Gastroprotective activity of synthetic coumarins: Role of endogenous prostaglandins, nitric oxide, non-protein sulfhydryls and vanilloid receptors

From lab to nature: Recent advancements in the journey of gastroprotective agents from medicinal chemistry to phytotherapy

Peptic ulcer, affecting 10 % of the global population, results from imbalances in gastric juice pH and diminished mucosal defences. Key underlying factors are non-steroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori infection, undermining mucosal resistance. Traditional treatments like proton pump inhibitors (PPIs) and histamine-2 (H2) receptor antagonists exhibit drawbacks such as adverse effects, relapses, and drug interactions. This review extensively explores the ethnomedicinal, synthetic and pharmacological facets of various potential peptic ulcer treatments. Rigorous methodologies involving electronic databases, and chemical structure verification via 'PubChem' and 'SciFinder' enhance the review's credibility. The provided information, spanning medicinal insights to intricate pharmacological mechanisms, establishes a robust groundwork for future research and the development of plant-derived or synthetic molecules for peptic ulcers, offering a promising alternative to conventional therapies.

Apium extract alleviates indomethacin-induced gastric ulcers in rats via modulating the VEGF and IK-κB/NF-κB p65 signaling pathway: insights from in silico and in vivo investigations

BACKGROUND

Gastric ulcers represent a worldwide health problem, characterized by erosions that affect the mucous membrane of the stomach and may even reach the muscular layer, leading to serious complications. Numerous natural products have been assessed as anti-ulcerogenic agents, and have been considered as new approaches for treatment or prevention of gastric ulcers. The present research investigated the preventive benefits of Apium graveolens L. (Apiaceae), known as celery, seed extract towards indomethacin-induced ulceration of the stomach in rats.

METHODS

Metabolomic profiling, employing liquid chromatography coupled to high-resolution electrospray ionization mass spectrometry (LC-HR-ESI-MS), was implemented with the aim of investigating the chemical profile of the seeds. Histopathological analysis of gastric tissues, as well as assessment of numerous inflammatory cytokines and oxidative stress indicators, confirmed the in vivo evaluation.

RESULTS

The prior treatment with A. graveolens seed extract resulted in a substantial reduction in the ulcer index when compared to the indomethacin group, indicating an improvement in stomach mucosal injury. Moreover, the gastroprotective effect was demonstrated through examination of the oxidative stress biomarkers which was significantly attenuated upon pre-treatment with A. graveolens seed extract. Vascular endothelial growth factor (VEGF), a fundamental angiogenic factor that stimulates angiogenesis, was markedly inhibited by indomethacin. A. graveolens seed extract restored this diminished level of VEGF. The dramatic reductions in NF-κB protein levels indicate a considerable attenuation of the indomethacin-induced IKκB/NF-κB p65 signaling cascade. These activities were also correlated to the tentatively featured secondary metabolites including, phenolic acids, coumarins and flavonoids, previously evidenced to exert potent anti-inflammatory and antioxidant activities. According to our network pharmacology study, the identified metabolites annotated 379 unique genes, among which only 17 genes were related to gastric ulcer. The PTGS2, MMP2 and PTGS1 were the top annotated genes related to gastric ulcer. The top biological pathway was the VEGF signaling pathway.

CONCLUSION

A. graveolens seed extract possesses significant anti-ulcer activity, similar to famotidine, against gastric lesions induced by indomethacin in rats. It is worth highlighting that the extract overcomes the negative effects of conventional chemical anti-secretory drugs because it does not lower stomach acidity.

First Evidence of Gastroprotection by Schinus molle: Roles of Nitric Oxide, Prostaglandins, and Sulfhydryls Groups in Its Mechanism of Action

Schinus molle is a plant traditionally used in Mexico to treat gastric disorders. However, no scientific evidence has been reported on its gastroprotective effect. The aim of the current contribution was to conduct a bioassay-guided study on S. molle to evaluate its gastroprotective activity in a model of Wistar rats given ethanol orally to induce gastric lesions. The hexane and dichloromethane extracts from the tested plant showed over 99% gastroprotection at a dose of 100 mg/kg. From the hexane extract, two of the three fractions (F1 and F2) afforded over 99% gastroprotection. The F1 fraction was subjected to column chromatography, which revealed a white solid. Based on the ESI-MS analysis, the two main compounds in this solid were identified. The predominant compound was probably a triterpene. This mixture of compounds furnished about 67% gastroprotection at a dose of 100 mg/kg. Pretreatment with L-NAME, indomethacin, and NEM was carried out to explore the possible involvement of nitric oxide, prostaglandins, and/or sulfhydryl groups, respectively, in the gastroprotective activity of the white solid. We found evidence for the participation of all three factors. No antisecretory activity was detected (tested by pylorus ligation). In conclusion, evidence is herein provided for the first time of the gastroprotective effect of S. molle.

Application of Heterocycles as an Alternative for the Discovery of New Anti-ulcer Compounds: A Mini-Review

Peptic ulcer is a lesion located in the esophagus, stomach, and upper intestine, caused by an imbalance between acid secretion and the release of protective mucus. This pathology is prevalent in approximately 14% of the world population and is commonly treated with proton pump inhibitors and type 2 histaminergic receptor antagonists, however, these drugs present concerning side effects that may lead to gastric cancer. In this sense, this research aimed to present the main heterocyclics studied in recent years. The screening method for the choice of articles was based on the selection of publications between 2000 and 2021 present in the Science Direct, Web of Science, Capes, and Scielo databases, by using the descriptors ''new derivatives'', "heterocyclics" "antiulcerogenic", "gastroprotective" and "antisecretor". This research showed that the most used rings in the development of antiulcer drugs were benzimidazole, quinazoline, thiazole, and thiadiazole. The results also portray several types of modern in silico, in vitro and in vivo assays, as well as the investigation of different mechanisms of action, with emphasis on proton pump inhibition, type 2 histaminergic receptor blockers, potassium competitive acid blockers, type E prostaglandin agonism, anti-secretory activity and antioxidant action. Additionally, the review evidenced the presence of the nitrogen atom in the heterocyclic ring as a determinant of the potential of the compound. This research suggests new alternatives for the treatment of gastric lesions, which may be more potent and cause fewer side effects than the currently used, and tend to evolve into more advanced studies in the coming years.

Tablet of Spondias mombin L. Developed from Nebulized Extract Prevents Gastric Ulcers in Mice via Cytoprotective and Antisecretory Effects

Spondias mombin L. (Anacardiaceae) has a worldwide distribution and is present in all regions of Brazil. Its leaves, flowers and bark are used as teas in folk medicine to treat diseases of the digestive system. This study aimed to evaluate the acute non-clinical toxicity, gastroprotective activity, and the related mechanisms of action of nebulized extract and tablets based on dried Spondias mombin (SmNE). SmNE screening showed the presence of flavonoids (0.65%), polyphenols (25.50%), where the major compound is gallic acid. In the acute oral toxicity assay, a dose of 2000 mg/kg of SmNE administered orally in Swiss mice did not induce any behavioral changes. SmNE (250 or 500 mg/kg p.o) significantly reduced the ulcerative lesion area when compared to the control group in ethanol and non-steroidal anti-inflammatory drug (NSAIDs) models. Results showed that treatment with SmNE (250 mg/kg) reduced acid secretion and gastric content, accompanied with an increase in pH. Previous administration of indomethacin and glibenclamide reversed the protection provided by SmNE, confirming the participation of prostaglandins (PGs) and ATP-sensitive potassium channels (KATP) in its gastroprotective effect. The SmNE tablets met the pharmacopeial quality requirements with gastroprotective activity and similar protection in comparison to the isolated extract administrated. In conclusion, SmNe has a gastroprotective activity related to cytoprotective mechanisms, such as the participation of endogenous prostaglandins and KATP channels, having an anti-secretory effect with systemic action. The formulation obtained presented gastroprotective effects similar to the administration of the extract, the tablets showed favorable compression characteristics by the direct route and met the pharmacopeial quality requirements.

Gastroprotective effects of irsogladine maleate on ethanol/hydrochloric acid induced gastric ulcers in mice

BACKGROUND/AIMS

This study was conducted to investigate the inhibitory effect of irsogladine maleate (IM) on gastric ulcers induced by ethanol and hydrochloric acid (HCl).

METHODS

Mice were pretreated with IM for 1 hours before ulcer induction. Gastric ulcers were induced by oral administration of an ethanol/HCl mixture. To clarify the action mechanism of IM, the roles of 3'5'-cyclic adenosine monophosphate (cAMP), nitric oxide (NO), adenosine triphosphate-sensitive potassium (KATP) channels, prostaglandins and transient receptor potential cation channel subfamily V member 1 (TRPV1) were investigated, and lipid peroxidation in the stomach of IM-treated and -untreated animals was also measured.

RESULTS

IM significantly reduced the extent of ethanol/HCl mixture-induced gastric ulceration. It exhibited dose-related gastroprotection against the ethanol/ HCl-induced lesions, while pretreatment with glibenclamide but not N(ω)-nitro- L-arginine methyl ester, reversed this action. While pretreatment with the TRPV1 antagonist capsazepine failed to effectively block the gastroprotective effect of IM, the non-selective cyclooxygenase inhibitor indomethacin almost abolished it. IM also decreased the level of thiobarbituric acid reactive substances.

CONCLUSION

We concluded that IM exhibited significant gastroprotective effects in an ethanol/HCl-induced ulcer model, which appear to be mediated, at least in part, by NO, cAMP, endogenous prostaglandins, KATP channel opening, activation of TRPV1 channels, and antioxidant properties.

Evaluation of Gastroprotective Activity of Linoleic acid on Gastric Ulcer in a Mice Model

BACKGROUND

Gastric ulcer has been a major cause of morbidity and mortality worldwide, and it has been linked to factors such as nutritional deficiency, smoking, stress, and continuous intake of non-steroidal anti-inflammatory drugs (NSAIDs). The search for new anti-ulcer therapeutic agents has been the subject of several studies. Recently, the gastroprotective effect of Celtis iguanaea has been reported, with linoleic acid (LA) responsible for many of the therapeutic effects of this medicinal plant.

AIM

This study aims to investigate the gastroprotective activity and the possible mechanisms in which LA may be involved, through different experimental assays in mice.

METHODS

The gastroprotective activity LA was evaluated in the ulcer induced by indomethacin, HCl/EtOH, hypothermicrestraint stress and pyloric ligation. For the gastroprotective mechanisms investigation the quantification of the volume (mL), pH and total acidity of gastric secretion were considered.

RESULTS

The oral administrations of 25 mg/kg, 50 mg/kg or 100 mg/kg of body weight of LA were capable of protecting the gastric mucosa against HCl/ethanol (10 mL/kg p.o.), and oral administrations of 50 mg/kg LA showed protection from ulcers induced by indomethacin, hypothermic-restraint stress and pyloric ligation.

CONCLUSION

The results of this study show the gastroprotective role of LA in gastric mucosal damage induced by all assayed distresses. The observed gastroprotection possibly occurs due to the mediated increase of mucosal defensive factors.

Umbelliferone (7-hydroxycoumarin): A non-toxic antidiarrheal and antiulcerogenic coumarin

Gastrointestinal diseases are very common problems; available treatments are very limited and come with a range of side effects. Coumarins are an extensive class of phenolic compounds that can be found in plants, fungi and bacteria. The 7-hydroxycoumarin, also known as umbelliferone (UMB), is a compound that comes from coumarin and has been showing biological activities in other studies. As of this scenario, the present study was designed to evaluate the acute oral toxicity, mutagenic, antidiarrheal, anti-bacterial, and antiulcerogenic effects, and antioxidant capacity of UMB. An investigation was conducted through the hippocratic screening method and through histopathological analysis in animals to evaluate the effects of acute oral administration of a dose of 50, 100 and 200 mg/kg of UMB. A micronucleus test on peripheral blood of Swiss mice, which were orally treated with three doses (50, 100 and 200 mg/kg), was conducted to evaluate mutagenic activities. The antiulcerogenic activity was accomplished through the ethanol-induced damage method. Antidiarrheal activities were tested for inducing diarrhea with castor oil and evaluating intestinal transit duration; additionally, the antimicrobial effect against some enteropathogenic bacteria was analyzed. Finally, the antioxidant capability was determined by the capacity of the UMB sample to kidnap the stable radical 2,2-diphenyl-1-picrylhydrazyl. Of the evaluated doses, signs of toxicity after acute administration of the compound were not observed. UMB presented antiulcerogenic activity (100 and 200 mg/kg), which was explained because of its antioxidant capacity. A gastro protective effect was similar to the positive control, and the UMB was able to significantly reduce intestinal transit, and also diarrheal symptoms. Furthermore, UMB had an anti-bacterial effect with minimum inhibitory concentration fluctuating between 62.5 and 1000 μg/mL. Based on these findings, we can suggest that UMB has important biological activities in vivo and in vitro and is not toxic under the evaluated circumstances, which demonstrates its large potential for pharmacological use.

Gastroprotection of Calein D against Ethanol-Induced Gastric Lesions in Mice: Role of Prostaglandins, Nitric Oxide and Sulfhydryls

Peptic ulcers are currently treated with various drugs, all having serious side effects. The aim of this study was to evaluate the gastroprotective activity of calein D (from Calea urticifolia), a sesquiterpene lactone with a germacrane skeleton. Gastric lesions were induced in mice by administering ethanol (0.2 mL) after oral treatment with calein D at 3, 10 and 30 mg/kg, resulting in 13.15 ± 3.44%, 77.65 ± 7.38% and 95.76 ± 2.18% gastroprotection, respectively, to be compared with that of the control group. The effect found for 30 mg/kg of calein D was not reversed by pretreatment with N^G-nitro-l-arginine methyl ester (l-NAME, 70 mg/kg, ip), indomethacin (10 mg/kg, sc) or N-ethylmaleimide (NEM, 10 mg/kg, sc). Hence, the mechanism of action of calein D does not involve NO, prostaglandins or sulfhydryl compounds. Calein D was more potent than carbenoxolone, the reference drug. The findings for the latter are in agreement with previous reports.

Anti-inflammatory activity and gastroprotective effect of Hertia cheirifolia L. roots extract

ETHNOPHARMACOLOGICAL RELEVANCE

Hertia cheirifolia L. is used traditionally to treat rheumatic pains and known as a medicinal plant having several pharmaceutical and biological activities. The present study evaluated in vivo the anti-inflammatory and gastroprotective effects of the methanolic extract from H. cheirifolia L.

MATERIALS AND METHODS

Reverse phase high-performance liquid chromatography (RP-HPLC) was performed to identify various chemical components of the plant extract. Anti-inflammatory and gastroprotective activities were assessed on carrageenan-induced paw edema and HCl/ethanol-induced gastric lesions in rats, respectively.

RESULTS

(RP-HPLC) analysis indicated that coumarin is the abundant component in the extract (53.80%). Intraperitoneal administration of the methanolic extract at different doses showed interesting activities in rats in a dose-dependent manner. At 100 mg/kg, this extract showed the highest acute anti-inflammatory activity and an important inhibition of gastric lesions with inhibition percentage of 79.41% and 88.53%, respectively.

CONCLUSION

Altogether, the results of this study reveal the anti-inflammatory and gastroprotective effects of H. cheirifolia extract and promote the traditional use of this plant in the treatment of different pain and inflammatory diseases.