Accelerated Ulcer Healing and Resistance to Ulcer Recurrence with Gastroprotectants in Rat Model of Acetic Acid-induced Gastric Ulcer

Treatment of gastric ulcer, traditional Chinese medicine may be a better choice

ETHNOPHARMACOLOGICAL RELEVANCE

Gastric ulcer (GU) is the injury of the gastric mucosa caused by the stimulation of various pathogenic factors penetrating the deep mucosal muscle layer. An increasing number of studies have shown that traditional Chinese medicine (TCM) is highly effective in treating GU due to its multitarget, multilevel, and multi-pathway effects.

AIM OF THE STUDY

To review the latest research progress in the treatment of GU by TCM, including clinical and experimental studies, focusing on the target and mechanism of action of drugs and providing a theoretical basis for the treatment of GU by natural herbs.

MATERIALS AND METHODS

Electronic databases (PubMed, Elsevier, Springer, Web of Science, and CNKI) were searched using the keywords "gastric ulcer", "gastric mucosal lesion", "TCM" and or paired with "peptic ulcer" and "natural drugs" for studies published in the last fifteen years until 2023.

RESULTS

TCM, including single components of natural products, Chinese patent medicines (CPM), and TCM decoction, is expected to treat GU by regulating various mechanisms, such as redox balance, inflammatory factors, angiogenesis, gastric mucosal protective factors, intestinal flora, apoptosis, and autophagy.

CONCLUSIONS

We discussed and summarized the mechanism of TCM in the treatment of GU, which provided a sufficient basis for TCM treatment of GU.

Gut homeostasis, injury, and healing: New therapeutic targets

The integrity of the gastrointestinal mucosa plays a crucial role in gut homeostasis, which depends upon the balance between mucosal injury by destructive factors and healing via protective factors. The persistence of noxious agents such as acid, pepsin, nonsteroidal anti-inflammatory drugs, or Helicobacter pylori breaks down the mucosal barrier and injury occurs. Depending upon the size and site of the wound, it is healed by complex and overlapping processes involving membrane resealing, cell spreading, purse-string contraction, restitution, differentiation, angiogenesis, and vasculogenesis, each modulated by extracellular regulators. Unfortunately, the gut does not always heal, leading to such pathology as peptic ulcers or inflammatory bowel disease. Currently available therapeutics such as proton pump inhibitors, histamine-2 receptor antagonists, sucralfate, 5-aminosalicylate, antibiotics, corticosteroids, and immunosuppressants all attempt to minimize or reduce injury to the gastrointestinal tract. More recent studies have focused on improving mucosal defense or directly promoting mucosal repair. Many investigations have sought to enhance mucosal defense by stimulating mucus secretion, mucosal blood flow, or tight junction function. Conversely, new attempts to directly promote mucosal repair target proteins that modulate cytoskeleton dynamics such as tubulin, talin, Ehm², filamin-a, gelsolin, and flightless I or that proteins regulate focal adhesions dynamics such as focal adhesion kinase. This article summarizes the pathobiology of gastrointestinal mucosal healing and reviews potential new therapeutic targets.

Salvianolic acid B decreases interleukin-1β-induced colitis recurrence in mice

BACKGROUND

Degree of mucosal recovery is an important indicator for evaluating the therapeutic effects of drugs in treatment of inflammatory bowel disease (IBD). Increasing evidences has proved that tight junction (TJ) barrier dysfunction is one of the pathological mechanisms of IBD. The aim of this study was to observe whether enhancement of TJ can decrease colitis recurrence.

METHODS

Eighty C57BL/6 mice were randomly divided into four groups including normal group, colitis group, sulfasalazine (SASP) treated group, and traditional Chinese drug salvianolic acid B (Sal B) treated group. Colitis was established in mice by free drinking water containing dextran sulfate sodium, after treatments by SASP and Sal B, recombinant human interleukin-1β (IL-1β) was injected intraperitoneally to induce colitis recurrence.

RESULTS

Compared with sham control, cell apoptosis in colitis group was increased from 100.85 ± 3.46% to 162.89 ± 11.45% (P = 0.0038), and TJ dysfunction marker myosin light chain kinase (MLCK) was also significantly increased from 99.70 ± 9.29% to 296.23 ± 30.78% (P = 0.0025). The increased cell apoptosis was reversed by both SASP (125.99 ± 8.45% vs. 162.89 ± 11.45%, P = 0.0059) and Sal B (104.27 ± 6.09% vs. 162.89 ± 11.45%, P = 0.0044). High MLCK expression in colitis group was reversed by Sal B (182.44 ± 89.42% vs. 296.23 ± 30.78%, P = 0.0028) but not influenced by SASP (285.23 ± 41.04% vs. 296.23 ± 30.78%, P > 0.05). The recurrence rate induced by recombinant human IL-1β in Sal B-treated group was significantly lower than that in SASP-treated group.

CONCLUSIONS

These results suggested a link between intestinal mucosal barrier dysfunction, especially TJ barrier dysfunction, and colitis recurrence. The TJ barrier dysfunction in remission stage of colitis increased the colitis recurrence. This study might provide potential treatment strategies for IBD recurrence.

Taxifolin and gastro-adhesive microparticles containing taxifolin promotes gastric healing in vivo, inhibits Helicobacter pylori in vitro and proton pump reversibly in silico

Taxifolin (3,5,7,3,4-pentahydroxy flavanone or dihydroquercetin, Tax) was identified as a gastroprotective compound and a gastroadhesive formulation was recently developed to prolong its residence time and release in the stomach. So, the gastric healing effectiveness of Tax and gastro-mucoadhesive microparticles containing Tax (MPTax) against the acetic acid induced-gastric ulcer in rats was investigated in this study. Moreover, the interactions between Tax and H⁺/K⁺-ATPase were investigated in silico, and its anti- H. pylori activity was determined in vitro. The oral treatment with MPTax (81.37 mg/kg, containing 12.29% of Tax) twice a day for seven days reduced the ulcer area by 63%, compared to vehicle-treated group (Veh: 91.9 ± 10.3 mm²). Tax (10 mg/kg, p.o) reduced the ulcer by 40% but with a p = 0.07 versus Veh group. Histological analysis confirmed these effects. Tax and MPTax increased the gastric mucin amount, reduced the myeloperoxidase activity, and increased the glutathione reduced content at ulcer site. However, only MPTax decreased the lipoperoxide accumulation at ulcer site. Besides, Tax and MPTax normalize the catalase and glutathione S-transferase activity. Tax showed reversible interaction with H⁺/K⁺-ATPase in silico and its anti-H. pylori effects was confirmed (MIC = 625 μg/mL). These results suggest that the antiulcer property of Tax involves the strengthening of the gastric protective factors in parallel to its inhibitory interaction with H⁺/K⁺-ATPase and H. pylori. Considering that ulcer healing action displayed by Tax was favored by gastroadhesive microparticles, this approach seems to be promising for its oral delivery to treat acid-peptic diseases.

Metabolites profiling and pharmacokinetics of troxipide and its pharmacodynamics in rats with gastric ulcer

Troxipide is widely used to treat gastric ulcer (GU) in the clinic. However, a lack of systematic metabolic, pharmacokinetic and pharmacological studies limits its clinical use. This study aimed to firstly explore the metabolic, pharmacokinetic and pharmacological mechanisms of troxipide in rats with GU compared to normal control (NC) rats. First, metabolic study was perormed by a highly selective, high-resolution mass spectrometry method. A total of 45 metabolites, including 9 phase I metabolites and 36 phase II metabolites, were identified based on MS/MS spectra. Subsequently, the pharmacokinetics results suggested that the Cmax, Ka, t1/2, AUC(0-t) and AUC(0-∞) of troxipide were significantly increased in rats with GU compared with NC rats. The Vz, K10 and absolute bioavailability of troxipide were obviously decreased in rats with GU compared with NC rats, and its tissue distribution (in the liver, lung and kidney) was significantly different between the two groups of rats. Additionally, the pharmacodynamic results suggested that the levels of biochemical factors (IL-17, IL-6, TNF-α, IFN-γ, AP-1, MTL, GAS, and PG-II) were significantly increased, the PG-Ӏ level was obviously decreased, and the protein expression levels of HSP-90, C-Cas-3 and C-PARP-1 were markedly increased in rats with GU compared with NC rats. The above results suggested that the therapeutic mechanisms underlying the metabolic, pharmacokinetic and pharmacological properties of troxipide in vivo in rats deserve further attention based on the importance of troxipide in the treatment of GU in this study, and these mechanisms could be targets for future studies.

Deficient Active Transport Activity in Healing Mucosa After Mild Gastric Epithelial Damage

BACKGROUND

Peptic ulcers recur, suggesting that ulcer healing may leave tissue predisposed to subsequent damage. In mice, we have identified that the regenerated epithelium found after ulcer healing will remain abnormal for months after healing.

AIM

To determine whether healed gastric mucosa has altered epithelial function, as measured by electrophysiologic parameters.

METHOD

Ulcers were induced in mouse gastric corpus by serosal local application of acetic acid. Thirty days or 8 months after ulcer induction, tissue was mounted in an Ussing chamber. Transepithelial electrophysiologic parameters (short-circuit current, I_sc. resistance, R) were compared between the regenerated healed ulcer region and the non-ulcerated contralateral region, in response to luminal hyperosmolar NaCl challenge (0.5 M).

RESULTS

In unperturbed stomach, luminal application of hyperosmolar NaCl transiently dropped I_sc followed by gradual recovery over 2 h. Compared to the starting baseline I_sc, percent I_sc recovery was reduced in 30-day healing mucosa, but not at 8 months. Prior to NaCl challenge, a lower baseline I_sc was observed in trefoil factor 2 (TFF2) knockout (KO) versus wild type (WT), with no I_sc recovery in either non-ulcerated or healing mucosa of KO. Inhibiting Na/H exchanger (NHE) transport in WT mucosa inhibited I_sc recovery in response to luminal challenge. NHE2-KO baseline I_sc was reduced versus NHE2-WT. In murine gastric organoids, NHE inhibition slowed recovery of intracellular pH and delayed the repair of photic induced damage.

CONCLUSION

Healing gastric mucosa has deficient electrophysiological recovery in response to hypertonic NaCl. TFF2 and NHE2 contribute to I_sc regulation, and the recovery and healing of transepithelial function.

Sex-specific effects of Eugenia punicifolia extract on gastric ulcer healing in rats

AIM

To evaluate the sex-specific effects of a hydroalcoholic extract from Eugenia punicifolia (HEEP) leaves on gastric ulcer healing.

METHODS

In this rat study involving males, intact (cycling) females, and ovariectomized females, gastric ulcers were induced using acetic acid. A vehicle, lansoprazole, or HEEP was administered for 14 d after ulcer induction. Body weight was monitored throughout the treatment period. At the end of treatment, the rats were euthanized and the following in vivo and in vitro investigations were performed: macroscopic examination of the lesion area and organ weights, biochemical analysis, zymography, and evaluation of protein expression levels. Additionally, the concentration-dependent effect of HEEP was evaluated in terms of subacute toxicity and cytotoxicity.

RESULTS

Compared to the vehicle, HEEP demonstrated a great healing capacity by substantially reducing the ulcerative lesion area in males (52.44%), intact females (85.22%), and ovariectomized females (65.47%), confirming that HEEP accelerates the healing of acetic acid-induced gastric lesions and suggesting that this effect is modulated by female sex hormones. The antiulcer effect of HEEP was mediated by prostaglandin E₂ only in male rats. Overall, the beneficial effect of HEEP was the highest in intact females. Notably, HEEP promoted the expression of vascular endothelial growth factor (intact vs ovariectomized females) and decreased the expression of Caspase-8 and Bcl-2 (intact female vs male or ovariectomized female). Additionally, HEEP enhanced fibroblast proliferation and migration into a wounded area in vitro, confirming its healing effect. Finally, no sign of subacute toxicity or cytotoxicity of HEEP was observed.

CONCLUSION

In gastric ulcers, HEEP-induced healing (modulated by female sex hormones; in males, mediated by prostaglandin) involves extracellular matrix remodeling, with gastric mucosa cell proliferation and migration.

Essential oil of Cymbopogon citratus (lemongrass) and geraniol, but not citral, promote gastric healing activity in mice

Cymbopogon citratus, popularly known as lemongrass, is used for the treatment of gastric, nervous and hypertensive disorders, in addition to its use in the food and pharmaceutical industries. This study evaluated the gastroprotective and gastric healing effect of essential oil of C. citratus (EOCC), citral and geraniol at doses of 1-100 mg/kg (p.o) on acute ethanol-induced ulcer and chronic acetic acid-induced ulcer. Histological and histochemical evaluation was also performed, as well as the in vitro evaluation of the effects of these phytochemicals on H⁺/K⁺-ATPase activity. In the ethanol-induced gastric ulcer, the minimum effective oral dose of EOCC, citral and geraniol were 10, 100 and 3 mg/kg, reducing the ulcer area by 51.67%, 96.57% and 55.74%, respectively, compared to vehicle group (25.82 ± 3.59 mm²). Moreover, EOCC (10 mg/kg, p.o) and geraniol (3 mg/kg), but not citral (100 mg/kg), accelerated the gastric healing process by 34.52 and 80.57%, compared to acetic-acid ulcerated group treated with vehicle (36.04 ± 1.03 mm²). These healing effects were confirmed histologically by the contraction of the ulcer base and by the enhancement on mucin staining in slices of ulcer site from mice treated with EOCC or geraniol. Interestingly, EOCC and citral at 100 μg/ml inhibited the H⁺/ K⁺-ATPase activity by 28.26% and 44.36%, whereas geraniol did not change this parameter. Together, these findings confirm the gastroprotective and healing gastric ulcer effects of essential oil from aerial parts of C. citratus and added the information that geraniol, but not citral, promotes healing effects on installed ulcers.

Hydroalcoholic extract from bark of Persea major (Meisn.) L.E. Kopp (Lauraceae) exerts antiulcer effects in rodents by the strengthening of the gastric protective factors

ETHOPHARMACOLOGICAL RELEVANCE

The Persea major (Meisn.) L.E. Kopp (Lauraceae) (botanical synonym: Persea pyrifolia (D. Don) Spreng, Persea pyrifolia Nees and Mart., Persea cordata var. major (Meisn.) Mez and Persea willdenovii Kosterm) is a medicinal plant native in the south of Brazil, where is popularly known as Pau de Andrade, Maçaranduba or Abacate-do-Mato. Its barks are commonly used to prepare an infusion which is administered orally or topically to treat ulcers and wounds, respectively. Thus, this study has been undertaken to contribute to the validation of the popular use of P. major to treat of ulcerative disorders from gastrointestinal system, using different experimental models in rodents.

MATERIAL AND METHODS

Firstly, ultra-performance liquid chromatography coupled to a mass spectrophotometer has been performed. Next, the potential gastroprotective of hydroalcoholic extract of P. major barks (HEPM) (30-300mg/kg) has been evaluated in ulcer models acute as: ethanol, ethanol/HCl and indomethacin-induced ulcer. The extract (300mg/kg) has been also tested in acetic acid-induced chronic ulcer model. Histological, toxicological, histochemical, oxidative stress and gastric secretion parameters were analyzed.

RESULTS

The main compounds found in HEPM were polyphenols as condensed tannins, flavonoids heterosides derivatives from quercetin and kaempferol. HEPM (300mg/kg, p.o) prevented gastric lesions induced by ethanol or indomethacin in rats by 58.98% and 97.48%, respectively, compared to vehicle group (148.00±14.83mm² and 12.07±1.61mm², respectively). In acetic acid-induced chronic ulcer model the HEPM (300mg/kg, p.o) reduced the ulcer are by 40.58%, compared to vehicle group (127.90±12.04mm²). The healing effect was confirmed histologically, by an increase in mucin content and by the reduction in oxidative and inflammatory parameters at the ulcer site. Neither significant effect on gastric acid secretion nor toxicological effects and cytotoxicity were provoked by administration of HEPM.

CONCLUSIONS

The results allows to conclude that HEPM exerts gastroprotective and gastric cicatrizing effects favoring on protective defenses, but not possess antisecretory effect in contrast to the current antiulcer therapy, besides the extract present good tolerability and absence of cytotoxicity. Moreover, the results presented here contribute to the validation to the popular use of the P. major in the treatment of gastric ulcer.

Baicalin protects against gastroduodenal ulcers via the modulation of Nrf2 expression: Experimental, biochemical, and histological analyses

BACKGROUND

The present study aimed to determine the mechanisms underlying the gastroprotective effects of baicalin using several animal models of chemically induced gastric ulcers.

METHODS

The gastroprotective effects of baicalin against ulcers induced by water immersion stress, alcohol-induced ligation, and indomethacin-induced pylorus ligation were assessed in the present study. Additionally, macroscopic evaluations were performed at the completion of the study and Western blot analyses of Nrf2 were conducted to determine the possible mechanisms of action underlying the effects of baicalin.

RESULTS

Compared to the effects of ranitidine in a confirmed model of indomethacin-induced ligation, treatment with various doses of baicalin resulted in significant (p <0.001) increases in protection against ulcers in a dose-dependent manner. Baicalin was 72% effective versus the reference drug and 80% effective against ethanol-induced ulcers. Additionally, in rat stomachs with pylorus ligatures, Western blot analyses revealed that baicalin was 82% protective and that cimetidine was 85% protective. Taken together, the present findings indicate that baicalin is an alternative medicine with the potential to be an effective gastroprotective agent.

CONCLUSION

The present findings suggest that the protective effects of baicalin may be regulated via Nrf2-mediated anti-secretory actions.

Nanocrystalline cerium dioxide efficacy for prophylaxis of erosive and ulcerative lesions in the gastric mucosa of rats induced by stress

In our previous works, the important therapeutic properties of nanocrystalline cerium dioxide such as strong antioxidant ability, prebiotical and antibiotic activity were shown. Such properties were obtained due to stabilization of nanoparticles with precise size 3-7nm. Such modification of nanocrystalline cerium dioxide has contributed to its remarkable efficacy and low toxicity. We have carried out the investigation of toxicity of the nanodrug and revealed that in the condition of the acute toxicity test, LD 50 was 2000mg/kg when it was administered per os. This indicator is approximately 1000 times greater than effective dose of the compound that proved the possibility of its usage for humans. Considering the strong antioxidant properties of this substance, we have performed the investigation of the influence of nanocrystalline cerium dioxide on the erosive-ulcerative lesions in gastric mucosa of rats induced by Selye's restraint stress. It was established that the studied compound significantly reduced the lesions area by 58.3% (p<0.05) induced by Selye's restraint stress. The attenuation of inflammation and decrease of lipid peroxidation in the conditions of gastric lesions and prophylactic administration of nanocrystalline cerium dioxide were shown. That was confirmed by the decrease of pro-inflammatory cytokines content (interleukin (IL) 1β, 12B p40) and raise of anti-inflammatory cytokines content (IL-10 and transforming growth factor β). Measurement of lipid peroxidation products has proved the antioxidant properties of nanocrystalline cerium dioxide as it decreased the content of conjugated dienes and thiobarbituric acid active products in the conditions of gastric ulceration induced by stress.

Epithelial Regeneration After Gastric Ulceration Causes Prolonged Cell-Type Alterations

BACKGROUND & AIMS

The peptic ulcer heals through a complex process, although the ulcer relapse often occurs several years later after healing. Our hypothesis is that even after visual evidence of healing of gastric ulceration, the regenerated epithelium is aberrant for an extended interval, increasing susceptibility of the regenerated epithelium to damage and further diseases.

METHODS

Gastric ulcers were induced in mice by serosal topical application of acetic acid.

RESULTS

Gastric ulcers induced by acetic acid visually healed within 30 days. However, regenerated epithelial architecture was poor. The gene profile of regenerated tissue was abnormal, indicating increased stem/progenitor cells, deficient differentiated gastric cell types, and deranged cell homeostasis. Despite up-regulation of PDX1 in the regenerated epithelium, no mature antral cell type was observed. Four months after healing, the regenerated epithelium lacks parietal cells, trefoil factor 2 (TFF2) and (sex-determining region Y)-box 9 (SOX9) remain up-regulated deep in the gastric gland, and the Na/H exchanger 2 (a TFF2 effector in gastric healing) remains down-regulated. Gastric ulcer healing was strongly delayed in TFF2 knockout mice, and re-epithelialization was accompanied with mucous metaplasia. After Helicobacter pylori inoculum 30 days after ulceration, we observed that the gastric ulcer selectively relapses at the same site where it originally was induced. Follow-up evaluation at 8 months showed that the relapsed ulcer was not healed in H pylori-infected tissues.

CONCLUSIONS

These findings show that this macroscopically regenerated epithelium has prolonged abnormal cell distribution and is differentially susceptible to subsequent damage by H pylori.

Protective effects of Weilikang decoction on gastric ulcers and possible mechanisms

Although Weilikang decoction (WLK) has been used for gastric ulcer (GU) therapy in a clinical setting with good curative effect for >20 years, the mechanism remains unclear. Several GU animal models, induced by ethanol, hydrochloric acid, aspirin, pylorus ligation, acetic acid and indomethacin, were used to investigate the gastroprotective effects of WLK decoction. Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME), indomethacin, and N-ethylmaleimide (NEM) were pretreated, respectively, to investigate the action mechanism. Real-time polymerase chain reaction and Western blot analysis methods were used to determine the effects of WLK on indomethacin-induced GUs. The WLK-administered groups (2.5, 1.25 and 0.625 g/kg) significantly reduced the GU areas induced by ethanol, hydrochloric acid and aspirin. Furthermore, the effects could be quenched by L-NAME and NEM, but not by indomethacin. The 2.5 and 1.25 g/kg WLK groups showed significantly decreased effects on GU areas induced by pylorus ligation and acetic acid. WLK treatment significantly decreased mRNA expression on cyclooxygenase (COX)-1, COX-2, interleukin-6, tumor necrosis factor α and inducible nitric oxide synthase (iNOS) mRNA, but showed no effect on endothelial nitric oxide synthase mRNA expression. Western blot analysis result showed that WLK-treated groups markedly downregulated COX-2 protein expression. The anti-ulcer potential of WLK can be primarily attributed to its regulatory effects on nitric oxide, sulfhydryl compounds, and reduction effect on mucosal expression of proinflammatory cytokines.

Pharmacological reports about gastroprotective effects of methanolic extract from leaves of Solidago chilensis (Brazilian arnica) and its components quercitrin and afzelin in rodents

Solidago chilensis Meyenmost (Asteraceae), popularly known as "Brazilian arnica" or "arnica-do-campo," is widely used in the folk medicine to treat gastric disorders. Based on this, the gastroprotective activity of S. chilensis methanolic extract was investigated. Besides, a phytochemical study allowed isolation of two flavonoids (quercitrin and afzelin). The gastroprotective effects were investigated in acute gastric ulcer models, and the antisecretory activity was assessed in vivo and in vitro. The adhered mucus levels, reduced glutathione (GSH) content and myeloperoxidase (MPO) activity were quantified in ulcerated tissues. The contribution of isolated compounds in extract effects was evaluated, and its doses were calculated according to its yield. To evaluate the in vivo healing properties of S. chilensis methanolic extract, a chronic gastric ulcer was induced in mice by 10 % acetic acid. Evaluation of tumor necrosis factor (TNF) levels was also performed at the site of the acetic acid-induced gastric ulcer. In parallel, effects on cell viability and cell proliferation of fibroblasts (L929 cells) were determined by in vitro trials. Firstly, the S. chilensis methanolic extract (100 or 300 mg/kg) reduced the ulcer area induced by ethanol/HCl in mice when compared to the vehicle group. Moreover, the S. chilensis extract (300 mg/kg) prevented the mucus depletion, the increase in MPO activity and the decrease in the GSH levels in the ulcerated gastric tissue. The S. chilensis extract also was able to decrease the indomethacin-induced gastric ulcer in rats at a dose of 100 mg/kg. The antisecretory effect of the extract (100 mg/kg, intraduodenal (i.d.)) was confirmed by the reduction in the volume and acidity in parallel to an increase in the pH of gastric content. In addition, quercitrin (1.38 mg/kg, but not 0.46 mg/kg) and afzelin (0.026 and 0.078 mg/kg) decreased the ethanol/HCl-induced gastric ulcer. In this model, quercitrin (1.38 mg/kg) prevented the depletion of gastric GSH content and both quercitrin (1.38 mg/kg) and afzelin (0.078 mg/kg) reduced the MPO activity. These compounds also inhibited the H(+),K(+)-ATPase activity at a concentration of 1-100 μg/ml. In addition, the participation of quercitrin and afzelin in these effects also was confirmed. Furthermore, after 4 days of the treatment, an oral administration of S. chilensis methanolic extract (100 mg/kg) reduced the area of the gastric ulcer induced by acetic acid and the regeneration of the gastric mucosa was accompanied by a reduction in gastric TNF levels. The healing properties of the extract also were confirmed by enhancement of proliferation and coverage of scratched wounds in a fibroblast monolayer. Together, our results confirmed the gastroprotective effect of S. chilensis methanolic extract as well as its gastric healing potential and provided some support to the traditional use of S. chilensis for prevention and treatment of gastric lesions in complementation to its known anti-inflammatory properties.

Salvianolic Acid B Restored Impaired Barrier Function via Downregulation of MLCK by microRNA-1 in Rat Colitis Model

Salvianolic acid B (Sal B) is isolated from the traditional Chinese medical herb Salvia miltiorrhiza and is reported to have a wide range of therapeutic benefits. The aim of this study was to investigate the effects of Sal B on epithelial barrier dysfunction in rat colitis and to uncover related mechanisms. Rat colitis model was established by intracolonic administration of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS). The intestinal barrier function was evaluated by measuring the serum recovery of fluorescein isothiocyanate-4 kD dextran in vivo and transepithelial electrical resistance in vitro respectively. The protein expression related to intestinal barrier function was studied using western blotting. The effects of Sal B on inflammatory responses, oxidative damage and colitis recurrence were also studied in this study. The intestinal barrier dysfunction in colitis was reversed by Sal B, accompanied with the decrease of tight junction proteins, and the effect could be blocked by microRNA-1(miR-1) inhibition. The inflammatory responses, oxidative damage and colitis recurrence were also decreased by Sal B. The colitis symptoms and recurrences were ameliorated by Sal B, and restoration of impaired barrier function via downregulation of MLCK by miR-1 maybe involved in this effect. This study provides some novel insights into both of the pathological mechanisms and treatment alternatives of inflammatory bowel disease.

Quality of healing of gastric ulcers: Natural products beyond acid suppression

Gastric ulcer is a chronic disease featured with unexpected complications, including bleeding, stenosis and perforation, as well as a high incidence of recurrence. Clinical treatments for gastric ulcer have allowed the rapid development of potent anti-ulcer drugs during the last several decades. Gastric ulcer healing is successful with conventional treatments including H₂-receptor antagonists, and proton pump inhibitors (PPIs) have been essential for ulcer healing and prevention of complications. Additionally, Helicobacter pylori eradication therapy is effective in reducing ulcer recurrence and leads to physiological changes in the gastric mucosa which affect the ulcer healing process. However, in spite of these advancements, some patients have suffered from recurrence or intractability in spite of continuous anti-ulcer therapy. A new concept of the quality of ulcer healing (QOUH) was initiated that considers the reconstruction of the mucosal structure and its function for preventing ulcer recurrence. Although several gastroprotection provided these achievements of the QOUH, which PPI or other acid suppressants did not accomplish, we found that gastroprotection that originated from natural products, such as a newer formulation from either Artemisia or S-allyl cysteine from garlic, were very effective in the QOUH, as well as improving clinical symptoms with fewer side effects. In this review, we will introduce the importance of the QOUH in ulcer healing and the achievements from natural products.

Inhibition of endogenous CO by ZnPP protects against stress-induced gastric lesion in adult male albino rats

Carbon monoxide (CO) has been found to be produced in every living cell in a biochemical reaction catalyzed by heme-oxygenase (HO) enzyme which degrades heme into biliverdin, CO, and iron. Endogenous CO is not a waste product, but acts as a chemical messenger mediating and modulating many intracellular biochemical reactions that regulate physiological functions. This study was designed to investigate the effect of inhibition of endogenous CO production by zinc protoporphyrin (ZnPP), an HO inhibitor, on the gastric secretion and ulceration induced by cold-restraint stress (CRS) in adult male albino rats. Rats were pylorically ligated and divided randomly into the following groups (six rats each): control, ZnPP treated (50 μmol/kg/day, s.c. for 10 days), CRS, and stressed ZnPP treated groups. Blood samples were collected from the retro-orbital sinus of anesthetized rats for determination of CO concentration. We found that ZnPP pretreatment significantly decreased HO-1 level, CO level, and volume of gastric juice as compared to the control non-stressed rats. In the present study, ZnPP pretreatment proved to be protective against development of ulcerative lesions in CRS model as evidenced by reduction of the ulcer index, and this could be mediated through reduction of free and total acidity of gastric secretion and decreased lipid peroxidation but with significantly decreased gastric protective nitric oxide and prostaglandin E(2) levels. In conclusion and according to our results, the protective effect of ZnPP on CRS-induced gastric ulcers despite of inhibition of endogenous CO could be attributed to the presence of zinc which is known to have a protective anti-ulcer effect.

BuTuo method improves the quality of ulcer healing in patients with hepatogenic gastric ulcer

AIM: To evaluate the efficacy and safety of BuTuo method in improving the quality of ulcer healing in patients with hepatogenic gastric ulcer.

METHODS: This was a randomized controlled study. One hundred and forty-three patients with hepatogenic gastric ulcer who had blood stasis due to Qi deficiency were randomly divided into two groups: experimental group and control group. The experimental group (n = 72) was given TuoLiTouNong Decoction, omeprazole and propranolol, while the control group (n = 71) was treated with omeprazole and propranolol. The treatment lasted for 4 wk. The response rate, S2-stage shift rate, and short- and long-term recurrence rates were compared between the two groups.

RESULTS: After treatment, the total response rate achieved in the experimental group was significantly higher than that in the control group (95.83% vs 80.28%, Q = 4.260, P < 0.05). The S2-stage shift rate was also significantly higher in the experimental group than in the control group (82.69% vs 30.95%, χ² = 25.826, P < 0.01). In addition, long-term (6-mo) recurrence rate was significantly lower in the experimental group than in the control group (26.92% vs 47.62%, χ² = 4.310, P < 0.05). No adverse effects were observed during the entire treatment course.

CONCLUSION: BuTuo method can significantly improve the quality of ulcer healing and reduce ulcer recurrence in patients with hepatogenic gastric ulcer.

Correlation of heat shock protein expression to gender difference in development of stress-induced gastric mucosal injury in rats

Recent studies have indicated that heat shock proteins (HSPs), which function as molecular chaperones, play important roles in cellular responses to stress-related events. However, the gender difference in the expression of HSP in the gastric mucosa remains unclear. In order to understand the mechanism of gender difference in the prevalence or severity of gastric mucosal lesions, the expression level of HSP and the correlation of estrogen to HSP induction in the gastric mucosa were evaluated in this study. The basal expression levels of HSP60 and HSP90 in the gastric mucosa were significantly higher in females than those in males. The gastric ulcer index was significantly higher in male rats compared to female rats observed after 12 h water immersion stress exposure. At this time point, the expression levels of HSP60 and HSP90 in the gastric mucosa were significantly higher in females than those in males. An estrogen-treatment significantly induced the expression of HSP60, HSP70 and HSP90 in the gastric mucosa. Inversely, an ovariectomy dramatically reduced the expression of HSP60, HSP70 and HSP90 in the gastric mucosa. Our results suggested that estrogen might play an important role in gastric mucosal protection with the induction of gastric mucosal HSPs.