Ginsenoside Rb1 alleviates colitis in mice via activation of endoplasmic reticulum-resident E3 ubiquitin ligase Hrd1 signaling pathway

Recent developments and new directions in the use of natural products for the treatment of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) represents a significant global health challenge, and there is an urgent need to explore novel therapeutic interventions. Natural products have demonstrated highly promising effectiveness in the treatment of IBD.

PURPOSE

This study systematically reviews the latest research advancements in leveraging natural products for IBD treatment.

METHODS

This manuscript strictly adheres to the PRISMA guidelines. Relevant literature on the effects of natural products on IBD was retrieved from the PubMed, Web of Science and Cochrane Library databases using the search terms "natural product," "inflammatory bowel disease," "colitis," "metagenomics", "target identification", "drug delivery systems", "polyphenols," "alkaloids," "terpenoids," and so on. The retrieved data were then systematically summarized and reviewed.

RESULTS

This review assessed the different effects of various natural products, such as polyphenols, alkaloids, terpenoids, quinones, and others, in the treatment of IBD. While these natural products offer promising avenues for IBD management, they also face challenges in terms of clinical translation and drug discovery. The advent of metagenomics, single-cell sequencing, target identification techniques, drug delivery systems, and other cutting-edge technologies heralds a new era in overcoming these challenges.

CONCLUSION

This paper provides an overview of current research progress in utilizing natural products for the treatment of IBD, exploring how contemporary technological innovations can aid in discovering and harnessing bioactive natural products for the treatment of IBD.

Sulforaphane decreases oxidative stress and inhibits NLRP3 inflammasome activation in a mouse model of ulcerative colitis

Excessive oxidative stress and NLRP3 inflammasome activation are considered the main drivers of inflammatory bowel disease (IBD), and inhibition of inflammasomes ameliorates clinical symptoms and morphological manifestations of IBD. Herein, we examined the roles of NLRP3 activation in IBD and modulation of NLRP3 by sulforaphane (SFN), a compound with multiple pharmacological activities that is extracted from cruciferous plants. To simulate human IBD, we established a mouse colitis model by administering dextran sodium sulfate in the drinking water. SFN (25, 50 mg·kg-1·d-1, ig) or the positive control sulfasalazine (500 mg/kg, ig) was administered to colitis-affected mice for 7 days. Model mice displayed pathological alterations in colon tissue as well as classic symptoms of colitis beyond substantial tissue inflammation. Expression of NLRP3, ASC, and caspase-1 was significantly elevated in the colonic epithelium. The expression of NLRP3 inflammasomes led to activation of downstream proteins and increases in the cytokines IL-18 and IL-1β. SFN administration either fully or partially reversed these changes, thus restoring IL-18 and IL-1β, substantially inhibiting NLRP3 activation, and decreasing inflammation. SFN alleviated the inflammation induced by LPS and NLRP3 agonists in RAW264.7 cells by decreasing the levels of reactive oxygen species. In summary, our results revealed the pathological roles of oxidative stress and NLRP3 in colitis, and indicated that SFN might serve as a natural NLRP3 inhibitor, thereby providing a new strategy for alternative colitis treatment.

Targeting programmed cell death in inflammatory bowel disease through natural products: New insights from molecular mechanisms to targeted therapies

Inflammatory bowel disease (IBD) is an autoimmune disorder primarily characterized by intestinal inflammation and recurrent ulceration, leading to a compromised intestinal barrier and inflammatory infiltration. This disorder's pathogenesis is mainly attributed to extensive damage or death of intestinal epithelial cells, along with abnormal activation or impaired death regulation of immune cells and the release of various inflammatory factors, which contribute to the inflammatory environment in the intestines. Thus, maintaining intestinal homeostasis hinges on balancing the survival and functionality of various cell types. Programmed cell death (PCD) pathways, including apoptosis, pyroptosis, autophagy, ferroptosis, necroptosis, and neutrophil extracellular traps, are integral in the pathogenesis of IBD by mediating the death of intestinal epithelial and immune cells. Natural products derived from plants, fruits, and vegetables have shown potential in regulating PCD, offering preventive and therapeutic avenues for IBD. This article reviews the role of natural products in IBD treatment by focusing on targeting PCD pathways, opening new avenues for clinical IBD management.

Ginsenosides from Panax ginseng as potential therapeutic candidates for the treatment of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by a chronic inflammation of the intestine, which significantly affects patients' quality of life. As a perennial plant with the homology of medicine and food, Panax ginseng is known for its substantial anti-inflammatory effects in various inflammatory disorders. Ginsenosides, the main bioactive compounds of P. ginseng, are recognized for their efficacy in ameliorating inflammation.

PURPOSE

Over the past decade, approximately 150 studies have investigated the effects of P. ginseng and ginsenosides on IBD treatment and new issues have arisen. However, there has yet to be a comprehensive review assessing the potential roles of ginsenosides in IBD therapy.

METHOD

This manuscript strictly adheres to the PRISMA guidelines, thereby guaranteeing systematic synthesis of data. The research articles referenced were sourced from major scientific databases, including Google Scholar, PubMed, and Web of Science. The search strategy employed keywords such as "ginsenoside", "IBD", "colitis", "UC", "inflammation", "gut microbiota", and "intestinal barrier". For image creation, Figdraw 2.0 was methodically employed.

RESULTS

Treatment with various ginsenosides markedly alleviated clinical IBD symptoms. These compounds have been observed to restore intestinal epithelia, modulate cellular immunity, regulate gut microbiota, and suppress inflammatory signaling pathways.

CONCLUSION

An increasing body of research supports the potential of ginsenosides in treating IBD. Ginsenosides have emerged as promising therapeutic agents for IBD, attributed to their remarkable efficacy, safety, and absence of side effects. Nevertheless, their limited bioavailability presents a substantial challenge. Thus, efforts to enhance the bioavailability of ginsenosides represent a crucial and promising direction for future IBD research.

Pharmacological effects of ginseng and ginsenosides on intestinal inflammation and the immune system

Intestinal inflammatory imbalance and immune dysfunction may lead to a spectrum of intestinal diseases, such as inflammatory bowel disease (IBD) and gastrointestinal tumors. As the king of herbs, ginseng has exerted a wide range of pharmacological effects in various diseases. Especially, it has been shown that ginseng and ginsenosides have strong immunomodulatory and anti-inflammatory abilities in intestinal system. In this review, we summarized how ginseng and various extracts influence intestinal inflammation and immune function, including regulating the immune balance, modulating the expression of inflammatory mediators and cytokines, promoting intestinal mucosal wound healing, preventing colitis-associated colorectal cancer, recovering gut microbiota and metabolism imbalance, alleviating antibiotic-induced diarrhea, and relieving the symptoms of irritable bowel syndrome. In addition, the specific experimental methods and key control mechanisms are also briefly described.

Casting Light on the Janus-Faced HMG-CoA Reductase Degradation Protein 1: A Comprehensive Review of Its Dualistic Impact on Apoptosis in Various Diseases

Nowadays, it is well recognized that apoptosis, as a highly regulated cellular process, plays a crucial role in various biological processes, such as cell differentiation. Dysregulation of apoptosis is strongly implicated in the pathophysiology of numerous disorders, making it essential to comprehend its underlying mechanisms. One key factor that has garnered significant attention in the regulation of apoptotic pathways is HMG-CoA reductase degradation protein 1, also known as HRD1. HRD1 is an E3 ubiquitin ligase located in the endoplasmic reticulum (ER) membrane. Its primary role involves maintaining the quality control of ER proteins by facilitating the ER-associated degradation (ERAD) pathway. During ER stress, HRD1 aids in the elimination of misfolded proteins that accumulate within the ER. Therefore, HRD1 plays a pivotal role in the regulation of apoptotic pathways and maintenance of ER protein quality control. By targeting specific protein substrates and affecting apoptosis-related pathways, HRD1 could be an exclusive therapeutic target in different disorders. Dysregulation of HRD1-mediated processes contributes significantly to the pathophysiology of various diseases. The purpose of this review is to assess the effect of HRD1 on the pathways related to apoptosis in various diseases from a therapeutic perspective.

Ginseng-derived nanoparticles alleviate inflammatory bowel disease via the TLR4/MAPK and p62/Nrf2/Keap1 pathways

Inflammatory bowel disease (IBD) is closely linked to the homeostasis of the intestinal environment, and exosomes can be used to treat IBD due to their high biocompatibility and ability to be effectively absorbed by the intestinal tract. However, Ginseng-derived nanoparticles (GDNPs) have not been studied in this context and their mechanism of action remains unclear. Here, we investigated GDNPs ability to mediate intercellular communication in a complex inflammatory microenvironment in order to treat IBD. We found that GDNPs scavenge reactive oxygen species from immune cells and intestinal epithelial cells, inhibit the expression of pro-inflammatory factors, promote the proliferation and differentiation of intestinal stem cells, as well as enhancing the diversity of the intestinal flora. GDNPs significantly stabilise the intestinal barrier thereby promoting tissue repair. Overall, we proved that GDNPs can ameliorate inflammation and oxidative stress in vivo and in vitro, acting on the TLR4/MAPK and p62/Keap1/Nrf2 pathways, and exerting an anti-inflammatory and antioxidant effect. GDNPs mitigated IBD in mice by reducing inflammatory factors and improving the intestinal environment. This study offers new evidence of the potential therapeutic effects of GDNPs in the context of IBD, providing the conceptual ground for an alternative therapeutic strategy.

Ginsenoside Rb1 Promotes Hepatic Glycogen Synthesis to Ameliorate T2DM Through 15-PGDH/PGE2/EP4 Signaling Pathway

Purpose

Ginsenoside Rb1 (Rb1), one of the crucial bioactive constituents in Panax ginseng C. A. Mey., possesses anti-type 2 diabetes mellitus (T2DM) property. Nevertheless, the precise mechanism, particularly the impact of Rb1 on hepatic glycogen production, a crucial process in the advancement of T2DM, remains poorly understood. 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is responsible for prostaglandin E2 (PGE2) inactivation. A recent study has reported that inhibition of 15-PGDH promoted hepatic glycogen synthesis and improved T2DM. Therefore, herein, we aimed to investigate whether Rb1 ameliorated T2DM through 15-PGDH/PGE2-regulated hepatic glycogen synthesis.

Methods

By combining streptozotocin with a high-fat diet, we successfully established a mouse model for T2DM. Afterward, these mice were administered Rb1 or metformin for 8 weeks. An insulin-resistant cell model was established by incubating LO2 cells with palmitic acid. Liver glycogen and PGE2 levels, the expression levels of 15-PGDH, serine/threonine kinase AKT (AKT), and glycogen synthase kinase 3 beta (GSK3β) were measured. Molecular docking was used to predict the binding affinity between 15-PGDH and Rb1.

Results

Rb1 administration increased the phosphorylation levels of AKT and GSK3β to enhance glycogen synthesis in the liver of T2DM mice. Molecular docking indicated that Rb1 had a high affinity for 15-PGDH. Moreover, Rb1 treatment resulted in the suppression of elevated 15-PGDH levels and the elevation of decreased PGE2 levels in the liver of T2DM mice. Furthermore, in vitro experiments showed that Rb1 administration might enhance glycogen production by modulating the 15-PGDH/PGE2/PGE2 receptor EP4 pathway.

Conclusion

Our findings indicate that Rb1 may enhance liver glycogen production through a 15-PGDH-dependent pathway to ameliorate T2DM, thereby offering a new explanation for the positive impact of Rb1 on T2DM and supporting its potential as an effective therapeutic approach for T2DM.

Amelioration of colitis progression by ginseng-derived exosome-like nanoparticles through suppression of inflammatory cytokines

Background

Damage to the healthy intestinal epithelial layer and regulation of the intestinal immune system, closely interrelated, are considered pivotal parts of the curative treatment for inflammatory bowel disease (IBD). Plant-based diets and phytochemicals can support the immune microenvironment in the intestinal epithelial barrier for a balanced immune system by improving the intestinal microecological balance and may have therapeutic potential in colitis. However, there have been only a few reports on the therapeutic potential of plant-derived exosome-like nanoparticles (PENs) and the underlying mechanism in colitis. This study aimed to assess the therapeutic effect of PENs from Panax ginseng, ginseng-derived exosome-like nanoparticles (GENs), in a mouse model of IBD, with a focus on the intestinal immune microenvironment.

Method

To evaluate the anti-inflammatory effect of GENs on acute colitis, we treated GENs in Caco2 and lipopolysaccharide (LPS) -induced RAW 264.7 macrophages and analyzed the gene expression of pro-inflammatory cytokines and anti-inflammatory cytokines such as TNF-α, IL-6, and IL-10 by real-time PCR (RT-PCR). Furthermore, we further examined bacterial DNA from feces and determined the alteration of gut microbiota composition in DSS-induced colitis mice after administration of GENs through 16S rRNA gene sequencing analysis.

Result

GENs with low toxicity showed a long-lasting intestinal retention effect for 48 h, which could lead to effective suppression of pro-inflammatory cytokines such as TNF-α and IL-6 production through inhibition of NF-κB in DSS-induced colitis. As a result, it showed longer colon length and suppressed thickening of the colon wall in the mice treated with GENs. Due to the amelioration of the progression of DSS-induced colitis with GENs treatment, the prolonged survival rate was observed for 17 days compared to 9 days in the PBS-treated group. In the gut microbiota analysis, the ratio of Firmicutes/Bacteroidota was decreased, which means GENs have therapeutic effectiveness against IBD. Ingesting GENs would be expected to slow colitis progression, strengthen the gut microbiota, and maintain gut homeostasis by preventing bacterial dysbiosis.

Conclusion

GENs have a therapeutic effect on colitis through modulation of the intestinal microbiota and immune microenvironment. GENs not only ameliorate the inflammation in the damaged intestine by downregulating pro-inflammatory cytokines but also help balance the microbiota on the intestinal barrier and thereby improve the digestive system.

Ginsenoside Rk1 inhibits HeLa cell proliferation through an endoplasmic reticulum signaling pathway

Background

Changes to work-life balance has increased the incidence of cervical cancer among younger people. A minor ginseng saponin known as ginsenoside Rk1 can inhibit the growth and survival of human cancer cells; however, whether ginsenoside Rk1 inhibits HeLa cell proliferation is unknown.

Methods and results

Ginsenoside Rk1 blocked HeLa cells in the G0/G1 phase in a dose-dependent manner and inhibited cell division and proliferation. Ginsenoside Rk1 markedly also activated the apoptotic signaling pathway via caspase 3, PARP, and caspase 6. In addition, ginsenoside Rk1 increased LC3B protein expression, indicating the promotion of the autophagy signaling pathway. Protein processing in the endoplasmic reticulum signaling pathway was downregulated in Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, consistent with teal-time quantitative PCR and western blotting that showed YOD1, HSPA4L, DNAJC3, and HSP90AA1 expression levels were dramatically decreased in HeLa cells treated with ginsenoside Rk1, with YOD1 was the most significantly inhibited by ginsenoside Rk1 treatment.

Conclusion

These findings indicate that the toxicity of ginsenoside Rk1 in HeLa cells can be explained by the inhibition of protein synthesis in the endoplasmic reticulum and enhanced apoptosis, with YOD1 acting as a potential target for cervical cancer treatment.

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.

miR-18a-5p shuttled by mesenchymal stem cell-derived extracellular vesicles alleviates early brain injury following subarachnoid hemorrhage through blockade of the ENC1/p62 axis

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have therapeutic potential in various diseases due to their capacity to transfer bioactive cargoes such as microRNAs (miRNAs or miRs) to recipient cells. The present study isolated EVs from rat MSCs and aimed to delineate their functions and molecular mechanisms in early brain injury following subarachnoid hemorrhage (SAH). We initially determined the expression of miR-18a-5p and ENC1 in hypoxia/reoxygenation (H/R)-induced brain cortical neurons and rat models of SAH induced by the endovascular perforation method. Accordingly, increased ENC1 and decreased miR-18a-5p were detected in H/R-induced brain cortical neurons and SAH rats. After MSC-EVs were co-cultured with cortical neurons, the effects of miR-18a-5p on neuron damage, inflammatory response, endoplasmic reticulum (ER) stress, and oxidative stress markers were evaluated based on ectopic expression and depletion experiments. miR-18a-5p overexpression in brain cortical neurons co-cultured with MSC-EVs was shown to impede neuron apoptosis, ER stress and oxidative stress while augmenting neuron viability. Mechanistically, miR-18a-5p bound to the 3'UTR of ENC1 and reduced its expression, weakening the interaction between ENC1 and p62. Through this mechanism, transfer of miR-18a-5p by MSC-EVs contributed to the eventual inhibition of early brain injury and neurological impairment following SAH. Overall, miR-18a-5p/ENC1/p62 may be a possible mechanism underlying the cerebral protective effects of MSC-EVs against early brain injury following SAH.

Transcriptome profiling Revealed the potential mechanisms of Shen Lin Bai Zhu San n-butanol extract on DSS induced Colitis in Mice and LC-MS analysis

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic and recurrent inflammatory disorder in gastrointestinal tract. Shen Ling Bai Zhu San (SLBZS), which has a long history of use in Traditional Chinese Medicine (TCM), has been widely used to treat gastrointestinal diseases. The isolated fractions of TCM have also been proved to possess an important potential for treating diseases, which are due to their effective components.

PURPOSE

In this study, we examined the possibility that SLBZS and its isolated active fractions may prevent DSS-induced colitis, and investigated the potential mechanisms by regulating genetic profile of colon.

METHODS

Colitis mice were induced by 2.5% DSS for 7 days, and then SLBZS and different SLBZS extracts were administrated to protect the mice for 7 days. Body weight, diarrhea, bleeding in stool, colon length, spleen weight, cytokines of serum and colon and pathology of colon were assessed. The level of Ginsenoside Rg1, Re and Rb1 in different SLBZS extracts and qualitative analysis of n-butanol extract of SLBZS (S-Nb) was performed by HPLC and LC-MS, respectively. And the effects of S-Nb on the transcriptome in colitis were investigated.

RESULTS

Our results showed that SLBZS and S-Nb significantly regained body weight, reduced DAI, splenomegaly and the length of colon and attenuated histological damage of the colon. Meanwhile, SLBZS and S-Nb markedly reduced the levels of TNF-α, IL-1β and IL-6 and increased the level of IL-10 in serum and colon. These effects may be associated with the high levels of Ginsenoside Rg1, Re and Rb1 and rich variety of compounds in S-Nb including 6 ginsenosides, glycyrrhizin, L-tryptophan, and so on. Transcriptome analysis revealed that S-Nb selectively regulated 103 differentially expressed genes (DEGs), 36 of which were changed in DSS-induced mice. And the genes of Per2, Per3, Npy and Serpina3m were closely related to colitis and also restored by S-Nb with different extent. Remarkably, these DEGs modulated the biological functions of colitis mice, including extracellular region, response to external stimulus, MAPK signaling pathway and arginine and proline metabolism.

CONCLUSIONS

These data indicated that SLBZS and S-Nb blunted DSS-induced colitis by modulating differentially expression gene profile and biological functions based on their ginsenosides and rich compounds.

Phillygenin Attenuated Colon Inflammation and Improved Intestinal Mucosal Barrier in DSS-induced Colitis Mice via TLR4/Src Mediated MAPK and NF-κB Signaling Pathways

Ulcerative colitis (UC) is a chronic, relapsing, and nonspecific inflammatory bowel disease (IBD). Phillygenin (PHI), a natural bioactive ingredient, isolated from Forsythiae Fructus, exhibits anti-inflammatory, anti-oxidative, and hepatoprotective activities. However, few reports provide direct evidence on the efficacy of PHI in improving colitis mice. The present study elucidated that the symptoms of DSS-induced colitis mice were alleviated after PHI administration, including body weight loss, the disease activity index, colon length shortening, colonic pathological damage, splenomegaly, and hepatomegaly. PHI treatment improved the intestinal mucosal barrier by protecting goblet cells, promoting gene expressions of Clca1, Slc26a3, and Aqp8, increasing tight junction proteins (TJs), and reducing epithelial cell apoptosis. In addition, the levels of oxidative stress (MPO, SOD, and MDA) and inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-10) were reversed by PHI in colitis mice. According to transcriptome and network pharmacology analysis, inflammatory pathway might be an important mechanism for PHI to improve colitis. Western blotting displayed that the PHI inhibited the activation of tyrosine kinase Src mediated by TLR4, and then reduced the phosphorylation of downstream proteins p38, JNK, and NF-κB in colitis mice. In summary, our results suggested that PHI might be an appropriate and effective drug candidate to protect colitis.

Ginsenoside Rb1 improves intestinal aging via regulating the expression of sirtuins in the intestinal epithelium and modulating the gut microbiota of mice

Intestinal aging seriously affects the absorption of nutrients of the aged people. Ginsenoside Rb1 (GRb1) which has multiple functions on treating gastrointestinal disorders is one of the important ingredients from Ginseng, the famous herb in tradition Chinese medicine. However, it is still unclear if GRb1 could improve intestinal aging. To investigate the function and mechanism of GRb1 on improving intestinal aging, GRb1 was administrated to 104-week-old C57BL/6 mice for 6 weeks. The jejunum, colon and feces were collected for morphology, histology, gene expression and gut microbiota tests using H&E staining, X-gal staining, qPCR, Western blot, immunofluorescence staining, and 16S rDNA sequencing technologies. The numbers of cells reduced and the accumulation of senescent cells increased in the intestinal crypts of old mice, and administration of GRb1 could reverse them. The protein levels of CLDN 2, 3, 7, and 15 were all decreased in the jejunum of old mice, and administration of GRb1 could significantly increase them. The expression levels of Tert, Lgr5, mKi67, and c-Myc were all significantly reduced in the small intestines of old mice, and GRb1 significantly increased them at transcriptional or posttranscriptional levels. The protein levels of SIRT1, SIRT3, and SIRT6 were all reduced in the jejunum of old mice, and GRb1 could increase the protein levels of them. The 16S rDNA sequencing results demonstrated the dysbiosis of the gut microbiota of old mice, and GRb1 changed the composition and functions of the gut microbiota in the old mice. In conclusion, GRb1 could improve the intestinal aging via regulating the expression of Sirtuins family and modulating the gut microbiota in the aged mice.

Therapeutic material basis and underling mechanisms of Shaoyao Decoction-exerted alleviation effects of colitis based on GPX4-regulated ferroptosis in epithelial cells

Background

Shaoyao Decoction (SYD) is a canonical herbal medicine prescription formulated by Liu Wan-Su in AD 1186. SYD has been widely used to treat inflammatory bowel disease by clearing heat and damp, removing stasis toxin in the intestine; however, the precise mechanisms and therapeutic material basis remain largely unclear. In the present study, we measured the effects of SYD on colitis symptom, epithelial barrier function, epithelial ferroptosis, colonic protein and mRNA expression of glutathione peroxidase 4 (GPX4) in colitis model, and determined whether SYD restored barrier loss in colitis by modulation of GPX4-regulated ferroptosis pathway.

Methods

Colitis was established by infusion with 1 mL 2,4,6-trinitrobenzene sulfonic acid (TNBS) dissolved in ethanol (40% v/v) in rats at a 125 mg/kg dose. Ferroptosis in epithelial cells was determined by flow cytometer. GPX4 promoter-firefly luciferase fusion construct was transfected to Caco-2 cell to determine GPX4 transcription. MS analysis was used to identified ingredients in SYD.

Results

Different doses of SYD significantly alleviated colitis, decreased ferroptosis in epithelial cells, knockout of GPX4 significantly reversed SYD-induced alleviation effects on colitis, restoration of epithelial barrier function, and epithelial ferroptosis. Wogonoside, wogonin, palmatine, paeoniflorin and liquiritin were identified as active ingredients of SYD-exerted alleviation effects of colitis based on GPX4 agonistic transcription.

Conclusion

SYD alleviated chemically induced colitis by activation of GPX4, inhibition of ferroptosis in epithelial cells and further restoration of barrier function. Wogonoside, wogonin, palmatine, paeoniflorin and liquiritin were identified as the key therapeutic material basis of SYD-exerted anti-colitis effects. The findings provide a scientific basis for the therapeutic effect of SYD on colitis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00652-1.

Atractylenolide-1 targets SPHK1 and B4GALT2 to regulate intestinal metabolism and flora composition to improve inflammation in mice with colitis

BACKGROUND

Atractylenolide-1, an active component of Atractylodes Lancea, which is widely used to improve the gastrointestinal function. However, the efficacy and mechanism remain unclear in treating ulcerative colitis (UC).

PURPOSE

This study aimed to investigate the efficacy and the underlying mechanism of atractylenolide-1in UC.

METHODS

A dextran sulfate sodium (DSS)-induced UC mouse model was used to investigate the efficacy of atractylenolide-1. 16S DNA sequencing, GC-MS technique and transcriptome sequencing were used to detect the composition of mouse intestinal flora, the changes of metabolites and gene expression in mouse intestine. Compound-reaction-enzyme-gene network was used to find drug targets. Recombinant plasmid overexpression was used to verify drug targets in DSS mouse models.

RESULTS

The results showed that Atractylenolide-1 could significantly improve weight loss, diarrhea, blood in the stool, shortening of the colon, the loss of colonic goblet cells, reduction in mucoprotein MUC2, and tight junction proteins (zo-1, occludin) in mice with colitis. It reduced the inflammatory factors TNF-α, IL-6, IL-1β as well. The 16S sequencing showed that Atractylenolide-1 regulated the diversity and abundance of the intestinal flora in mice with colitis, and the analysis of flora enrichment indicated that the regulation of intestinal flora by atractylenolide-1 may be related to the regulation of metabolism. Correlation analysis of metabolomics and transcriptome showed that two genes SPHK1 and B4GALT2 related to the metabolism of fructose and galactose were regulated by atractylenolide-1. Further verification showed that atractylenolide-1 significantly inhibited the aberrance of SPHK1 and B4GALT2 in the colon with colitis. Meanwhile, it inhibited the activation of the PI3K-AKT pathway. SPHK1 and B4GALT2 overexpressing reversed the therapeutic effect of atractylenolide-1 in mice with colitis.

CONCLUSION

Atractylenolide-1 is a potential drug for the treatment of colitis by suppressing inflammation via the SPHK1/PI3K/AKT axis and by targeting SPHK1 and B4GAT2 to regulate fructose/galactose-related metabolism, thereby regulating the composition of the intestinal flora.

Dehydrocostus Lactone Suppresses Dextran Sulfate Sodium-Induced Colitis by Targeting the IKKα/β-NF-κB and Keap1-Nrf2 Signalling Pathways

Dehydrocostus lactone (DCL) is a major sesquiterpene lactone isolated from Aucklandia lappa Decne, a traditional Chinese herbal medicine that used to treat gastrointestinal diseases. This study aimed to examine the therapeutic effects of DCL on dextran sulfate sodium (DSS)-induced colitis with a focus on identifying the molecular mechanisms involved in DCL-mediated anti-inflammatory activity in macrophages. First, oral administration of DCL (5–15 mg/kg) not only ameliorated symptoms of colitis and colonic barrier injury, but also inhibited the expression of proinflammatory cytokines and myeloperoxidase in colon tissues in DSS-challenged mice. Furthermore, DCL also exhibited significant anti-inflammatory activity in LPS/IFNγ-stimulated RAW264.7 macrophages. Importantly, DCL significantly suppressed the phosphorylation and degradation of IκBα and subsequent NF-κB nuclear translocation, and enhanced the nuclear accumulation of Nrf2 in LPS/IFNγ-treated RAW264.7 cells. Mechanistically, DCL could directly interact with IKKα/β and Keap1, thereby leading to the inhibition of NF-κB signalling and the activation of Nrf2 pathway. Furthermore, DCL-mediated actions were abolished by dithiothreitol, suggesting a thiol-mediated covalent linkage between DCL and IKKα/β or Keap1. These findings demonstrated that DCL ameliorates colitis by targeting NF-κB and Nrf2 signalling, suggesting that DCL may be a promising candidate in the clinical treatment of colitis.

Ubiquitin-modifying enzymes as regulators of colitis

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disorder of the gastrointestinal tract. Although the pathophysiology of IBD is multifaceted, ubiquitination, a post-translational modification, has been shown to have essential roles in its pathogenesis and development. Ubiquitin-modifying enzymes (UMEs) work in synergy to orchestrate the optimal ubiquitination of target proteins, thereby maintaining intestinal homeostasis. Genome-wide association studies (GWAS) have identified multiple UME genes as IBD susceptibility loci, implying the importance of UMEs in IBD. Furthermore, accumulative evidence demonstrates that UMEs affect intestinal inflammation by regulating various aspects, such as intestinal barrier functions and immune responses. Considering the significant functions of UMEs in IBD, targeting UMEs could become a favorable therapeutic approach for IBD.

Natural Products Modulate Cell Apoptosis: A Promising Way for the Treatment of Ulcerative Colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease impacting patients’ quality of life and imposing heavy societal and economic burdens. Apoptosis of intestinal epithelial cells (IECs) has been considered an early event during the onset of UC and plays a crucial role in disease development. Thus, effectively inhibiting apoptosis of IECs is of critical significance for the clinical management of UC, presenting a potential direction for the research and development of pharmacotherapeutic agents. In recent years, research on the ameliorative effects of natural products on UC through inhibiting IECs apoptosis has attracted increasing attention and made remarkable achievements in ameliorating UC. In this review, we summarized the currently available research about the anti-apoptotic effects of natural products on UC and its mechanisms involving the death-receptor mediated pathway, mitochondrial-dependent pathway, ERS-mediated pathway, MAPK-mediated pathway, NF-κB mediated pathway, P13k/Akt pathway, JAK/STAT3 pathway, and NLRP3/ASC/Caspase-1 pathway. Hopefully, this review may yield useful information about the anti-apoptotic effects of natural products on UC and their potential molecular mechanisms and provide helpful insights for further investigations.

The Role of E3 Ubiquitin Ligases and Deubiquitinases in Inflammatory Bowel Disease: Friend or Foe?

Inflammatory bowel disease (IBD), which include Crohn’s disease (CD) and ulcerative colitis (UC), exhibits a complex multifactorial pathogenesis involving genetic susceptibility, imbalance of gut microbiota, mucosal immune disorder and environmental factors. Recent studies reported associations between ubiquitination and deubiquitination and the occurrence and development of inflammatory bowel disease. Ubiquitination modification, one of the most important types of post-translational modifications, is a multi-step enzymatic process involved in the regulation of various physiological processes of cells, including cell cycle progression, cell differentiation, apoptosis, and innate and adaptive immune responses. Alterations in ubiquitination and deubiquitination can lead to various diseases, including IBD. Here, we review the role of E3 ubiquitin ligases and deubiquitinases (DUBs) and their mediated ubiquitination and deubiquitination modifications in the pathogenesis of IBD. We highlight the importance of this type of posttranslational modification in the development of inflammation, and provide guidance for the future development of targeted therapeutics in IBD.

Arbutin Ameliorates Murine Colitis by Inhibiting JAK2 Signaling Pathway

Background and objective: Abnormal activation of Janus kinase 2 (JAK2) promotes the pathogenesis and progress of inflammatory bowel disease (IBD) by stimulating the cytokine traffic. Based on docking studies, arbutin, a natural product extracted from a traditional medicinal plant bearberry, was found to bind to JAK2. The study aimed to investigate the effects and mechanisms of regulating JAK2 by arbutin on colitis in mice.

Methods: A mice colitis model was established to mimic human IBD. The mice freely drank water containing dextran sulfate sodium. Inflammation in epithelial (IEC6) and immune (RAW264.7) cells was analyzed following treatment with lipopolysaccharides (LPS).

Results: Colitis symptoms, including body weight loss, increased disease activity index, and increased colon weight/length ratio, were significantly alleviated by arbutin. Mediators of colonic pro-inflammatory cytokines as well as apoptosis markers in colitis were suppressed by the glycoside. High expression of phosphorylated JAK2 in colitis was significantly reversed by arbutin. The effects of arbutin treatment on colitis were considerably inhibited by the JAK2 inhibitor AG490. LPS-induced inflammatory responses were also suppressed by arbutin, which was notably inhibited by the JAK2 inhibitor AG490.

Conclusion: The findings obtained herein suggest the protective role of arbutin and provide novel insights into alternative colitis treatments, which involve inhibition of the JAK2 signaling pathway.

Naringin Exerts Therapeutic Effects on Mice Colitis: A Study Based on Transcriptomics Combined With Functional Experiments

Naringin has been shown to exert protective effects in an animal model of ulcerative colitis, but detailed mechanisms remain unclear. This study aimed to investigate function and signaling mechanisms underlying naringin-induced therapeutic effects on colitis. Two mouse models were established to mimic human Inflammatory bowel disease (IBD) by treating drinking water with dextran sodium sulphate or intra-colonic administration of 2, 4, 6-trinitrobenzene sulfonic acid. Transcriptomics combined with functional experiments were used to investigate underlying mechanisms. Colitis symptoms, including weight loss and high disease activity index were significantly reversed by naringin. The inflammatory response, oxidative reactions, and epithelial cell apoptosis that occur with colitis were also alleviated by naringin. After naringin treatment, transcriptomics results identified 753 differentially expressed mRNAs that were enriched in signaling pathways, including the neuroactive ligand-receptor interaction, calcium signaling, and peroxisome proliferator-activated receptor (PPAR) signaling. The naringin-induced alleviation of colitis was significantly inhibited by the PPAR-γ inhibitor BADGE. In IEC-6 and RAW264.7 cells incubated with lipopolysaccharide (LPS), NF-κB-p65, a downstream protein of PPAR-γ, was significantly increased. Naringin suppressed LPS-induced high expression of NF-κB-p65, which was inhibited by small interfering RNA targeting PPAR-γ. Our study clarifies detailed mechanisms underlying naringin-induced therapeutic effects on mice colitis, and PPAR-γ was found to be the main target of naringin by functional experiments both in vivo and in vitro. Our study supplies new scientific information for the use of naringin in colitis treatment.