LL202 protects against dextran sulfate sodium-induced experimental colitis in mice by inhibiting MAPK/AP-1 signaling

Walnut Protein Peptides Ameliorate DSS-Induced Ulcerative Colitis Damage in Mice: An in Silico Analysis and in Vivo Investigation

Walnut (Juglans regia L.) is a food with food-medicine homology, whose derived protein peptides have been shown to have anti-inflammatory activity in vitro. However, the effects and mechanisms of walnut protein peptides on ulcerative colitis (UC) in vivo have not been systematically and thoroughly investigated. In this study, we applied virtual screening and network pharmacology screening of bioactive peptides to obtain three novel WPPs (SHTLP, HYNLN, and LGTYP) that may alleviate UC through TLR4-MAPK signaling. In vivo studies have shown that WPPs improve intestinal mucosal barrier dysfunction and reduce inflammation by inhibiting activation of the TLR4-MAPK pathway. In addition, WPPs restore intestinal microbial homeostasis by reducing harmful bacteria (Helicobacter and Bacteroides) and increasing the relative abundance of beneficial bacteria (Candidatus_Saccharimonas). Our study showed that the WPPs obtained by virtual screening were effective in ameliorating colitis, which has important implications for future screening of bioactive peptides from medicinal food homologues as drugs or dietary supplements.

Icosapent ethyl alleviates acetic acid-induced ulcerative colitis via modulation of SIRT1 signaling pathway in rats

Ulcerative colitis (UC) is a global inflammatory bowel disease. This study aimed to assess the effects of icosapent ethyl on acetic acid-induced colitis in rats as well as the underlying mechanisms involved. 36 male Wister rats were equally divided into six groups: control, UC, mesalamine 100 mg/kg, icosapent 150mg/kg, icosapent 300 mg/kg, and EX527-icosapent 300 mg/kg groups. Except for control group, UC was induced by acetic acid instillation into colon. Drugs were administered once daily for one week then under thiopental anaesthesia, colons were excised. Colitis macroscopic and microscopic scores were assessed. A part of colon was homogenized for detection of malondialdehyde (MDA), inerleukin1 (IL-1β), tumor necrosis factor (TNF-α), superoxide dismutase (SOD), phosphorylated Akt (pAkt) and caspase 3 levels. Silent information regulator 1 (SIRT1), heme oxygenase 1 (HO-1), and nuclear factor erythroid 2 (Nrf2) mRNA expressions were detected. Mallory-stained colonic sections were examined for collagen fibres detection. Immunohistochemistry of NF-κB and p53 expressionsin colonic sections were assessed. Acetic acid induced colitis with increments in MDA, IL-1β, TNF-α, and caspase 3 levels while decreased SOD, pAkt, SIRT1, HO-1, and Nrf2 with increased collagen fibres as well as NF-κB and p53. Icosapent decreased macro& microscopic colitis scores, MDA, IL-1β, TNF-α, and caspase 3 levels while increased SOD, pAkt, SIRT1, HO-1, and Nrf2 with decreased collagen fibres as well as NF-κB and p53. The effects of icosapent 300 mg/kg were similar to mesalamine. Icosapent effects were antagonized by EX527. Icosapent alleviated acetic acid-induced colitis via its anti-inflammatory, antioxidant, and anti-apoptotic effects mediated in part by SIRT1 pathway activation.

Pharmacology Mechanism of Polygonum Bistorta in Treating Ulcerative Colitis Based on Network Pharmacology

Aim. Ulcerative colitis (UC) is a refractory gastrointestinal disease. The study aimed to expound the mechanism of Polygonum bistorta (PB) in treating UC by network pharmacology, molecular docking, and experiment verification. Methods. The compositions and targets of PB and UC-associated targets were obtained by searching the websites and the literature. The potential mechanism of PB in the treatment of UC was predicted by protein-protein interaction network construction, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Molecule docking was performed by AutoDock. In vitro experiments explored the mechanism of quercetin (Que), the main active composition of PB, in treating UC. Results. Six compositions, 139 PB targets, and 934 UC-associated targets were obtained. 93 overlapping targets between PB and UC were identified, and 18 of them were the core targets. 467 biological processes, 10 cell components, and 30 molecular functions were obtained by GO analysis. 102 pathways were enriched through KEGG analysis. Among them, the IL-17 signaling pathway had high importance. The core targets FOS, JUN, IL-1β, CCL2, CXCL8, and MMP9 could dock with Que successfully. Act1, TRAF6, FOS, and JUN were identified by KEGG as the key proteins of the IL-17 signaling pathway. The expressions of the abovementioned proteins were increased in Caco-2 cells stimulated by Dextran sulfate sodium and decreased after being treated by Que. Conclusion. PB might treat UC by downregulating the IL-17 signaling pathway. It is worth doing further research on PB treating UC in vivo.

Berberine Suppresses Colonic Inflammation in Dextran Sulfate Sodium-Induced Murine Colitis Through Inhibition of Cytosolic Phospholipase A2 Activity

Ulcerative colitis (UC) causes chronic inflammation and damage to the colonic mucosal layer. Recent studies have reported significant changes in phosphatidylcholine (PC) and lysophosphatidylcholine (LPC) in UC patients and oral administration of PC has considerable therapeutic effects against UC, suggesting the metabolism of phosphatidylcholine may be involved in the UC development. Our previous work has demonstrated that berberine effectively suppresses inflammation and protects colonic mucosa injury in DSS-induced colitic mice. However, whether the therapeutic effects of berberine are attributed to its action on the PC metabolism remains unknown. In the present study, we have shown that berberine significantly reduces the lysophosphatidylcholine (LPC) levels in the sera of DSS-induced experimental colitis mice and LPS-stimulated macrophage RAW 264.7 cells. The cytosolic phospholipase A2a (PLA2G4A), an enzyme for hydrolyzing PC to LPC, was found to be up-regulated in the colon tissue of experimental colitis mice and inflamed macrophage RAW 264.7 cells. We then demonstrated berberine inhibits the phosphorylation of cytosolic phospholipase A2a (PLA2G4A) in the colon tissue of experimental colitis mice and inflamed macrophage RAW 264.7 cells. Subsequently, we revealed berberine suppressed the expression of pro-inflammatory factors including TNF-alpha and IL-6 through regulating PLA2G4A dysfunction in macrophage RAW 264.7 cells. Mechanistically, we found that berberine directly binds to PLA2G4A and inhibits MAPK/JNK signaling pathway to inhibit PLA2G4A activity in inflammatory status. Therefore, we concluded that berberine inhibits colonic PLA2G4A activity to ameliorate colonic inflammation in experimental colitic mice, suggesting modulation of the PC metabolism via PLA2G4A might be beneficial for establishing new therapies strategy for UC.

Ginsenoside from ginseng: a promising treatment for inflammatory bowel disease

Inflammatory bowel disease (IBD) is an autoimmune disease mediated by immune disorder and termed as one of the most refractory diseases by the Word Health Organization. Its morbidity has increased steadily over the past half century worldwide. Environmental, genetic, infectious, and immune factors are integral to the pathogenesis of IBD. Commonly known as the king of herbs, ginseng has been consumed in many countries for the past 2000 years. Its active ingredient ginsenosides, as the most prominent saponins of ginseng, have a wide range of pharmacological effects. Recent studies have confirmed that the active components of Panax ginseng have anti-inflammatory and immunomodulatory effects on IBD, including regulating the balance of immune cells, inhibiting the expression of cytokines, as well as activating Toll-like receptor 4, Nuclear factor-kappa B (NF-κB), nucleotide-binding oligomerization domain-like receptor (NLRP), mitogen-activated protein kinase signaling, and so on. Accumulated evidence indicates that ginsenosides may serve as a potential novel therapeutic drug or health product additive in IBD prevention and treatment in the future.

Dihydroartemisinin Protects against Dextran Sulfate Sodium-Induced Colitis in Mice through Inhibiting the PI3K/AKT and NF-κB Signaling Pathways

Ulcerative colitis is a common inflammatory bowel disease, and the activation of thePI3K/AKT and NF-κB signaling pathways plays a pivotal role in its pathogenesis. Dihydroartemisinin (DHA) is a widely used antimalarial drug and has shown anticancer effect partially through inhibiting the activation of PI3K/AKT and NF-κB. This study aimed to investigate the effect of dihydroartemisinin on ulcerative colitis and its mechanism. Adult male C57 mice were subjected to 3.0% dextran sulfate sodium (DSS) for seven days; simultaneously, dihydroartemisinin or control saline was administered by oral gavage once a day. In vitro, the intestinal epithelial cell-6 was treated with LPS for 24 hours with or without dihydroartemisinin combined with PI3K/Akt activator 740 Y-P or NF-κB activator phorbol myristate acetate. Western blotting was used to test the activation of PI3K/AKT and NF-κB. Dihydroartemisinin significantly ameliorated body weight loss, shortened colon length, and increased DAI in DSS-induced colitis. Meanwhile, histological damage was improved and was accompanied by decreased expression and secretion of proinflammatory cytokines. Moreover, DSS-induced elevation of phosphorylation of PI3K, AKT, IKKα, IκBα, and NF-κB (p65) was remarkably blunted by dihydroartemisinin both in vivo and in vitro, indicating an inhibitive property on the PI3K/AKT and NF-κB signaling pathways. Furthermore, administration of 740 Y-P or PMA significantly blocked protective activity of dihydroartemisinin against colitis in vitro. In conclusion, dihydroartemisinin can attenuate DSS-induced colitis, and its anticolitis effect might be mediated via the PI3K/AKT and NF-κB signaling pathways. DHA might serve as a promising drug for patients with ulcerative colitis.

Curcumin and Intestinal Inflammatory Diseases: Molecular Mechanisms of Protection

Intestinal inflammatory diseases, such as Crohn’s disease, ulcerative colitis, and necrotizing enterocolitis, are becoming increasingly prevalent. While knowledge of the pathogenesis of these related diseases is currently incomplete, each of these conditions is thought to involve a dysfunctional, or overstated, host immunological response to both bacteria and dietary antigens, resulting in unchecked intestinal inflammation and, often, alterations in the intestinal microbiome. This inflammation can result in an impaired intestinal barrier allowing for bacterial translocation, potentially resulting in systemic inflammation and, in severe cases, sepsis. Chronic inflammation of this nature, in the case of inflammatory bowel disease, can even spur cancer growth in the longer-term. Recent research has indicated certain natural products with anti-inflammatory properties, such as curcumin, can help tame the inflammation involved in intestinal inflammatory diseases, thus improving intestinal barrier function, and potentially, clinical outcomes. In this review, we explore the potential therapeutic properties of curcumin on intestinal inflammatory diseases, including its antimicrobial and immunomodulatory properties, as well as its potential to alter the intestinal microbiome. Curcumin may play a significant role in intestinal inflammatory disease treatment in the future, particularly as an adjuvant therapy.

Puerarin attenuates angiotensin II-induced cardiac fibroblast proliferation via the promotion of catalase activity and the inhibition of hydrogen peroxide-dependent Rac-1 activation

The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of H₂O₂ in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac1 was dependent on the levels of intracellular H₂O₂. Puerarin blocked the phosphorylation of extracellular regulated protein kinases (ERK)1/2, abolished activator protein (AP)-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of H₂O₂-dependent Rac1 activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregulation of catalase expression and H₂O₂-dependent Rac1 activation.

Anti-Inflammatory Potential of Carpomitra costata Ethanolic Extracts via Inhibition of NF-κB and AP-1 Activation in LPS-Stimulated RAW264.7 Macrophages

Marine algae have valuable health and dietary benefits. The present study aimed to investigate whether an ethanol extract of Carpomitra costata (CCE) could inhibit the inflammatory response to LPS. CCE attenuated the production of proinflammatory mediators, such as prostaglandin E₂ (PGE₂) and nitric oxide (NO), by inhibiting inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in LPS-induced RAW264.7 macrophages. CCE also inhibited the expression of proinflammatory cytokines such as IL-1β, TNF-α, and IL-6. CCE suppressed the LPS-induced DNA-binding activity of (NF-κB) and activator protein-1 (AP-1). In addition, CCE attenuated the LPS-stimulated phosphorylation of c-Jun N-terminal kinase/stress-activated protein kinase (JNK) and phosphatidylinositol 3′-kinase/Akt (PI3K/Akt). Functional aspects of the JNK and Akt signaling pathways were analyzed using specific inhibitors, which attenuated the LPS-induced production of proinflammatory cytokines, and NO and PGE₂ expression by suppressing AP-1 and NF-κB activity. In particular, the AP-1 signaling pathway is not involved in the production of inflammatory cytokines, such as IL-6, TNF-α, and IL-1β. These results suggested that CCE might exert its anti-inflammatory action by downregulating transcriptional factors (NF-κB and AP-1) through JNK and Akt signaling pathways. The current study suggested that CCE might be a valuable candidate for the treatment of inflammatory disorders.

Shizukaol B, an active sesquiterpene from Chloranthus henryi, attenuates LPS-induced inflammatory responses in BV2 microglial cells

The objective of the current study was to evaluate the anti-inflammatory effects of shizukaol B, a lindenane-type dimeric sesquiterpene isolated from the whole plant of Chloranthus henryi, on lipopolysaccharide (LPS)-induced activation of BV2 microglial cells in vitro. Our data showed that shizukaol B concentration-dependently suppressed expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), production of nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in LPS-stimulated BV2 microglia. Meanwhile, shizukaol B concentration- and time-dependently inhibited LPS-mediated c-Jun N-terminal kinase 1/2 (JNK) activation, but had little effect on extracellular signal-regulated kinase 1/2 or p38 phosphorylation. Furthermore, shizukaol B significantly blocked LPS-induced activator protein-1 (AP-1) activation, evidenced by reduced phosphorylation and nuclear translocation of c-Jun and DNA binding activity of AP-1. Taken together, our findings suggest that shizukaol B exerts anti-inflammatory effects in LPS-activated microglia partly by modulating JNK-AP-1 signaling pathway.