Compound sophorae decoction enhances intestinal barrier function of dextran sodium sulfate induced colitis via regulating notch signaling pathway in mice

Inflammatory bowel disease: an overview of Chinese herbal medicine formula-based treatment

Inflammatory bowel disease (IBD) is a chronic recurrent inflammatory disease of the intestine, including Crohn's disease (CD) and ulcerative colitis (UC), whose etiology and pathogenesis have not been fully understood. Due to its prolonged course and chronic recurrence, IBD imposes a heavy economic burden and psychological stress on patients. Traditional Chinese Herbal Medicine has unique advantages in IBD treatment because of its symptomatic treatment. However, the advantages of the Chinese Herbal Medicine Formula (CHMF) have rarely been discussed. In recent years, many scholars have conducted fundamental studies on CHMF to delay IBD from different perspectives and found that CHMF may help maintain intestinal integrity, reduce inflammation, and decrease oxidative stress, thus playing a positive role in the treatment of IBD. Therefore, this review focuses on the mechanisms associated with CHMF in IBD treatment. CHMF has apparent advantages. In addition to the exact composition and controlled quality of modern drugs, it also has multi-component and multi-target synergistic effects. CHMF has good prospects in the treatment of IBD, but its multi-agent composition and wide range of targets exacerbate the difficulty of studying its treatment of IBD. Future research on CHMF-related mechanisms is needed to achieve better efficacy.

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.

Diosmetin has therapeutic efficacy in colitis regulating gut microbiota, inflammation, and oxidative stress via the circ-Sirt1/Sirt1 axis

Diosmetin (3',5,7 -trihydroxy-4'-methoxy flavone) is a natural flavonoid compound in the citrus species, it exhibits a variety of pharmacological activities, but little is known of its effects on colitis. In this study we evaluated the therapeutic effects of diosmetin on mouse models of chronic and acute colitis. Chronic colitis was induced in mice by drinking water containing 3% dextran sulfate sodium (DSS) from D0 to D8, followed by administration of diosmetin (25, 50 mg · kg^-1 · d^-1) for another 8 days. Acute colitis was induced by drinking water containing 5% DSS from D0 to D7, the mice concomitantly received diosmetin (25, 50 mg · kg^-1 · d^-1) from D1 to D7. During the experiments, body weight and disease activity index (DAI) were assessed daily. After the mice were sacrificed, colon tissue and feces samples were collected, and colon length was measured. We showed that in both models, diosmetin administration significantly decreased DAI score and ameliorated microscopic colon tissue damage; increased the expression of tight junction proteins (occludin, claudin-1, and zonula occludens-1), and reduced the secretion of proinflammatory cytokines IL-1β, IL-6, TNF-α, and Cox-2 in colon tissue. We found that diosmetin administration remarkably inhibited colon oxidative damage by adjusting the levels of intracellular and mitochondrial reactive oxygen species, GSH-Px, SOD, MDA and GSH in colon tissue. The protection of diosmetin against intestinal epithelial barrier damage and oxidative stress were also observed in LPS-treated Caco-2 and IEC-6 cells in vitro. Furthermore, we demonstrated that diosmetin markedly increased the expression of Nrf2 and HO-1 and reduced the ratio of acetylated NF-κB and NF-κB by activating the circ-Sirt1/Sirt1 axis, which inhibited oxidative stress and inflammation in vivo and in vitro. Diosmetin reversed the effects of si-circSirt1 and si-Sirt1 in LPS-treated Caco-2 and IEC-6 cells. When the gut microbiota was analyzed in the mouse model of colitis, we found that diosmetin administration modulated the abundance of Bacteroidetes, Actinobacteria, Cyanobacteria and Firmicutes, which were crucial for inflammatory bowel disease. Our results have linked colitis to the circ-Sirt1/Sirt1 signaling pathway, which is activated by diosmetin. The results imply that diosmetin may be a novel candidate to alleviate DSS-induced colitis and can be a lead compound for future optimization and modification.

Lycopene Alleviates Chronic Stress-Induced Spleen Apoptosis and Immunosuppression via Inhibiting the Notch Signaling Pathway in Rats

Chronic stress induction in immunosuppression and splenocyte apoptosis is commonly associated with increased susceptibility to various diseases. Lycopene (LYC) is a member of the carotenoid family with immune restoration and anti-apoptotic function. However, little is known about the mechanisms underlying the protective roles of LYC against spleen injury induced by chronic stress. Herein, male Wistar rats were undergoing chronic restraint stress and/or administered LYC (10 mg/kg) for 21 days. The effective model establishment was validated by open-field tests and levels of corticosterone in serum. Histopathological staining observation displayed that LYC could reduce chronic stress-induced spleen structure damage. Furthermore, LYC treatment significantly reduced the number of apoptotic-positive splenocytes caused by chronic stress via the death receptor apoptotic pathway. We detected the interleukin 4 and interferon γ levels in serum and spleen to determine the ratio of Th1 and Th2 and found that LYC can alleviate the immunosuppression induced by chronic stress. Notably, western blot and real-time polymerase chain reaction indicated that LYC can reduce the expression of the Notch-pathway-related proteins and mRNA in rats exposed to chronic stress. Further study of the potential mechanisms by adding the Notch pathway inhibitor DAPT revealed that LYC alleviates the structure damage, apoptosis, and immunosuppression caused by chronic stress via the suppression of the Notch pathway. Overall, this study presents a strong rationale to target LYC as a treatment strategy to relieve chronic stress-induced spleen injury.

ROS-responsive nanoparticles for oral delivery of luteolin and targeted therapy of ulcerative colitis by regulating pathological microenvironment

Oxidative stress, caused by excessive production of reactive oxygen species (ROS), plays a crucial role in the occurrence and development of ulcerative colitis (UC). We developed ROS-responsive nanoparticles (NPs) as an efficacious nanomedicine against UC with oral administration. The NPs were fabricated with a d-α-tocopherol polyethylene glycol succinate-b-poly(β-thioester) copolymer (TPGS-PBTE) for ROS cleavage via the colitis-targeted delivery of luteolin (LUT), a natural flavonoid with good anti-inflammation and radical-scavenging activity. Owing to the thioether bond in the polymer main chain, the TPGS-PBTE NPs exhibited an ROS-responsive size change and drug release, which benefited the ROS-scavenging and selective accumulation of LUT in the inflamed colon. In a dextran sulfate sodium-induced acute colitis murine model, LUT@TPGS-PBTE NPs alleviated body weight loss, colon length shortening, and damage to the colonic tissues due to the suppression of ROS and proinflammatory cytokines (e.g., IL-17A, IL-6, interferon-γ, tumor necrosis factor-α), as well as upregulation of glutathione and anti-inflammatory factors (e.g., IL-10, IL-4). More importantly, LUT@TPGS-PBTE NPs regulated the inflammatory microenvironment by modulating the T helper (Th)1/Th2 and Th17/regulatory T cell (Treg) balance (i.e., increased numbers of Tregs and Th2 cells and decreased numbers of Th1 and Th17 ​cells), thus resolving inflammation and accelerating the healing of the intestinal mucosa. Additionally, the LUT@TPGS-PBTE NPs formulation enabled the reduction of the effective dose of LUT and showed excellent biosafety in the mouse model, demonstrating its potential as a targeted UC therapeutic oral preparation.

Ginsenoside Rg1 ameliorated experimental colitis by regulating the balance of M1/M2 macrophage polarization and the homeostasis of intestinal flora

Aberrant M1/M2 macrophage polarization and dysbiosis are involved in the pathogenesis of ulcerative colitis (UC). Ginsenoside Rg1 exhibits optimal immunomodulatory and anti-inflammatory effects in treating UC of humans and animals, but the action mechanism through the regulation of M1/M2 macrophage polarization and intestinal flora composition remain unclear. Here, experimental colitis was induced in BALB/c mice using dextran sulfate sodium, and Rock1 inhibitor Y27632 was used to explore the action mechanism of ginsenoside Rg1. Following treatment with ginsenoside Rg1 (200 mg/kg/day) and Y27632 (10 mg/kg/day) for 14 consecutive days, the rate of change in mouse body weight, mouse final weight, colonic weight, colonic length, colonic weight index and pathological damage scores of colitis mice were effectively improved, accompanied by less ulcer formation and inflammatory cell infiltration, lower levels of interleukin (IL)-6, IL-33, chemokine (C-C motif) ligand 2 (CCL-2), tumor necrosis factor alpha (TNF-α), and higher IL-4 and IL-10. Importantly, ginsenoside Rg1 and Y27632 significantly down-regulated CD11b+F4/80+, CD11b+F4/80+Tim-1+ and CD11b+F4/80+TLR4+ macrophages, and CD11b+F4/80+iNOS+ M1 macrophages, and significantly up-regulated CD11b+F4/80+CD206+ and CD11b+F4/80+CD163+ M2 macrophages in colitis mice; concomitantly, ginsenoside Rg1 improved the diversity of colonic microbiota and regulated Lachnospiraceae, Staphylococcus, Bacteroide and Ruminococcaceae_UCG_014 at genus level in colitis mice, but the flora regulated by Y27632 was not identical to it. Moreover, ginsenoside Rg1 and Y27632 down-regulated the protein levels of Rock1, RhoA and Nogo-B in colitis mice. These results suggested that ginsenoside Rg1 and Y27632 ameliorated colitis by regulating M1/M2 macrophage polarization and microbiota composition, associated with inhibition of the Nogo-B/RhoA signaling pathway.

Mechanism of HSP90 Inhibitor in the Treatment of DSS-induced Colitis in Mice by Inhibiting MAPK Pathway and Synergistic Effect of Compound Sophorae Decoction

BACKGROUND

The mechanism of Heat Shock Protein 90 (HSP90) in Ulcerative Colitis (UC) has been studied, and mitogenic-activated protein kinases (MAPK) also contribute to the pathogenesis of UC. However, the effect of the HSP90/MAPK pathway in UC is still unclear. Therefore, the mainstay of this research is to explore the mechanism of action of this pathway in UC. Compound sophorae decoction (CSD), as a Chinese herbal decoction, can synergistically affect the above process.

OBJECTIVE

This study aimed to uncover the synergistic effects of HSP90 inhibitors regulating the MAPK pathway for treating DSS-induced colitis in mice and the synergistic effects of CSD.

METHODS

This experiment used oral administration of standard diets containing 3% dextran sodium sulfate (DSS) to establish an experimental colitis model in mice. The model was treated with HSP90 inhibitor, CSD, or dexamethasone. Mouse feces, mobility, body weight, colon length, and colon histopathology scores were recorded daily to assess the degree of colitis inflammation. Expression levels of HSP90 and MAPK pathway-related genes and proteins were evaluated by Western blot and qPCR. The evaluation of intestinal mucosal permeability was measured by enzyme-linked immunosorbent assay (ELISA), which could detect the protein level of D-Amino Acid Oxidase (DAO) and D-lactic acid (D-LA). The same went for downstream molecules AFT-2, p53, and apoptosis-related proteins BAX, BCL-2, Caspase3, and survivin in the MAPK pathway. Immunohistochemical measured p-38, p-JNK, and p-ERK expressions. JAM-A and claudin-1 connexin were tested by immunofluorescence staining. The TUNEL method was for measuring the apoptosis rate of colonic epithelial cells. CBA kit determined the level of inflammatory factors of colons.

RESULTS

HSP90 inhibitor can improve the degree of pathological damage in the colon of mice treated with DSS, increase the mice's weight and the length of the colon, and significantly reduce the disease activity index (DAI) score. Intraperitoneal injection of HSP90 inhibitor can reduce the expression of MAPK pathway markers P38, JNK, ERK, and their phosphorylation and decrease the content of AFT-2 and p53, which is downstream of the MAPK pathway. In addition, treatment of the HSP90 inhibitor up-regulated the expression of anti-apoptotic proteins BCL-2 and survivin, as well as down-regulated apoptotic protein caspase3, BAX in the colon of mice with colitis. Lower levels of inflammatory factors such as IL-6, MCP-1, IFN-γ, TNF, IL-12p70, and increased IL-10 were observed after HSP90 inhibitor therapy. Furthermore, the combination treatment of CSD can enhance the effect of the single HSP90 inhibitor treatment and play a synergistic effect.

CONCLUSION

These data suggest that an HSP90 inhibitor is available to treat UC by inhibiting the MAPK signaling pathway. This axis can restore the intestinal mucosa barrier's function by reducing intestinal mucosa's permeability and inhibiting apoptosis of intestinal epithelial cells. The specific mechanism is that HSP90 inhibitor can reduce the pathological damage and inflammation levels of colitis mice, and reduce the apoptosis rate of colonic epithelial cells and the mucosal permeability, thereby restoring the mucosal barrier function. During this process, CSD works synergistically to improve the therapeutic effect of the HSP90 inhibitor.

Modified Gegen Qinlian Decoction Regulates Treg/Th17 Balance to Ameliorate DSS-Induced Acute Experimental Colitis in Mice by Altering the Gut Microbiota

Inflammatory bowel disease (IBD) is characterized by chronic pathology associated with extensive intestinal microbial dysregulation and intestinal inflammation. Thus, efforts are underway to manipulate the gut microbiome to improve inflammatory pathology. Gegen Qinlian decoction (GQD), a traditional Chinese medicine prescription, has been widely utilized for treating diarrhea and ulcerative colitis (UC) for thousands of years. However, the underlying mechanism of its efficacy and whether its protective effect against colitis is mediated by the gut microbiota are poorly understood. In the present study, our data demonstrated that modified GQD (MGQD) administration significantly improved the pathological phenotypes and colonic inflammation challenged by DSS in mice, which were specifically manifested as reduced loss of body weight, shortening of colon length, DAI score, histological score and suppressed inflammatory response. 16S rRNA sequencing and targeted metabonomics analysis showed that MQGD altered the diversity and community landscape of the intestinal microbiota and the metabolic profiles. In particular, MQGD significantly boosted the abundance of the intestinal microbiota producing short-chain fatty acids (SCFAs), which are causally associated with promoting the development of Treg cells and suppressing the differentiation of pro-inflammatory Th17 cells. More importantly, transferring fecal microbiota from MGQD-treated or healthy controls exhibited equivalent alleviative effects on colitis mice. However, this protective effect could not be replicated in experiments of mice with depleted intestinal microbes through broad-spectrum antibiotic cocktails (ABX), further supporting the importance of SCFA-producing gut microbiota in the beneficial role of MGQD. In general, MGQD therapy has the potential to remodel the intestinal microbiome and reestablish immune homeostasis to ameliorate DSS-induced colitis.

Efficient Stool Collection Methods for Evaluating the Diarrhea Score in Mouse Diarrhea Models

BACKGROUND/AIM

The mouse diarrhea score is usually determined by evaluating stool consistency and shape. Thus, defecated stools should be collected without damage or contamination. The study aimed to develop improved mouse stool collection methods and diarrhea-scoring criteria.

MATERIALS AND METHODS

We developed improved stool collection methods (paper towel methods) and compared them with previously used ones (stool collection using regular cages containing bedding chips or filter paper and metabolic cages).

RESULTS

Compared to previously used methods, paper towel methods collected stools without bedding chips-induced contamination, mouse body/foot-induced damage, or sampling errors. When using paper towel methods, wet stools create water marks (diarrhea marks) on paper towels with strong water absorption capacity, by which diarrheal severity can be analyzed semi-quantitatively. To improve the objectivity in determining diarrhea scores, practical diarrhea-scoring criteria were also proposed.

CONCLUSION

These results would be helpful to researchers facing difficulties in evaluating the mouse diarrhea score.