the past decades. The Hippo pathway is involved in cell proliferation, tissue and organ damage, energy metabolism, tumor formation, and other physiologic processes. Ferroptosis is a form of programmed cell death characterized by the accumulation of iron and lipid peroxides. The Hippo pathway and ferroptosis are associated with various intestinal diseases; however, the crosstalk between them is unclear. This review elaborates on the current research on the Hippo pathway and ferroptosis in the context of intestinal diseases. We summarized the connection between the Hippo pathway and ferroptosis to elucidate the underlying mechanism by which these pathways influence intestinal diseases. We speculate that a mutual regulatory mechanism exists between the Hippo pathway and ferroptosis and these two pathways interact in several ways to regulate intestinal diseases.

Omeprazole activates aryl hydrocarbon receptor to reduce hyperoxia-induced oxidative stress in the peripheral blood mononuclear cells from premature infants

OBJECTIVE

To investigate the correlation between the aryl hydrocarbon receptor (AhR) and reactive oxygen species (ROS) in peripheral blood mononuclear cells (PBMCs) of premature infants, to demonstrate the protective role of AhR against hyperoxia-induced oxidative stress in premature infants and to provide a rational basis for the use of omeprazole (OM) as a new treatment for bronchopulmonary dysplasia (BPD).

METHODS

From January 2021 to June 2021, 1-3 ml of discarded peripheral blood was collected from premature infants of gestational age less than 32 weeks who were not taking inhaled oxygen and were admitted to the Department of Neonatology of the Affiliated Hospital of Southwest Medical University. Using a random number table, the PBMCs were randomly assigned to each of the following groups: the control group, air + OM group, hyperoxia group, and hyperoxia + OM group. After 48 h of in vitro modeling and culture, PBMCs and the culture medium of each group were collected. Immunofluorescence analysis was used to examine ROS levels in PBMCs. A full-spectrum spectrophotometer was used to examine malondialdehyde (MDA) levels in the culture medium. Enzyme-linked immunosorbent assay (ELISA) was used to examine monocyte chemotactic protein 1 (MCP-1) levels in culture medium. Immunofluorescence analysis was used to examine the intracellular localization of AhR. Western blotting was used to examine the expression level of AhR in PBMCs.

RESULTS

Compared with those in the control group, the levels of ROS, MDA, and MCP-1 and the cytoplasm-nuclear translocation rate of AhR in the air + OM group did not change significantly (p > 0.05), but the expression level of AhR increased significantly (p < 0.05). The levels of ROS, MDA, and MCP-1 and the cytoplasm-nuclear translocation rate of AhR significantly increased in the hyperoxia group (p < 0.05), and the expression level of AhR was significantly reduced (p < 0.05). Compared with those in the hyperoxia group, the levels of ROS, MDA, and MCP-1 in the hyperoxia + OM group were significantly reduced (p < 0.05), and the cytoplasm-nuclear translocation rate of AhR and the expression level of AhR were significantly increased (p < 0.05), but did not reach the level of the control group (p < 0.05).

CONCLUSION

OM can activate AhR to inhibit hyperoxia-induced oxidative stress in the PBMCs from premature infants.

Genistein upregulates AHR to protect against environmental toxin-induced NASH by inhibiting NLRP3 inflammasome activation and reconstructing antioxidant defense mechanisms

We have previously proven that the environmental toxin could accelerate the development and progression of nonalcoholic steatohepatitis (NASH). However, the underlying mechanism associated with such excessive inflammation hasn't been fully illustrated. Although Genistein has been well accepted for its capability in anti-inflammation and anti-oxidation, its effect in ameliorating contaminants-induced NASH still needs to be identified. In this study, using chickens and primary chicken hepatocytes as models, we found that NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome were over-activated in bromoacetic acid (BAA, one of the typical environmental toxins)-induced NASH, characterized by the infiltration of inflammatory cell, and the increase of NLRP3, Caspase-1 p20, and cytokines (IL-1β, IL-18) expressions. Interestingly, genistein treatment could recover these changes, with the signs of restored activities of anti-oxidases, decreased expressions of NLRP3 inflammasome components, and increased levels of elements in phase I metabolic system. The detailed mechanism was that, via up-regulating aryl hydrocarbon receptor (AHR), genistein lifted mRNA levels of Cyp1-related genes to reconstruct cytochrome P450 (CYP450) systems, and the raised AHR negatively regulated NLRP3 inflammasome activity to relieve inflammation. More important, the interaction and co-localization between AHR and NLRP3 was first proved, and genistein could promote the levels of AHR that interacted with NLRP3, which thereafter blocked the activation of NLRP3 inflammasome. Conclusively, in this research, we confirmed the AHR-dependent protective role of genistein in environmental toxin-linked NASH, which shed light on the potential precautions for contaminants-induced NASH.

Alpinia katsumadai Hayata Volatile Oil Is Effective in Treating 5-Fluorouracil-Induced Mucositis by Regulating Gut Microbiota and Modulating the GC/GR Pathway and the mPGES-1/PGE2/EP4 Pathways

This study was aimed to investigate the therapeutic effect and mechanism of AKHO on 5-fluorouracil (5-FU)-induced intestinal mucositis in mice. Mouse body weight, diarrhea score, and H&E staining were applied to judge the therapeutic effect of AKHO. 16S rDNA and nontargeted metabolomics have been used to study the mechanism. WB, ELISA, and immunohistochemistry were adopted to validate possible mechanisms. The results demonstrated that AKHO significantly reduced diarrhea scores and intestinal damage induced by 5-FU in mice. AKHO lowered the serum levels of LD and DAO, and upregulated the expressions of ZO-1 and occludin in the ileum. Also, AKHO upregulated the abundance of Lactobacillus in the gut and suppressed KEGG pathways such as cortisol synthesis and secretion and arachidonic acid metabolism. Further validation studies indicated that AKHO downregulated the expressions of prostaglandin E2 (PGE2), microsomal prostaglandin E synthase-1 (mPGES-1), and PGE2 receptor EP4, as well as upregulated the expression of glucocorticoid (GC) receptor (GR), leading to improved intestinal epithelial barrier function. Taken together, AKHO elicited protective effects against 5-FU-induced mucositis by regulating the expressions of tight junction proteins via modulation of GC/GR and mPGES-1/PGE2/EP4 pathway, providing novel insights into the utilization and development of this pharmaceutical/food resource.

Redox Regulation of Nucleotide-Binding and Oligomerization Domain-Like Receptors Inflammasome

Significance: Inflammasomes are multimeric complexes that, as part of the innate immune response, sense a wide range of pathogenic and sterile stimuli. They consist of three components, namely a sensor protein, an adaptor, and procaspase-1, which once activated result in secretion of proinflammatory interleukin (IL)-1β and IL-18 and, eventually, in a gasdermin D-dependent lytic cell death called pyroptosis. Recent Advances: Since their discovery 20 years ago, the molecular mechanisms underlying the regulation of inflammasomes have been extensively studied. Oxidative stress appears as a major contributor to modulate inflammasomes, especially NLRP3 as well as NLRP1, NLRP6, and NLRC4. Growing evidence supports the idea that the positive feedback between redox imbalance and inflammasome-driven inflammation fuels an OxInflammatory state in a variety of human pathologies. Critical Issues: The current knowledge about the redox signaling pathways involved in inflammasomes activation and functions are here highlighted. In addition, we discuss the role of this complex molecular network interaction in the onset and progression of pathological conditions including neurological and metabolic diseases as well as skin disorders, also with an insight on COVID-19-related pathology. Finally, the therapeutic strategies able to mitigate the redox-mediated inflammasome activation with synthetic and natural compounds as well as by acting on inflammasome-related post-translational modifications and microRNAs are also addressed. Future Directions: Further investigations leading to a deeper understanding of the reciprocal interaction between inflammasomes and reactive oxygen species will help identify other molecular targets for modulating their hyperactivated state, and to design novel therapeutics for chronic OxInflammatory conditions. Antioxid. Redox Signal. 39, 744-770.

NOD-like Receptor Signaling Pathway in Gastrointestinal Inflammatory Diseases and Cancers

Nucleotide-binding and oligomerization domain (NOD)-like receptors (NLRs) are intracellular proteins with a central role in innate and adaptive immunity. As a member of pattern recognition receptors (PRRs), NLRs sense specific pathogen-associated molecular patterns, trigger numerous signaling pathways and lead to the secretion of various cytokines. In recent years, cumulative studies have revealed the significant impacts of NLRs in gastrointestinal (GI) inflammatory diseases and cancers. Deciphering the role and molecular mechanism of the NLR signaling pathways may provide new opportunities for the development of therapeutic strategies related to GI inflammatory diseases and GI cancers. This review presents the structures and signaling pathways of NLRs, summarizes the recent advances regarding NLR signaling in GI inflammatory diseases and GI cancers and describes comprehensive therapeutic strategies based on this signaling pathway.

NOD-like receptors mediate homeostatic intestinal epithelial barrier function: promising therapeutic targets for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic gastrointestinal inflammatory disease that involves host genetics, the microbiome, and inflammatory responses. The current consensus is that the disruption of the intestinal mucosal barrier is the core pathogenesis of IBD, including intestinal microbial factors, abnormal immune responses, and impaired intestinal mucosal barrier. Cumulative data show that nucleotide-binding and oligomerization domain (NOD)-like receptors (NLRs) are dominant mediators in maintaining the homeostasis of the intestinal mucosal barrier, which play critical roles in sensing the commensal microbiota, maintaining homeostasis, and regulating intestinal inflammation. Blocking NLRs inflammasome activation by botanicals may be a promising way to prevent IBD progression. In this review, we systematically introduce the multiple roles of NLRs in regulating intestinal mucosal barrier homeostasis and focus on summarizing the activities and potential mechanisms of natural products against IBD. Aiming to propose new directions on the pathogenesis and precise treatment of IBD.

Cinnamaldehyde protects donor heart from cold ischemia-reperfusion injury via the PI3K/AKT/mTOR pathway

With the growing shortage of organs, improvements in donor organ protection are needed to meet the increasing demands for transplantation. Here, the aim was to investigate the protective effect of cinnamaldehyde against ischemia-reperfusion injury (IRI) in donor hearts exposed to prolonged cold ischemia. Donor hearts were harvested from rats pretreated with or without cinnamaldehyde, then subjected to 24 h of cold preservation and 1 h of ex vivo perfusion. Hemodynamic changes, myocardial inflammation, oxidative stress, and myocardial apoptosis were evaluated. The PI3K/AKT/mTOR pathway involved in the cardioprotective effects of cinnamaldehyde was explored through RNA sequencing and western blot analysis. Intriguingly, cinnamaldehyde pretreatment remarkably improved cardiac function through increasing coronary flow, left ventricular systolic pressure, +dp/dtmax, and -dp/dtmax, decreasing coronary vascular resistance and left ventricular end-diastolic pressure. Moreover, our findings indicated that cinnamaldehyde pretreatment protected the heart from IRI by alleviating myocardial inflammation, attenuating oxidative stress, and reducing myocardial apoptosis. Further studies showed that the PI3K/AKT/mTOR pathway was activated after cinnamaldehyde treatment during IRI. The protective effects of cinnamaldehyde were abolished by LY294002. In conclusion, cinnamaldehyde pretreatment alleviated IRI in donor hearts suffering from prolonged cold ischemia. Cinnamaldehyde exerted cardioprotective effects through the activation of the PI3K/AKT/mTOR pathway.

Boesenbergia rotunda displayed anti-inflammatory, antioxidant and anti-apoptotic efficacy in doxorubicin-induced cardiotoxicity in rats

This study evaluated the cardioprotective properties of Boesenbergia rotunda extract (BrE) against doxorubicin (DOX) induced cardiotoxicity. Rats received oral gavage of BrE for 28 days and DOX (5 mg/kg/week for 3 weeks). Thereafter the animals were sacrificed, blood and cardiac samples were collected for biochemical, histological and immunohistochemical analyses. The results indicated that BrE attenuated DOX triggered body and cardiac weight loss and prevented against cardiac injury by mitigating histopathological alterations in cardiac tissues as well as serum cardiac function enzymes. BrE significantly reduced serum levels of aspartate transaminase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), troponin T (TnT) and creatine kinase-MB (CK-MB) in DOX-treated rats. Furthermore, BrE alleviated cardiotoxicity by reducing DOX instigated oxidative stress and potentiating the level of glutathione, as well as the activities superoxide dismutase and catalase in cardiac tissues. In addition, BrE significantly decreased the characteristic indices of DOX-induced cardiac inflammation and apoptosis. Immuno-histochemical analysis revealed that BrE decreased the stain intensity of p53 and myeloperoxidase (MPO) proteins compared to the DXB alone group. In conclusion, our results indicated that BrE modulated oxidative stress, inflammation and apoptosis to attenuate DOX-induced cardiac damage.

The NLRP3 inflammasome: contributions to inflammation-related diseases

The NOD-like receptor protein 3 (NLRP3) inflammasome is a protein complex that regulates innate immune responses by activating caspase-1 and the inflammatory cytokines interleukin (IL)-1β and IL-18. Multiple studies have demonstrated the importance of the NLRP3 inflammasome in the development of immune and inflammation-related diseases, including arthritis, Alzheimer's disease, inflammatory bowel disease, and other autoimmune and autoinflammatory diseases. This review first explains the activation and regulatory mechanism of the NLRP3 inflammasome. Secondly, we focus on the role of the NLRP3 inflammasome in various inflammation-related diseases. Finally, we look forward to new methods for targeting the NLRP3 inflammasome to treat inflammation-related diseases, and provide new ideas for clinical treatment.

A natural chalcone cardamonin inhibits necroptosis and ameliorates dextran sulfate sodium (DSS)-induced colitis by targeting RIPK1/3 kinases

Necroptosis, a new form of programmed cell death, is involved in the pathogenesis of ulcerative colitis (UC). Inhibition of necroptosis represents an attractive strategy for UC therapy. Herein, cardamonin, a natural chalcone isolated from Zingiberaceae family, was firstly identified as a potent necroptosis inhibitor. In vitro, cardamonin significantly inhibited necroptosis in TNF-α plus Smac mimetic and z-VAD-FMK (TSZ)-, cycloheximide plus TZ (TCZ)-, or lipopolysaccharide plus SZ (LSZ)-stimulated HT29, L929, or RAW264.7 cell lines. Furthermore, TSZ-induced elevated population of necrotic cells, release of LDH and HMGB1 also could be inhibited by cardamonin in HT29 cells. Cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) assay combined with molecular docking demonstrated that cardamonin interacted with RIPK1/3. Furthermore, cardamonin blocked the phosphorylation of RIPK1/3, thereby disrupting RIPK1-RIPK3 necrosome formation and MLKL phosphorylation. In vivo, orally administration of cardamonin attenuated dextran sulfate sodium (DSS)-induced colitis, which mainly manifested as mitigated intestinal barrier damage, suppressed necroinflammation, and reduced phosphorylation of MLKL. Taken together, our findings revealed that dietary cardamonin is a novel necroptosis inhibitor and has great potential for UC therapy by targeting RIPK1/3 kinases.

Protective role of flavonoids quercetin and silymarin in the viral-associated inflammatory bowel disease: an updated review

Inflammatory bowel disease (IBD) is a chronic recurrent inflammation of the gastrointestinal tract (GIT). IBD patients are susceptible to various infections such as viral infections due to the long-term consumption of immunosuppressive drugs and biologics. The antiviral and IBD protective traits of flavonoids have not been entirely investigated. This study objective included an overview of the protective role of flavonoids quercetin and silymarin in viral-associated IBD. Several viral agents such as cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV) and enteric viruses can be reactivated and thus develop or exacerbate the IBD conditions or eventually facilitate the disease remission. Flavonoids such as quercetin and silymarin are non-toxic and safe bioactive compounds with remarkable anti-oxidant, anti-inflammatory and anti-viral effects. Mechanisms of anti-inflammatory and antiviral effects of silymarin and quercetin mainly include immune modulation and inhibition of caspase enzymes, viral binding and replication, RNA synthesis, viral proteases and viral assembly. In the nutraceutical sector, natural flavonoids low bioavailability and solubility necessitate the application of delivery systems to enhance their efficacy. This review study provided an updated understanding of the protective role of quercetin and silymarin against viral-associated IBD.

Oxyberberine ameliorates TNBS-induced colitis in rats through suppressing inflammation and oxidative stress via Keap1/Nrf2/NF-κB signaling pathways

BACKGROUND

Ulcerative colitis (UC) is a chronic, unspecific inflammatory bowel disorder lacking effective therapeutic targets and radical drugs. Oxyberberine (OBB), a novel intestinal flora-elicited oxidative metabolite of berberine (BBR), has been revealed to exhibit diverse pharmacological properties.

PURPOSE

In this follow-up study, we attempted to shed light on the possible therapeutic effect and latent mechanism of OBB on 2, 4, 6-trinitrobenzenesulfonic acid (TNBS)-evoked UC in rats.

METHODS

UC rats were established via a gentle enema of TNBS. Rats were sacrificed after intragastric administration of drugs for seven days. The weight reduction, disease activity index, macroscopic and histological colonic alterations were assessed. Further investigation on molecular mechanisms was conducted by ELISA, qRT-PCR, immunohistochemistry, or Western blot.

RESULTS

OBB treatment remarkably decreased the weight loss, macroscopic scores, and colonal weight/length ratio, as well as mitigated the colonic pathological deterioration and MPO vitality in colitis rats, achieving a superior protective effect to BBR. Additionally, OBB modulated the disequilibrium between pro- and anti-inflammatory factors by promoting the production of IL-13 and IL-4, and lowering the contents of TNF-α, IL-2, IL-8, and IL-22. Furthermore, OBB pretreatment dramatically ameliorated oxidative stress via enhancing antioxidant defense genes expressions (including HO-1, GCLM, GCLC, and NQO-1), thereby increasing SOD and GSH, and decreasing MDA and ROS activities. Furthermore, OBB strikingly restrained the translocation of NF-κB p65 and phosphorylation of IκBα, promoted HO-1 expression, Keap1 degradation and Nrf2 nuclear translocation.

CONCLUSION

The study firstly indicated that OBB had a superior therapeutic effect than BBR against TNBS-elicited colitis in rats. The protective effect of OBB might be closely related to the modulation of Keap1/Nrf2/NF-κB-mediated inflammatory response and oxidant stress. The evidences highlight the potentiality of OBB as a prospective candidate for the amelioration of colitis.

Modulating AHR function offers exciting therapeutic potential in gut immunity and inflammation

Aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a classical exogenous synthetic ligand of AHR that has significant immunotoxic effects. Activation of AHR has beneficial effects on intestinal immune responses, but inactivation or overactivation of AHR can lead to intestinal immune dysregulation and even intestinal diseases. Sustained potent activation of AHR by TCDD results in impairment of the intestinal epithelial barrier. However, currently, AHR research has been more focused on elucidating physiologic AHR function than on dioxin toxicity. The appropriate level of AHR activation plays a role in maintaining gut health and protecting against intestinal inflammation. Therefore, AHR offers a crucial target to modulate intestinal immunity and inflammation. Herein, we summarize our current understanding of the relationship between AHR and intestinal immunity, the ways in which AHR affects intestinal immunity and inflammation, the effects of AHR activity on intestinal immunity and inflammation, and the effect of dietary habits on intestinal health through AHR. Finally, we discuss the therapeutic role of AHR in maintaining gut homeostasis and relieving inflammation.

Cardamonin targets KEAP1/NRF2 signaling for protection against atherosclerosis

Atherosclerosis (AS)-induced cardiovascular disease is a leading cause of death worldwide. To date, there is still a lack of effective approaches for AS intervention. Cardamonin (CAD) is a bioactive food component, but its effect on AS is unknown. In this work, CAD was investigated for its effect on AS using low-density lipoprotein receptor knockout mice and tumor necrosis factor-alpha (TNF-α)-stimulated endothelial cells (ECs). After a 12-week intervention, CAD was found to significantly prevent AS formation in the aortic root and aortic tree, reduce the necrotic core area, and inhibit aortic inflammation and oxidative stress. Moreover, CAD quenched TNF-α-provoked inflammation and oxidative stress in ECs. RNA-sequencing identified nuclear factor erythroid-2 related factor 2 (NFE2L2, NRF2)/heme oxidase 1 (HO1) signaling to be drastically activated by CAD. CAD is a known activator of the aryl hydrocarbon receptor (AHR) which is a transcription factor of the NFE2L2 gene. Surprisingly, AHR was not required for CAD's action on the activation of NRF2/HO1 signaling since AHR gene silencing did not reverse this effect. Furthermore, a molecular docking assay showed a strong binding potential of CAD to the Kelch domain of the Kelch-like ECH-associated protein 1 (KEAP1) which sequesters NRF2 in the cytoplasm. Both CAD and the Kelch domain inhibitor Ki696 promoted NRF2 nuclear translocation, whereas the combination of CAD and Ki696 did not yield a greater effect compared with either CAD or Ki696, confirming the interaction of CAD with the Kelch domain. This work provides an experimental basis for CAD as a novel and effective bioactive food component in future AS interventions.

Portrayal of NLRP3 Inflammasome in Atherosclerosis: Current Knowledge and Therapeutic Targets

We are witnessing the globalization of a specific type of arteriosclerosis with rising prevalence, incidence and an overall cardiovascular disease burden. Currently, atherosclerosis increasingly affects the younger generation as compared to previous decades. While early preventive medicine has seen improvements, research advances in laboratory and clinical investigation promise to provide us with novel diagnosis tools. Given the physio-pathological complexity and epigenetic patterns of atherosclerosis and the discovery of new molecules involved, the therapeutic field of atherosclerosis has room for substantial growth. Thus, the scientific community is currently investigating the role of nucleotide-binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, a crucial component of the innate immune system in different inflammatory disorders. NLRP3 is activated by distinct factors and numerous cellular and molecular events which trigger NLRP3 inflammasome assembly with subsequent cleavage of pro-interleukin (IL)-1β and pro-IL-18 pathways via caspase-1 activation, eliciting endothelial dysfunction, promotion of oxidative stress and the inflammation process of atherosclerosis. In this review, we introduce the basic cellular and molecular mechanisms of NLRP3 inflammasome activation and its role in atherosclerosis. We also emphasize its promising therapeutic pharmaceutical potential.

Flavone and Hydroxyflavones Are Ligands That Bind the Orphan Nuclear Receptor 4A1 (NR4A1)

It was recently reported that the hydroxyflavones quercetin and kaempferol bind the orphan nuclear receptor 4A1 (NR4A1, Nur77) and act as antagonists in cancer cells and tumors, and they inhibit pro-oncogenic NR4A1-regulated genes and pathways. In this study, we investigated the interactions of flavone, six hydroxyflavones, seven dihydroxyflavones, three trihydroxyflavones, two tetrahydroxyflavones, and one pentahydroxyflavone with the ligand-binding domain (LBD) of NR4A1 using direct-binding fluorescence and an isothermal titration calorimetry (ITC) assays. Flavone and the hydroxyflavones bound NR4A1, and their KD values ranged from 0.36 µM for 3,5,7-trihydroxyflavone (galangin) to 45.8 µM for 3'-hydroxyflavone. KD values determined using ITC and KD values for most (15/20) of the hydroxyflavones were decreased compared to those obtained using the fluorescence assay. The results of binding, transactivation and receptor-ligand modeling assays showed that KD values, transactivation data and docking scores for these compounds are highly variable with respect to the number and position of the hydroxyl groups on the flavone backbone structure, suggesting that hydroxyflavones are selective NR4A1 modulators. Nevertheless, the data show that hydroxyflavone-based neutraceuticals are NR4A1 ligands and that some of these compounds can now be repurposed and used to target sub-populations of patients that overexpress NR4A1.

Antioxidants as Protection against Reactive Oxidative Stress in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) belongs to a group of chronic diseases characterised by periods of exacerbation and remission. Despite many studies and observations, its aetiopathogenesis is still not fully understood. The interactions of genetic, immunological, microbiological, and environmental factors can induce disease development and progression, but there is still a lack of information on these mechanisms. One of the components that can increase the risk of occurrence of IBD, as well as disease progression, is oxidative stress. Oxidative stress occurs when there is an imbalance between reactive oxygen species (ROS) and antioxidants. The endogenous and exogenous components that make up the body's antioxidant defence can significantly affect IBD prophylaxis and reduce the risk of exacerbation by neutralising and removing ROS, as well as influencing the inflammatory state.

Chalcone: A potential scaffold for NLRP3 inflammasome inhibitors

Overactivated NLRP3 inflammasome has been shown to associate with an increasing number of disease conditions. Activation of the NLRP3 inflammasome results in caspase-1-catalyzed formation of active pro-inflammatory cytokines (IL-1β and IL-18) resulting in pyroptosis. The multi-protein composition of the NLRP3 inflammasome and its sensitivity to several damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) make this extensively studied inflammasome an attractive target to treat chronic conditions. However, none of the known NLRP3 inhibitors has been approved for clinical use. Sulfonylurea and covalent inhibitors with electrophilic warhead (Michael acceptor) are among the prominent classes of compounds explored for their NLRP3 inhibitory effects. Chalcone, a small molecule with α, β unsaturated carbonyl group (Michael acceptor), has also been studied as a promising scaffold for the development of NLRP3 inhibitors. Low molecular weight, easy to manipulate lipophilicity and cost-effectiveness have attracted many to use chalcone scaffold for drug development. In this review, we highlight chalcone derivatives with NLRP3 inflammasome inhibitory activities. Recent developments and potential new directions summarized here will, hopefully, serve as valuable perspectives for investigators including medicinal chemists and drug discovery researchers to utilize chalcone as a scaffold for developing novel NLRP3 inflammasome inhibitors.

Total flavone of flowers of Abelmoschus manihot (L.) Medic inhibits the expression of adhesion molecules in primary mesenteric arterial endothelial cells and ameliorates dextran sodium sulphate-induced ulcerative colitis in mice

BACKGROUND

Flowers of Abelmoschus manihot (L.) medic (AM) is a traditional Chinese medicine used to treat chronic nephritis, nephrotic syndrome, diabetic nephropathy, and colonic inflammation.

PURPOSE

This study aimed to explore the influence of the total flavone of AM flowers (TFA) on acute ulcerative colitis (UC) and the potential underlying mechanism.

METHODS

Efficacy of TFA (30, 60, 120 mg/kg) on UC was evaluated in a dextran sodium sulphate (DSS)-induced colonic inflammatory mouse model by analyzing disease activity index (DAI), histopathological score, colon length, and cytokine expression. Expression levels of critical adhesion molecules and nuclear factor kappa B (NF-κB) were examined by qRT-PCR, Western blotting, or immunofluorescence labeling. Myeloperoxidase activity was examined using ELISA. In vitro THP-1 adhesion assay was used to evaluate monocyte adhesion.

RESULTS

TFA significantly reduced DAI score, prevented colon shortening, and ameliorated histological injuries of colons in DSS-treated mice. TFA inhibited the expression of cytokines (IL-1β and TNF-α) and adhesion molecules (ICAM-1, VCAM-1, and MAdCAM-1) in colon tissues of DSS mice. In vitro studies on mesenteric arterial endothelial cells (MAECs) showed that TFA attenuated TNF-α-induced upregulation of ICAM-1, VCAM-1, and MAdCAM-1, as well as THP-1 cell adhesion to MAECs. TFA also suppressed the phosphorylation and nuclear translocation of NF-κB in MAECs.

CONCLUSION

TFA efficaciously ameliorates UC possibly by inhibiting monocyte adhesion through blocking TNF-α-induced NF-κB activation, which in turn suppresses the upregulation of adhesive molecules in colon endothelial cells. Inhibiting the expression of adhesion molecule in MAECs may represent a useful strategy for therapeutic development to treat UC, with TFA being a safe and efficacious therapeutic agent.

Deficiency of lipopolysaccharide binding protein facilitates adipose browning, glucose uptake and oxygen consumption in mouse embryonic fibroblasts via activating PI3K/Akt/mTOR pathway and inhibiting autophagy

This study aimed to explore the role of lipopolysaccharide-binding protein (LBP) in adipose browning. Mouse embryonic fibroblasts (MEFs) were treated with differentiation induction reagents and Perifosine (Akt inhibitor), with the transfection of Atg5, short hairpin RNA targeting LBP (shLBP), and Atg5 (shAtg5). The expression levels of LBP, inflammatory markers , brown fat markers, lipid metabolism marker, autophagy markers, insulin signaling-related molecules , p-mTOR, mTOR, p-Akt, Akt, p-PI3K, and PI3K were quantified or determined by Western blot, qRT-PCR, and immunofluorescence assay. The formation of lipid was examined through Oil red O staining assay. The consumption of oxygen was assessed using a Seahorse XF96 analyzer, and the uptake of glucose was evaluated by [³H]-2-deoxy-D-glucose uptake assay. Deficiency of LBP promoted adipose browning, oxygen consumption, glucose uptake, and insulin sensitivity in differentiated MEFs, where it inhibited inflammation and autophagy. All of the effects above were reversed by Atg5 overexpression. Meanwhile, the knockdown of Atg5 strengthened the activation of PI3K/Akt/mTOR pathway induced by the depletion of LBP, while Perifosine partly reversed the activation of differentiated MEFs. The knockdown of LBP facilitated adipose browning, glucose uptake, and oxygen consumption in MEFs via the activation of PI3K/Akt/mTOR pathway and the inhibition of autophagy.

Treatment Effects of Natural Products on Inflammatory Bowel Disease In Vivo and Their Mechanisms: Based on Animal Experiments

Inflammatory bowel disease (IBD) is a chronic, non-specific inflammatory disease of the intestine that can be classified as ulcerative colitis (UC) and Crohn's disease (CD). Currently, the incidence of IBD is still increasing in developing countries. However, current treatments for IBD have limitations and do not fully meet the needs of patients. There is a growing demand for new, safe, and highly effective alternative drugs for IBD patients. Natural products (NPs) are used in drug development and disease treatment because of their broad biological activity, low toxicity, and low side effects. Numerous studies have shown that some NPs have strong therapeutic effects on IBD. In this paper, we first reviewed the pathogenesis of IBD as well as current therapeutic approaches and drugs. Further, we summarized the therapeutic effects of 170 different sources of NPs on IBD and generalized their modes of action and therapeutic effects. Finally, we analyzed the potential mechanisms of NPs for the treatment of IBD. The aim of our review is to provide a systematic and credible summary, thus supporting the research on NPs for the treatment of IBD and providing a theoretical basis for the development and application of NPs in drugs and functional foods.

Effects of Medicinal Plants and Phytochemicals in Nrf2 Pathways during Inflammatory Bowel Diseases and Related Colorectal Cancer: A Comprehensive Review

Inflammatory bowel diseases (IBDs) are related to nuclear factor erythroid 2-related factor 2 (Nrf2) dysregulation. In vitro and in vivo studies using phytocompounds as modulators of the Nrf2 signaling in IBD have already been published. However, no existing review emphasizes the whole scenario for the potential of plants and phytocompounds as regulators of Nrf2 in IBD models and colitis-associated colorectal carcinogenesis. For these reasons, this study aimed to build a review that could fill this void. The PubMed, EMBASE, COCHRANE, and Google Scholar databases were searched. The literature review showed that medicinal plants and phytochemicals regulated the Nrf2 on IBD and IBD-associated colorectal cancer by amplifying the expression of the Nrf2-mediated phase II detoxifying enzymes and diminishing NF-κB-related inflammation. These effects improve the bowel environment, mucosal barrier, colon, and crypt disruption, reduce ulceration and microbial translocation, and consequently, reduce the disease activity index (DAI). Moreover, the modulation of Nrf2 can regulate various genes involved in cellular redox, protein degradation, DNA repair, xenobiotic metabolism, and apoptosis, contributing to the prevention of colorectal cancer.

Plant-derived compounds for treating autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD), the most common monogenic hereditary kidney disease, is the fourth leading cause of end-stage kidney disease worldwide. In recent years, significant progress has been made in delaying ADPKD progression with different kinds of chemical drugs, such as tolvaptan, rapamycin, and somatostatin. Meanwhile, numerous plant-derived compounds have been investigated for their beneficial effects on slowing ADPKD progression. Among them, saikosaponin-d, Ganoderma triterpenes, curcumin, ginkgolide B, steviol, resveratrol, Sparganum stoloniferum Buch.-Ham, Cordyceps sinensis, triptolide, quercitrin, naringin, cardamonin, gambogic acid, and olive leaf extract have been found to retard renal cyst development by inhibiting cell proliferation or promoting cell apoptosis in renal cyst-lining epithelial cells. Metformin, a synthesized compound derived from French lilac or goat's rue (Galega officinalis), has been proven to retard the progression of ADPKD. This review focuses on the roles and mechanisms of plant-derived compounds in treating ADPKD, which may constitute promising new therapeutics in the future.

The mechanism of NLRP3 inflammasome activation and its pharmacological inhibitors

NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) is a cytosolic pattern recognition receptor (PRR) that recognizes multiple pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). Once activated, NLRP3 initiates the inflammasome assembly together with the adaptor ASC and the effector caspase-1, leading to caspase-1 activation and subsequent cleavage of IL-1β and IL-18. Aberrant NLRP3 inflammasome activation is linked with the pathogenesis of multiple inflammatory diseases, such as cryopyrin-associated periodic syndromes, type 2 diabetes, non-alcoholic steatohepatitis, gout, and neurodegenerative diseases. Thus, NLRP3 is an important therapeutic target, and researchers are putting a lot of effort into developing its inhibitors. The review summarizes the latest advances in the mechanism of NLRP3 inflammasome activation and its pharmacological inhibitors.

Naringenin protects against acute pancreatitis-associated intestinal injury by inhibiting NLRP3 inflammasome activation via AhR signaling

Background: In this study, we examined the functions and mechanisms by which naringenin protects against SAP (severe acute pancreatitis)-related intestinal injury by modulating the AhR/NLRP3 signaling pathway. Material and methods: Fifteen healthy male C57BL/6 mice were randomly divided into SAP (n = 12) and normal (n = 3) groups. Mice in the SAP group received caerulein and lipopolysaccharide intraperitoneal injections and were then randomly assigned to the SAP, NAR, CH223191, and Dexamethasone (DEX) groups. Pathological changes in the pancreatic and intestinal mucosa were observed by Hematoxylin & Eosin (H&E) staining. In vitro, RAW264.7 cells were exposed to lipopolysaccharide and treated with naringenin. The levels of NLRP3, AhR, IL-1β, TNF, and IL-6 in the SAP model and RAW264.7 cells were evaluated by enzyme-linked immunosorbent assay (ELISA), quantitative real-time PCR (qRT-PCR), western blot, and immunohistochemistry. The nuclear translocation of AhR was shown by immunofluorescence. AutoDockTools was used to predict the conformations of naringenin-AhR binding, and PyMol 2.4 was used to visualize the conformations. Results: Mouse pancreatic and intestinal injury was alleviated by treatment with naringenin. Naringenin inhibited the activation of the NLRP3 inflammasome and inhibited damage to intestinal tight junctions. Moreover, naringenin increased AhR nuclear translocation and activated the AhR pathway. Conclusion: Naringenin can reduce SAP-associated intestinal injury by inhibiting the activation of the NLRP3 inflammasome via the AhR signaling pathway.

Inhibition of the NLRP3 Inflammasome by a Quercus Serrata Extract and Isolation of the Component Compounds for the Treatment of Arthritis

Quercus serrata belongs to the Fagaceae family. There are 600 known species of Quercus worldwide. Q. serrata is distributed nationally in Korea, Japan, and China and grows to a height of 10-15 m. It exhibits a light grey bark with longitudinal furrows; the leaves are 6-12 cm long and 2.5-5 cm wide. The Quercus genus reportedly exhibits several types of bioactivity, including antioxidant, anti-inflammatory, antifungal, antimicrobial, and anticancer activity. Additionally, it has been reported that Quercus produces diverse phytochemicals, including tannins, flavonoids, and triterpenoids. Herein, we describe the column chromatographic isolation of five compounds from a Q. serrata extract. The compounds included caffeic acid (1), myricetin-3-O-cellobioside (2), phloroglucinol (3), (S)-2,3-HHDP-D-glucopyranoside (4), and pedunculagin (5). We assessed the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity, antioxidant activity, NLR family pyrin domain-containing 3 (NLRP3) inflammasome (including NLRP3, ASC, and caspase-1) inhibitory effects, and collagenase inhibition activity of the Q. serrata extract and its constituent compounds. Our results indicated that the Q. serrata extract and the isolated constituent compounds showed inhibitory activity with reference to nitric oxide production, inflammasome component expression, and collagenase activity. Our findings imply that the Q. serrata extract and the isolated constituent compounds are potential candidates for the treatment of inflammatory diseases such as arthritis.

Surfactin Containing Bacillus licheniformis-Fermented Products Alleviate Dextran Sulfate Sodium-Induced Colitis by Inhibiting Colonic Inflammation and the NLRP3 Inflammasome in Mice

Inflammatory bowel disease (IBD) is a non-infectious disease characterized by chronic inflammation of the gastrointestinal tract. Currently, management of IBD is still a clinical challenge. The purpose of this study was to investigate the therapeutic potential of surfactin containing Bacillus licheniformis-fermented products (SBLF) and commercial surfactin (CS) on the treatment of dextran sulfate sodium (DSS)-induced colitis in a mouse model. We found that mice that received drinking water containing 3% DSS developed significant colitis symptoms, including increased disease activity index, body weight loss, shortening of the colon length, splenomegaly, colonic inflammation and colonic NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome activation. Notably, orally received SBLF, CS or clinical anti-inflammatory drug 5-aminosalicylic acid improved DSS-induced colitis symptoms in mice. These findings show that SBLF can improve IBD in mice by reducing colonic inflammation and inhibiting the NLRP3 inflammasome activation, suggesting that SBLF has the potential to be used as a nutraceutical in humans or a feed additive in economic and companion animals for preventing IBD.

NLRP3 inflammasome in digestive diseases: From mechanism to therapy

Digestive system diseases remain a formidable challenge to human health. NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is the most characteristic multimeric protein complex and is involved in a wide range of digestive diseases as intracellular innate immune sensors. It has emerged as a research hotspot in recent years. In this context, we provide a comprehensive review of NLRP3 inflammasome priming and activation in the pathogenesis of digestive diseases, including clinical and preclinical studies. Moreover, the scientific evidence of small-molecule chemical drugs, biologics, and phytochemicals, which acts on different steps of the NLRP3 inflammasome, is reviewed. Above all, deep interrogation of the NLRP3 inflammasome is a better insight of the pathomechanism of digestive diseases. We believe that the NLRP3 inflammasome will hold promise as a novel valuable target and research direction for treating digestive disorders.

Research trends in ulcerative colitis: A bibliometric and visualized study from 2011 to 2021

Background: Ulcerative colitis (UC) is an idiopathic inflammatory bowel disease with repeated relapses and remissions. Despite decades of effort, numerous aspects, including the initiating event and pathogenesis of UC, still remain ambiguous, which requires ongoing investigation. Given the mass of publications on UC, there are multidimensional challenges to evaluating the scientific impact of relevant work and identifying the current foci of the multifaceted disease. Accordingly, herein, we aim to assess the global growth of UC research production, analyze patterns of research areas, and evaluate trends in this area.

Methods: The Web of Science Core Collection of Clarivate Analytics was searched for articles related to UC published from 2011 to 2021. Microsoft Office Excel 2019 was used to visualize the number of publications over time. Knowledge maps were generated using CiteSpace and VOSviewer to analyze collaborations among countries, institutions, and authors and to present the journey of UC research as well as to reveal the current foci of UC research.

Results: A total of 5,088 publications were evaluated in the present study. China had the most publications (1,099, 22.5%). Univ Calif San Diego was the most productive institution (126, 2.48%). William J Sandborn published the greatest number of articles (100, 1.97%). Toshifumi Hibi was the most influential author in the field with a betweenness centrality of 0.53. Inflammatory bowel diseases was identified as the most prolific journal (379, 7.45%). Gastroenterology was the most co-cited journal (3,730, 4.02%). “Vedolizumab,” “tofacitinib,” “Faecalibacterium prausnitzii,” “fecal microbiota transplantation (FMT),” “toll-like receptor 4,” and “nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome” were considered the hot topics.

Conclusion: In UC research, manuscripts that had high impacts on the scientific community provided an evidence base. UC therapy has entered the era of personalized and precision therapy. As research on FMT, anti-integrin antibodies, Janus kinase inhibitors, and anti-tumor necrosis factor drugs continues to grow, their use in the clinical setting may also expand.

Gut Microbiota Regulation of AHR Signaling in Liver Disease

Liver health plays a vital role in human health and disease. Emerging evidence has shown the importance of the aryl hydrocarbon receptor (AHR) in liver diseases such as alcoholic liver disease, fatty liver disease, and liver failure. As a ligand-activated transcription factor, AHR can be activated by endogenous ligands of microbial metabolites such as tryptophan (Trp), kynurenine (Kyn) or indole derivatives locally or distantly. However, the therapeutic effects of the gut microbiota-regulated AHR pathway remain to be clarified. In this review, we summarize recent progress and examine the role of AHR signaling as a target for gut microbiota intervention in liver diseases. The focus on AHR signaling will identify a promising target in the gut microbiota for better understanding and therapeutic opportunities in liver diseases.

Pros and cons of NRF2 activation as adjunctive therapy in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease with an important inflammatory component accompanied by deregulated redox-dependent signaling pathways that are feeding back into inflammation. In this context, we bring into focus the transcription factor NRF2, a master redox regulator that exerts exquisite antioxidant and anti-inflammatory effects. The review does not intend to be exhaustive, but to point out arguments sustaining the rationale for applying an NRF2-directed co-treatment in RA as well as its potential limitations. The involvement of NRF2 in RA is emphasized through an analysis of publicly available transcriptomic data on NRF2 target genes and the findings from NRF2-knockout mice. The impact of NRF2 on concurrent pathologic mechanisms in RA is explained by its crosstalk with major redox-sensitive inflammatory and cell death-related pathways, in the context of the increased survival of pathologic cells in RA. The proposed adjunctive therapy targeted to NRF2 is further sustained by the existence of promising NRF2 activators that are in various stages of drug development. The interference of NRF2 with conventional anti-rheumatic therapies is discussed, including the cytoprotective effects of NRF2 for alleviating drug toxicity. From another perspective, the review presents how NRF2 activation would be decreasing the efficacy of synthetic anti-rheumatic drugs by increasing drug efflux. Future perspectives regarding pharmacologic NRF2 activation in RA are finally proposed.

Inflammasome-targeting natural compounds in inflammatory bowel disease: Mechanisms and therapeutic potential

Inflammatory bowel disease (IBD), mainly including Crohn’s disease and ulcerative colitis, seriously affects human health and causes substantial social and economic burden. The pathogenesis of IBD is still not fully elucidated, whereas recent studies have demonstrated that its development is associated with the dysfunction of intestinal immune system. Accumulating evidence have proven that inflammasomes such as NLRP3 and NLRP6 play a prominent role in the pathogenesis of IBD. Thus, regulating the activation of inflammasomes have been considered to be a promising strategy in IBD treatment. A number of recent studies have provided evidence that blocking inflammasome related cytokine IL-1β can benefit a group of IBD patients with overactivation of NLRP3 inflammasome. However, therapies for targeting inflammasomes with high efficacy and safety are rare. Traditional medical practice provides numerous medical compounds that may have a role in treatment of various human diseases including IBD. Recent studies demonstrated that numerous medicinal herb derived compounds can efficiently prevent colon inflammation in animal models by targeting inflammasomes. Herein, we summarize the main findings of these studies focusing on the effects of traditional medicine derived compounds on colitis treatment and the underlying mechanisms in regulating the inflammasomes. On this basis, we provide a perspective for future studies regarding strategies to improve the efficacy, specificity and safety of available herbal compounds, and to discover new compounds using the emerging new technologies, which will improve our understanding about the roles and mechanisms of herbal compounds in the regulation of inflammasomes and treatment of IBD.

Activation of LRP1 Ameliorates Cerebral Ischemia/Reperfusion Injury and Cognitive Decline by Suppressing Neuroinflammation and Oxidative Stress through TXNIP/NLRP3 Signaling Pathway in Mice

Cerebral ischemia/reperfusion (I/R) injury is a clinical event associated with high morbidity and mortality. Neuroinflammation plays a crucial role in the pathogenesis of I/R-induced brain injury and cognitive decline. Low-density lipoprotein receptor-related protein-1 (LRP1) can exert strong neuroprotection in experimental intracerebral hemorrhage. However, whether LRP1 can confer neuroprotective effects after cerebral I/R is yet to be elucidated. The present study is aimed at investigating the effects of LRP1 activation on cerebral I/R injury and deducing the underlying mechanism involving TXNIP/NLRP3 signaling pathway. Cerebral I/R injury was induced in mice by bilateral common carotid artery occlusion. LPR1 ligand, apoE-mimic peptide COG1410, was administered intraperitoneally. To elucidate the underlying mechanism, overexpression of TXNIP was achieved via the hippocampal injection of AAV-TXNIP before COG1410 treatment. Neurobehavioral tests, brain water content, immunofluorescence, Western blot, enzyme-linked immunosorbent assay, HE, and terminal deoxynucleotidyl transferase dUTP nick end labeling staining were performed. Our results showed that the expressions of endogenous LRP1, TXNIP, NLRP3, procaspase-1, and cleaved caspase-1 were increased after cerebral I/R. COG1410 significantly ameliorated cerebral I/R-induced neurobehavioral deficits, brain edema, histopathological damage, and poor survival rate. Interestingly, COG1410 inhibited microglia proinflammatory polarization and promoted anti-inflammatory polarization, decreased oxidative stress, attenuated apoptosis, and inhibited the expression of the TXNIP/NLRP3 signaling pathway. However, the benefits of COG1410 were abolished by TXNIP overexpression. Thus, our study suggested that LRP1 activation with COG1410 attenuated cerebral I/R injury at least partially related to modulating microglial polarization through TXNIP/NLRP3 signaling pathway in mice. Thus, COG1410 treatment might serve as a promising therapeutic approach in the management of cerebral I/R patients.

Dioscin ameliorates cisplatin-induced intestinal toxicity by mitigating oxidative stress and inflammation

Cisplatin is the most widely prescribed drug in chemotherapy, but its gastrointestinal toxicity reduces therapeutic efficacy. Oxidative stress and inflammation are considered to be the main pathogenesis of cisplatin-induced intestinal toxicity. Dioscin is a steroidal saponin with potential anti-cancer, antioxidant, and anti-inflammatory activities. In this study, we established a rat model of intestinal injury by tail vein injection of cisplatin, and intragastrically administered dioscin to evaluate its effect on intestinal injury. Biochemical markers, western blotting, qRT-PCR and histopathological staining were used to analyze intestinal injury according to various molecular mechanisms. The results revealed that dioscin significantly inhibited cisplatin-induced intestinal mucosal damage and decreased DAO levels in rats. Furthermore, dioscin activated the Nrf2/HO-1 pathway to increase the level of antioxidant enzymes and reduce the levels of MDA and H₂O₂. In addition, dioscin pretreatment significantly reduced ileum epithelial NLRP3 inflammasome formation and decreased the levels of inflammatory factors compared with the cisplatin group. In parallel, Nrf2 inhibitor ML385 blocked the therapeutic effect of dioscin in rat with cisplatin-induced intestinal toxicity. In terms of mechanisms, dioscin reversed cisplatin-induced up-regulation of MAPKs and up-regulated p-PI3K and p-AKT levels. Meanwhile, dioscin potently promoted Wnt3A/β-catenin signaling to relieve cisplatin-induced proliferation inhibition. In conclusion, our study suggests that dioscin could ameliorate the cisplatin-induced intestinal toxicity by reducing oxidative stress and inflammation.