In Vivo and In Vitro Study on the Efficacy of Terpinen-4-ol in Dextran Sulfate Sodium-Induced Mice Experimental Colitis

Beta-hydroxy-beta-methylbutyrate (HMB) ameliorates DSS-induced colitis by inhibiting ERK/NF-κB activation in macrophages

BACKGROUND

β-Hydroxy β-Methylbutyrate (HMB), derived from leucine, is known for its role in anti-oxidation and anti-inflammation. But, the application of HMB in IBD treatment is not fully understood, highlighting the requirement for further research.

PURPOSE

We aimed to examine the effects of HMB treatment on DSS-induced chronic colitis in mice and explore its underlying mechanisms.

METHODS

To simulate colonic inflammation, a murine colitis model was generated by using DSS induction. Critical indicators such as body weight, colon length, disease activity index (DAI), and gross pathology were thoroughly monitored. Immunohistochemistry assay was conducted to assess the expression of Occludin and F4/80. Flow cytometry was employed to evaluate the expression levels of CD80 and CD86. qPCR was performed to measure cytokine expression (IL-6, IL-1β, TNF-α, IL-22, CXCL2, iNOS). RNA sequencing was carried out using bone-marrow derived dendritic macrophage cells (BMDMs).

RESULTS

Our study indicates that HMB treatment substantially mitigated colonic damage in murine models of DSS-induced colitis, highlighting its anti-inflammatory potential. Notably, HMB significantly enhanced the expression of Occludin in these mice. Furthermore, HMB downregulated proinflammatory markers such as IL-6, IL-1β, and TNF-α as well as CXCL2 in the colon tissue. In vitro experiments also revealed that HMB reduced production of proinflammatory cytokines induced by DSS and suppressed the expression levels of CD80 and CD86 in macrophage cells. On a mechanistic level, we demonstrated the anti-inflammatory effects of HMB by reducing the phosphorylation of p-ERK and p-p65, thereby limiting cytokine production in both in vivo and in vitro settings.

CONCLUSION

These findings indicate that HMB possesses anti-inflammation against intestinal inflammation and may hold promise as a potential therapeutic candidate for IBD treatment. There's growing interest in combining traditional anti-inflammatory agents with supplements like HMB to improve outcomes in complex IBD cases. HMB's role in established muscle preservation and reduction of systemic inflammation as described in this study could make it a valuable adjunct in IBD therapy.

Zanthoxylum piperitum Benn. Attenuates Monosodium Urate-Induced Gouty Arthritis: A Network Pharmacology Investigation of Its Anti-Inflammatory Mechanisms

Background: Monosodium urate crystal accumulation in the joints is the cause of gout, an inflammatory arthritis that is initiated by elevated serum uric acid levels. It is the most prevalent form of inflammatory arthritis, affecting millions worldwide, and requires effective treatments. The necessity for alternatives with fewer side effects is underscored by the frequent adverse effects of conventional therapies, such as urate-lowering drugs. IL-1β is a potential therapeutic target due to its significant role in the inflammatory response induced by MSU. Zanthoxylum piperitum Benn. (ZP), a shrub that possesses antibacterial, antioxidant, and anti-inflammatory properties, has demonstrated potential in the treatment of inflammatory conditions. Methods: For anti-inflammatory properties of ZP, Raw264.7 cell stimulated LPS were treated ZP and using RNA-seq with Bone marrow derived macrophage, we observed to change inflammatory gene. Pharmacological networks were conducted to select target gene associated with ZP. For in vivo, mice were injected MSU in footpad for induce gouty arthritis model. The components of ZP were analyzed using GC-MS, and distilled extracts of ZP (deZP) were prepared. Results: In vitro, deZP decreased inflammatory cytokines. However, in vivo, it also decreased paw thickness and IL-1β levels. The anti-inflammatory effects of deZP are believed to be mediated through the NLRP3 inflammasome pathway, as indicated by RNA sequencing and network pharmacology analyses. Conclusions: ZP has an anti-inflammatory effect and regulation of the NLRP3 inflammasome in vitro and in vivo. Further research, including clinical trials, is required to confirm the safety of deZP, determine the optimal dosing, and evaluate its long-term effects.

Terpinen-4-ol Improves the Intestinal Barrier Function of the Colon in Immune-Stressed Weaning Piglets

The aim of this study was to investigate the effects of terpinen-4-ol (TER) supplementation on the intestinal barrier function of pigs. Five groups of fifty 28-day-old piglets with comparable body weights were randomly assigned to the following groups: the control group (CON), the lipopolysaccharide group (LPS), the low TER group (PLT), the middle TER group (PMT), and the high TER group (PHT). The basal diet was given to the CON and LPS groups, and 30, 60, or 90 mg/kg TER was added to the basal diet for the TER groups. After the 21-day trial period, piglets in the LPS and TER groups received an intraperitoneal injection of 100 μg/kg body weight of LPS, whereas the piglets in the CON group received an injection of 0.9% normal saline solution. The results showed that LPS stimulation resulted in a decrease (p < 0.05) in the depth of colonic crypts in piglets, which was greater (p < 0.05) in the TER group. Compared with those in the CON group, the number of goblet cells and MUC2 expression were decreased in the colon of piglets in the LPS group, while these parameters were increased in the PMT group (p < 0.05). The malondialdehyde (MDA) content was greater in the colon of the LPS group than in that of the CON group, while the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) were lower in the colon of the LPS group; conversely, the MDA content was lower in the colons of the PLT and PMT groups than in those of the LPS group (p < 0.05). TER also reduced (p < 0.05) LPS-induced upregulation of IL-1β and TNF-α expression, along with the relative gene expression of NLRP3, ASC, and caspase-1 in the colon of piglets (p < 0.05). Compared with those in the CON group, the abundances of Firmicutes and UCG-005 in the LPS group were lower (p < 0.05), and those in the TER group were significantly greater than those in the LPS group. Compared with those in the CON group, the abundance of Proteobacteria in the LPS group increased (p < 0.05), while the abundance of Actinobacteria and Phascolarctobacterium increased (p < 0.05) in the colon of the PHT group compared with that in the LPS group. In conclusion, TER effectively improved the intestinal barrier function of the colon in weaning piglets. Based on the results of this study, the appropriate dose of TER in the diets of weaning piglets was 60 mg/kg.

The Gut Microbiota Contributes to the Development of LPS-Induced Orchitis by Disrupting the Blood-Testosterone Barrier in Mice

Orchitis is a frequent inflammatory reproductive disease that causes male infertility and a decline in sperm quality. Gut microbiota can regulate systemic and local inflammation, spermatogenesis and blood-testosterone barrier (BTB). In this study, we investigated correlation between gut microbiota and orchitis by establishing a mouse gut microbiota imbalance model induced by antibiotics (ABX) treatment and orchitis model induced by lipopolysaccharide (LPS) infection. Based on these two models, 16s rRNA sequencing and feces microbiota transplantation (FMT) experiments were combined to examine the function and regulatory mechanisms of the gut microbiota in host defense against orchitis. Compared with control mice, gut microbiota imbalance resulted in increasing inflammatory responses, modulating oxidative stress related enzyme activity, testosterone levels and the permeability of blood testosterone barrier, which are restored after FMT. Subsequently, we tested the relationship between the gut microbiota imbalance and testicular inflammation severity in orchitis. It was found that the ABX and LPS co-treated mice had more severe inflammatory responses, lower testosterone levels and greater permeability of the BTB than the LPS-treated mice, but these changes could be partially recovered by gut microbiota transplantation. In conclusion, these above results proved for the first time that gut microbiota is involved in the pathogenesis of orchitis, which laid a good foundation for the subsequent development of anti-orchitis drugs and probiotic targeting intestinal flora.

Harnessing nature's pharmacy: investigating natural compounds as novel therapeutics for ulcerative colitis

Backgrounds

Ulcerative colitis (UC) is a form of chronic inflammatory bowel disease, and UC diagnosis rates continue to rise throughout the globe. The research and development of new drugs for the treatment of UC are urgent, and natural compounds are an important source. However, there is a lack of systematic summarization of natural compounds and their mechanisms for the treatment of UC.

Methods

We reviewed the literature in the databases below from their inception until July 2023: Web of Science, PubMed, China National Knowledge Infrastructure, and Wanfang Data, to obtain information on the relationship between natural compounds and UC.

Results

The results showed that 279 natural compounds treat UC through four main mechanisms, including regulating gut microbiota and metabolites (Mechanism I), protecting the intestinal mucosal barrier (Mechanism II), regulating intestinal mucosal immune response (Mechanism III), as well as regulating other mechanisms (Mechanism Ⅳ) such as cellular autophagy modulation and ferroptosis inhibition. Of these, Mechanism III is regulated by all natural compounds. The 279 natural compounds, including 62 terpenoids, 57 alkaloids, 52 flavonoids, 26 phenols, 19 phenylpropanoids, 9 steroids, 9 saponins, 8 quinonoids, 6 vitamins, and 31 others, can effectively ameliorate UC. Of these, terpenoids, alkaloids, and flavonoids have the greatest potential for treating UC. It is noteworthy to highlight that a total of 54 natural compounds exhibit their therapeutic effects by modulating Mechanisms I, II, and III.

Conclusion

This review serves as a comprehensive resource for the pharmaceutical industry, researchers, and clinicians seeking novel therapeutic approaches to combat UC. Harnessing the therapeutic potential of these natural compounds may significantly contribute to the improvement of the quality of life of patients with UC and promotion of disease-modifying therapies in the future.

Nicotine improves DSS-induced colitis by inhibiting NLRP3 and altering gut microbiota

Ulcerative colitis (UC) is a chronic recurrent inflammatory disease affecting the rectum and colon. Numerous epidemiological studies have identified smoking as a protective factor for UC. Dysbiosis of intestinal microbiota and release of inflammatory factors are well-established characteristics associated with UC. Therefore, we have observed that nicotine exhibits the potential to ameliorate colitis symptoms in UC mice. Additionally, it exerts a regulatory effect on colonic microbiota dysbiosis by promoting the growth of beneficial bacteria while suppressing harmful bacteria. Combined in vivo and in vitro investigations demonstrate that nicotine primarily impedes the assembly of NLRP3, subsequently inhibiting downstream IL-1β secretion.

KLF4 interacts with TXNIP to modulate the pyroptosis in ulcerative colitis via regulating NLRP3 signaling

INTRODUCTION

Ulcerative colitis (UC) is one of the most common diseases in the gastrointestinal tract related to abnormal inflammation. Pyroptosis, which is characterized by the formation of inflammasome, activation of caspase-1, and separation of N- and C-terminus of gasdermin D (GSDMD), and may be involved in the pathogenesis of IBD. Krüppel-like factor 4 (KLF4) is a zinc finger transcription factor expressed in differentiated epithelial cells. KLF4 mediates proinflammatory signaling in macrophages. Here, we tested whether KLF4 is functional in pyroptosis of UC.

METHODS

In human UC tissues and/or lipopolysaccharide (LPS)/adenosine 5-triphosphate (ATP) stimulation human colon epithelial cells, KLF4, TXNIP, Cleave-Caspase-1, and GSDMD expression were detected through quantitative reverse transcription polymerase chain reaction (PCR), immunohistochemical and western blot assay. Interleukin (IL)-1β and IL-18 levels were quantified by enzyme-linked immunosorbent assay. We successfully constructed a KLF4-silenced colon epithelial cell line using an adenovirus vector. We apply the UCSC and JASPAR to predict the KLF4 binding sites in the promoter region of TXNIP.

RESULTS

In human UC tissues and/or LPS/ATP stimulation human colon epithelial cells, KLF4, TXNIP, Caspase-1, and GSDMD expression level were significantly elevated via quantitative reverse transcription PCR, immunohistochemical and western blot assay. Moreover, We identified that there is an interaction between KLF4 and TXNIP through Yeast double hybrid assay and CO-IP assay. We successfully constructed a KLF4-silenced human intestinal epithelial cell line. In LPS/ATP stimulation KLF4-silenced human intestinal epithelial cells, KLF4, TXNIP, Cleave Caspase-1, ASC, and GSDMD expression level were significantly decreased via quantitative reverse transcription PCR.

CONCLUSION

Our results confirm that KLF4 can positively regulate the expression of TXNIP and regulate the pyroptosis process of UC through the TXNIP/NLRP3 pathway.

Progress on Regulation of NLRP3 Inflammasome by Chinese Medicine in Treatment of Ulcerative Colitis

Ulcerative colitis (UC) is a chronic, non-specific intestinal disease that not only affects the quality of life of patients and their families but also increases the risk of colorectal cancer. The nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome is an important component of inflammatory response system, and its activation induces an inflammatory cascade response that is involved in the development and progression of UC by releasing inflammatory cytokines, damaging intestinal epithelial cells, and disrupting the intestinal mucosal barrier. Chinese medicine (CM) plays a vital role in the prevention and treatment of UC and is able to regulate NLRP3 inflammasome. Many experimental studies on the regulation of NLRP3 inflammasome mediated by CM have been carried out, demonstrating that CM formulae with main effects of clearing heat, detoxifying toxicity, drying dampness, and activating blood circulation. Flavonoids and phenylpropanoids can effectively regulate NLRP3 inflammasome. Other active components of CM can interfere with the process of NLRP3 inflammasome assembly and activation, leading to a reduction in inflammation and UC symptoms. However, the reports are relatively scattered and lack systematic reviews. This paper reviews the latest findings regarding the NLRP3 inflammasome activation-related pathways associated with UC and the potential of CM in treating UC through modulation of NLRP3 inflammasome. The purpose of this review is to explore the possible pathological mechanisms of UC and suggest new directions for development of therapeutic tools.

Saccharina japonica Ethanol Extract Ameliorates Dextran Sulfate Sodium-Induced Colitis via Reshaping Intestinal Microenvironment and Alleviating Inflammatory Response

Saccharina japonica belongs to brown macro-alga with various potential health benefits; its antioxidant and anti-inflammatory activities indicate the potential to improve inflammatory bowel diseases. Here, the potential anti-colitis effect of Saccharina japonica extract (SJE) was evaluated on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in C57B/L6 mice. The mice were treated with mesalazine (MES) and various doses of SJE by gavage for 14 days. Results showed that both MES and SJE treatment decreased the disease activity index scores, relieving the short colon. SJE increased the occludin and zonula occludens-1 levels, and the beneficial effects were better than MES. MES and SJE exerted similar effects in decreasing inflammatory cytokines and oxidative stress. Moreover, SJE reshaped the intestinal microbiota by increasing α-diversity and reducing plenty of harmful bacteria. Dietary SJE was significant to relieving the reduction in short-chain fatty acids. The results revealed the protective effect of SJE on colitis and potential mechanisms, which is important for the rational use of SJE in UC prevention.

Phytotherapy of mood disorders in the light of microbiota-gut-brain axis

BACKGROUND

Clinical research in natural product-based psychopharmacology has revealed a variety of promising herbal medicines that may provide benefit in the treatment of mild mood disorders, however failed to unambiguously indicate pharmacologically active constituents. The emerging role of the microbiota-gut-brain axis opens new possibilities in the search for effective methods of treatment and prevention of mood disorders.

PURPOSE

Considering the clinically proven effectiveness juxtaposed with inconsistencies regarding the indication of active principles for many medicinal plants applied in the treatment of anxiety and depression, the aim of the review is to look at their therapeutic properties from the perspective of the microbiota-gut-brain axis.

METHOD

A literature-based survey was performed using Scopus, Pubmed, and Google Scholar databases. The current state of knowledge regarding Hypericum perforatum, Valeriana officinalis, Piper methysticum, Passiflora incarnata, Humulus lupulus, Melissa officinalis, Lavandula officinalis, and Rhodiola rosea in terms of their antimicrobial activity, bioavailability, clinical effectiveness in depression/anxiety and gut microbiota - natural products interaction was summarized and analyzed.

RESULTS

Recent studies have provided direct and indirect evidence that herbal extracts and isolated compounds are potent modulators of gut microbiota structure. Additionally, some of the formed postbiotic metabolites exert positive effects and ameliorate depression-related behaviors in animal models of mood disorders. The review underlines the gap in research on natural products - gut microbiota interaction in the context of mood disorders.

CONCLUSION

Modification of microbiota-gut-brain axis by natural products is a plausible explanation of their therapeutic properties. Future studies evaluating the effectiveness of herbal medicine and isolated compounds in treating mild mood disorders should consider the bidirectional interplay between phytoconstituents and the gut microbiota community.

Therapeutic interventions target the NLRP3 inflammasome in ulcerative colitis: Comprehensive study

One of the significant health issues in the world is the prevalence of ulcerative colitis (UC). UC is a chronic disorder that mainly affects the colon, beginning with the rectum, and can progress from asymptomatic mild inflammation to extensive inflammation of the entire colon. Understanding the underlying molecular mechanisms of UC pathogenesis emphasizes the need for innovative therapeutic approaches based on identifying molecular targets. Interestingly, in response to cellular injury, the NLR family pyrin domain containing 3 (NLRP3) inflammasome is a crucial part of the inflammation and immunological reaction by promoting caspase-1 activation and the release of interleukin-1β. This review discusses the mechanisms of NLRP3 inflammasome activation by various signals and its regulation and impact on UC.

Ginsenoside Rg3 Ameliorates DSS-Induced Colitis by Inhibiting NLRP3 Inflammasome Activation and Regulating Microbial Homeostasis

Ulcerative colitis (UC) is a recurrent inflammatory disease without a specific cure or treatment for improvement. Here, we investigated the potential therapeutic effect and mechanism of ginsenoside Rg3 (Gin Rg3) on UC. We constructed an in vitro cellular inflammatory model and a dextran sulfate sodium (DSS)-induced UC mouse model. We also used Gin Rg3, MCC950 (NLRP3 inhibitor), MSU (NLRP3 activator), and fecal transplantation (FMT) to intervene the model. The results showed that Gin Rg3 inhibited NLRP3 inflammasome activation, pyroptosis, and apoptosis in vitro and in vivo. DSS-induced changes in the abundance of gut microbiota at the phylum or genus level were partially restored by Gin Rg3. Furthermore, gin Rg3 affected intestinal metabolism in mice by inhibiting the activation of NLRP3 inflammasome. The gut microbiota treated with Gin Rg3 was sufficient to alleviate DSS-induced UC. In summary, Gin Rg3 alleviated DSS-induced UC by inhibiting NLRP3 inflammasome activation and regulating gut microbiota homeostasis.

Distribution of bacteria in different regions of the small intestine with Zanthoxylum bungeanum essential oil supplement in small-tailed Han sheep

Zanthoxylum bungeanum essential oil (EOZB) as an extract of Zanthoxylum bungeanum has a range of pharmacological effects such as antibacterial, anti-inflammatory, and antioxidant. However, there were no relevant studies on the regulation of gut microbes by EOZB in ruminants. In this study, the effects of different doses of EOZB on the structure and distribution of microorganisms in the small intestine of small-tailed Han sheep (STH) were investigated by 16s rRNA gene sequencing technique. We found that with the intervention of EOZB. The differential bacteria of duodenal at the phylum level were Firmicutes, Bacteroidetes, Tenericutes and Proteobacteria, and genus level differential bacteria were Prevotella 1, Ruminococcus 2 and Eubacterium coprostanoligenes group. The differential bacteria of jejunal at the phylum level were Firmicutes, Bacteroidetes, Tenericutes and Proteobacteria, and genus level differential bacteria were Prevotella 1, Rikenellaceae RC9 gut group, Christensenellaceae R-7 group, Ruminococcaceae UCG-014, Saccharofermentans, Ruminococcaceae NK4A214 group and Prevotellaceae UCG-001. The differential bacteria of ileal at the phylum level were Firmicutes, Bacteroidetes and Tenericutes, and genus level differential bacteria were Prevotella 1, Christensenellaceae R-7 group, Romboutsia and Ruminococcaceae UCG-014. In addition, at the same dose of EOZB, the five most abundant genera of bacteria varied in different regions of the small intestine. Among them, the abundance of Prevotella 1, Christensenellacea R-7 group and Ruminococcus 2 in ALW group was the highest in jejunum, duodenum and ileum, respectively. The abundance of Prevotella 1, Christensenellacea R-7 group and Rikenellacea RC9 gut group in BLW group was the highest in duodenum, jejunum and ileum, respectively. The abundance of Prevotella 1, Christensenellacea R-7 group and Ruminococcaeae NK4A214 group in CLW group was the highest in jejunum, duodenum and ileum, respectively. The abundance of Prevotella 1, Ruminococcus 2 and Ruminococcus NK4A214 groups in DLW group was the highest in jejunum, duodenum and ileum, respectively. Differential bacteria formed under the regulation of EOZB are associated with the digestion and absorption of nutrients and the state of intestinal health in the host. This study is the first to investigate the effect of EOZB on the distribution and structure of bacteria in the small intestine of STH. The results of the study enriched the structure and distribution of bacteria in the small intestine of ruminants and provided new insights into the future application of herbal medicine in ruminant production. Additionally, it provides a theoretical basis for the selection of probiotic bacteria for ruminants and the development and application of microecological preparations.

Kui Jie Tong Ameliorates Ulcerative Colitis by Regulating Gut Microbiota and NLRP3/Caspase-1 Classical Pyroptosis Signaling Pathway

Ulcerative colitis (UC) is one of the most refractory digestive diseases in the world. Kui jie tong (KJT) is an effective traditional Chinese medicine used clinically to treat UC. This study observed the regulatory effects of KJT on NIMA-related kinase 7- (NEK7-) activated nod-like receptor protein-3 (NLRP3)/caspase-1 classical pyroptosis pathway and intestinal flora in UC model rats. KJT components were analyzed using an ultraperformance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS). A UC Sprague Dawley (SD) rat model was established using sodium dextran sulfate (DSS). Rats were randomly divided into four groups: control group (CG), UC model group (UG), KJT group (KG), and sulfasalazine (SASP) group (SG). After seven days of intervention, each group's body weight, disease activity index (DAI) scores, and colon length were recorded. Intestinal mucosal injury to each group was observed using hematoxylin-eosin staining. Additionally, we investigated the expression levels of NEK7, NLRP3, ASC, caspase-1, and GSDMD in intestinal mucosa, as well as serum interleukin- (IL-) 1β, IL-18, and IL-33 proinflammatory factors. Intestinal microflora was analyzed using 16s rRNA sequencing. KJT controlled weight loss; decreased DAI scores; restored colon length; improved pathological injury in the colon; inhibited NEK7, NLRP3, ASC, caspase-1, cleaved-caspase-1, GSDMD, and GSDMD-N expression; and decreased IL-1β, IL-18, and IL-33 contents in UG rats' serum and colon tissue (P <0.001 or P <0.05). KJT also increased Ruminococcaceae, unclassified_f_Ruminococcaceae, and unclassified_g_Ruminococcus_1 levels and decreased Erysipelotrichia, Erysipelotrichales, Erysipelotrichaceae, Turicibacter, and uncultured_bacterium_g_Turicibacter levels. KJT alleviated UC immune-inflammatory responses to NLRP3/caspase-1 by inhibiting the NEK-7-activated classic pyroptosis pathway and improving intestinal microflora.

Revealing the Mechanism of Friedelin in the Treatment of Ulcerative Colitis Based on Network Pharmacology and Experimental Verification

Objectives

Ulcerative colitis (UC) is a chronic inflammatory disease affecting the colon, and its incidence is rising worldwide. This study was designed to uncover the healing effect of friedelin, a bioactive compound against UC through bioinformatics of network pharmacology and experimental verification of UC model mice.

Materials and Methods

Targets of friedelin and potential mechanism of friedelin on UC were predicted through target searching, PPI network establishing, and enrichment analyzing. We explored effects of friedelin on dextran sulfate sodium (DSS)-induced colitis. Severity of UC was investigated by body weight, disease activity index (DAI), and length of the colon. Inflammation severity was examined by determination of proinflammatory and anti-inflammatory cytokines. The numbers of autophagosome around the epithelial cells were observed by autophagy inhibition via a transmission electron microscope. The expressions of autophagy-related ATG5 protein and AMPK-mTOR signaling pathway were determined by immunofluorescence staining.

Results

In this study, 17 potential targets of friedelin and 1111 UC-related targets were identified. 10 therapeutic targets of friedelin against UC were acquired from overlapped targets of UC and friedelin. PPI network construction filtered 14 core targets through target amplification and confidence enhancement. The results of molecular docking showed that the docking scores of the top 5 active targets were higher than the threshold values. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were carried out, showing friedelin alleviates UC through anti-inflammatory pathways and molecular function of autophagy. Subsequently, animal-based experiments revealed the intraperitoneal injection of friedelin ameliorated DSS-induced body weight loss, DAI decrease, colon length shortening and colonic pathological damage with lower myeloperoxidase and proinflammatory cytokines (IL-1β and IL-6) and higher IL-10 levels, and more autophagosomes in transmission electron microscope results. The AMPK-mTOR signaling pathway plays important role in the friedelin's effect in autophagy as KEGG pathway result and experiment verification. Furthermore, the 3 ma validated the role of autophagy as an improvement in the friedelin's pharmacologic effect to UC model mice.

Conclusions

Friedelin ameliorated DSS-induced colitis in mice through of inflammatory inhibition and regulation of autophagy.

Sesamin protects against DSS-induced colitis in mice by inhibiting NF-κB and MAPK signaling pathways

OBJECTIVE

To investigate the protective effects and mechanisms of sesamin (SES) on dextran sulfate sodium (DSS)-induced experimental colitis in mice.

METHODS

SES (50, 100, and 200 mg kg-1) were orally administered to C57BL/6 male mice after DSS instillation. The anti-inflammatory effect of SES on colonic damage was assessed by clinical, macroscopic, microscopic, and inflammatory signaling pathways.

RESULTS AND CONCLUSIONS

It could be found that bodyweight and colon length of mice treated with DSS was significantly decreased while that were increased by SES treatment. SES treatment reduced the DAI values and improved the histopathology of the colon in the DSS-treated mice. SES also reduced TNF-α, IL-1β and IL-6 production caused by DSS. We also measured the expression of the phosphorylation of p65, IκB, p38, ERK and JNK protein and found that SES can alleviate colon damage via the NF-κB and MAPK signaling pathways. The findings of this study suggested that SES had anti-inflammatory effects on intestinal inflammation and can be used as a new therapeutic candidate for inflammatory bowel disease.

Phytochemical inhibitors of the NLRP3 inflammasome for the treatment of inflammatory diseases

The NLRP3 inflammasome holds a crucial role in innate immune responses. Pathogen- and danger-associated molecular patterns may initiate inflammasome activation and following inflammatory cytokine release. The inflammasome formation and its-associated activity are involved in various pathological conditions such as cardiovascular, central nervous system, metabolic, renal, inflammatory and autoimmune diseases. Although the mechanism behind NLRP3-mediated disorders have not been entirely illuminated, many phytochemicals and medicinal plants have been described to prevent inflammatory disorders. In the present review, we mainly introduced phytochemicals inhibiting NLRP3 inflammasome in addition to NLRP3-mediated diseases. For this purpose, we performed a systematic literature search by screening PubMed, Scopus, and Google Scholar databases. By compiling the data of phytochemical inhibitors targeting NLRP3 inflammasome activation, a complex balance between inflammasome activation or inhibition with NLRP3 as central player was pointed out in NLRP3-driven pathological conditions. Phytochemicals represent potential therapeutic leads, enabling the generation of chemical derivatives with improved pharmacological features to treat NLRP3-mediated inflammatory diseases.

Antioxidant and Anti-Inflammatory Activities of Zingiber montanum Oil in HepG2 Cells and Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

Improvement of antioxidant and anti-inflammatory functions is believed to be an effective strategy for protection against various diseases such as cancer, aging, and neurodegenerative disease. This study focused on investigating antioxidant and anti-inflammatory abilities of Zingiber montanum oil (ZMO) extracted by the supercritical CO₂ fluid system in HepG2 cells and lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. Ten predominant constituents of ZMO were identified, in which triquinacene, 1,4-bis (methoxy), terpinen-4-ol, triquinacene, 1,4,7-tris (methoxy), α-terpinene, sabinene hydrate, and (E and Z)-1-(3,4-dimethoxyphenyl)butadiene account for 86.47%. ZMO exhibited anti-inflammatory capacity by inhibiting the formation of pro-inflammatory markers such as nitric oxide, inducible nitric oxide synthase, cyclooxygenase-2, interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein-1 in LPS-treated macrophages. The LPS-induced stimulation of nuclear factor-kappa B, signal transducer and activator of transcription 3 (Stat3) and mitogen-activated protein kinase (MAPK) pathways as evident from increased phosphorylation of IKKα/β, IκBα, p65, Stat3, ERK, JNK, and p38 MAPK was also suppressed by ZMO pretreatment. Further, ZMO enhanced the expression of nuclear factor erythroid 2-related factor (Nrf2) and heme oxygenase-1 (HO-1), and concurrently, reduced intracellular reactive oxygen species accumulation in LPS-treated RAW 264.7 cells. In addition, ZMO treatment markedly upregulated the expression of Nrf2 as well as its target genes, HO-1 and NAD(P)H:quinone oxidoreductase 1 in HepG2 cells. These data propose that ZMO may be a potent candidate for prevention and/or treatment of inflammatory and oxidative conditions.

Therapeutic Potential of Volatile Terpenes and Terpenoids from Forests for Inflammatory Diseases

Forest trees are a major source of biogenic volatile organic compounds (BVOCs). Terpenes and terpenoids are known as the main BVOCs of forest aerosols. These compounds have been shown to display a broad range of biological activities in various human disease models, thus implying that forest aerosols containing these compounds may be related to beneficial effects of forest bathing. In this review, we surveyed studies analyzing BVOCs and selected the most abundant 23 terpenes and terpenoids emitted in forested areas of the Northern Hemisphere, which were reported to display anti-inflammatory activities. We categorized anti-inflammatory processes related to the functions of these compounds into six groups and summarized their molecular mechanisms of action. Finally, among the major 23 compounds, we examined the therapeutic potentials of 12 compounds known to be effective against respiratory inflammation, atopic dermatitis, arthritis, and neuroinflammation among various inflammatory diseases. In conclusion, the updated studies support the beneficial effects of forest aerosols and propose their potential use as chemopreventive and therapeutic agents for treating various inflammatory diseases.

EZH2 inhibition promotes ANGPTL4/CREB1 to suppress the progression of ulcerative colitis

AIMS

Enhancer of zeste homolog 2 (EZH2) is associated with ulcerative colitis development. However, the mechanism of EZH2 in ulcerative colitis progression remains unclear.

MAIN METHODS

Lipopolysaccharide (LPS)-treated Caco-2 cells and dextran sodium sulfate (DSS)-treated mice were used as model of ulcerative colitis. The levels of EZH2, angiopoietin-like 4 (ANGPTL4) and cyclic adenosine monophosphate response element-binding protein 1 (CREB1) were tested via quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Cell viability and apoptosis was measured via 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide or flow cytometry. The abundances of inflammatory cytokines were examined via qRT-PCR and enzyme-linked immunosorbent assay. The association between EZH2 and ANGPTL4 was explored via chromatin immunoprecipitation. The colon damage in DSS-treated mice was investigated by colon length, histological analysis, inflammatory response and apoptosis.

KEY FINDINGS

LPS induced viability inhibition, inflammatory response and apoptosis in Caco-2 cells. EZH2 expression was increased but ANGPTL4 and CREB1 levels were decreased in LPS-challenged Caco-2 cells. Overexpression of ANGPTL4 or CREB1 suppressed LPS-induced damage in Caco-2 cells. EZH2 could target ANGPTL4 to mediate CREB1 expression. Inhibition of EZH2 suppressed LPS-caused injury. Moreover, knockdown of ANNGPTL4 or CREB1 attenuated the role of EZH2 inhibition. DSS caused the reduced colon length and increased inflammatory response as well as apoptosis. EZH2 expression was up-regulated but ANGPTL4 and CREB1 expression were down-regulated in DSS-treated mice.

SIGNIFICANCE

Inhibition of EZH2 declined LPS-induced injury in Caco-2 cells by mediating ANGPTL4 and CREB1, indicating the potential of EZH2 in treatment of ulcerative colitis.

The Abilities of Salidroside on Ameliorating Inflammation, Skewing the Imbalanced Nucleotide Oligomerization Domain-Like Receptor Family Pyrin Domain Containing 3/Autophagy, and Maintaining Intestinal Barrier Are Profitable in Colitis

Salidroside (Sal), as a major glycoside extracted from Rhodiola rosea L., has exhibited its mighty anti-aging, anti-oxidant, anti-cancer, anti-inflammation, and neuroprotective effects in many diseases. Recently, it has showed its protective effect in colitis mice by activating the SIRT1/FoxOs pathway. Whereas, it is not known whether Sal has other protective mechanisms on dextran sulfate sodium (DSS)-induced colitis in mice. In this study, we investigated the protective effects and mechanisms of Sal on DSS-induced colitis in mice. The results demonstrated Sal was a competent candidate in the treatment of ulcerative colitis (UC). Sal remitted DSS-induced disease activity index (DAI), colon length shortening, and colonic pathological damage. Simultaneously, Sal alleviated excessive inflammation by reversing the IL-1β, TNF-α, and IL-10 protein levels in DSS-treated mice. Western blot analysis revealed that Sal inhibited p65 and p38 activation together with peroxisome proliferator-activated receptor (PPARγ) up-regulation. In addition, Sal skewed the imbalanced activation of nucleotide oligomerization domain-like receptor family pyrin domain containing 3 inflammasome and autophagy contributing to colitis recovery. The damaged intestinal barrier induced by DSS was also alleviated along with plasma lipopolysaccharides (LPS) reduction after Sal treatment. In vitro, Sal showed PPARγ-dependent anti-inflammatory effect in LPS-stimulated RAW264.7 cells. In summary, our results demonstrated that Sal might be an effective factor for UC treatment and its pharmacological value deserved further development.

2-O-β-d-Glucopyranosyl-l-ascorbic Acid, an Ascorbic Acid Derivative Isolated from the Fruits of Lycium Barbarum L., Modulates Gut Microbiota and Palliates Colitis in Dextran Sodium Sulfate-Induced Colitis in Mice

In this study, the effects of 2-O-β-d-glucopyranosyl-l-ascorbic acid (AA-2βG), a natural ascorbic acid derivative from the fruits of Lycium barbarum, on treating the dextran sulfate sodium (DSS)-induced colitis in mice were investigated. The results revealed that AA-2βG had palliating effects on DSS-induced inflammatory bowel disease (IBD) in terms of slowing down the trends of body weight and solid fecal mass loss, reducing colitis disease activity index, improving serum physiological and biochemical indicators, increasing colon length, blocking proinflammatory cytokines, and increasing tight junction proteins. Additionally, AA-2βG treatment could promote the production of short-chain fatty acids and modulate the composition of the gut microbiota. The key bacteria related to IBD were found to be Porphyromonadaceae, Prevotellaceae, Rikenellaceae, Parasutterella, Parabacteroides, and Clostridium. The results indicated that AA-2βG might treat IBD through the regulation of gut microbiota, suggesting that AA-2βG has the potential to be used as a dietary supplement in the treatment of IBD.

Toosendanin alleviates dextran sulfate sodium-induced colitis by inhibiting M1 macrophage polarization and regulating NLRP3 inflammasome and Nrf2/HO-1 signaling

Toosendanin (TSN), a triterpenoid extracted from the bark of fruit of Melia toosendan Sieb et Zucc, has been proven to have various biological activities including anti-inflammatory activity. But its effects on experimental colitis remain unreported. Herein, we investigated the role and potential mechanisms of TSN in dextran sulfate sodium (DSS) induced colitis in mice. The results showed that, TSN reduced colitis-associated disease activity index (DAI), shortened colon length, and weakened the pathological damage of the colon tissues in murine colitis models. Further studies disclosed that, TSN inhibited the secretion of proinflammatory cytokines and oxidative stress, and suppressed M1 macrophage polarization and the activation of NLR family pyrin domain containing 3 (NLRP3) inflammasome, but upregulated HO-1/Nrf2 expression in murine colitis. In addition, TSN maintained intestinal barrier by regulating zonula occludens-1 (ZO-1) and occludin expression. In conclusion, our findings demonstrated that, TSN alleviates DSS-induced experimental colitis by inhibiting M1 macrophage polarization and regulating NLRP3 inflammasome and Nrf2/HO-1 signaling, and may provide a novel Chinese patent medicine for the treatment of murine colitis.

Beneficial effects of nutritional supplements on intestinal epithelial barrier functions in experimental colitis models in vivo

Acute and chronic colitis affect a huge proportion of the population world-wide. The etiology of colitis cases can be manifold, and diet can significantly affect onset and outcome of colitis. While many forms of acute colitis are easily treatable, chronic forms of colitis such as ulcerative colitis and Crohn's disease (summarized as inflammatory bowel diseases) are multifactorial with poorly understood pathogenesis. Inflammatory bowel diseases are characterized by exacerbated immune responses causing epithelial dysfunction and bacterial translocation. There is no cure and therapies aim at reducing inflammation and restoring intestinal barrier function. Unfortunately, most drugs can have severe side effects. Changes in diet and inclusion of nutritional supplements have been extensively studied in cell culture and animal models, and some supplements have shown promising results in clinical studies. Most of these nutritional supplements including vitamins, fatty acids and phytochemicals reduce oxidative stress and inflammation and have shown beneficial effects during experimental colitis in rodents induced by dextran sulphate sodium or 2,4,6-trinitrobenzene sulfonic acid, which remain the gold standard in pre-clinical colitis research. Here, we summarize the mechanisms through which such nutritional supplements contribute to epithelial barrier stabilization.

Targeting NLRP3 Inflammasome in Inflammatory Bowel Disease: Putting out the Fire of Inflammation

Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the colon and small intestine, comprised of ulcerative colitis and Crohn's disease. Among the complicated pathogenic factors of IBD, the overaction of inflammatory and immune reaction serves as an important factor. Inflammasome is a form of innate immunity as well as inflammation. Among all kinds of inflammasomes, the NOD-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome is the most studied one, and has been revealed to be involved in the pathogenesis and progression of IBD. Here, in this review, the association between the NLRP3 inflammasome and IBD will be discussed. Furthermore, several NLRP3 inflammasome inhibitors which have been demonstrated to be effective in the alleviation of IBD will be described in this review.

Pingwei San ameliorates dextran sulfate sodium-induced chronic colitis in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Ping weisan (PWS), a famous traditional Chinese medicinal, is published in the Prescriptions of Taiping Benevolent Dispensary. PWS has been proven to be effective for many diseases, especially chronic diseases.

AIM OF THE STUDY

The purpose of this study was to investigate the effect and potential mechanism of PWS on chronic colitis in mice.

MATERIALS AND METHODS

Chronic colitis was induced in mice using 2.5% DSS for two cycles of 5 days, and different doses of PWS (2, 4, 8 g/kg) were administered throughout the experiment. The disease activity index (DAI), length of colon and pathological changes were measured. Cytokine levels in vivo and in vitro were detected by ELISA. The protein levels of TLR4, PPARγ and the key proteins in NF-κB pathway and NLRP3 inflammasome were measured by western blot.

RESULTS

PWS decreased DSS-induced DAI, colon length shortening and colonic pathological damage. PWS also reduced TNF-α, IL-1β and IL-12 production. In addition, PWS suppressed NF-κB pathway activation by regulating the expression of TLR4 and PPARγ. Our data also indicated that PWS could inhibit NLRP3 inflammasome activation.

CONCLUSIONS

PWS treatment alleviated the degree of colitis caused by DSS, suggesting that PWS might be a novel agent for the treatment of chronic colitis.

Evodiamine prevents dextran sulfate sodium-induced murine experimental colitis via the regulation of NF-κB and NLRP3 inflammasome

Evodiamine (EVO), an extraction from the traditional Chinese medicine Evodia rutaecarpa, has been reported to possess anti-inflammatory, anti-tumor and other pharmacological activities. However, the effectiveness of EVO to relieve dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) has not been evaluated. In this study, the protective effects and mechanisms of EVO on DSS-induced UC mice were investigated. The results indicated that treatment with EVO ameliorated DSS-induced UC mice body weight loss, disease activity index (DAI), colon length shortening, colonic pathological damage, and myeloperoxidase (MPO) activity. The production of TNF-α, IL-1β and IL-6 was also significantly inhibited by EVO. Further mechanistic results showed that EVO restrained the inflammation by regulating NF-κB signal and NLRP3 inflammasome. Furthermore, results also showed that EVO contributed to the tight junction (TJ) architecture integrity by modulating the expression of zonula occludens-1 (ZO-1) and occludin during colitis. Surprisingly, treatment with EVO reduced the concentration of plasmatic lipopolysaccharide (LPS) and re-balanced the levels of Escherichia coli and Lactobacillus. These findings suggested that EVO may have a potential protective effect on DSS-induced colitis and may be useful for the prevention and treatment of UC.

The protective role of phloretin against dextran sulfate sodium-induced ulcerative colitis in mice

Phloretin, a dihydrogen chalcone flavonoid, is mainly isolated from apples and strawberries. Phloretin has been proven to have many biological activities such as anti-inflammatory and anti-oxidative. Herein, we investigated the protective efficacy and potential mechanism of phloretin in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. The results showed that phloretin resulted in a reduced DSS-induced disease activity index (DAI), colon length shortening and colonic pathological damage. The levels of pro-inflammatory cytokines in the colon were also decreased by the administration of phloretin. Exploration of the potential mechanism demonstrated that phloretin suppressed the inflammatory response by regulating the nuclear factor-κB (NF-κB), toll-like receptor 4 (TLR4) and peroxisome proliferator-activated receptor γ (PPARγ) pathways. Phloretin also inhibited the DSS-induced (NOD)-like receptor family and pyrin domain containing 3 (NLRP3) inflammasome activations. Further studies found that phloretin reduced key markers of oxidative stress as well as regulated the expression of zonula occludens-1 (ZO-1) and occludin. Interestingly, the concentration of serum lipopolysaccharide (LPS) was significantly decreased. Escherichia coli (E. coli) and Lactobacillus levels were also re-balanced after phloretin treatment. These results indicate that phloretin might be a new dietary strategy for the treatment of UC.

Disruption of blood-brain barrier by an Escherichia coli isolated from canine septicemia and meningoencephalitis

Escherichia coli (E. coli) is one of the common pathogenic bacteria in veterinary clinical infection. As an opportunistic microorganism, E. coli normally does not cause diseases. However, it causes infections under certain circumstance to domesticated animal and poultry, resulting in severe diarrhea, septicemia, and respiratory infections. Although there are increasing reports regarding the infections of E. coli to domestic animals and poultry, the infection of E. coli in dogs is relatively less reported, especially on septicemia and meningoencephalitis. Here, we reported the isolation and identification of an E. coli isolate named CEC-GZL17 from dogs characterized by septicemia and sudden death, and found that CEC-GZL17 is able to cause meningoencephalitis. Exploration on the potential mechanism underlying meningoencephalitis demonstrated that CEC-GZL17 infection significantly increases TNF-α expression and inhibits ZO-1 and occludin expressions in brain tissue, indicating that the E coli likely use the mechanism to penetrate the blood-brain barrier via disrupting tight junction architecture, thus leading to the invasion to brain tissue.

Protective Effect of Naringin on DSS-Induced Ulcerative Colitis in Mice

Peroxisome proliferator-activated receptor γ (PPARγ) is an important member of the nuclear receptor superfamily. Previous studies have shown the satisfactory anti-inflammatory role of PPARγ in experimental colitis models, mainly through negatively regulating several transcription factors such as nuclear factor-κB (NF-κB). Therefore, regulating PPARγ and PPARγ-related pathways has great promise for treating ulcerative colitis (UC). In the present study, our objective was to explore the potential effect of naringin on dextran sulfate sodium (DSS) induced UC in mice and its involved potential mechanism. We found that naringin significantly relieved DSS-induced disease activities index (DAI), colon length shortening, and colonic pathological damage. Exploration of the potential mechanisms demonstrated that naringin significantly activated DSS-induced PPARγ and subsequently suppressed NF-κB activation. PPARγ inhibitor GW9662 largely abrogated the roles of naringin in vitro. Moreover, DSS induced the activation of mitogen-activated protein kinase (MAPK) and (NOD)-like receptor family pyrin domain containing 3 (NLRP3) inflammasome was inhibited by naringin. Tight junction (TJ) architecture in naringin groups was also maintained by regulating zonula occludens-1 (ZO-1) expression. These results suggested that naringin may be a potential natural agent for protecting mice from DSS-induced UC.

Medicinal properties of terpenes found in Cannabis sativa and Humulus lupulus

Cannabaceae plants Cannabis sativa L. and Humulus lupulus L. are rich in terpenes - both are typically comprised of terpenes as up to 3-5% of the dry-mass of the female inflorescence. Terpenes of cannabis and hops are typically simple mono- and sesquiterpenes derived from two and three isoprene units, respectively. Some terpenes are relatively well known for their potential in biomedicine and have been used in traditional medicine for centuries, while others are yet to be studied in detail. The current, comprehensive review presents terpenes found in cannabis and hops. Terpenes' medicinal properties are supported by numerous in vitro, animal and clinical trials and show anti-inflammatory, antioxidant, analgesic, anticonvulsive, antidepressant, anxiolytic, anticancer, antitumor, neuroprotective, anti-mutagenic, anti-allergic, antibiotic and anti-diabetic attributes, among others. Because of the very low toxicity, these terpenes are already widely used as food additives and in cosmetic products. Thus, they have been proven safe and well-tolerated.

Influence of Microbiota on Intestinal Immune System in Ulcerative Colitis and Its Intervention

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) with chronic and recurrent characteristics caused by multiple reasons. Although the pathogenic factors have not been clarified yet, recent studies have demonstrated that intestinal microbiota plays a major role in UC, especially in the immune system. This review focuses on the description of several major microbiota communities that affect UC and their interactions with the host. In this review, eight kinds of microbiota that are highly related to IBD, including Faecalibacterium prausnitzii, Clostridium clusters IV and XIVa, Bacteroides, Roseburia species, Eubacterium rectale, Escherichia coli, Fusobacterium, and Candida albicans are demonstrated on the changes in amount and roles in the onset and progression of IBD. In addition, potential therapeutic targets for UC involved in the regulation of microbiota, including NLRPs, vitamin D receptor as well as secreted proteins, are discussed in this review.