Luteolin alleviates ulcerative colitis through SHP-1/STAT3 pathway

Treatment with human placental extracts inhibits allergic rhinitis by modulating AMPK/SHP1/SHP2/STING signaling

The present study aimed to investigate the regulatory effects and mechanisms of human placental extracts (HPE) on rats and cell models of ovalbumin (OVA)‑induced allergic rhinitis (AR). IFN‑y and LPS induced AR in vitro. A total of 32 male Sprague‑Dawley (SD) rats were randomly divided into the following four groups: Sham group, model group, model + HPE group and model + HPE + AMPK inhibitor group (n=8 rats/group). With the exception of the sham group, the remaining three groups were sensitized with OVA to establish an AR model, followed by various treatments. Hematoxylin and eosin staining was utilized to observe morphological changes in the nasal mucosa, ELISA was employed to measure serum levels of IL‑1β, interferon (IFN)β, immunoglobulin (Ig)E, IgG1 and IgG2a, and western blotting was conducted to assess protein expression across the groups. The sham group exhibited intact tissue structure with no notable pathological alterations. The model group demonstrated pronounced pathological features, including extensive infiltration of inflammatory cells, tissue shedding and edema. The model + HPE group revealed a gradual restoration of tissue architecture, characterized by reduced edema and inflammatory infiltration, whereas the model + HPE + AMPK inhibitor group again exhibited significant inflammatory cell infiltration and other pathological manifestations. Compared with the sham operation group, the levels of IL‑1β, IFNβ, IgE, IgG1 and IgG2a in the serum of the model group were elevated. The levels of IL‑1β, IFNβ, IgE, IgG1 and IgG2a in the model + HPE group were lower than those in the model group. In addition, the levels of IL‑1β, IFNβ, IgE, IgG1 and IgG2a in the model + HPE + AMPK inhibitor group were higher than those in the model + HPE group. Relative to the sham group, the expression levels of phosphorylated (p)‑AMPK/total (t)‑AMPK, p‑Src homology 2‑containing phosphatase (SHP)1/t‑SHP1 and p‑SHP2/t‑SHP2 were diminished, whereas the expression levels of p‑STING/t‑STING and p‑TBK1/t‑TBK1 were heightened in the model group. In comparison to the model group, the expression levels of p‑AMPK/t‑AMPK, p‑SHP1/t‑SHP1 and p‑SHP2/t‑SHP2 were enhanced, whereas the expression levels of p‑STING/t‑STING and p‑TBK1/t‑TBK1 were reduced in the model + HPE group. Conversely, when compared with the model + HPE group, the expression levels of p‑AMPK/t‑AMPK, p‑SHP1/t‑SHP1 and p‑SHP2/t‑SHP2 were decreased, whereas those of p‑STING/t‑STING and p‑TBK1/t‑TBK1 were increased in the model + HPE + AMPK inhibitor group. In conclusion, HPE may inhibit AR by modulating the AMPK/SHP1/SHP2/STING signaling pathway.

The emerging role of honeysuckle flower in inflammatory bowel disease

Crohn's disease (CD) and ulcerative colitis (UC), referred to as inflammatory bowel disease (IBD), pose considerable challenges in treatment because they are chronic conditions that easily relapse. The occurrence of IBD continues to rise in developing countries. Nonetheless, the existing therapies for IBD have limitations and fail to address the needs of the patients thoroughly. There is an increasing need for new, safe, and highly effective alternative medications for IBD patients. Traditional Chinese Medicine (TCM) is employed in drug development and disease management due to its wide-range of biological activities, minimal toxicity, and limited side effects. Extensive research has shown that certain TCM exhibits significant therapeutic benefits for IBD treatments. Honeysuckle (Lonicera japonica) was used in TCM research and clinical settings for the treatment of IBD. Bioactive metabolites in L. japonica, such as luteolin, quercetin, cyanidin, chlorogenic acid (CGA), caffeic acid (CA), and saponin, exhibit significant therapeutic benefits for managing IBD. The honeysuckle flower is a potential candidate in the treatment of IBD due to its anti-inflammatory, immune system-regulating, and antioxidant qualities. This paper reviews the metabolites of the honeysuckle flower as a candidate for the treatment of IBD. It discusses the fundamental mechanism of L. japonica and the potential of its bioactive metabolites in the prevention and treatment of IBD.

A Comprehensive Review of Traditional Chinese Medicine in the Management of Ulcerative Colitis

Ulcerative colitis (UC) is a chronic, nonspecific inflammatory disorder characterized by symptoms such as abdominal pain, diarrhea, hematochezia, and urgency during defecation. While the primary site of involvement is the colon, UC can extend to encompass the entire rectum and colon. The causes and development mechanisms of UC are still not well understood; nonetheless, it is currently held that factors including environmental influences, genetic predispositions, intestinal mucosal integrity, gut microbiota composition, and immune dysregulation contribute to its development. Dysregulated immune responses are pivotal in the pathophysiology of UC, and these aberrant responses are considered key contributors to the disease onset. In patients with UC, immune cells become hyperactive and erroneously target normal intestinal tissue, resulting in inflammatory cascades and damage to the intestinal mucosa. The therapeutic strategies currently employed for UC include immunosuppressive agents such as aminosalicylates and corticosteroids. However, these treatments often prove costly and carry significant adverse effects - imposing a considerable burden on patients. Traditional Chinese Medicine (TCM) has attracted worldwide attention because of its multi-target approach, minimal side effects, cost-effectiveness, and favorable efficacy profiles. In this review, the ways in which TCM modulates inflammatory responses in the treatment of ulcerative colitis have been outlined. Research into TCM modalities for modulating inflammatory pathways in the treatment of UC, which has yielded promising advancements, including individual herbs, herbal formulations, and their derivatives, has been summarized. TCM has been utilized to treat UC and the immune system plays a key role in regulating intestinal homeostasis. It is imperative to facilitate large-scale evidence-based medical research and promote the clinical application of TCM in the management of UC.

Luteolin in Inflammatory Bowel Disease and Colorectal Cancer: A Disease Continuum Perspective

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that may progress to colorectal cancer (CRC), presenting significant challenges to global health. With shifts in lifestyle, the incidence of both conditions continues to rise, underscoring the urgent need for effective treatments. While traditional therapies can be effective, their high recurrence rates and associated adverse reactions limit their broader application. Luteolin, a flavonoid derived from natural plants, has emerged as a promising focus in both IBD and CRC research due to its multi-target therapeutic potential. This article reviews the molecular mechanisms and signaling pathways through which luteolin regulates immune cell differentiation, mitigates inflammation and oxidative stress, modulates gut microbiota, and restores intestinal mucosal barrier function in IBD. In the context of CRC, luteolin demonstrates significant anti-tumor effects by inhibiting cancer cell proliferation, inducing apoptosis, and suppressing cell migration and invasion. Notably, luteolin has demonstrated significant improvements in IBD symptoms by influencing the differentiation of T cell subsets, decreasing the expression of inflammatory mediators, activating antioxidant pathways, and enhancing the structure of gut microbiota. Furthermore, advancements in formulation technology, such as the use of polymer micelles and responsive nanoparticles, have greatly improved the bioavailability and efficacy of luteolin. However, further investigation is needed to address the bioavailability and potential toxicity of luteolin, particularly in the critical transition from IBD to CRC. This article emphasizes the potential of luteolin in the treatment of IBD and CRC and anticipates its promising prospects for future clinical applications as a natural therapeutic agent.

Butyric acid alleviates LPS-induced intestinal mucosal barrier damage by inhibiting the RhoA/ROCK2/MLCK signaling pathway in Caco2 cells

Butyric acid (BA) can potentially enhance the function of the intestinal barrier. However, the mechanisms by which BA protects the intestinal mucosal barrier remain to be elucidated. Given that the Ras homolog gene family, member A (RhoA)/Rho-associated kinase 2 (ROCK2)/Myosin light chain kinase (MLCK) signaling pathway is crucial for maintaining the permeability of the intestinal epithelium, we further investigated whether BA exerts a protective effect on epithelial barrier function by inhibiting this pathway in LPS-induced Caco2 cells. First, we aimed to identify the optimal treatment time and concentration for BA and Lipopolysaccharide (LPS) through a CCK-8 assay. We subsequently measured Trans-epithelial electrical resistance (TEER), FITC-Dextran 4 kDa (FD-4) flux, and the mRNA expression of ZO-1, Occludin, RhoA, ROCK2, and MLCK, along their protein expression levels, and average fluorescence intensity following immunofluorescence staining. We then applied the ROCK2 inhibitor Y-27632 and reevaluated the TEER, FD-4 flux, and mRNA, and protein expression of ZO-1, Occludin, RhoA, ROCK2, and MLCK, as well as their distribution in Caco2 cells. The optimal treatment conditions were determined to be 0.2 mmol/L BA and 5 μg/mL LPS for 24 hours. Compared with LPS treatment alone, BA significantly mitigated the reduction in the TEER, decreased FD-4 flux permeability, increased the mRNA expression of ZO-1 and Occludin, and normalized the distribution of ZO-1 and Occludin in Caco2 cells. Furthermore, BA inhibited the expression of RhoA, ROCK2, and MLCK, and normalized their localization within Caco2 cells. Following treatment with Y-27632, the epithelial barrier function, along with the mRNA and protein expression and distribution of ZO-1 and Occludin were further normalized upon inhibition of the pathway. These findings contribute to a deeper understanding of the potential mechanisms through which BA attenuates LPS-induced impairment of the intestinal epithelial barrier.

SHP-1 alleviates acute liver injury caused by Escherichia coli sepsis through negatively regulating the canonical and non-canonical NFκB signaling pathways

SHP-1, as a protein tyrosine phosphatase, plays a key role in inflammation-related diseases. However, its function and regulatory mechanism in the imbalance of inflammatory response and acute liver injury during sepsis are still unknown. Herein, we constructed a murine model of Escherichia coli (E. coli) sepsis and demonstrated the function and novel mechanism of SHP-1 in sepsis. Overexpression of SHP-1 significantly reduced the mortality rate of mice and alleviated the histopathological deterioration of liver. In addition, it inhibited the expression and release of pro-inflammatory mediators in liver tissue and serum, but upregulated the expression of anti-inflammatory molecules. Silencing SHP-1 exhibited the completely opposite effects. Furthermore, the transcriptome data of mice liver showed that SHP-1 suppressed the progression of sepsis by negatively regulating the activation of multiple inflammation-related signaling pathways. More importantly, we fully revealed the regulation mechanism of SHP-1 on both canonical and non-canonical nuclear factor kappa-B (NFκB) signaling pathways during sepsis for the first time. SHP-1 significantly inhibited the phosphorylation and nuclear translocation of p50, while p65 inhibition was mainly achieved by inhibiting its transcription and translation levels. Meanwhile, SHP-1 inhibited the phosphorylation and nuclear translocation of p52, thereby inhibiting the activation of non-canonical NFκB signaling pathways. In summary, SHP-1 negatively regulated canonical and non-canonical NFκB signaling pathways, thereby blocking the occurrence of excessive inflammatory response and acute liver injury caused by E. coli sepsis. Our findings systematically elucidate the role and mechanism of SHP-1 during sepsis, providing new insights into the prevention and treatment of inflammation and immune-related diseases.

Modulation of the Respiratory Epithelium Physiology by Flavonoids-Insights from 16HBEσcell Model

Extensive evidence indicates that the compromise of airway epithelial barrier function is closely linked to the development of various diseases, posing a significant concern for global mortality and morbidity. Flavonoids, natural bioactive compounds, renowned for their antioxidant and anti-inflammatory properties, have been used for centuries to prevent and treat numerous ailments. Lately, a growing body of evidence suggests that flavonoids can enhance the integrity of the airway epithelial barrier. The objective of this study was to investigate the impact of selected flavonoids representing different subclasses, such as kaempferol (flavonol), luteolin (flavone), and naringenin (flavanone), on transepithelial electrical resistance (TEER), ionic currents, cells migration, and proliferation of a human bronchial epithelial cell line (16HBE14σ). To investigate the effect of selected flavonoids, MTT assay, trypan blue staining, and wound healing were assessed. Additionally, transepithelial resistance and Ussing chamber measurements were applied to investigate the impact of the flavonoids on the electrical properties of the epithelial barrier. This study showed that kaempferol, luteolin, and naringenin at micromolar concentrations were not cytotoxic to 16HBE14σ cells. Indeed, in MTT tests, a statistically significant change in cell metabolic activity for luteolin and naringenin was observed. However, our experiments showed that naringenin did not affect the proliferation of 16HBE14σ cells, while the effect of kaempferol and luteolin was inhibitory. Moreover, transepithelial electrical resistance measurements have shown that all of the flavonoids used in this study improved the epithelial integrity with the slightest effect of kaempferol and the significant impact of naringenin and luteolin. Finally, our observations suggest that luteolin increases the Cl- transport through cystic fibrosis transmembrane conductance regulator (CFTR) channel. Our findings reveal that flavonoids representing different subclasses exert distinct effects in the employed cellular model despite their similar chemical structures. In summary, our study sheds new light on the diverse effects of selected flavonoids on airway epithelial barrier function, underscoring the importance of further exploration into their potential therapeutic applications in respiratory health.

Effects of Luteolin in an In Vitro Model of Porcine Intestinal Infections

Intestinal infections caused by Escherichia coli and Salmonella enterica pose a huge economic burden on the swine industry that is exacerbated by the development of antimicrobial resistance in these pathogens, thus raising the need for alternative prevention and treatment methods. Our aim was to test the beneficial effects of the flavonoid luteolin in an in vitro model of porcine intestinal infections. We infected the porcine intestinal epithelial cell line IPEC-J2 with E. coli and S. enterica subsp. enterica serovar Typhimurium (106 CFU/mL) with or without previous, concurrent, or subsequent treatment with luteolin (25 or 50 µg/mL), and measured the changes in the reactive oxygen species and interleukin-6 and -8 levels of cells. We also tested the ability of luteolin to inhibit the adhesion of bacteria to the cell layer, and to counteract the barrier integrity damage caused by the pathogens. Luteolin was able to alleviate oxidative stress, inflammation, and barrier integrity damage, but it could not inhibit the adhesion of bacteria to IPEC-J2 cells. Luteolin is a promising candidate to be used in intestinal infections of pigs, however, further studies are needed to confirm its efficacy. The use of luteolin in the future could ultimately lead to a reduced need for antibiotics in pig production.

Analysis of phytochemical components of Tibetan medicine Pedicularis flava and Pedicularis muscicola by GC-MS and UHPLC-TOF-MS

Traditional medicine, 'LuRu', is a commonly used Tibetan medicine for clearing away heat and detoxifying. Dried products of Pedicularis flava and Pedicularis muscicola are often used as 'LuRu' in the market. This study aims to compare the chemical constituents of P. flava and P. muscicola using GC-MS and UPLC-TOF-MS, and confirm which plant species is more suitable to be used as 'LuRu'. A total of 46 and 68 compounds were identified from the volatile and non-volatile components, respectively. Out of these, 17 and 37 volatile and non-volatile components, respectively, had pharmacological activities. P. flava showed a higher content of the same active components than P. muscicola. Good biological activities are only observed in the unique components in P. flava, and not in P. muscicola. The two herbs should not be mixed in clinical medication. Our study shows that P. flava is better suited as a high-quality herb for the Tibetan medicine, 'LuRu'.

The progression of inorganic nanoparticles and natural products for inflammatory bowel disease

There is a growing body of evidence indicating a close association between inflammatory bowel disease (IBD) and disrupted intestinal homeostasis. Excessive production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), along with an increase in M1 proinflammatory macrophage infiltration during the activation of intestinal inflammation, plays a pivotal role in disrupting intestinal homeostasis in IBD. The overabundance of ROS/RNS can cause intestinal tissue damage and the disruption of crucial gut proteins, which ultimately compromises the integrity of the intestinal barrier. The proliferation of M1 macrophages contributes to an exaggerated immune response, further compromising the intestinal immune barrier. Currently, intestinal nanomaterials have gained widespread attention in the context of IBD due to their notable characteristics, including the ability to specifically target regions of interest, clear excess ROS/RNS, and mimic biological enzymes. In this review, we initially elucidated the gut microenvironment in IBD. Subsequently, we delineate therapeutic strategies involving two distinct types of nanomedicine, namely inorganic nanoparticles and natural product nanomaterials. Finally, we present a comprehensive overview of the promising prospects associated with the application of nanomedicine in future clinical settings for the treatment of IBD (graphic abstract). Different classes of nanomedicine are used to treat IBD. This review primarily elucidates the current etiology of inflammatory bowel disease and explores two prominent nanomaterial-based therapeutic approaches. First, it aims to eliminate excessive reactive oxygen species and reactive nitrogen species. Second, they focus on modulating the polarization of inflammatory macrophages and reducing the proportion of pro-inflammatory macrophages. Additionally, this article delves into the treatment of inflammatory bowel disease using inorganic metal nanomaterials and natural product nanomaterials.

Luteolin Attenuates Oxidative Stress and Colonic Hypermobility in Water Avoidance Stress Rats by Activating the Nrf2 Signaling Pathway

SCOPE

Irritable bowel syndrome (IBS) is an intestinal disorder, whose symptoms can be alleviated by certain dietary phytochemicals. This study explores the role and potential mechanisms of a natural flavonoid luteolin (LUT) in alleviating the excessive motility of colonic smooth muscles and reducing oxidative stress in IBS with diarrhea (IBS-D) rats.

METHODS AND RESULTS

LUT reduces excessive intestinal motility and lowers reactive oxygen species (ROS) levels in a water avoidance stress (WAS) rat model. Moreover, LUT increases the protein expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), activates the nuclear translocation of Nrf2, and greatly reduces the hydrogen peroxide (H2 O2 )-induced oxidative damage in intestinal epithelial cells.

CONCLUSIONS

LUT, a phyto-active component, protects against excessive intestinal motility and diarrhea by regulating the Nrf2 signaling pathway and effectively reduces oxidative stress damage in the colon.

Pomegranate (Punica granatum L.) and Its Rich Ellagitannins as Potential Inhibitors in Ulcerative Colitis

Ulcerative colitis, an immune-mediated inflammatory disease of the gastrointestinal tract, places a significant financial burden on patients and the healthcare system. Recently, reviews of the pomegranate and the abundant medicinal applications of its ellagitannins, as well as its pharmacological action, phytochemicals, metabolism, and pharmacokinetics, have been completed. However, summaries on their anti-ulcerative colitis effects are lacking. Numerous preclinical animal investigations and clinical human trial reports demonstrated the specific therapeutic effects of pomegranate and the effect of its ellagitannins against ulcerative colitis. According to the literature collected by Sci-finder and PubMed databases over the past 20 years, this is the first review that has compiled references regarding how the rich ellagitannins found in pomegranate have altered the ulcerative colitis. It was suggested that the various parts of pomegranates and their rich ellagitannins (especially their primary components, punicalagin, and ellagic acid) can inhibit oxidant and inflammatory processes, regulate the intestinal barrier and flora, and provide an anti-ulcerative colitis resource through dietary management.

Natural flavones from edible and medicinal plants exhibit enormous potential to treat ulcerative colitis

Ulcerative colitis (UC) is a chronic aspecific gut inflammatory disorder that primarily involves the recta and colons. It mostly presents as a long course of repeated attacks. This disease, characterized by intermittent diarrhoea, fecal blood, stomachache, and tenesmus, severely decreases the living quality of sick persons. UC is difficult to heal, has a high recurrence rate, and is tightly related to the incidence of colon cancer. Although there are a number of drugs available for the suppression of colitis, the conventional therapy possesses certain limitations and severe adverse reactions. Thus, it is extremely required for safe and effective medicines for colitis, and naturally derived flavones exhibited huge prospects. This study focused on the advancement of naturally derived flavones from edible and pharmaceutical plants for treating colitis. The underlying mechanisms of natural-derived flavones in treating UC were closely linked to the regulation of enteric barrier function, immune-inflammatory responses, oxidative stress, gut microflora, and SCFAs production. The prominent effects and safety of natural-derived flavones make them promising candidate drugs for colitis treatment.

Luteolin and Vernodalol as Bioactive Compounds of Leaf and Root Vernonia amygdalina Extracts: Effects on α-Glucosidase, Glycation, ROS, Cell Viability, and In Silico ADMET Parameters

The aqueous decoctions of Vernonia amygdalina (VA) leaves and roots are widely used in traditional African medicine as an antidiabetic remedy. The amount of luteolin and vernodalol in leaf and root extracts was detected, and their role was studied regarding α-glucosidase activity, bovine serum albumin glycation (BSA), reactive oxygen species (ROS) formation, and cell viability, together with in silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties. Vernodalol did not affect α-glucosidase activity, whereas luteolin did. Furthermore, luteolin inhibited the formation of advanced glycation end products (AGEs) in a concentration-dependent manner, whereas vernodalol did not reduce it. Additionally, luteolin exhibited high antiradical activity, while vernodalol demonstrated a lower scavenger effect, although similar to that of ascorbic acid. Both luteolin and vernodalol inhibited HT-29 cell viability, showing a half-maximum inhibitory concentration (IC₅₀) of 22.2 µM (-Log IC₅₀ = 4.65 ± 0.05) and 5.7 µM (-Log IC₅₀ = 5.24 ± 0.16), respectively. Finally, an in silico ADMET study showed that both compounds are suitable candidates as drugs, with appropriate pharmacokinetics. This research underlines for the first time the greater presence of vernodalol in VA roots compared to leaves, while luteolin is prevalent in the latter, suggesting that the former could be used as a natural source of vernodalol. Consequently, root extracts could be proposed for vernodalol-dependent antiproliferative activity, while leaf extracts could be suggested for luteolin-dependent effects, such as antioxidant and antidiabetic effects.

Spermidine protects intestinal mucosal barrier function in mice colitis via the AhR/Nrf2 and AhR/STAT3 signaling pathways

BACKGROUND

Aryl hydrocarbon receptor (AhR) activation promotes intestinal barrier repair and enhances the gut mucosal barrier function in inflammatory bowel diseases (IBD). Spermidine is beneficial in several murine models of IBD and may affect AhR activity. However, the precise effects of spermidine on the intestinal barrier and AhR remain unclear. This study was designed to investigate whether spermidine affects AhR and gut barrier function in IBD models as well as, its underlying mechanism.

METHODS

We used dextran sulfate sodium (DSS)- and 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced mice, as well as, Caco2 cells incubated with TNF-α and IFN-γ to establish multiple IBD models, followed by spermidine intervention. Alcian blue/Periodic acid-Schiff (AB/PAS) staining, Fluorescein isothiocyanate (FITC)-dextran permeability assay, transepithelial electrical resistance (TER), tight junction protein (TJs) expression, and 16S rRNA scope in situ hybridization were performed to assess intestinal barrier function. AhR expression and the associated pathways were measured. AhR-targeted adeno-associated virus (AAV) and siRNA were used to explore the related molecular mechanisms.

RESULTS

Spermidine significantly attenuated the increased intestinal permeability, decreased TER, abnormal distribution of TJs in colitis, and bacterial translocation from the gut tract. Additionally, it significantly increased AhR and Nrf2 expression and inhibited STAT3 phosphorylation. However, the protective effects of spermidine and the related alterations in pathway proteins were largely abolished by the specific inhibition of AhR.

CONCLUSION

Our study demonstrated that spermidine rescues intestinal barrier defects in mice with colitis via the AhR-Nrf2 and AhR-STAT3 pathways, providing a potential therapeutic agent for IBD and other conditions associated with dysregulated gut barrier function.

Application Potential of Luteolin in the Treatment of Viral Pneumonia

Aim of the Review. This study aims to summarize the therapeutic effect of luteolin on the pathogenesis of viral pneumonia, explore its absorption and metabolism in the human body, evaluate the possibility of luteolin as a drug to treat viral pneumonia, and provide a reference for future research. Materials and Methods. We searched MEDLINE/PubMed, Web of Science, China National Knowledge Infrastructure, and Google Scholar and collected research on luteolin in the treatment of viral pneumonia and related diseases since 2003. Then, we summarized the efficacy and potential of luteolin in directly inhibiting viral activity, limiting inflammatory storms, reducing pulmonary inflammation, and treating pneumonia complications. Results and Conclusion. Luteolin has the potential to treat viral pneumonia in multiple ways. Luteolin has a direct inhibitory effect on coronavirus, influenza virus, and respiratory syncytial virus. Luteolin can alleviate the inflammatory factor storm induced by multiple factors by inhibiting the function of macrophages or mast cells. Luteolin can reduce pulmonary inflammation, pulmonary edema, or pulmonary fibrosis induced by multiple factors. In addition, viral pneumonia may cause multisystem complications, while luteolin has extensive protective effects on the gastrointestinal system, cardiovascular system, and nervous system. However, due to the first-pass metabolism mediated by phase II enzymes, the bioavailability of oral luteolin is low. The bioavailability of luteolin can be improved, and its potential value can be further developed by changing the dosage form or route of administration.

Enhancement of oral bioavailability and anti-colitis effect of luteolin-loaded polymer micelles with RA (rosmarinic acid)-SS-mPEG as carrier

OBJECTIVE

Polymer micelles were prepared (L-RSPMs) with luteolin and synthetic RA-SS-mPEG polymeric material before evaluation of their anti-inflammatory effect on 2, 4, 6-trinitro-benzene-sulfonic acid (TNBS)-induced ulcerative colitis (UC) model in rats.

METHODS

The synthetic RA-SS-mPEG was characterized with NMR spectroscopy, before preparation of luteolin-coated RA-SS-mPEG polymer micelles. The in vitro characterization and evaluation of the formulation were accomplished, couple with its pharmacokinetic parameters. The levels of PEG2, MDA, CRP and GSH, as well as concentrations of TNF-α, IL1-β, IL-6 and IL-10 in serum and colon tissue were detected via ELISA kit. The degree of colon injury and inflammation was evaluated via histopathologic examination.

RESULTS

L-RSPMs displayed small average droplet size (133.40 ± 4.52 nm), uniformly dispersed (PDI: 0.163 ± 0.011), good stability, slow release and enhanced solubility. We observed 353.28% increase in the relative bioavailability of L-RSPMs compared to free luteolin, while the half-life of the micelle was extended by 6.16h. Compared to model (M) group, luteolin (low and high doses) and L-RSPMs (low and high doses) significantly reduced levels of MDA, PEG2, CRP, TNF-α, IL-6 and IL-1β in colon tissue and serum of colitic rats but dose dependently increased IL-10 and SOD levels (p < 0.01). Histopathologic examination of colon showed that luteolin (low and high doses) and L-RSPMs (low and high doses) improved colonic inflammation in colitic rats to varying degrees compared to M group.

CONCLUSION

L-RSPMs could improve TNBS-induced colon inflammation by enhancing bioavailability, promoting antioxidant effects and regulating cytokine release, which may become a potential agent for UC treatment in clinical settings.

Network Pharmacology and Molecular Docking Analysis on Molecular Mechanism of Qingzi Zhitong Decoction in the Treatment of Ulcerative Colitis

Ulcerative colitis (UC) is a disease with complex pathological mechanisms. We explored the potential molecular mechanisms behind the therapeutic functions of Qingzi Zhitong decoction (QZZTD) in the treatment of UC by network pharmacology and molecular docking. QZZTD is a formula of Chinese traditional medicine consisting of 10 herbs. The potential active ingredients of QZZTD and their target genes were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform database, and UC-related target genes were obtained from GeneCards and OMIM databases. A total of 138 co-identified target genes were obtained by plotting the intersection target Venn diagram, and then the STRING database and Cytoscape software were used to establish protein-protein interaction networks and herb-ingredient-target networks. Four key active compounds and nine key proteins were identified. Then, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses showed that the biological functions of potential target genes were associated with DNA transcription, signaling receptor and ligand activity, cytokine activity, cellular autophagy, and antioxidant pathways, with related pathways involving the phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway, advanced glycosylation end product (AGE)-RAGE signaling pathway, tumor necrosis factor (TNF) signaling pathway, and IL-17 signaling pathway. Moreover, the binding activities of key target genes and essential active compounds of Chinese herbal medicines in QZZTD were further validated by molecular docking. This demonstrated that quercetin, luteolin, hyndarin, and beta-sitosterol had good binding to eight key proteins, and Akt1 was the target protein with the best binding activity, suggesting that Akt1 could be the essential mediator responsible for signaling transduction after QZZTD administration. The rat experiment verified that QZZTD inhibited PI3K-Akt pathway activation and reduced inflammation in UC. In conclusion, our study suggested four potential key active components, including quercetin, were identified in QZZTD, which could interact with Akt1 and modulate the activation of the PI3K-Akt pathway. The other three pathways may also be involved in the signaling transduction induced by QZZTD in the treatment of UC.

In Vitro Protective Effects of a Standardized Extract From Cynara Cardunculus L. Leaves Against TNF-α-Induced Intestinal Inflammation

Inflammatory bowel disease (IBD) represents a group of progressive disorders characterized by recurrent chronic inflammation of the gut. New unconventional therapies based on plant derived compounds capable of preventing and/or reducing acute or chronic inflammation could represent a valid alternative for the treatment or prevention of IBDs. Cynara cardunculus L. leaves, considered a food-waste suitable as a rich source of bioactive polyphenols including luteolin and chlorogenic acid, has been reported for its positive effects in digestive tract. The aim of the present work was to evaluate the in vitro molecular mechanisms of beneficial effects of a standardized polyphenol-rich extract obtained from the leaves of Cynara cardunculus L (CCLE) against acute intestinal inflammation induced by TNF-α on intestinal epithelial Caco-2 cells. CCLE prevented TNF-α-induced NF-κB inflammatory pathway and the overexpression of IL-8 and COX-2. In addition, CCLE was able to improve basal intracellular antioxidant power in both TNF-α-unexposed or -exposed Caco-2 cells and this effect was associated to the activation of Nrf2 pathway, a master regulator of redox homeostasis affecting antioxidant and phase II detoxifying genes, stimulating an adaptive cellular response. In conclusion, our data clearly evidenced that, although considered a waste, Cynara cardunculus leaves may be used to obtain extracts rich in bioactive polyphenols potentially useful for prevention and treatment of inflammatory intestinal diseases.

Exploring the Potential Mechanism of Xiaokui Jiedu Decoction for Ulcerative Colitis Based on Network Pharmacology and Molecular Docking

Introduction

Network pharmacology is in line with the holistic characteristics of TCM and can be used to elucidate the complex network of interactions between disease-specific genes and compounds in TCM herbal medicines. Here, we investigate the pharmacological mechanism of Xiaokui Jiedu decoction (XJD) for the treatment of ulcerative colitis (UC).

Methods

The Computational Systems Biology Laboratory Platform (TCMSP) database was searched and screened for the active ingredients of all drugs in XJD. The Uniport database was used to retrieve possible gene targets for the therapeutic effects of XJD. GeneCards, PharmGKB, TTD, and OMIM databases were used to retrieve XJD-related gene targets. A herb-compound-protein network and a protein-protein interaction (PPI) network were constructed, and hub genes were screened for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Finally, molecular docking was performed to validate the interrelationship between disease target proteins and active drug components.

Results

A total of 135 XJD potential action targets, 5097 UC-related gene targets, and 103 XJD-UC intersection gene targets were screened. The hub gene targets of XJD that exert therapeutic effects on UC are RB1, MAPK1, TP53, JUN, NR3C1, MAPK3, and ESR1. GO enrichment analysis showed 741 biofunctional enrichments, and KEGG enrichment analysis showed 124 related pathway enrichments. Molecular docking showed that the active components of XJD (β-sitosterol, kaempferol, formononetin, quercetin, and luteolin) showed good binding activities to five of the six hub gene targets. Discussion. The active ingredients of XJD (β-sitosterol, kaempferol, formononetin, quercetin, and luteolin) may regulate the inflammatory and oxidative stress-related pathways of colon cells during the course of UC by binding to the hub gene targets. This may be a potential mechanism of XJD in the treatment of UC.

SHP-1/STAT3 Interaction Is Related to Luteolin-Induced Myocardial Ischemia Protection

Prevention and management of myocardial ischemia/reperfusion (I/R) injury is a key step in coronary heart disease surgery. Luteolin is a falconoid compound that has an antioxidant effect, but its mechanism in I/R injury in vivo and in vitro is still under explored. This study attempted to reveal the role of luteolin (Lut) in I/R through mediation of the Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1)/Signal transducer and activator of transcription 3 (STAT3) pathway. To establish I/R rat models, the left anterior descending artery (LAD) was ligated for 30 min and re-perfused for 1 h in Lut-pretreated or nude rats. Comparisons between infarct area, cardiac dysfunction, and myocardial cell death and inflammatory reaction were performed in I/R-induced rats. Hypoxia/reoxygenation (H/R) cell models were established by stimulating H9c2 cells with 95% nitrogen and 5% carbon dioxide. Simultaneously, H/R-related cell death and inflammatory reactions were investigated following Lut treatment. The target protein of Lut was identified using western blotting. Pro-inflammatory cytokines were also measured in serum or Lut-pretreated cell culture medium. The results revealed that compared with the I/R group, Lut treatment could significantly decrease myocardial infarction (MI) area, increase left ventricular ejection fraction (LVEF), and decrease cell death and pro-inflammatory cytokines in the serum. Decreased apoptosis and inflammatory cytokines were also observed in H/R cells after Lut treatment. Lut treatment downregulated SHP-1 expression and subsequently upregulated STAT3 phosphorylation in both I/R rat heart tissue and H9c2 cells. The findings of the current study suggest that Lut can protect the heart and reduce MI area, cell apoptosis rate, and inflammatory level in I/R models.

Herbal Medicine, Gut Microbiota, and COVID-19

Coronavirus Disease 19 (COVID-19) is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has grown to a worldwide pandemic with substantial mortality. The symptoms of COVID-19 range from mild flu-like symptoms, including cough and fever, to life threatening complications. There are still quite a number of patients with COVID-19 showed enteric symptoms including nausea, vomiting, and diarrhea. The gastrointestinal tract may be one of the target organs of SARS-CoV-2. Angiotensin converting enzyme 2 (ACE2) is the main receptor of SARS-CoV-2 virus, which is significantly expressed in intestinal cells. ACE2 links amino acid malnutrition to microbial ecology and intestinal inflammation. Intestinal flora imbalance and endotoxemia may accelerate the progression of COVID-19. Many herbs have demonstrated properties relevant to the treatment of COVID-19, by supporting organs and systems of the body affected by the virus. Herbs can restore the structure of the intestinal flora, which may further modulate the immune function after SARS-CoV-2 infection. Regulation of intestinal flora by herbal medicine may be helpful for the treatment and recovery of the disease. Understanding the role of herbs that regulate intestinal flora in fighting respiratory virus infections and maintaining intestinal flora balance can provide new ideas for preventing and treating COVID-19.