Antiulcer mechanisms of Vernonia condensata Baker: A medicinal plant used in the treatment of gastritis and gastric ulcer

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.

Gastroprotective effect of Artemisia absinthium L.: A medicinal plant used in the treatment of digestive disorders

ETHNOPHARMACOLOGICAL RELEVANCE

Wormwood (Artemisia absinthium L.) is traditionally used for stomach pain and gastric relief. However, its possible gastroprotective effect has not yet been experimentally evaluated.

AIM OF THE STUDY

This study evaluated the gastroprotective effect of aqueous extracts obtained through hot and room temperature maceration of A. absinthium aerial parts in rats.

MATERIALS AND METHODS

The gastroprotective effect of hot aqueous extract (HAE) and room temperature aqueous extract (RTAE) from A. absinthium aerial parts were evaluated in rats using a model of acute gastric ulcer induced by ethanol p.a. The stomachs were collected to measure the gastric lesion area and histological and biochemical analysis. UHPLC-HRMS/MS analysis was used to determine the chemical profile of the extracts.

RESULTS

Eight main peaks in the UHPLC chromatogram were identified in both HAE and RTAE extracts: tuberonic acid glycoside (1), rupicolin (2), 2-hydroxyeupatolide (3), yangabin (4), sesartemin (5), artemetin (6), isoalantodiene (7), and dehydroartemorin (8). For RTAE, a higher diversity of sesquiterpene lactones was observed. The groups treated with RTAE at 3%, 10%, and 30% presented a gastroprotective effect, reducing the lesion area by 64.68%, 53.71%, and 90.04%, respectively, when compared with the vehicle (VEH)-treated group. On the other hand, the groups treated with HAE at 3%, 10%, and 30% presented values of lesion areas higher than those of the VEH group. Changes in the submucosa layer, inflammatory process with edema, cellular infiltration, and mucin depletion were detected in the gastric mucosa exposed to ethanol, which was fully prevented by RTAE treatment. Neither HAE nor RTAE could increase the reduced glutathione levels in the injured gastric tissue, but RTAE (30%) reduced the formation of lipid hydroperoxides. When the rats were pre-treated with NEM (a chelator of non-protein thiols) or L-NAME (non-selective nitric oxide synthase inhibitor), the RTAE lost the ability to protect the gastric mucosa.

CONCLUSIONS

This study corroborates the ethnopharmacological use of this specie to treat gastric disorders revealing the gastroprotective effect of the room-temperature aqueous extract of A. absinthium aerial parts. Its mode of action may involve the ability of the infusion to maintain the gastric mucosal barrier integrity.

Dimethyl Cardamonin from Fruits of Campomanesia reitziana D. Legrand Promotes Gastroprotection and Gastric Healing Effects in Rodents

Campomanesia reitziana D. Legrand (Myrtaceae) displays antiulcer properties when given to rodents. The major active chemical components of C. reitziana are chalcones, including 4',6'-dihydroxy-2'-methoxy-3',5'-dimethylchalcone or dimethyl cardamonin (DMC); therefore, we hypothesized that this compound could have antiulcer effects and the present study aimed to evaluate its gastroprotective and gastric healing properties. DMC was isolated from the fruits of C. reitziana, and its gastroprotective effect was evaluated by ethanol and indomethacin-induced gastric ulcer models in mice (0.1 mg/kg, i.p. and 1 and 3 mg/kg, p.o.). Oxidative stress and inflammatory parameters were analyzed in the gastric tissue. Moreover, its gastric healing effect was evaluated in rats. In addition, the compound's mode of action was evaluated in vivo and in vitro by measuring H⁺ -K⁺ -ATPase activity. Finally, the cytotoxic potential of DMC was tested in fibroblasts and human gastric adenocarcinoma cells. The DMC reduced the ethanol-induced gastric ulcer in mice by 77 %, increased the adhered mucus, and reduced lipoperoxides levels. The block of nonprotein sulfhydryls (NP-SH) compounds by pretreatment with N-ethylmaleimide (NEM), the inhibition of nitric oxide synthase with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME), or the antagonism of α₂ receptor using yohimbine reversed the gastroprotective effects of DMC. Furthermore, DMC reduced the acidity of gastric content in pylorus-ligated rats but did not change H⁺ , K⁺ -ATPase (isolated from rabbit) activity in vitro. DMC reduced the lesion area in acetic acid-induced ulcers and decreased myeloperoxidase activity. DMC did not change the viability of fibroblast cells (L929) but reduced the viability of human gastric adenocarcinoma cells (AGS). The results confirmed that DMC could significantly enhance the gastric healing process and prevent ulcers due to improving protective factors on the gastric mucosa and reducing gastric acid secretion.

An insight into the anti-ulcerogenic potentials of medicinal herbs and their bioactive metabolites

ETHNOPHARMACOLOGICAL RELEVANCE

Peptic ulcer disease (PUD) ranks top among the most prominent gastrointestinal problems prevalent around the world. Long-term use of non-steroidal anti-inflammatory drugs, pathogenic infection by Helicobacter pylori, imbalances between gastrointestinal regulatory factors and pathological hyperacidity are major contributors towards the development of peptic ulcers. Although synthetic drugs of multiple pharmacological classes are abundantly available, inadequacy of such agents in ensuring complete recovery in not uncommon. Therefore, pharmacological explorations of herbal products including plant extracts and their respective isolated phytoconstituents, for potential gastroprotective and antiulcer properties, are regular practice among the scientific community. Moreover, the historical preferences of a significant share of world population towards herbal-based medication over modern synthetic drugs also contribute significantly to such endeavors.

AIM OF THE REVIEW

This review has endeavored to present ethnomedicinal and pharmacological prospects of a significant number of authenticated plant species in terms of their capacity to exert gastroprotection and antiulcer activities both in vitro and in vivo. The information delineated along the way was further subjected to critical analysis to ascertain the possible future prospects of such findings into designing plant-derived products in future for the treatment of peptic ulcer.

MATERIALS AND METHODS

Electronic version of prominent bibliographic databases, including Google Scholar, PubMed, Scopus, ScienceDirect, Wiley Online Library, SpringerLink, Web of Science, and MEDLINE were explored extensively for the identification and compilation of relevant information. The plant names and respective family names were verified through the Plant List (version 1.1) and World Flora Online 2021. All relevant chemical structures were verified through PubChem and SciFinder databases and illustrated with ChemDraw Ultra 12.0.

RESULTS

A colossal number of 97 plant species categorized under 58 diverse plant families have been discussed in the review for their gastroprotective and antiulcer properties. In vivo illustrations of the pharmacological properties were achieved for almost all the species under consideration. 29 individual phytoconstituents from these sources were also characterized with similar pharmacological potentials. Majority of the plant extracts as well as their constituents were found to exert their gastroprotective effects through antioxidative pathway featuring both enzymatic and nonenzymatic mechanism. Moreover, active inhibition of acid secretion, upregulation of gastroprotective mediators and downregulation of pro-inflammatory cytokines, were also associated with a prominent number of plants or products thereof.

CONCLUSIONS

Comparative evaluations of the plant sources for their antiulcer activities, both as individual and as combination formulations, are necessary to be conducted in human subjects under properly regulated clinical conditions. Moreover, the efficacy and safety of such products should also be evaluated against those of the currently available treatment options. This will further facilitate in ascertaining their suitability and superiority, if any, in the treatment of peptic ulcer diseases. Implementation of these endeavors may eventually lead to development of more efficient treatment options in the future.

Gastroprotective Effects of the Aqueous Extract from Taraxacum officinale in Rats Using Ultrasound, Histology, and Biochemical Analysis

Taraxacum officinale F.H. Wigg. belonging to the family Asteraceae is an edible medicinal plant distributed worldwide. This study aimed to determine the gastroprotective effects of aqueous extract of T. officinale (AETo) in rats using ultrasound, histological, and biochemical analyses. In this study, gastric ulceration was induced by ethanol or piroxicam. Rats were then treated with AETo (3, 30, or 300 mg/kg). The area and histological appearance of gastric ulcers were quantified, and histochemical analysis was performed. The activity of AETo on inflammatory and oxidative stress markers was assessed in the ulcerated tissue. In addition, we investigated the thickness of the gastric wall using the ultrasound technique. Moreover, chemical analyses of AETo were performed. In rats with ethanol- or piroxicam-induced ulcers, AETo reduced the ulceration area, elevated mucin level, and the gastroprotective effect was confirmed by histological analysis. The gastroprotective effect was accompanied by increased activities of SOD, CAT, and GST, as well as an increase in GSH level and reduction in MPO activity. Furthermore, AETo reduced the thickness of the gastric wall in rats. Phytochemical analysis of AETo indicated phenolic acids and flavonoids as the main active compounds. In conclusion, the gastroprotective effect of AETo involves reduction in oxidative stress and inflammatory injury and increase in mucin content. This study advances in the elucidation of mechanisms of gastric protection of T. officinale, contributes to the prospection of new molecules gastroprotective, and proposes the ultrasonographic analyses as a new gastroprotective assessment tool in preclinical studies.

The protective effects of quercetin nano-emulsion on intestinal mucositis induced by 5-fluorouracil in mice

BACKGROUND

Intestinal mucositis is one of chemotherapeutics' most common adverse effects, such as 5-fluorouracil (5-FU). Quercetin (QRC), a naturally occurring flavonoid, has approved antioxidant and anti-inflammatory properties. Thus, in this article, the preventive and curative effects of emulsion and nano-emulsion formulations of QRC were investigated in a model of 5-FU-induced intestinal mucositis using biochemical, histopathological, and molecular approaches.

METHOD

Thirty-six mice were divided into six different groups: Control (normal saline), 5-FU (a single dose of 5-FU 300 mg/kg), pre-treatment groups (pre-QRC, and pre-QRC-nano, receiving QRC 5 mg/kg emulsion and nano-emulsion before the induction of mucositis, respectively), and post-treatment groups (post-QRC, and post-QRC-nano, receiving QRC 5 mg/kg emulsion and nano-emulsion after the induction of mucositis, respectively).

FINDING

The administration of quercetin emulsion and nano-emulsion could significantly alleviate the oxidant-antioxidant balance of mice serum samples and reverse the destructive histopathologic changes induced by 5-FU in the intestine tissue. Nevertheless, although the expression of both pro-inflammatory genes, NF-κB and HIF-1α, was decreased when quercetin was administered to mice, this reduction was not statistically significant.

CONCLUSION

The administration of quercetin emulsion and nano-emulsion formulations could ameliorate the oxidative damage induced by chemotherapeutics, such as the 5-FU. Therefore, if confirmed in further studies, it could be used in clinical settings as a preventive and curative agent to decrease such catastrophic adverse events in chemotherapy patients.

Kolaviron: A Biflavonoid with Numerous Health Benefits

BACKGROUND

The increasing interests on the healing properties of medicinal plants have led to a paradigm shift from the use of synthetic drug to the search of natural medicines for the treatment and management of several diseases. Like other phenolics flavonoids have been continuously explored for their medicinal benefits, with their potent antioxidant activity being a major interest. Kolaviron (KVN) is a biflavonoid isolated from Garcinia kola Heckel, which has been reported for its potent antioxidant and anti-inflammatory properties. These properties have been explored in several disease models including reproductive toxicity, cardiotoxicity, diabetes mellitus, gastrotoxicity and hepatotoxicity.

OBJECTIVES

The present study was aimed to review the reported medicinal properties of KVN in order to provide some guidelines and direction to researchers on KVN research.

METHODS

A literature search was conducted with the aim of identifying peer-reviewed published data on KVN and their biological activities. Different academic and/or scientific search engines were utilized including but not limited to Google Scholar, PubMed, ScienceDirect and so on.

RESULTS

Among all the studied disease models obtained from the literatures, the effect of KVN on reproductive toxicity was the most studied as it represented 25% of all the studies, followed by neuroprotective, cardioprotective and hepatoprotective activities of Kolaviron. From our identified studies, KVN has been shown to have antidiabetic, cardioprotective, neuroprotective, hematoprotective, nephroprotective, gastroprotective, hepatoprotective activities. KVN also has effects on malaria and reproductive health, which can be explored for novel drug and nutraceutical developments for related ailments. Unfortunately, while toxicity data are lacking, most studies are limited to in vitro and/or in vivo models, which may impede translation in this area of research.

CONCLUSION

Based on data gathered from the literature search, it is evident that KVN possesses numerous health benefits, which can be attributed to its potent antioxidant and anti-inflammatory activities. However, more studies are required in this area of research to validate the medicinal value of kolaviron, which may positively influence the economic value of plant, Garcinia kola.

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.

The gastroprotective effect of red propolis extract from Northeastern Brazil and the role of its isolated compounds

ETHNOPHARMACOLOGICAL RELEVANCE

Propolis has been used in folk medicine to treat gastric disorders for centuries. However, although studies have been conducted to validate the gastroprotective and anti-ulcer activity of some types of propolis, red propolis activity remains unknown.

AIM OF THE STUDY

The present study aimed to evaluate the gastroprotective effect of the hydroalcoholic extract of red propolis (HERP), its mode of action, and the main compounds involved in its activity, therefore contributing to validate the chemical and pharmacological potential of this product.

MATERIAL AND METHODS

The effect of HERP (30, 100 and 300 mg/kg p.o. and 30 mg/kg i.p.), and the isolated compounds vestitol (VS), neovestitol (NV), methylvestitol (MV), medicarpin (MD), and oblongifolin AB (OB) (10 mg/kg p.o.) were evaluated on gastric ulcers induced by 60% ethanol/0.3 M HCl (5 mL/kg, p.o.) in mice. Histological changes and mucin levels were assessed by HE and PAS, respectively. Moreover, oxidative stress parameters and myeloperoxidase activity were analyzed on ulcerated tissue. The effect of HERP on gastric acid secretion was evaluated by pyloric ligature model and the mechanisms involved in its gastroprotective effect were investigated by pretreating mice with L-NAME (a non-selective nitric oxide synthase inhibitor, 70 mg/kg, i.p.), NEM (a sulfhydryl group chelator, 10 mg/kg, i.p.), yohimbine (an alpha-adrenergic receptor antagonist, 2 mg/kg, i.p.) and indomethacin (a non-selective cyclooxygenase inhibitor, 10 mg/kg, i.p.).

RESULTS

HERP (300 mg/kg p.o. or 30 mg/kg i.p.), MV, and MD (10 mg/kg p.o.) protected gastric mucosa against the damage induced by ethanol/HCl. Histological changes were attenuated by the HERP, MV, and MD. Moreover, HERP and MV increased mucin levels. Besides, oxidative stress and MPO activity were reduced by the three treatments. HERP did not display anti-secretory action, but its effect was abolished by indomethacin treatment.

CONCLUSIONS

HERP displays gastroprotective property against ethanol/HCl-induced damage. Its effect is dependent on prostaglandins and mucin production. The compounds MV and MD may have an essential role in the activity of HERP. Our data contribute to validate the traditional use of propolis for gastric disorders.

A Review of the Role of Flavonoids in Peptic Ulcer (2010-2020)

Peptic ulcers are characterized by erosions on the mucosa of the gastrointestinal tract that may reach the muscle layer. Their etiology is multifactorial and occurs when the balance between offensive and protective factors of the mucosa is disturbed. Peptic ulcers represent a global health problem, affecting millions of people worldwide and showing high rates of recurrence. Helicobacter pylori infection and the use of non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most important predisposing factors for the development of peptic ulcers. Therefore, new approaches to complementary treatments are needed to prevent the development of ulcers and their recurrence. Natural products such as medicinal plants and their isolated compounds have been widely used in experimental models of peptic ulcers. Flavonoids are among the molecules of greatest interest in biological assays due to their anti-inflammatory and antioxidant properties. The present study is a literature review of flavonoids that have been reported to show peptic ulcer activity in experimental models. Studies published from January 2010 to January 2020 were selected from reference databases. This review refers to a collection of flavonoids with antiulcer activity in vivo and in vitro models.

Role of Daucus carota in Enhancing Antiulcer Profile of Pantoprazole in Experimental Animals

The carrot plant (Daucus carota) and its components are traditionally reported for the management of gastric ulcers. This study was performed to evaluate the role of carrot when administered concurrently with a conventional antiulcer treatment, pantoprazole, in alleviating gastric and duodenal ulcers in female experimental animals. The study involved standard animal models to determine the ulcer preventive effect using pylorus ligation, ethanol, and stress induced acute gastric ulcer models and duodenal ulcer models involving cysteamine. Acetic acid-induced chronic gastric ulcer and indomethacin-induced gastric ulcer models were used to evaluate the ulcer healing effect. Carrot fruit (500 mg/kg) and its co-administration with pantoprazole produced significant protection in an ethanol- and stress-induced acute gastric ulcer and cysteamine-induced duodenal ulcer. The healing of the acetic acid-induced chronic gastric ulcer was also augmented with this combination. Both total proteins and mucin contents were significantly increased in indomethacin-induced gastric ulcers. Similarly, in pylorus ligation, the pepsin content of gastric juice, total acidity, and free acidity were reduced. Overall, both ulcer preventive effects and ulcer healing properties of the pantoprazole were significantly enhanced in animals who received the co-administration of carrot fruit (500 mg/kg).

Sildenafil attenuates nonsteroidal anti-inflammatory-induced gastric ulceration in mice via antioxidant and antigenotoxic mechanisms

Sildenafil (SIL) has potential as an interesting gastroprotective drug. However, the pathways of its protective effect still needs to be clarified, and its use as a potential gastroprotective agent validated. This study aims to evaluate the effects of SIL via modulation of oxidative stress in a NSAID-induced gastric lesion model. Male Swiss mice were divided into six groups: control (CON, water), nonsteroidal anti-inflammatory drug (NSAID, water), proton pump inhibitor (PPI, 30 mg/kg of lansoprazole), SIL 5 (5 mg/kg), SIL 25 (25 mg/kg) and SIL 50 (50 mg/kg). The animals were treated by gavage (a single dose) after 24 hours of fasting, and gastric lesions were performed after 30 minutes, with indomethacin (40 mg/kg, by gavage). After 6h, the animals were killed and the stomach was removed to evaluate reactive oxygen species (ROS) production, oxidation of macromolecules, quantification of antioxidant enzymes, DNA fragmentation, apoptosis and macroscopic and histologic analysis of gastric lesions. SIL exerts a dose-dependent gastroprotective effect against NSAID-induced mucosal injury, also reducing cytoplasmic levels of ROS and consequent oxidative damage to macromolecules. In addition, SIL increases nitric oxide bioavailability, antioxidant enzymes and gastric cellular viability, as well as restoring important factors involved in gastroprotection. Our results demonstrate that different doses of SIL prevent indomethacin-induced gastric ulcer in mice via different, but complementary antioxidant, antigenotoxic and antiapoptotic mechanisms.

Traditional Chinese Medicine Li-Zhong-Tang accelerates the healing of indomethacin-induced gastric ulcers in rats by affecting TLR-2/MyD88 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Li-Zhong-Tang (LZT) is a well-known Chinese herbal formulation first described in one of traditional Chinese medicine (TCM) scriptures, Treatise on Febrile Diseases. LZT has been commonly prescribed for the treatment of various gastrointestinal diseases for over 1800 years, and has demonstrated pronounced therapeutic effects on patients with gastric ulcers.

AIM OF THE STUDY

The present study aimed to scientifically evaluate protective effects of LZT on indomethacin (IND)-induced gastric injury in rats and to elucidate whether LZT exerts its gastro-protective effects via enhancing mucosal immunity by regulating TLR-2/MyD88 signaling pathway.

MATERIAL AND METHODS

Gastric ulcers were induced in male Sprague-Dawley (SD) rats with a single oral dose of 150 mg/kg IND. Ulcer index (UI) and curative index (CI) were evaluated. Histopathological examinations were performed and microscopic score (MS) was macroscopically calculated. The volume of gastric juice, free acidity, total acidity, and gastric pH was measured. The gastroprotective and inflammatory biomarkers including levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α), prostaglandin E₂ (PGE₂), and malondialdehyde (MDA) were determined. Expression levels of TLR-2 and MyD88 mRNA were assessed by qRT-PCR. The expression, distribution, and co-localization of TLR-2 and MyD88 protein were determined by Western blot, immunohistochemistry, and immunofluorescence, respectively.

RESULTS

Induction of gastric ulcers in rats resulted in very significantly increased UI and elevated volume and acidity of gastric juice, which were markedly attenuated by LZT treatment. Microscopic examinations of the IND-induced gastric ulcers revealed severe gastric hemorrhagic necrosis, submucosal edema, and destruction of epithelial cells, which were significantly attenuated in LZT-treated rats. Moreover, treatment with LZT remarkably increased gastric mucosal levels of PGE₂ and NO, and lowered highly elevated levels of TNF-α and MDA in gastric ulcerative rats. Mechanistically, LZT inhibited mRNA and protein expression of TLR-2 and MyD88 and enhanced immune function in gastric mucosa. Immunohistochemical analyses and immunofluorescent detection further confirmed a markedly decreased co-localization of TLR-2 and MyD88 protein in the gastric mucosa of LZT-treated rats as compared to that of gastric ulcerative rats.

CONCLUSIONS

These findings indicate that LZT alleviates serious gastric mucosal ulcerations induced by IND. Protective effects of LZT on gastric ulcers are believed to be associated with the intensification of the anti-oxidative defense system, mitigation of proinflammatory cytokines, stimulation of the production of cytoprotective mediators, and improvement of the mucosal immunity through TLR-2/MyD88 signaling pathway.

Chemical profile and gastroprotective effect of Jatropha elliptica (Pohl) Oken roots

Jatropha elliptica (Pohl) Oken (Euphorbiaceae) roots are used in folk medicine to treat gastric ulcers. The purpose of this work was to evaluate the gastroprotective activity of ethanol extract (JER) and hexane fraction (ERH) of J. elliptica roots in mice, as well as to analyze the acute toxicity of the extract and identify the potential active compounds. No signs of toxicity were observed in JER. In both acidified ethanol and indometacin-induced gastric ulcer models, all doses tested of JER and ERH significantly reduced gastric lesions. Dereplication of JER was performed by HPLC-DAD-ESI-MS/MS and resulted in the annotation of compounds fraxetin, propacin, jatrophone and jatropholones A and B. GC-MS analysis of ERH revealed the diterpenes jatrophone, jatropholone A and jatropholone B as the major components. The chemical study of this fraction has led to the isolation of these compounds, in addition to the sequiterpene cyperenoic acid and the diterpene 2β-hydroxyjatrophone, both reported for the first time in J. elliptica. The isolated compounds were tested against L929 cells and only cyperenoic acid and the mixture of jatropholones A and B did not show toxicity, being then selected as good candidates for bioassays using acidified ethanol-induced gastric ulcer model. Cyperenoic acid significantly decreased gastric lesions and preserved gastric mucus layer. The mixture of jatropholones A and B caused a smaller reduction of gastric lesions, without preservation of the gastric mucus layer. The study showed that J. elliptica roots present gastroprotective activity in mice, without causing acute toxic effects. The activity is related, at least in part, to the occurrence of terpenes, mainly the sesquiterpene cyperenoic acid.

Estragole prevents gastric ulcers via cytoprotective, antioxidant and immunoregulatory mechanisms in animal models

BACKGROUND

Estragole is an aromatic organic compound belonging to the class of phenylpropanoids derived from cinnamic aldehydes and present in essential oils of plant species, such asRavensara anisata (madeira), Ocimum basilicum (manjericão/alfavaca) and Croton zehntneri (canelinha). Pharmacological studies report its anti-inflammatory, antioxidant and vasorelaxant activity.

HYPOTHESIS/PURPOSE

This study aimed to evaluate the acute non-clinical toxicity, gastroprotective activity and the related mechanisms of action.

METHODS

Acute toxicity was assessed according to OECD guide 423 in mice. Ethanol, stress, piroxicam and pylorus ligation-induced gastric ulcer models were used to investigate antiulcer properties. The related mechanisms of action were using the ethanol-gastric lesions protocol.

RESULTS

In the acute oral toxicity assay, doses of 300 or 2000 mg/kg of estragole administered orally in Swiss mice did not induce any behavioral changes. However, the dose of 2000 mg/kg showed a decrease in water and feed intake. Lethal dose 50 % (LD50) was set to be equal to or greater than 2500 mg/kg, according to OECD. In all evaluated protocols, estragole (31.25, 62.5, 125 and 250 mg/kg) significantly reduced the area of ​​ulcerative lesion when compared to control groups. To investigate the mechanisms involved in the gastroprotective activity, the antisecretory or neutralizing of gastric secretion, cytoprotectant, antioxidant and immunoregulatory effects were evaluated. Results showed that treatment with estragole (250 mg/kg) reduced (p < 0.05) the volume of the gastric juice. Besides, sulfhydryl groups, nitric oxide, mucus and prostaglandins seems to be involved in the gastroprotective property. Treatment also increased (p < 0.001) levels of reduced glutathione (GSH), interleukin-10 (IL-10) and positive cells marked for glutathione peroxidase (GPx) and cyclooxygenase 2 (COX-2). It also reduced (p < 0.001) malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and inducible nitric oxide synthase (iNOS) (p < 0.05) levels.

CONCLUSION

Thus, it is possible to infer that estragole presents gastroprotective activity related to antisecretory, cytoprotective, antioxidant and immunomodulatory mechanisms.

Gastroprotective and Healing Effects of Polygonum cuspidatum Root on Experimentally Induced Gastric Ulcers in Rats

Polygonum cuspidatum is widely used as food and medicine in Korea, China, and Japan. Its major bioactive components, resveratrol and emodin, reportedly protect against gastric lesions. We therefore aimed to investigate: (1) the gastroprotective effects of P. cuspidatum roots in hydrochloric acid/ethanol (HCl/EtOH)- and indomethacin-induced acute gastric ulcer rat models; (2) the healing effects in an acetic acid-induced ulcer model; and (3) potential mechanisms by measuring gastric acid secretion-related parameters in a pyloric ligation-induced ulcer model, and by measuring antioxidant enzyme and prostaglandin E₂ levels in the gastric tissue of HCl/EtOH-treated rats. Oral administration of P. cuspidatum extract (PCE) at doses of 100 and 300 mg/kg significantly decreased HCl/EtOH- and indomethacin-induced gastric lesions. PCE at 300 mg/kg significantly reduced gastric lesions in acetic acid-induced ulcers. PCE increased superoxide dismutase (SOD)activity and glutathione(GSH) and prostaglandin E₂ levels in gastric tissue, whereas it did not alter gastric acid secretion-related parameters. Our findings indicate that PCE has gastroprotective effects against HCl/EtOH and non-steroidal anti-inflammatory drugs(NSAIDs) and promotes healing of acetic acid-induced ulcers. These gastric mucosal protection and ulcer healing effects are associated with antioxidant effects and the augmentation of prostaglandin E₂ and suggest that P. cuspidatum might be a promising preventive and therapeutic agent for treating gastric ulcers.

Gastroprotective effect of the alkaloid boldine: Involvement of non-protein sulfhydryl groups, prostanoids and reduction on oxidative stress

Boldine is the main alkaloid of Peumus boldus Molina, widely used in the traditional medicine for the treatment of digestive disorders. It is a compound with excellent antioxidant and anti-inflammatory properties already described. Despite the widespread use of P. boldus for digestive disorders treatment, the gastroprotective effect of Boldine remains unknown. Considering the need for new approaches to treat gastric ulcers with fewer side effects than current therapy, this study aimed to investigate the gastroprotective effect of Boldine in mice, as well as the mechanisms underlying this effect. The gastroprotective effect of Boldine was evaluated on gastric ulcer induced by 60% ethanol/0.3 M HCl or indomethacin (100 mg/kg) in mice. Histological analysis and the mucin-like glycoprotein content were evaluated in ethanol-ulcerated tissue, as well as, oxidative stress and inflammatory parameters. The mechanisms involved in the effect of Boldine were evaluated by pretreating mice with NEM (a sulfhydryl group chelator, 10 mg/kg, i.p.), l-NAME (a non-selective nitric oxide synthase inhibitor, 70 mg/kg, i.p.), yohimbine (an alpha-adrenergic receptor antagonist, 2 mg/kg, i.p.) and indomethacin (a cyclooxygenase inhibitor, 10 mg/kg, i.p.). In addition, the in vitro effect of Boldine on H⁺/K⁺-ATPase activity was determined. Boldine was able to protect gastric mucosa against the damage induced by ethanol/HCl and indomethacin, as evidenced by reduced lesion area and histological analysis. Moreover, the alkaloid reduced oxidative stress and inflammatory mediators in ethanol-ulcerated tissue, beyond has increased mucin-like glycoprotein amount. Finally, Boldine effect is dependent on non-protein sulfhydryl groups and prostanoids but does not involve the inhibition of H+/K + -ATPase activity, being a promising natural resource for gastric ulcer treatment.

Gastroprotective activity of hydroalcoholic extract of the leaves of Urera baccifera in rodents

ETHNOPHARMACOLOGICAL IMPORTANCE

The species Urera baccifera (L.) Gaudich. ex Wedd. (Urticaceae) is native to the Americas and is distributed widely throughout Brazil, where it is known as urtiga-brava, urtiga-vermelha, or urtigão. The leaves are often used as anti-inflammatory and antirheumatic agents and for the treatment of gastric disorders. However, the pharmacological mode of action underlying the gastroprotection induced by this species has not been investigated.

AIM OF THE STUDY

To contribute to the knowledge of the gastroprotective mode of action of the hydroalcoholic extract of U. baccifera (HEU) leaves.

MATERIALS AND METHODS

Antiulcerogenic effect of HEU against ethanol-induced acute gastric ulcer was evaluated in rats and mice at doses of 3-300 mg/kg. NO-synthase inhibitor (L-NAME), SH blocker (NEM), cyclooxygenase inhibitor (indomethacin) and alpha 2-adrenergic receptor antagonist yohimbine were used to evaluate the participation of cytoprotective factors in HEU gastroprotection. Moreover, the levels of reduced gluthatione (GSH) and cytokines (TNF, IL-6, IL4 and IL-10), as well as the enzymatic activity of gluthatione S-transferase (GST), myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) were measure. Moreover, the samples were analyzed histologically and the antisecretory capability of HEU were quantified using pylorus ligated rats.

RESULTS

The phytochemical analysis of HEU (UPLC/ESI-IT-MS) identified the flavonoids diosmetin and apigenin glucuronide. Furthermore, HEU decreased the occurrence of ethanol-induced ulcers at 30 and 300 mg/kg by 57% and 66%, respectively, compared with the vehicle. The gastroprotective effects were accompanied by increased GSH levels and GST and SOD activity as well as by reduced MPO activity in vivo and in vitro, revealing antioxidant effects and inhibition of neutrophil infiltration. The beneficial effects of 30 and 300 mg/kg HEU were also observed upon histological analyses. Regarding the mode of action, the gastroprotective effect of HEU was abolished by the pre-administration of L-NAME, NEM, indomethacin or yohimbine. Moreover, HEU was able to decrease the IL-6, IL-4 and IL-10 in ulcerated tissue, as well as the pepsin activity of the gastric juice in pylorus-ligated rats.

CONCLUSION

Together, the results confirmed that the gastroprotection elicited by HEU was due reduction in oxidative damage, neutrophil migration, and peptic activity. This work validates the popular use of U. baccifera to treat gastric disorders and supports important future research for the identification of gastroprotective molecules from this species.

Luteolin prevents irinotecan-induced intestinal mucositis in mice through antioxidant and anti-inflammatory properties

BACKGROUND AND PURPOSE

Intestinal mucositis refers to mucosal damage caused by cancer treatment, and irinotecan is one of the agents most associated with this condition. Focusing on the development of alternatives to prevent this important adverse effect, we evaluated the activity of the flavonoid luteolin, which has never been tested for this purpose despite its biological potential.

EXPERIMENTAL APPROACH

The effects of luteolin were examined on irinotecan-induced intestinal mucositis in mice. Clinical signs were evaluated. Moreover, histological, oxidative, and inflammatory parameters were analysed, as well as the possible interference of luteolin in the anti-tumour activity of irinotecan.

KEY RESULTS

Luteolin (30 mg·kg^-1 ; p.o. or i.p.) prevented irinotecan-induced intestinal damage by reducing weight loss and diarrhoea score and attenuating the shortening of the duodenum and colon. Histological analysis confirmed that luteolin (p.o.) prevented villous shortening, vacuolization, and apoptosis of cells and preserved mucin production in the duodenum and colon. Moreover, luteolin treatment mitigated irinotecan-induced oxidative stress, by reducing the levels of ROS and LOOH and augmenting endogenous antioxidants, and inflammation by decreasing MPO enzymic activity, TNF, IL-1β, and IL-6 levels and increasing IL-4 and IL-10. Disruption of the tight junctions ZO-1 and occludin was also prevented by luteolin treatment. Importantly, luteolin did not interfere with the anti-tumour activity of irinotecan.

CONCLUSION AND IMPLICATIONS

Luteolin prevents intestinal mucositis induced by irinotecan and therefore could be a potential adjunct in anti-tumour therapy to control this adverse effect, increasing treatment adherence and consequently the chances of cancer remission.

Gastroprotective activity and pharmacological safety evaluation of Eupatorium aschenbornianum

Eupatorium aschenbornianum has been widely used in traditional Mexican and folk medicine for the treatment of wounds, skin lesions, hemorrhages and gastric ulcers in humans. Phytochemical studies have indicated that hexane extracts of E. aschenbornianum have anti-microbial and anti-fungal activities. In the present study, an accurate and reliable approach using a murine model was pursued to evaluate the anti-ulcer activity, lipid peroxidation properties and acute toxicity of powdered dried stem of E. aschenbornianum. The results indicated that administration of E. aschenbornianum exerted an anti-ulcerative effect and decreased lipid peroxidation in gastric ulcers induced by acetylsalicylic acid. An acute toxicity assay indicated normal behavior and no significant variations in the weight and food consumption of animals. In addition, quantitative analysis of biochemical parameters did not indicate any liver or kidney damage. The results indicated that E. aschenbornianum may be a safe therapeutic agent for the prevention of gastric ulcers.

Role of the antioxidant properties in the gastroprotective and gastric healing activity promoted by Brazilian green propolis and the healing efficacy of Artepillin C

Green propolis is a resinous substance used in folk medicine given its anti-inflammatory, antibacterial, and anti-ulcer effects. Our research group has already confirmed the gastroprotective activity of hydroalcoholic extract from green propolis (HEGP), as well as of its main isolated compounds. In continuity, this study evaluated the antioxidant mode of action involved in the preventive effect induced by HEGP, and its therapeutic gastric healing potential on installed ulcers. In addition, the healing effect of its main compound Artepillin C was also investigated. Acute and chronic ulcers were induced in rats by given ethanol or acetic acid, respectively. In acute model, the rats were orally pre-treated with vehicle (water plus 1% Tween, 1 mL/kg), HEGP (30-300 mg/kg), or carbenoxolone (200 mg/kg) 1 h prior the ulcer induction. In the chronic ulcer protocol, the rats received vehicle (water plus 1% Tween, 1 mL/kg), HEGP (300 mg/kg), or omeprazole (20 mg/kg) twice a day by 7 days, whereas groups of mice received vehicle (water plus 1% Tween, 1 mL/kg), Artepillin C (18 mg/kg), or ranitidine (20 mg/kg) twice a day by 4 days. Ulcerated tissue was collected for histological, histochemical, immunostaining, oxidative, and inflammatory analyses. The in vitro scavenger activity of HEGP was also verified using the DPPH assay. The oral pre-treatment with HEGP (100 and 300 mg/kg) prevented the gastric epithelial damage promoted by ethanol. Besides, HEGP (100 and 300 mg/kg) reduced SOD activity about 11% and 26%, respectively, and increased the activity of GST around 20% and CAT in 80%. HEGP (300 mg/kg) also reduced the production of reactive oxygen species, as well as lipoperoxidation levels in the ethanol-ulcerated tissue. In the acetic acid-induced chronic ulcer, the daily treatment with HEGP (300 mg/kg) accelerates the healing process by 71%. In this model, HEGP normalized SOD and CAT activity and increased GST activity by 109% when compared to non-ulcerated rats. In both models, the extract administration increased the mucin PAS staining and reduced the myeloperoxidase activity at the ulcer site. Moreover, the treatment with HEGP enhanced the PCNA immunostaining, but did not alter the concentration of collagen in the acetic acid-ulcerated tissue. The extract had a direct DPPH radical-scavenging ability (LogIC₅₀: 0.56). Besides, as expected, HPLC analysis showed Artepillin C as a major compound and its administration at 18 mg/kg also accelerated the gastric healing ulcer process in mice. Our findings confirm that HEGP displays both gastroprotective and gastric healing properties, contributing to the validation of its popular use as preventive and therapeutic approaches. These actions occur through the increase in mucin production and the reestablishment of the oxidative balance due to a reduction in gastric inflammation.

Hydroalcoholic extract from Baccharis dracunculifolia recovers the gastric ulcerated tissue, and p-coumaric acid is a pivotal bioactive compound to this action

Baccharis dracunculifolia is a medicinal plant native to southeastern Brazil and is the main botanical source used by bees (Apis mellifera) in the manufacture of green propolis and display similar gastroprotective action and chemical profile. This article reports the healing gastric ulcer activity of the hydroethanolic extract of B. dracunculifolia (HEBD) in an acetic acid-induced ulcer model. In addition to the extract, the isolated compounds ferulic acid, p-coumaric acid, caffeic acid, baccharin, and aromadendrin-4'-O-methyl ether were also assayed. HEBD at a dose of 300 mg/kg reduced the ulcerated area by 49.4% after treatment for 7 days, twice a day. Histological analyses revealed that the margins and base of the ulcer obtained significant regeneration, and periodic acid Schiff base staining showed a 78.2% increase in the mucin levels. The action on the enzymatic antioxidant system demonstrated an increased activity of superoxide dismutase and glutathione-S-transferase, in addition to raising glutathione reduced levels and myeloperoxidase activity. HEBD did not show cytotoxicity in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylterazole bromine test. In vitro, HEBD inhibited the H⁺ /K⁺ -ATPase enzyme and showed antioxidant activity in the 2,2 diphenyl-1-picryllydrazyl test. Regarding the isolated compounds, oral administration of p-coumaric acid (15 mg/kg) reduced the ulcerated area by 66.2%. The results suggest that HEBD recovers the gastric ulcerated tissue, raising mucus and antioxidant enzyme levels, and reducing the H⁺ /K⁺ -ATPase activity. In addition, the findings confirm that p-coumaric acid is a pivotal bioactive compound on the gastric healing effects elicited by HEBD. © 2019 BioFactors, 45(3):479-489, 2019.

Cochlospermum regium (Mart. ex Schrank) Pilg.: Evaluation of chemical profile, gastroprotective activity and mechanism of action of hydroethanolic extract of its xylopodium in acute and chronic experimental models

ETHNOPHARMACOLOGICAL RELEVANCE

Cochlospermum regium (Bixaceae) is a native shrub of Brazil and its xylopodium (infusion/decoction) is being used for the treatment of gastritis, ulcers, arthritis, intestinal infections, gynaecological infections, skin diseases, among others. The aim of the present study was to evaluate the gastroprotective/antiulcer activity and the mechanism of action of hydroethanolic extract of C. regium xylopodium (HECr), using in vitro and in vivo models. Additionally, phytochemical constituents were identified by high-performance liquid chromatography (HPLC).

MATERIALS AND METHODS

C. regium xylopodium was macerated with ethanol/water to obtain the HECr. The phytochemical characterisation was carried out by HPLC. The antiulcer efficacy of HECr (25, 100 and 400 mg/kg, p.o.) was evaluated using acute acidified ethanol (HCl/EtOH), piroxicam and water immersion-induced experimental ulcer models. Chronic gastric ulcer healing activity of HECr was evaluated through acetic acid (99.8%) - induced model. Histological analysis and myeloperoxidase (MPO), glutathione (GSH), catalase (CAT) activities were also evaluated in chronic ulcer induced gastric tissues. The plausible mode of action of the HECr was assessed by estimation of gastric wall mucus production and the role of gastric secretion in pylorus ligature. The animals were also pre-treated with various inhibitors which includes indomethacin (10 mg/kg, p.o.) a selective inhibitor of cyclooxygenase, L-NAME (10 mg/kg, i.p.), an inhibitor of nitric oxide synthase, glibenclamide, a ATP-sensitive potassium channels (K⁺_ATP) blocker (5 mg/kg, p.o.) or yohimbine (2 mg/kg, i.p.), an α₂-adrenergic receptor antagonist. In vitro, Helicobacter pylori action was done by broth microdilution method.

RESULTS

The HPLC analysis data revealed the presence of gallic acid, rutin, myricetin, morin and kaempferol. HECr promoted protective effect against acute ulcers induced by HCl/EtOH with inhibitions of 47.52% (p < 0.01) and 62.69% (p < 0.001) at 100 and 400 mg/kg, and in piroxicam by 34.11% (p < 0.05), 49.14% (p < 0.01) and 61.34% (p < 0.001), at 25, 100 or 400 mg/kg, respectively, and in water restraint stress by 78.26% inhibition, p < 0.001, at the dose of 400 mg/kg when compared to the vehicle control group respectively. In the chronic gastric ulcer model, HECr (25, 100 and 400 mg/kg p.o.) significantly (p < 0.001) decreased the injured area by 58.80%, 77.87% and 71.10% respectively. Histological examination indicated that oral treatment of HECr promoted healing of gastric lesions by regenerating gastric mucosa layer with less inflammatory cells. HECr augmented the GSH, CAT activities and reduced MPO level. The pre-treatment with HECr increased the gastric wall mucus production. It also significantly altered the gastric secretion parameters by causing the reduction in the gastric juice volume, elevated the pH level and reduced the total acidity at all doses tested when compared with the vehicle group. HECr at the most active dose (100 mg/kg) reversed completely the reduction of PGs, NO production, closure of K⁺_ATP- channels and α₂-adrenoreceptor blockage - induced damages. In microdilution assay, the HECr showed good anti-Helicobacter pylori effect with MIC = 100 µg/mL.

CONCLUSION

The HECr presented preventive and curative effects in the experimental gastric ulcer models, besides good anti-Helicobacter pylori activity, which supports the traditional medicinal use of the xylopodium of this plant for gastrointestinal diseases. The underlying mechanisms of this antiulcerogenic/antiulcer action involve, at least, augmentation of mucus production, inhibition of gastric secretion, stimulation of PGs and NO synthesis. And that it involves activation of K⁺_ATP channels and α-2-adrenergic receptors, in addition to an antioxidant activity, probably due to the presence of gallic acid and flavonoids in HECr.

Avocado seeds (Persea americana Mill.) prevents indomethacin-induced gastric ulcer in mice

The long-term use of anti-inflammatory drugs is the most common cause of gastric ulcer disease, one of the major gastrointestinal disorders affecting people worldwide. Persea americana Mill. (avocado) seed is a by-product generally discarded as waste, but can be used to treat gastric disorder due to its anti-inflammatory, antioxidant and antimicrobial activities. The aim of the present study was to evaluate the potential protective effects of the ethyl acetate fraction of avocado seeds (SEAP) extracts against indomethacin-induced gastric ulcer in mice. It was found that SEAP were effective in mitigating oxidative stress through a decrease on the oxidized products levels (reduction of 90% in lipid peroxidation in plasma) and increasing superoxide dismutase enzyme (SOD) activity (4.25-fold increase compared to the indomethacin group), also preventing the rise in ulcer and lesions areas (92% of protection) and histological changes induced by indomethacin. Chemical analysis using mass spectrometry by (-)-ESI-FT-ICR MS revealed the presence of (-)-epicatechin and (+)-catechin, confirmed by HPLC-DAD, and other important phenolic compounds in avocado seeds, such as caffeoylquinic acid, flavonoids, phenylpropanoids and tannins, substances that promote inhibition of pathways involved in gastric ulcer formation. Thus, avocado seeds extract may be a suitable natural source for the prevention and treatment of gastric ulcer.

Gastroprotective Activity of Parastrephia quadrangularis (Meyen), Cabrera from the Atacama Desert

Forty-three metabolites including several methoxylated flavonoids, tremetones, and ent-clerodane diterpenes were accurately identified for the first time in the ethanolic extract of P. quadrangularis by means of hyphenated UHPLC-quadrupole Orbitrap mass spectrometry, and seven isolated compounds were tested regarding gastroprotective activity using the HCl/EtOH-induced lesion model in mice. A new tremetone (compound 6) is reported based on spectroscopic evidence. The isolated clerodanes and tremetones showed gastroprotective activity in a mouse model, evidenced by compound 7 (p-coumaroyloxytremetone), which showed the highest gastroprotective activity (76%), which was higher than the control drug lansoprazole (72%). Our findings revealed that several constituents of this plant have gastroprotective activity, and particularly, p-coumaroyloxytremetone could be considered as a lead molecule to explore new gastroprotective agents. This plant is a rich source of biologically active tremetones and terpenoids which can support the ethnobotanical use of the plant.

Antiulcer Agents: From Plant Extracts to Phytochemicals in Healing Promotion

In this narrative review, we have comprehensively reviewed the plant sources used as antiulcer agents. From traditional uses as herbal remedies, we have moved on to preclinical evidence, critically discussing the in vitro and in vivo studies focusing on plant extracts and even isolated phytochemicals with antiulcerogenic potential. A particular emphasis was also paid to Helicobacter pylori activity, with emphasis on involved mechanisms of action. Lastly, the issue of safety profile of these plant products has also been addressed.

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.

Gastroprotective actions of Taraxacum coreanum Nakai water extracts in ethanol-induced rat models of acute and chronic gastritis

ETHNOPHARMACOLOGICAL RELEVANCE

Taraxacum coreanum Nakai has been traditionally used for treating inflammatory diseases including gastrointestinal diseases.

AIM OF THE STUDY

We studied whether water extracts of Taraxacum coreanum Nakai (TCN) had a protective effect on acute and chronic gastritis induced by ethanol/HCl in an animal model of gastritis and its mechanism was also explored.

MATERIALS AND METHODS

In the acute study, rats were orally administered 0.15g/mL dextrin (normal-control), 0.15g/mL dextrin (control), 0.05g/mL TCN (TCN-L), 0.15g/mL TCN (TCN-H), or 0.01g/mL omeprazole (orally; positive-control), followed by oral administration of 1mL of 60% ethanol plus 150mM HCl (inducer). In the chronic study, rats were administered 10% diluted inducer in drinking water, and 0.6% dextrin, 0.2% or 0.6% TCN, and 0.05% omeprazole were administered in chow for 4 weeks. Acid content, gastric structure, oxidative stress, and markers of inflammation in the stomach tissue were measured at the end of experiment.

RESULTS

Acute and chronic ethanol/HCl administration caused the inner layer of the stomach to redden, hemorrhage, and edema in the control group; TCN-H reduced these symptoms more effectively than did the omeprazole positive-control. Acid production and total acidity in the stomach increased in the control group, which was markedly suppressed by omeprazole. TCN also reduced the acid production and acidity, but not to the same degree as omeprazole. H-E and PAS staining revealed that in the inner layer of the stomach, cellular structure was disrupted, with an increased nuclear size and thickness, disarrangement, and decreased mucin in the control group. TCN prevented the cellular disruption in the inner layer, and TCN-H was more effective than the positive-control. This was associated with oxidative stress and inflammation. TCN dose-dependently reduced the infiltration of mast cells and TNF-α expression in the inner layer of the stomach, and decreased lipid peroxides by increasing superoxide dismutase and glutathione peroxidase expression.

CONCLUSIONS

TCN-H acutely and chronically protected against gastritis and gastric ulcer by reducing oxidative stress and inflammation, not by completely suppressing gastric acid production.

Constituents of leaves from Bauhinia curvula Benth. exert gastroprotective activity in rodents: role of quercitrin and kaempferol

The Bauhinia genus is known as "Pata-de-Vaca" and a wide variety of these species are used in Brazilian folk medicine due to their gastroprotective properties. This study aimed to investigate the antiulcer efficacy of the hydroalcoholic extract from B. curvula (HEBC) leaves, as well as its semi-purified fraction (SPFr) and the contribution of their phytochemicals constituents for this effect. For that, ethanol 60%/HCl 0.3 M- and indomethacin-induced gastric ulcer were performed in rodents. Gastric ulcerated tissues were processed for histological, histochemical and biochemical analysis. The oral treatment with HEBC and SPFr decreased the gastric ulcer induced by ethanol/HCl in mice and by indomethacin (only HEBC) in rats. The gastroprotective effect of HEBC was abolished in mice pretreated with Nω-Nitro-L-arginine methyl ester, N-Ethylmaleimide, glibenclamide or indomethacin. Both HEBC and SPFr reduced myeloperoxidase activity in parallel with a decrease of lipoperoxides content at the site of the lesion. On the other hand, HEBC did not alter volume, pH, total acidity or pepsin activity of acid gastric secretion in rats, and neither inhibited the in vitro H(+),K(+)-ATPase activity. Additionally, the compounds identified and isolated from the SPFr, the flavonoids quercitrin (65%) and kaempferol (35%), were able to diminish the extent of ulcerated area induced by both ethanol/HCl and indomethacin. Taking together, these findings show that B. curvula extracts present gastroprotective effect, mainly explained by the presence of flavonoids quercitrin and kaempferol, which may possibly improve the defensive factors of gastric mucosa.

Effects of methanolic extract from leaves of Rubus imperialis in DSS-induced colitis in mice

This study investigated the effects of Rubus imperialis, a berry known as "amora-branca", in colitis dextran sulfate sodium (DSS)-induced in mice. Animals were treated orally with vehicle (water), 5-aminosalicylic acid (100 mg/kg) or methanolic extract from leaves of R. imperialis (MERI, 100 mg/kg), once a day during seven days. The disease activity index (DAI) was observed daily. Colons were collected for histological, histochemical and biochemical analysis. The administration of MERI exacerbated colitis, as indicated by DAI heightened weight loss and increased histological colonic injury. MERI also decreased the colon mucin levels and increased colonic TNF content. The colonic levels of reduced glutathione and the superoxide dismutase activity in colitic group treated with MERI were decreased. Despite the worsening of colitis, MERI not altered the intestinal transit, body weight, colon length or organs weight in normal mice. Tormentic acid (TA) and 2β,3β,19α-trihydroxyursolic acid (THA), compounds isolated from MERI, reduced the L929 cells viability. Thus, MERI may have aggravated the DSS-induced colitis through intense intestinal mucus barrier impairment, which would lead to inflammatory responses, TA and THA contribute to the intestinal damage verified suggesting caution about the use of R. imperialis preparations, particularly in inflammatory bowel diseases.