The coumarin component isofraxidin targets the G-protein-coupled receptor S1PR1 to modulate IL-17 signaling and alleviate ulcerative colitis.

OBJECTIVE: The increasing global prevalence of ulcerative colitis (UC) underscores the imperative to explore novel therapeutic approaches. Traditional Chinese medicine has historically shown potential in addressing this ailment. The current study aimed to elucidate the functional attributes and underlying mechanisms of isofraxidin, a coumarin derivative from Acanthopanax, in the context of UC. METHODS: A murine model of dextran sodium sulfate (DSS)-induced UC was established, and we conducted a comprehensive assessment of the influence of isofraxidin on UC symptomatology, colonic histopathological manifestations, the inflammatory response, and apoptosis. The potential receptor of isofraxidin was initially identified through the Target database and molecular docking analysis. Subsequent in vivo and in vitro experiments were conducted to determine the effects of isofraxidin on the identified receptor and associated signaling pathways. Transfection was used to examine the receptor's role in the regulatory mechanism of isofraxidin. RESULTS: Isofraxidin reduced UC symptoms and colonic histopathological impairments. Furthermore, isofraxidin ameliorated the DSS-induced inflammatory response and apoptosis in tissues. S1PR1 was identified as a target of isofraxidin and effectively suppressed activation of the IL-17 signaling pathway. Intriguingly, cellular experiments indicated that overexpression of S1PR1 counteracted the protective effect of isofraxidin. DISCUSSION: In summary, our investigation revealed that isofraxidin could modulate S1PR1 and regulate the IL-17 signaling pathway, thus ameliorating DSS-induced UC. These findings establish a robust foundation for considering isofraxidin as a prospective therapeutic intervention to treat UC.

Hypersampsonone H attenuates ulcerative colitis via inhibition of PDE4 and regulation of cAMP/PKA/CREB signaling pathway.

BACKGROUND AND OBJECTIVES: Ulcerative colitis (UC) is a recurrent intestinal inflammatory disease which poses a serious threat to the life of patients. However, there are no specific drugs for UC yet. Hypericum sampsonii Hance (HS) is a Chinese herbal medicine traditionally used to treat enteritis and dysentery. Our previous studies have demonstrated that HS holds potential anti-UC effects, and a novel compound named Hypersampsonone H (HS-1) isolated from HS possesses significant anti-inflammatory activity. However, the beneficial effects of HS-1 on UC remain unclear. This study aimed to investigate the therapeutic effects of HS-1 on UC and its potential mechanisms, both in vitro and in vivo. METHODS: The in vitro model was employed using LPS-induced RAW264.7 cells to investigate the anti-inflammatory effects of HS-1 and its possible mechanisms. Furthermore, the therapeutic efficacy and potential mechanisms of HS-1 against dextran sulfate sodium (DSS)-induced acute colitis were assessed through histopathological examination, biochemical analysis, and molecular docking. RESULTS: In vitro, HS-1 significantly reduced LPS-induced inflammatory responses, as indicated by inhibiting NO production, down-regulating the overexpression of COX-2 and iNOS, as well as regulating the imbalanced levels of IL-6, TNF-α, and IL-10. Moreover, HS-1 also inhibited the expression of PDE4, elevated the intracellular cAMP level, and promoted the phosphorylation of CREB, thereby activating the PKA/CREB pathway in RAW264.7 cells. In vivo, HS-1 demonstrated therapeutic capacity against DSS-induced colitis by alleviating the symptoms of colitis mice, regulating the abnormal expression of inflammatory mediators, protecting the integrity of intestinal epithelial barrier, and reducing tissue fibrosis. Consistently, HS-1 was found to decrease the expression of PDE4 isoforms, subsequently activating the cAMP/PKA/CREB signaling pathway. Furthermore, the molecular docking results indicated that HS-1 exhibited a high affinity for PDE4, particularly PDE4D. Further mechanistic validation in vitro demonstrated that HS-1 possessed a synergistic effect on forskolin and an antagonistic effect on H-89 dihydrochloride, thereby exerting anti-inflammatory effects through the cAMP/PKA/CREB signaling pathway. CONCLUSION: We disclose that HS-1 serves as a promising candidate drug for the treatment of UC by virtue of its ability to reduce DSS-induced colitis via the inhibition of PDE4 and the activation of cAMP/PKA/CREB signaling pathway.

Isofraxidin attenuates dextran sulfate sodium-induced ulcerative colitis through inhibiting pyroptosis by upregulating Nrf2 and reducing reactive oxidative species.

BACKGROUND: Ulcerative colitis (UC), a non-specific gastrointestinal disease, is commonly managed with aminosalicylic acids and immunosuppressive agents to control inflammation and relieve symptoms, despite frequent relapses. Isofraxidin is a coumarin compound extracted from traditional Chinese medicine, exhibiting anti-inflammatory and antioxidant properties; however, its alleviating effect on UC remains unclear. Therefore, we investigated the mechanism of isofraxidin in lipopolysaccharide (LPS)-induced cell inflammation in human intestinal epithelial cell (HIEC) and human colorectal adenocarcinoma cells (Caco-2), as well as in dextran sulfate sodium (DSS)-induced UC in mice. METHODS: We established colitis models in HIEC and Caco-2 cells and mice with LPS and DSS, respectively. Additionally, NLRP3 knockout mice and HIEC cells transfected with NLRP3 silencing gene and ML385 illustrated the role of isofraxidin in pyroptosis and oxidative stress. Data from cells and mice analyses were subjected to one-way analysis of variance or a paired t-test. RESULTS: Isofraxidin significantly alleviated LPS-induced cell inflammation and reduced lactic dehydrogenase release. Isofraxidin also reversed DSS- or LPS-induced pyroptosis in vivo and in vitro, increasing the expression of pyroptosis-related proteins. Moreover, isofraxidin alleviated oxidative stress induced by DSS or LPS, reducing reactive oxidative species (ROS), upregulation nuclear factor erythroid 2-related factor 2 (Nrf2), and promoting its entry into the nucleus. Mechanistically, ML385 reversed the inhibitory effect of isofraxidin on ROS and increased pyroptosis. CONCLUSION: Isofraxidin can inhibit pyroptosis through upregulating Nrf2, promoting its entry into the nucleus, and reducing ROS, thereby alleviating DSS-induced UC. Our results suggest isofraxidin as a promising therapeutic strategy for UC treatment.

peu-MIR2916-p3-enriched garlic exosomes ameliorate murine colitis by reshaping gut microbiota, especially by boosting the anti-colitic Bacteroides thetaiotaomicron.

Plant-derived exosome-like nanoparticles (ELNs) have drawn considerable attention for oral treatment of colonic diseases. However, the roles of ELNs derived from garlic on colitis remain unclear. Here, we demonstrate that garlic ELNs (GELNs), with desirable particle sizes (79.60 nm) and trafficking large amounts of functional proteins and microRNAs, stably roam in the gut and confer protection against ulcerative colitis (UC). In mice with DSS-induced colitis, orally administered GELNs effectively ameliorated bloody diarrhea, normalized the production of proinflammatory cytokines, and prevented colonic barrier impairment. Mechanistically, GELNs were taken up by gut microbes and reshaped DSS-induced gut microbiota dysbiosis, in which Bacteroides was the dominant respondent genus upon GELNs treatment. Notably, GELNs-enriched peu-MIR2916-p3 specifically promoted the growth of Bacteroides thetaiotaomicron, an intestinal symbiotic bacterium with palliative effects on colitis. Our findings provide new insights into the medicinal application of GELNs and highlight their potential as natural nanotherapeutic agents for preventing and treating UC.

Gentianine alleviates dextran sulfate sodium-induced ulcerative colitis via inhibition of TLR4/NLRP3-mediated pyroptosis.

OBJECTIVES: Ulcerative colitis (UC) is a common inflammatory bowel disorder. Gentiana scabra Bunge is a traditional medicinal plant that is used to treat a variety of diseases. Studies have shown that gentianine (GTN) from Gentiana scabra inhibits the development of inflammatory diseases. The purpose of this study was to investigate the effect and possible mechanism of action of GTN on UC in mice. METHODS: An animal model of UC was established using dextran sulfate sodium (DSS). Mice were administered intraperitoneally with GTN (12.5, 25, or 50 mg/kg/day) for seven days. Body weight and disease activity index (DAI) were monitored daily during GTN administration. Colon length, pathological changes, and myeloperoxidase (MPO) activity were measured following GTN administration. The signalling pathways regulated by GTN were analysed using machine learning. HT-29 cells were used to verify the effect and mechanism of action of GTN on UC in vitro. RESULTS: GTN suppressed weight loss, shortened colon length, alleviated colon injury, and reduced the DAI score and MPO activity of mice with UC in a dose-dependent manner. Further analysis showed that GTN inhibited the NOD-like receptor (NLR) signalling pathway. GTN markedly decreased the levels of NLR signalling pathway-related proteins. Moreover, GTN decreased the levels of pyroptosis-related proteins, IL-1ß and IL-18. The in vitro data were consistent with those of animal experiments. Furthermore, TLR4 and NLRP3 overexpression eliminated the protective effects of GTN in HT-29 cells. CONCLUSION: Gentianine alleviated DSS-induced UC by inhibiting TLR4/NLRP3-mediated pyroptosis.

1,25(OH)2D3 alleviates oxidative stress and inflammation through up-regulating HMGCS2 in DSS-induced colitis.

BACKGROUND: Previous study found that supplements with active vitamin D3 alleviated experimental colitis. The objective of this study was to investigate the possible role of 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), a ketone synthase, on vitamin D3 protecting against experimental colitis. METHODS: HMGCS2 and vitamin D receptor (VDR) were measured in UC patients. The effects of vitamin D deficiency (VDD) and exogenous 1,25(OH)2D3 supplementation on experimental colitis were investigated in dextran sulfate sodium (DSS)-treated mice. DSS-induced oxidative stress and inflammation were analyzed in HT-29 cells. HMGCS2 was detected in 1,25(OH)2D3-pretreated HT-29 cells and mouse intestines. HMGCS2 was silenced to investigate the role of HMGCS2 in 1,25(OH)2D3 protecting against experimental colitis. RESULTS: Intestinal HMGCS2 downregulation was positively correlated with VDR reduction in UC patients. The in vivo experiments showed that VDD exacerbated DSS-induced colitis. By contrast, 1,25(OH)2D3 supplementation ameliorated DSS-induced colon damage, oxidative stress and inflammation. HMGCS2 was up-regulated after 1,25(OH)2D3 supplementation both in vivo and in vitro. Transfection with HMGCS2-siRNA inhibited antioxidant and anti-inflammatory effects of 1,25(OH)2D3 in DSS-treated HT-29 cells. CONCLUSION: 1,25(OH)2D3 supplementation up-regulates HMGCS2, which is responsible for 1,25(OH)2D3-mediated protection against oxidative stress and inflammation in DSS-induced colitis. These findings provide a potential therapeutic strategy for alleviating colitis-associated oxidative stress and inflammation.

Oral administration of Huanglian-Houpo herbal nanoemulsion loading multiple phytochemicals for ulcerative colitis therapy in mice.

How to achieve stable co-delivery of multiple phytochemicals is a common problem. This study focuses on the development, optimization and characterization of Huanglian-HouPo extract nanoemulsion (HLHPEN), with multiple components co-delivery, to enhance the anti-ulcerative colitis (UC) effects. The formulation of HLHPEN was optimized by pseudo-ternary phase diagram combined with Box-Behnken design. The physicochemical properties of HLHPEN were characterized, and its anti-UC activity was evaluated in DSS-induced UC mice model. Based on preparation process optimization, the herbal nanoemulsion HLHPEN was obtained, with the droplet size, PDI value, encapsulation efficiency (EE) for 6 phytochemicals (berberine, epiberberine, coptisine, bamatine, magnolol and honokiol) of 65.21 ± 0.82 nm, 0.182 ± 0.016, and 90.71 ± 0.21%, respectively. The TEM morphology of HLHPEN shows the nearly spheroidal shape of particles. The optimized HLHPEN showed a brownish yellow milky single-phase and optimal physical stability at 25 °C for 90 days. HLHPEN exhibited the good particle stability and gradual release of phytochemicals in SGF and SIF, to resist the destruction of simulated stomach and small intestine environment. Importantly, the oral administration of HLHPEN significantly restored the shrunk colon tissue length and reduced body weight, ameliorated DAI value and colon histological pathology, decreased the levels of inflammatory factors in DSS-induced UC mice model. These results demonstrated that HLHPEN had a significant therapeutic effect on DSS-induced UC mice, as a potential alternative UC therapeutic agent.

[Mechanism of famous classical formula Huaihua Powder in treatment of ulcerative colitis based on metabonomics].

Ultra-high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry(UHPLC-Q-TOF-MS) was employed in this study to observe the effect of Huaihua Powder on the serum metabolites of mice with ulcerative colitis and reveal the mechanism of Huaihua Powder in the treatment of ulcerative colitis. The mouse model of ulcerative colitis was established by dextran sodium sulfate salt(DSS). The therapeutic effect of Huaihua Powder on ulcerative colitis was preliminarily evaluated based on the disease activity index(DAI), colon appearance, colon tissue morphology, and the content of inflammatory cytokines such as tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), and interleukin-1ß(IL-1ß). UHPLC-Q-TOF-MS was employed to profile the endogenous metabolites of serum samples in blank control group, model group, and low-, medium-, and high-dose Huaihua Powder groups. Multivariate analyses such as principal component analysis(PCA), partial least squares discriminant analysis(PLS-DA), and orthogonal partial least squares discriminant analysis(OPLS-DA) were performed for pattern recognition. Potential biomarkers were screened by Mass Profiler Professional(MPP) B.14.00 with the thresholds of fold change≥2 and P<0.05. The metabolic pathways were enriched by MetaboAnalyst 5.0. The results showed that Huaihua Powder significantly improved the general state and colon tissue morphology of mice with ulcerative colitis, reduced DAI, and lowered the levels of TNF-α, IL-6, and IL-1ß in serum. A total of 38 potential biomarkers were predicted to be related to the regulatory effect of Huaihua Powder, which were mainly involved in glycerophospholipid metabolism, glycine, serine, and threonine metabolism, mutual transformation of glucuronic acid, and glutathione metabolism. This study employed metabolomics to analyze the mechanism of Huaihua Powder in the treatment of ulcerative colitis, laying a foundation for the further research.

Isochlorogenic acid A alleviates dextran sulfate sodium-induced ulcerative colitis in mice through STAT3/NF-кB pathway.

Isochlorogenic acid A (ICGA-A) is a dicaffeoylquinic acid widely found in various medicinal plants or vegetables, such as Lonicerae japonicae Flos and chicory, and multiple properties of ICGA-A have been reported. However, the therapeutic effect of ICGA-A on colitis is not clear, and thus were investigated in our present study, as well as the underlying mechanisms. Here we found that ICGA-A alleviated clinical symptoms of dextran sodium sulfate (DSS) induced colitis model mice, including disease activity index (DAI) and histological damage. In addition, DSS-induced inflammation was significantly attenuated in mice given ICGA-A supplementation. ICGA-A reduced the fraction of neutrophils in peripheral blood and the infiltration of neutrophils and macrophages in colon tissue, and reduced pro-inflammatory cytokine production and tight junctions in mouse models. Furthermore, ICGA-A down-regulated expression of STAT3 and up-regulated the protein level of IκBα. Our in vitro studies confirmed that ICGA-A inhibited the mRNA expression of pro-inflammatory cytokines. ICGA-A blocked the phosphorylation of STAT3, p65, and IκBα, suppressed the expression STAT3 and p65. In addition, the present study also demonstrated that ICGA-A had no obvious toxicity on normal cells and organs. Taken together, we conclude that ICGA-A mitigates experimental ulcerative colitis (UC) at least in part by inhibiting the STAT3/NF-кB signaling pathways. Hence, ICGA-A may be a promising and effective drug for treating UC.

Dioscin modulates macrophages polarization and MDSCs differentiation to inhibit tumorigenesis of colitis-associated colorectal cancer.

It has been reported that colitis is one of risk factors in colorectal cancer (CRC). Intervention of intestinal inflammation and in the early stage of tumorigenesis is of great significance to control the incidence and mortality of CRC. In recent years, natural active products of traditional Chinese medicine have been confirmed that they had made great progress in disease prevention. Here, we showed that Dioscin, a natural active product of Dioscorea nipponica Makino, inhibited initiation and tumorigenesis of AOM/DSS-induced colitis-associated colon cancer (CAC), including alleviating colonic inflammation, improving intestinal barrier function and decreasing tumor burden. In addition, we also explored the immunoregulatory effect of Dioscin on mice. The results showed that Dioscin modulated M1/M2 macrophages phenotype in spleen and decreased monocytic myeloid-derived suppressor cells (M-MDSCs) population in blood and spleen of mice. The in vitro assay demonstrated that Dioscin promoted M1 as well as inhibited M2 macrophages phenotype in LPS- or IL-4-induced bone marrow-derived macrophages (BMDMs) model. Based on the plasticity of MDSCs and its ability to differentiate into M1/M2 macrophages, we here found that Dioscin increased M1- and decreased M2-like phenotype during the process of MDSCs differentiation in vitro, suggesting Dioscin promoted MDSCs differentiate into M1 as well as inhibited its differentiation into M2 macrophages. Taken together, our study indicated that Dioscin had the inhibitory effect on the initial of tumorigenesis at early stage of CAC via the ant-inflammatory effect, which provided a natural active candidate for effective prevention of CAC.

Sodium houttuyfonate derived from Houttuynia cordata Thunb improves intestinal malfunction via maintaining gut microflora stability in Candida albicans overgrowth aggravated ulcerative colitis.

Candida albicans is a common opportunistic pathogen and normally resides in the human gut. Increasing number of reports link the overgrowth of C. albicans to the severity of ulcerative colitis (UC). Sodium houttuyfonate (SH), a derivative of the medicinal herb Houttuynia cordata Thunb, has been demonstrated to exhibit decent antifungal and anti-inflammatory activities. We showed previously that SH could ameliorate colitis mice infected with C. albicans. However, it is unclear whether the therapeutic effect of SH is connected to its modulation of intestinal microflora in UC. In this study, the impact of SH on the gut microbiota was explored in both cohabitation and non-cohabitation patterns. The results showed that in UC mice inflicted by C. albicans, the administration of SH could greatly improve the pathological signs, weaken the oxidative stress and inflammatory response, and enhance the intestinal mucosal integrity. By 16S rRNA gene sequencing, we found that C. albicans interference caused intestinal microbiota dysbiosis accompanied by an increase of some harmful pathogens including Klebsiella and Bacteroides. In contrast, SH could modulate the abundance and diversity of microbiota with an increase of several beneficial bacteria comprising short-chain fatty acid-producing bacteria (Lachnospiraceae_NK4A136_group, Intestinimonas) and probiotics (Lactobacillus and Alloprevotella). Furthermore, the cohabitation strategy could also prove the efficacy of SH, indicating a role of transmissible gut flora in the colitis model. These findings suggest that SH might be an effective compound for the treatment of UC complicated by C. albicans overgrowth through maintaining gut microbiota homeostasis, thereby improving intestinal function.

The Role of AMPK Signaling in Ulcerative Colitis.

Ulcerative colitis (UC) is a chronic non-specific inflammatory bowel disease characterized by inflammation and ulcer formation of the intestinal mucosa. Due to its high recurrence rate, prolonged course, limited curative options, and significant impact on patients' quality of life, along with a notable potential for malignant transformation, UC is designated as a refractory global health challenge by the World Health Organization (WHO). The elucidation of the pathogenesis and therapeutic strategies for UC requires further in-depth investigation. AMP-activated protein kinase (AMPK) serves as a central regulator of cellular energy metabolic homeostasis. Emerging evidence indicates that interventions involving traditional Chinese medicine (TCM) components, as well as other pharmacological measures, exert beneficial effects on the intestinal mucosal inflammation and epithelial barrier dysfunction in UC by modulating AMPK signaling, thereby influencing biological processes such as cellular autophagy, apoptosis, inflammatory responses, macrophage polarization, and NLRP3 inflammasome-mediated pyroptosis. The role of AMPK in UC is of significant importance. This manuscript provides a comprehensive overview of the mechanisms through which AMPK is involved in UC, as well as a compilation of pharmacological agents capable of activating the AMPK signaling pathway within the context of UC. The primary objective is to facilitate a deeper comprehension of the pivotal role of AMPK in UC among researchers and clinical practitioners, thereby advancing the identification of novel therapeutic targets for interventions in UC.

Protective effects of amoxicillin and probiotics on colon disorders in an experimental model of acute diverticulitis disease.

Acute diverticulitis disease is associated with inflammation and infection in the colon diverticula and may lead to severe morbidity. This study aimed to evaluate and compare the protective effects of amoxicillin antibiotic, either alone or in combination with probiotics (Lactobacillus acidophilus and Bifidobacterium lactis), in a rat model of acute diverticulitis disease. Acute diverticulitis was induced, in albino rats, by adding 3% weight/volume of dextran sulfate sodium (DSS) to the rats' drinking water; daily for 7 days, in addition to injecting lipopolysaccharide (LPS) enema (4 mg/kg). The impact of treatments was assessed by measuring the physiological and immunological parameters and evaluating colon macroscopic and microscopic lesions. The results showed that both treatments (especially probiotics with amoxicillin) alleviated the adverse effects of DSS and LPS. This was obvious through the modulation of the rats' body weight and the colon weight-to-length ratio. Also, there was a significant (p < 0.001) decrease in the colon macroscopic lesion score. The pro-inflammatory cytokines [(TNF)-α, (IL)-1ß, (IFN)-γ, and (IL)-18]; in the colon tissue; were significantly (p < 0.001) decreased. Also, both treatments significantly ameliorated the elevation of myeloperoxidase activity and C-reactive protein levels, in addition to improving the histopathological alterations in the colon tissue. In conclusion, amoxicillin and probiotics-amoxicillin were effective in preventing the development of experimentally induced acute diverticulitis, through their anti-inflammatory and immunomodulatory effects. Furthermore, this study has explored the role of probiotics in preventing DSS/LPS-induced acute diverticulitis, so it can be applied as a promising treatment option for acute diverticulitis disease.

Demethyleneberberine blocked the maturation of IL-1ß in inflammation by inhibiting TLR4-mitochondria signaling.

Demethyleneberberine (DMB) is a natural product from traditional Chinese medicinal herb the rhizome of Coptis chinensis Franch., which has been reported to possess multiple pharmacological activities, especially anti-inflammation and immunoregulation. However, the potential mechanism of DMB in inflammation is still a mystery. In this study, a mouse model of ulcerative colitis (UC) was induced by Dextran sulfate sodium salt (DSS), and in vitro experiments were performed in RAW264.7 macrophages and the primary intestinal macrophages which obtained from Toll-Like receptor 4 (TLR4) and NOD-Like receptor protein 3 (NLRP3) knockout fetal mouse. Mitochondrial was increased by overexpression of peroxlsome proliferator-activated receptor-γ coactlvator-1α (PGC-1α) and exhausted by adding Ethidium Bromide (EtBr) in RAW264.7 to evaluate the function of mitochondria in the maturation of IL-1ß. Additionally, the safety of DMB (50 mg/kg/d) in mice was assessed by orally administrating for 98 days. DMB siginificantly improved colon atrophy, colonic tissue mass score, neutrophil infiltration and histological damage, which was mainly attributed to the anti-inflammatory effect of DMB. Further in vitro analysis showed that DMB blocked the excessive mitochondrial biosynthesis and maintained the homeostasis of mitochondria in inflammatory response. Moreover, the maturation of IL-1ß was suppressed by DMB in a mitochondria dependent manner. Crucially, DMB was a candidate agent for UC with free of toxicity and side effects. These findings demonstrated that DMB ameliorated inflammatory response by inhibiting TLR4-mitochondria signaling, and revealed the effectiveness and mechanism of DMB for alleviation of UC and provided an additional strategy for UC intervention.

Effect and Mechanism of Pharmaceutical Excipients on Berberine to Alleviate Ulcerative Colitis via Regulating Gut Microbiota.

BACKGROUND: Various potential effect of drugs on alleviating diseases by regulating intestinal microbiome as well as the pharmaceutical excipients on gut microbiota has been revealed. However, the interaction between them is rarely investigated. METHODS: Histological analysis, immunohistochemistry analysis, enzyme-linked immunosorbent assay (ELISA) analysis, RT-qPCR, and 16S rRNA analysis were utilized to explore the effect mechanism of the five excipients including hydroxypropyl methylcellulose (HPMC) F4M, Eudragit (EU) S100, chitosan (CT), pectin (PT), and rheum officinale polysaccharide (DHP) on berberine (BBR) to cure UC. RESULTS: The combined BBR with PT and DHP group exhibited better therapeutic efficacy of UC with significantly increased colon length, and decreased hematoxylin-eosin (H&E) scores than other groups. Furthermore, the expression of tight junction ZO-1 and occludin in colon tissue were upregulated, and claudin-2 was downregulated. Ultimately, the serum content of tumor necrosis (TNF)-α, interleukin (IL)-1ß, and IL-6 was decreased. Moreover, the combined BBR with PT significantly promoted the restoration of gut microbiota. The relative abundance of Firmicutes and Lactobacillus was significantly increased by the supplement of PT and DHP, and the relative abundance of Proteobacteria was downregulated. CONCLUSIONS: Our study may provide a new perspective that the selection of pharmaceutical excipients could be a crucial factor affecting the drugs' therapeutic efficiency outcome.

Effects of oral administration and intravenous injection of polygalacturonic acid on the immunomodulation and gut microbiota in UC mice.

This study aimed to compare the differences between oral administration and intravenous injection of polygalacturonic acid (PGA) in the regulation of immune and intestinal microflora in ulcerative colitis (UC) mice. PGA was administered orally or intravenously. PGA in the high-dose ig group was the most effective in treating UC by increasing colon length and downregulating disease activity index, histopathological score and proinflammatory cytokine levels. In spleen, the efficacy of PGA on restoring Th17/Treg balance in the high-dose iv group was better than that in the high-dose ig group, the opposite was observed in the lamina propria. The level of colonic IL-17A in the high-dose ig group was lower than that in the high-dose iv group, the opposite was observed for that of colonic IL-10. Western blot and immunohistochemistry analysis revealed that PGA in the high-dose ig group decreased the protein expression of RORγt, and increased that of FOXP3. Furthermore, PGA in the high-dose ig group was more effective than that in the high-dose iv group in improving the intestinal microflora structure. Our results suggest that in immune regulation, oral PGA is more effective in the lamina propria and gut microbiota while intravenous PGA is more effective in the spleen.

Honokiol alleviates ulcerative colitis by targeting PPAR-γ-TLR4-NF-κB signaling and suppressing gasdermin-D-mediated pyroptosis in vivo and in vitro.

Ulcerative colitis (UC) is a chronic, idiopathic relapsing inflammatory bowel disease. Honokiol is a major active component of the traditional Chinese medicinal herb Magnolia officinalis, which has been widely used in traditional prescriptions to treat tumors, inflammation, and gastrointestinal disorders. In this study, we investigated the ability of this polyphenolic compound to suppress UC in mice and the possible regulatory mechanism. A mouse model of UC induced with dextran sulfate sodium (DSS) in 40 male C57BL/6J mice was used for the in vivo study, and in vitro experiments were performed in mouse RAW264.7 macrophages. Lipopolysaccharide was used to induce the inflammatory response. The mouse bodyweights, stool consistency, and bleeding were determined and the disease activity indices calculated. RAW264.7 macrophages were cultured with or without either honokiol or lipopolysaccharide. Gene and protein expression was analyzed with RT-PCR and western blotting, respectively. GW6471 and GW9662 were used to interrupt the transcription of peroxisome proliferator activated receptor alpha (PPAR-α) and peroxisome proliferator activated receptor gamma (PPAR-γ). Both the in vivo and in vitro experimental results showed that the oral administration of honokiol markedly attenuated the severity of UC by reducing the inflammatory signals and restoring the integrity of the colon. Honokiol dramatically reduced the proinflammatory cytokines TNF-α, IL6, IL1ß, and IFN-γ in mice with DSS-induced UC. It also upregulated PPAR-γ expression, and downregulated the TLR4-NF-κB signaling pathway. Moreover, honokiol inhibited gasdermin-D-mediated cell pyroptosis. These findings demonstrate for the first time that honokiol exerts a strong anti-inflammatory effect in a mouse model of UC, and that its underlying mechanism is associated with the activation of the PPAR-γ-TLR4-NF-κB signaling pathway and gasdermin-D-mediated macrophage pyroptosis. Therefore, honokiol may be a promising new drug for the clinical management of UC.

Cryptotanshinone ameliorates dextran sulfate sodium-induced murine acute and chronic ulcerative colitis via suppressing STAT3 activation and Th17 cell differentiation.

Ulcerative colitis (UC) is a chronically relapsing inflammatory disease in the intestinal tract. Current unsatisfactory treatments prompt people to seek for alternative therapies and drug candidates. Cryptotanshinone (CTS), a diterpene quinoneextractedfromthe roots ofSalviamiltiorrhiza, has recently been shown to inhibit acute colitis by reducing pro-inflammatory mediators. However, whether CTS can protect against chronic UC and its effect on T lymphocytes remain unknown. In this study, CTS (20, 60 mg/kg) showed potent inhibitory activity against dextran sulfate sodium (DSS)-induced acute UC, as determined by weight loss, disease activity, colon length and histology. Similarly, in a model of DSS-induced chronic colitis, the administration of CTS prevented the disease progression with longer colon length, lower histological scores, and less expression of fibrosis-related collagen and α-smooth muscle actin in the colon. CTS also reduced the proportion of CD4+IL-17A+ Th17 cells in spleen and mesenteric lymph nodes of mice with acute or chronic colitis. However, CTS at 20 mg/kg had no effect on regulatory T cells (Tregs). In addition, CTS reduced the phosphorylation of signal transduction and transcription activator 3 (STAT3) in DSS-treated colon tissue. Further study showed that CTS concentration-dependently suppressed the differentiation of naïve CD4+ T cells into Th17 cells. CTS could not inhibit the activation and proliferation of T lymphocytes or attenuate the secretion of cytokines including IL-10, IL-2, IL-6 and IFN-γ, but could inhibit the production of IL-17A and TNF-α in Con A-stimulated splenocytes. CTS suppressed IL-6-induced phosphorylation and nuclear translocation of STAT3. In conclusion, our study demonstrated that CTS alleviated acute and chronic UC by suppressing STAT3 activation and Th17 cell differentiation, suggesting that it may be a promising candidate drug for the treatment of UC.

Anti-inflammatory effects of the Aralia elata and Cirsium japonicum in Raw264.7 cells and in vivo colitis model in mice and dogs.

Ulcerative colitis (UC) is a severe inflammatory disease that has spread throughout the world. Cirsium japonicum (CJ) and Aralia elata (AE) are natural herbs with potent antioxidative antidiabetics and anti-inflammatory effects. In this investigation, we studied the defensive role of the combination of CJ and AE against LPS-induced inflammation in RAW 264.7 cells, dextran sulfate sodium (DSS)-induced colitis in mice, and acetic acid-induced colitis in dogs. MTT assay was performed to identify the toxic effect of CJ and AE extracts. NO, and MDA level was also measured by NO and MDA assay. To measure the pro-inflammatory protein expression, a western blot was performed. To induce colitis, 3% DSS was used for mice and 6% acetic acid was used for dogs. Histopathology and colonoscopy were executed to detect the effect of extracts. CJ and AE pretreatment reduced the level of NO, MDA, and the expression of pro-inflammatory proteins cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) in RAW 264.7. Compared to the separate doses of CJ and AE, the combined dose of CJ and AE significantly reduced clinical symptoms induced by DSS in mice and acetic acid in dogs including weight loss, bloody stool, shortening of the colon, and the severity of colitis and degree of histological damage in the colon. Therefore, these results indicated that a combined dose of CJ and AE has a protective effect against LPS-induced RAW 264.7 cells, DSS-mediated colonic inflammation in mice, and acetic acid-induced colitis in dogs.

Taxifolin Alleviates DSS-Induced Ulcerative Colitis by Acting on Gut Microbiome to Produce Butyric Acid.

Taxifolin is a bioflavonoid which has been used to treat Inflammatory Bowel Disease. However, taxifolin on DSS-induced colitis and gut health is still unclear. Here, we studied the effect of taxifolin on DSS-induced intestinal mucositis in mice. We measured the degree of intestinal mucosal injury and inflammatory response in DSS treated mice with or without taxifolin administration and studied the changes of fecal metabolites and intestinal microflora using 16S rRNA. The mechanism was further explored by fecal microbiota transplantation. The results showed that the weight loss and diarrhea score of the mice treated with taxifolin decreased in DSS-induced mice and longer colon length was displayed after taxifolin supplementation. Meanwhile, the expression of GPR41 and GPR43 in the colon was significantly increased by taxifolin treatment. Moreover, the expression of TNF-α, IL-1ß, and IL-6 in colon tissue was inhibited by taxifolin treatment. The fecal metabolism pattern changed significantly after DSS treatment, which was reversed by taxifolin treatment. Importantly, taxifolin significantly increased the levels of butyric acid and isobutyric acid in the feces of DSS-treated mice. In terms of gut flora, taxifolin reversed the changes of Akkermansia, and further decreased uncultured_bacterium_f_Muribaculaceae. Fecal transplantation from taxifolin-treated mice showed a lower diarrhea score, reduced inflammatory response in the colon, and reduced intestinal mucosal damage, which may be related to the increased level of butyric acid in fecal metabolites. In conclusion, this study provides evidence that taxifolin can ameliorate DSS-induced colitis by altering gut microbiota to increase the production of SCFAs.