Ameliorative effects of Magnolia sieboldii buds hexane extract on experimental reflux esophagitis

Xuanfu Daizhe Tang alleviates reflux esophagitis in rats by inhibiting the STAT1/TREM-1 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Reflux esophagitis (RE) is a common chronic inflammatory disease of the esophageal mucosa with a high prevalence and recurrence rate, for which a satisfactory therapeutic strategy is still lacking. Chinese medicine has its characteristics and advantages in treating RE, and the clinical application of Xuanfu Daizhe Tang (XDT) in treating RE has achieved sound therapeutic effects. However, there needs to be more research on its mechanism of action.

AIM OF THE STUDY

The present work aimed to investigate the mechanism of XDT action in RE through the Signal Transducer and Activator of Transcription 1 (STAT1)/Triggering Receptor Expressed on Myeloid cells-1 (TREM-1) pathway.

MATERIALS AND METHODS

The main active components of XDT were analyzed by ultra-performance liquid chromatography-mass spectrometer (UPLC-MS). The effect of XDT on RE was evaluated in a rat model of RE induced by "Cardioplasty + pyloric ligation + Roux-en-Y esophagojejunostomy". Each administration group was treated by gavage. The degree of damage to the esophageal mucosa was evaluated by visual observation, and the Potential of Hydrogen (PH) method and Hematoxylin-eosin staining (HE) staining were performed. Serum levels of Interleukin-1β (IL-1β), Interleukin-6 (IL-6), Tumor Necrosis Factor alpha (TNF-α), and Inducible Nitric Oxide Synthase (iNOS) were measured by ELISA. Quantitative Real-time PCR (qPCR), Western Blot (WB), and Immunofluorescence (IF) methods were used to detect Claudin-4, Claudin-5, TREM-1, and p-STAT1 in esophageal tissues for studying the mechanism of action and signaling pathway of XDT. Immunohistochemistry (IHC) analysis was used to detect the expression of TREM-1 and CD68 in esophageal tissues. Flow Cytometry (FC) was used to detect the polarization of macrophages in the blood. After conducting preliminary experiments to verify our hypothesis, we performed molecular docking between the active component of XDT and STAT1 derived from rats and parallel experiments with STAT1 inhibitor. The selective increaser of STAT1 transcription (2-NP) group was used to validate the mechanism by which XDT acts.

RESULTS

XDT alleviated esophageal injury and attenuated histopathological changes in RE rats. XDT also inhibited the inflammatory response and decreased serum IL-1β, IL-6, TNF-α, and iNOS levels in RE rats. qPCR and WB results revealed that XDT inhibited the expression of Claudin-4, Claudin-5, TREM-1, and STAT1 in the esophageal mucosa of RE rats. IHC and FC results showed that XDT reduced TREM-1 levels in esophageal tissues and polarized macrophages toward M2. The molecular docking results showed that rat-derived STAT1 can strongly bind to Isochronogenic acid A in XDT. The parallel experimental results of STAT1 inhibitor showed that XDT has anti-inflammatory effects similar to STAT1 inhibitors. The 2-NP group confirmed that XDT exerts its therapeutic effect on reflux esophagitis through the STAT1/TREM-1 pathway, with STAT1 as the upstream protein.

CONCLUSIONS

This study suggests that XDT may treat reflux esophagitis by modulating the STAT1/TREM-1 pathway.

Efficacy of an oral suspension containing xyloglucan and pea proteins on a murine model of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is the most common foregut disease, affecting about 20% of the adult population. Esophageal epithelial barrier plays a fundamental role in the pathophysiology of GERD; however, pharmacological therapies mainly aim to reduce the acidity of the gastroesophageal environment rather than to protect esophageal tissue integrity. This study aims to evaluate the efficacy of an oral solution containing xyloglucan and pea proteins (XP) in reestablishing gastroesophageal tissue integrity and biochemical markers. To induce GERD, C57BL/6 mice were alternatively overfed and fasted for 56 days and then treated with XP, sodium alginate, omeprazole, or omeprazole+XP twice daily for 7 days. Gastric pain and inflammatory markers were evaluated after 3 and 7 days of treatment. After sacrifice, the esophagi and stomachs were surgically removed for macroscopic and histological examination. Gastric pain was significantly reduced at days 3 and 7 by XP, omeprazole, and omeprazole+XP, while alginates were ineffective at day 3. XP was able to diminish gastric macroscopic damage and demonstrated the same efficacy as omeprazole in reducing esophageal damage. XP significantly reduced histological damage, with an efficacy comparable to that of omeprazole, but superior to alginates. Inflammatory markers were significantly reduced by XP, with superior efficacy compared with alginates at day 7. Interestingly, XP was also able to significantly increase gastric pH. This study demonstrated that XP restored gastric homeostasis, improved esophageal integrity, and decreased inflammation and pain with a similar efficacy to omeprazole and greater than alginates.

Efficiency and Mechanism Evaluation of Magnolia officinalis Water Extract in Preventing Gastric Ulcer

In this study we aimed at demonstrating the ability of Magnolia officinalis water extract to ameliorate gastric ulcers in in vitro and in vivo experiments. The gastric mucosa epithelial cell line, RGM 1, was pretreated with Magnolia officinalis water extract (0, 0.1, 1, 2, 5, or 10 mg/ml) and cultured in DMEM/F12 medium (pH 7.4) for 2 h and then in DMEM/F12 medium (pH 4.0) for 10 min. Magnolia officinalis water extract protected the cell viability and decreased reactive oxygen species formation by the acidic medium. In the in vivo experiment, Magnolia officinalis water extract (100 mg/kg) was administrated daily for 28 days in ICR mice via oral gavage, and then Shay’s ulcer surgical method was performed to induce gastric ulcers. We analyzed the pH value of stomach acid and the pathological section, inflammation, and cannabinoid receptor type 2 (CB2) cDNA levels of the stomach. Magnolia officinalis water extract not only enhanced the pH value of stomach acid but also ameliorated the ulcer index and inflammation and increased CB2 expression effectively. These results suggest that Magnolia officinalis water extract might be used to decrease the incidence of gastric ulcer.

NF-κB: A novel therapeutic pathway for gastroesophageal reflux disease?

Although gastroesophageal reflux disease (GERD), a common chronic disease in clinical practice, has been widely studied, its potential adverse impact on patients is still a significant clinical concern. It is necessary to understand the pathogenesis of the disease and choose appropriate treatment according to its mechanism. The pathogenesis of GERD is diverse and complex. As the traditional treatment methods are expensive and ineffective in alleviating symptoms in some patients, new treatment options need to be explored. Our previous study suggested that the activation of nuclear factor-kappa beta (NF-κB) in esophageal mucosa may be related to the injury of epithelial barrier function caused by reflux. Based on the literature and our previous study results, it is speculated that inhibition of NF-κB activation may block the insult of GERD on the esophageal mucosal barrier. NF-κB may play an important role in the development of GERD. This article reviews the pathogenesis of GERD and the relationship between NF-κB and GERD, in order to provide new strategies for the treatment of GERD.

Network Pharmacology Analysis of Hewei Jiangni Granule for Gastroesophageal Reflux Disease and Experimental Verification of Its Anti-Neurogenic Inflammation Mechanism

Purpose

Proton pump inhibitors, as the first-line drugs for treating gastroesophageal reflux disease (GERD), are unable to completely relieve patients’ symptoms and patients are prone to recurrence after prolonged drug withdrawal. Thus, it is crucial to find herbal medicines as a complementary and alternative treatment. Hewei Jiangni granule (HWJNG) is a classical Chinese medicinal formula with clinical therapeutic effects on GERD, but its pharmacological mechanism of action remains unclear. This study aimed to explore and then verify the pharmacological mechanisms of HWJNG in GERD therapy.

Methods

A network pharmacology approach was applied to explore and then verify the pharmacological mechanisms of HWJNG in GERD therapy. The active ingredients of HWJNG, as well as therapeutic targets of GERD were acquired from specialized databases. The “herb-ingredient-gene-target” network for HWJNG in GERD treatment was built. The protein–protein interaction (PPI) network was constructed to screen the core coincident targets. Then, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. The core targets and signaling pathways associated with the anti-neurogenic inflammatory effect were partially verified via experiments in vivo at molecular level.

Results

In total, 179 chemical ingredients in HWJNG and 298 intersection targets between GERD and HWJNG were selected from databases. A large proportion of core targets and top signaling pathways were involved in neurogenic inflammation. HWJNG significantly alleviated pathological injuries of esophagus and reversed dilated intracellular spaces. Additionally, HWJNG markedly inhibited the excessive release of inflammatory cytokines such as interleukin (IL)-1β, IL-6, tumor necrosis factor receptor (TNF-a), as well as regulated stimulation sensors including transient receptor potential vanilloid type 1 (TRPV1) and its related neuroinflammatory mediators in GERD mice.

Conclusion

HWJNG is a promising therapeutic strategy for GERD treatment via regulation of multiple targets and pathways, its effects in alleviating neurogenic inflammation are especially acknowledged.