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

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 potential of red onion (Allium cepa L.) peel in ethanol-induced gastric injury in rats: Involvement of Nrf2/HO-1 and HMGB-1/NF-κB trajectories

ETHNOPHARMACOLOGICAL RELEVANCE

The utilization of plants with therapeutic properties in traditional medicine has a longstanding practice. Among them, the well-known Allium cepa L. commonly known as onion has been valued for its anti-inflammatory and antioxidant potential in the treatment of various ailments, including gastric ulcers.

AIM OF THE STUDY

This study investigated the gastroprotective potential of red onion peel extract and its fractions in a rat model of ethanol-induced gastric ulcer. Moreover, their phytochemical profiles were compared to identify the active metabolites.

MATERIALS AND METHODS

Mass spectrometry-based metabolomics and chemometrics were performed for phytochemical analysis. Ethanol-induced gastric ulcer model was used to assess the gastroprotective activity. Nine groups of rats were allocated as follows: Group 1 was the normal control; Group 2 rats were used as a positive control/model and received 1 mL of absolute ethanol; and Group 3 rats were treated with famotidine at a dose of 20 mg/kg orally. Group 4 and 5 rats were treated with total acidified ethanolic extract (T1, T2). Group 6 and 7 rats were treated with anthocyanins-rich fractions (P1, P2). Groups 8 and 9 were the flavonoids-rich fraction (S1, S2) treatment. Prior to scarification, the ulcer index in mm was obtained from gastric tissues photographed beside a ruler with further analysis using ImageJ software.

RESULTS

Seventy key major and discriminatory metabolites were identified including flavonoids, anthocyanins, phenolic acids, and miscellaneous compounds. The examined extract and its fractions significantly reduced the ulcer index and inflammatory cytokines via downregulating HMGB-1/NF-κB. Also, they augmented the expression of Nrf2/HO-1 and reduced NOX1/4 mRNA expression. Moreover, there was a significant reduction in the oxidative stress and apoptotic biomarkers as well as a noticeable enhancement in histopathological changes of the stomach tissues.

CONCLUSION

Red onion peels have a promising dose dependent gastroprotective potential in alcohol-induced ulcers via modulating Nrf2/HO-1 and HMGB-1/NF-κB trajectories. This highlights the potential of red onion peels in treating gastric ulcers.

Effectiveness of natural biomaterials in the protection and healing of experimentally induced gastric mucosa Ulcer in rats

BACKGROUND

A gastric ulcer is a painful lesion of the gastric mucosa that can be debilitating or even fatal. The effectiveness of several plant extracts in the therapy of this illness has been demonstrated in traditional pharmacopoeias.

AIM

this study was aimed to see if propolis, ginseng in normal or nano form, and amygdalin might help in preventing the ulcerative effects of absolute ethanol.

METHODS

Gastroprotective properties of pretreatments before ethanol gavage in rats were compared to omeprazole. The ulcer and stomach parameters (ulcerated regions) were measured (mm2), ulcer inhibition percentage, the stomachs were assessed macroscopically with gastric biopsy histological examinations.

RESULTS

Amygdalin, normal and nano ginseng, nano propolis followed by propolis all showed great efficacy in protecting the cyto-architecture and function of the gastric mucosa. The number of ulcerated sites was greatly reduced, and the percentage of stomach protection was increased. Histopathological examination had confirmed great protective effects of the nanoformulations followed by amygdalin. The protection and healing rate was completed to about 100% in all tested materials while ulcer areas were still partially unhealed in normal propolis and omeprazole. Quantitative assay of the m-RNA levels Enothelin 1(ET-1), leukotriene4 (LT-4), and caspase 3(Cas-3) genes and Histamine were done and revealed significant up-regulations in ethanol group and the maximum protective effect was reported with ginseng nano, moreover the histamine content was significantly decreased with nano- formulated extracts.

CONCLUSION

Amygdalin and the nanoformulated ginseng and propolis had exhibited a marked protective effect against the ulcerative toxic effects of ethanol.

In vitro anti-inflammatory activity and ameliorative effects on gastric ulcers of Licania rigida benth seed extract

Licania rigida Benth., a Brazilian endemic plant, has been traditionally used for treating inflammation and stomach pain. This work investigates the anti-inflammatory and gastroprotective activities of the ethanolic extract from L. rigida seeds (EELr) by in vitro and in vivo methods. The phytochemical profile was determined and the in vitro antioxidant activity was investigated by radical scavenging and thiobarbituric acid reactive substances methods. The ovalbumin denaturation method was used with sodium diclofenac as standard for the in vitro anti-inflammatory activity assessment. Acetylsalicylic acid was used to induce gastric ulcers in male mice and then to evaluate the preventive and therapeutic gastroprotective effect of EELr, using omeprazole as the reference drug. The extract exhibited relevant amount of phenolic compounds and flavonoids, in particular, demonstrating in vitro antioxidant capacity. EELr was able to inhibit almost 60% of ovalbumin denaturation at a concentration considered low. It also prevented the decrease of biochemical markers for oxidative stress such as superoxide dismutase (SOD) and reduced glutathione (GSH) in the stomach and SOD and catalase (CAT) in the liver. EELr also significantly decreased the number of lesions as well as reduced the ulcerated area when used as therapy. The observed effect may be due to its phenolic compounds, such as chlorogenic acid, caffeic acid and tannins, as previously reported. EELr is a potential source of compounds with anti-inflammatory activity, protects the liver from oxidative damage and improves healing of aspirin-induced ulcers. This work contributes to the knowledge of L. rigida species.

Campomanesia lineatifolia Ruiz & Pavón (Myrtaceae): Isolation of major and minor compounds of phenolic-rich extract by high-speed countercurrent chromatography and anti-inflammatory evaluation

ETHNOPHARMACOLOGICAL RELEVANCE

Campomanesia lineatifolia Ruiz & Pavón (Myrtaceae), an edible species found in Brazilian Forest, possesses leaves that are traditionally used for the treatment of gastrointestinal disorders in Brazil. Extracts of C. lineatifolia are rich in phenolics and exhibit antioxidant, and gastric antiulcer properties. Furthermore, Campomanesia spp. have been described to possess anti-inflammatory properties, but studies related to chemical constituents of C. lineatifolia are scarce in the literature.

AIM OF THE STUDY

This work aims to identify the chemical composition of the phenolic-rich ethanol extract (PEE) from C. lineatifolia leaves and evaluate the anti-inflammatory activity that could be related to its ethnopharmacological use.

MATERIALS AND METHODS

The high-speed countercurrent chromatography (HSCCC), using an isocratic and a step gradient elution method, and NMR, HPLC-ESI-QTOF-MS/MS were used to isolate and identify the chemicals of PEE, respectively. Lipopolysaccharide-(LPS)-stimulated THP-1 cells were used to evaluate the anti-inflammatory activities from PEE and the two majority flavonoids isolated by measure TNF-α and NF-κB inhibition assays.

RESULTS

Fourteen compounds were isolated from the PEE, further identified by NMR and HPLC-ESI-QTOF-MS/MS, twelve of them are new compounds, and two others are already known for the species. The PEE, quercitrin and myricitrin promoted a concentration-dependent inhibition of TNF-α, and PEE promoted an inhibition of NF-κB pathway.

CONCLUSIONS

PEE from C. lineatifolia leaves demonstrated significant anti-inflammatory activity that may be related to the traditional use to treat gastrointestinal disorders.

A Mixture of Kaempferol-3-O-sambubioside and Kaempferol-3-O-sophoroside from Malvaviscus arboreus Prevents Ethanol-Induced Gastric Inflammation, Oxidative Stress, and Histologic Changes

Malvaviscus arboreus is used in traditional Mexican medicine to treat gastrointestinal diseases. Therefore, a mixture of Kaempferol-O-sambubioside and Kaempferol-O-sophoroside (MaSS) isolated from flowers of this species was tested as a preventive treatment on gastric lesions induced with ethanol in rats. MaSS was obtained by chromatographic methods and administered by oral pathway to male Sprague Dawley rats with ethanol-induced gastric lesions. Pretreatment with MaSS at doses of 30, 90, 120, and 180 mg/kg significantly prevents gastric lesions, inhibits the increment in relative stomach weight (%) in gastric IL-6, and also provokes an increment of IL-10 concentration and catalase activity. Finally, MaSS prevented edema in the mucosa and submucosa and diminished microscopic gastric lesions provoked by ethanol.

Metabolic Profiling of Heliotropium crispum Aerial Parts Using HPLC and FTIR and In Vivo Evaluation of Its Anti-Ulcer Activity Using an Ethanol Induced Acute Gastric Ulcer Model

This study explored the antiulcer potential of methanol extract and fractions of Heliotropium crispum roots against the ethanol-induced gastric ulcer model in rats. Metabolic profiling of H. crispum aerial parts using Fourier-transform infrared spectroscopy (FTIR) revealed the presence of different metabolites with various functional groups. Meanwhile, High Performance Liquid Chromatography (HPLC) revealed the presence of three main peaks assigned to myricetin, quercetin, and kaempferol. In vivo, antiulcer activity results showed that the disease control group displayed five tiny ulcers less than 2 mm in diameter in addition to two hemorrhagic streaks. However, in the standard control group, only one small ulcer was visible for the total methanol extract. Gastric tissues and contents were evaluated to determine many parameters such as ulcer score, ulcer index, percentage inhibition of ulcer, gastric pH, gastric juice volume, and acidity. Results were endorsed by histopathological evaluation; gastric pH and mucus content were significantly increased, but gastric juice volume was significantly decreased. All fractions showed a significant decrease in ulcer index and % inhibition except the n-hexane fraction, whose results were insignificant compared to the disease control group. Thus, it was concluded that H. crispum shows an antiulcer effect by decreasing gastric juice volume and acidity, whereas gastric pH and mucus contents were increased that is attributed to the synergistic action of its detected polyphenolic compounds.

Herbal Medicines in the Treatment of Dyspepsia: An Overview

This review focuses on the efficacy of herbal medicines for managing dyspepsia in humans and animals. Searches were conducted on the PubMed, Science Direct, and Medline databases, for publications in the last 3 years. In each database, the search terms used consisted of the 2 key terms describing the disorder and subtypes plus each of the terms relating to the therapy. The key terms used were "natural product" and "medicinal plant" in a cross-over with "dyspepsia" and "functional dyspepsia" (i.e., gastroprotection, Helicobacter pylori infection, prokinetic). We included all human and animal studies on the effects of herbal medicines reporting the key outcome of dyspepsia symptoms. Preclinical studies using critically validated models showed that most medicinal plants with gastroprotective action had antioxidant, anti-inflammatory, anti-apoptotic, and antisecretory effects. Moreover, several species displayed anti Helicobacter pylori and prokinetic efficacy. The data availability of controlled clinical studies is currently minimal. The use of different methodologies and the minimal number of patients raise doubts about the effects of these preparations. Only adequate clinical trials with scientifically validated methods can determine whether different herbal medicines can be used as viable alternatives to the conventional pharmacological treatments used to control dyspepsia symptoms.

The Genus Alternanthera: Phytochemical and Ethnopharmacological Perspectives

Ethnopharmacological relevance: The genus Alternanthera (Amaranthaceae) comprises 139 species including 14 species used traditionally for the treatment of various ailments such as hypertension, pain, inflammation, diabetes, cancer, microbial and mental disorders.

Aim of the review: To search research gaps through critical assessment of pharmacological activities not performed to validate traditional claims of various species of Alternanthera. This review will aid natural product researchers in identifying Alternanthera species with therapeutic potential for future investigation.

Materials and methods: Scattered raw data on ethnopharmacological, morphological, phytochemical, pharmacological, toxicological, and clinical studies of various species of the genus Alternanthera have been compiled utilizing search engines like SciFinder, Google Scholar, PubMed, Science Direct, and Open J-Gate for 100 years up to April 2021.

Results: Few species of Alternanthera genus have been exhaustively investigated phytochemically, and about 129 chemical constituents related to different classes such as flavonoids, steroids, saponins, alkaloids, triterpenoids, glycosides, and phenolic compounds have been isolated from 9 species. Anticancer, antioxidant, antibacterial, CNS depressive, antidiabetic, analgesic, anti-inflammatory, and immunomodulator effects have been explored in the twelve species of the genus. A toxicity study has been conducted on 3 species and a clinical study on 2 species.

Conclusions: The available literature on pharmacological studies of Alternanthera species reveals that few species have been selected based on ethnobotanical surveys for scientific validation of their traditional claims. But most of these studies have been conducted on uncharacterized and non-standardized crude extracts. A roadmap of research needs to be developed for the isolation of new bioactive compounds from Alternanthera species, which can emerge out as clinically potential medicines.

Chemistry, pharmacokinetics, pharmacological activities, and toxicity of Quercitrin

Quercitrin is a naturally available type of flavonoid that commonly functions as the dietary ingredient and supplement. So far, a wide spectrum of bioactivities of quercitrin have been revealed, including antioxidative stress, antiinflammation, anti-microorganisms, immunomodulation, analgesia, wound healing, and vasodilation. Based on these various pharmacological activities, increasing studies have focused on the potency of quercitrin in diverse diseases in recent years, such as bone metabolic diseases, gastrointestinal diseases, cardiovascular and cerebrovascular diseases, and others. In this paper, by collecting and summarizing publications from the recent years, the natural sources, pharmacological activities and roles in various diseases, pharmacokinetics, structure-activity relationship, as well as the toxicity of quercitrin were systematically reviewed. In addition, the underlying molecular mechanisms of quercitrin in treating related diseases, the dose-effect relationships, and the novel preparations were discussed on the purpose of broadening the application prospect of quercitrin as functional food and providing reference for its clinical application. Notably, clinical studies of quercitrin are insufficient at present, further high-quality studies are needed to firmly establish the clinical efficacy of quercitrin.

Propolis and Its Gastroprotective Effects on NSAID-Induced Gastric Ulcer Disease: A Systematic Review

Gastric ulcer disease induced by the consumption of NSAIDs is a major public health problem. The therapy used for its treatment causes adverse effects in the patient. Propolis is a natural product that has been used for the treatments of different diseases around the world. Nevertheless, there is little information about the activity of propolis in gastric ulcers caused by treatment with NSAIDs. Therefore, this review evaluates and compares the gastroprotective potential of propolis and its function against NSAID-induced gastric ulcers, for which a systematic search was carried out in the PubMed and ScienceDirect databases. The main criteria were articles that report the gastroprotective activity of propolis against the damage produced by NSAIDs in the gastric mucosa. Gastroprotection was related to the antioxidant, antisecretory, and cytoprotective effects, as well as the phenolic compounds present in the chemical composition of propolis. However, most of the studies used different doses of NSAIDs and propolis and evaluated different parameters. Propolis has proven to be a good alternative for the treatment of gastric ulcer disease. However, future studies should be carried out to identify the compounds responsible for these effects and to determine their potential use in people.

Quantitative Determination of Quercitrin Levels in Rat Plasma Using UHPLC-MS/MS and its Application in a Pharmacokinetic Study after the Oral Administration of Polygoni Cuspidati Folium Capsules

BACKGROUND

Quercitrin is widely found in herbal medicines, and it is particularly important in the design of new therapeutic agents. Because of its wide range of biological activities, methods for detecting quercitrin and its pharmacokinetics in biological samples must be investigated.

OBJECTIVE

To develop and validate a sensitive and reliable ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the quantitative determination of quercitrin levels in rat plasma and test its application in a pharmacokinetic investigation after the oral administration of Polygoni cuspidati folium capsules (HC).

METHODS

First, a rapid analytical method implementing UHPLC-MS/MS for the quantification of quercitrin levels in rat plasma was developed and validated. The analyte and internal standard (IS) tinidazole were extracted from rat plasma via protein precipitation with 800 μL of methanol and 50 μL of 1% formic acid solution. Chromatographic separation was performed using an Agilent ZORBAX C18 column within 4 min. Mass spectrometry was performed for quantification using a triple-quadrupole mass spectrometer employing electrospray ionization in the negative ion mode. The MRM transitions for quercitrin and IS were m/z 447.2→229.9 and m/z 246.0→125.8, respectively. The UHPLC-MS/MS method for the quantitative determination of quercitrin levels in rat plasma was then applied to investigate its pharmacokinetics after the oral administration of HC in rats.

RESULTS

The developed UHPLC-MS/MS method for detecting quercitrin in rat plasma was linear over the range of 0.1-160 ng/mL. The linear regression equation was Y = (0.7373 ± 0.0023)X - (0.0087 ± 0.0021) (r2 = 0.9978). The intra- and interday precision values were within 7.8%, and the recoveries of quercitrin and IS exceeding 67.3%. The UHPLC-MS/MS method was successfully applied to characterize the pharmacokinetic profile of quercitrin in eight rats after the oral administration of HC. The experimentally obtained values were fit to a one-compartment, first-order pharmacokinetic model, and they appeared to fit the concentration-time curve.

CONCLUSION

Quercitrin was proven to be stable during sample storage, preparation, and analytical procedures. The pharmacokinetic parameters suggested that quercitrin may be present in the peripheral tissues of rats.

Evaluation of the gastroprotective effects of Chihuahua propolis on indomethacin- induced gastric ulcers in mouse

The aim of this work was to evaluate the gastroprotective activity of a Mexican propolis on indomethacin-induced gastric ulcers in a mouse model. The following contents of the ethanolic extract of propolis of Chihuahua (EEPCh) were determined: antioxidant activity (SA50), total phenolic content (TPC), total flavonoid content (TFC), and chemical composition by HPLC-DAD and HPLC-MS, as well as acute toxicity by OECD Guideline 423. Gastric lesions were induced by intragastric indomethacin treatment in male ICR mice. As the positive control, omeprazole was administered, and three doses of EEPCh were evaluated (50, 150 and 300 mg/kg). Gastric mucosal injury, histological changes and mucosal content were evaluated by means of H&E and PAS staining. For homogenized gastric tissues, the following were evaluated: TBARS, MPO, and PGE2 levels; SOD and GPx antioxidant enzymatic activity; and the concentrations of the proinflammatory cytokines, TNF-α, IL-1β and IL-6. EEPCh had a significant SA50 of 41.55 µg/mL. The TPC of EEPCh was 860 mg GAE/g, and its TFC was 49.58 mg QE/g. Different phenolic compounds were identified in the extract and were not toxic. The EEPCh doses decreased mucosal damage and histological injuries, maintained the mucosal content and reduced the TBARS, MPO and concentrations of proinflammatory cytokines in gastric ulcer tissues. The 150 and 300 mg/kg doses increased the SOD activity and maintained the PGE2 content. Only the 300 mg/kg dose increased the GPx activity. The results of this study suggest that EEPCh displays gastroprotective effects by means of its antioxidant activity and anti-inflammatory effects and promotes ulcer protection through the maintenance of mucosal content and PGE2 levels.

Simultaneous Quantification of Four Marker Compounds in Bauhinia coccinea Extract and Their Potential Inhibitory Effects on Alzheimer's Disease Biomarkers

Bauhinia coccinea is a tropical woody plant widely distributed in Vietnam and Unnan in southern China. Although many studies have shown the biological activities of extracts from various other species in the genus, no studies have investigated the effects of B. coccinea extracts on biological systems. In the present study, a quantitative analysis of four marker compounds of ethanol extracts of B. coccinea branches (EEBC) was performed using the high performance liquid chromatography (HPLC)-photodiode array (PDA) method. Among gallic acid, (+)-catechin, ellagic acid, and quercitrin contained in EEBC, the most abundant compound was (+)-catechin (18.736 mg/g). In addition, we investigated the EEBC on neuroprotection, antioxidation, and Alzheimer’s disease (AD) marker molecules, acetylcholinesterase (AChE), and amyloid-β (Aβ). EEBC significantly inhibited hydrogen peroxide (H₂O₂)-induced cell death in a HT22 neuronal cell line and increased 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl scavenging activity markedly. EEBC also inhibited AChE and Aβ aggregation. Among the four compounds, gallic acid exhibited strong inhibitory effects against AChE activation. In the Aβ aggregation assay, the four marker compounds exhibited inhibitory effects lower than 30%. According to the results, EEBC could exert anti-AChE activation and Aβ aggregation activities based on the interactive effects of the marker compounds. Our findings suggest that EEBC are sources of therapeutic candidates for application in the development of AD medication based on AChE and Aβ dual targeting.

First phytochemical study and biological activity of the leaves ethanolic extract from Cissus spinosa Cambess

AIMS: The objective of this study was to identify the phytochemical profile and to evaluate the biological effects of the crude ethanolic extract (EE) and the ethanolic fraction (EF) of leaves of the species Cissus spinosa Cambess, after oxidative stress induced by cyclophosphamide (CP) in mice.METHODS: Phytochemical profile was performed detecting functional groups and, analysis of total flavonoids and phenols concentration, as well as the antiradical activity in EE and EF. The phytochemical characterization was done for the identification of flavonoids present in the leaves of the plant. In the biochemical tests, hematological parameters, glucose and total cholesterol dosages in plasma, enzymatic and non-enzymatic antioxidants and lipid damage marker were evaluated in different tissues (liver, kidney and heart), besides genotoxic and immunological analyzes. The animals received 15 days of treatment, via gavage, with EE (50 mg kg-1) or EF (50 mg kg-1) and on the 15th day, an intraperitoneal injection of CP (100 mg kg-1) or saline (0.9%). After 24 h the last treatment, the animals were anesthetized for blood withdrawal, sacrificed and removal of the organs.RESULTS: In the phytochemical analyzes, the presence of alkaloids, flavonoids and phenols was identified, the latter presented a higher concentration for EF. Eight flavonoids were identified - Rutin, Quercetin-3-β-D-glucoside, Quercitrin, Taxifolin, Quercetin, Canferol, Luteolin and Apigenin. In the biochemical analyzes, in general, EE showed a better antioxidant action against oxidative damages, hypoglycemic and antitilipemic action when comparing with EF, probably due to the synergism caused by flavonoids. It was observed the reduction and an increase of micronucleated polychromatic erythrocytes, due to the action of antioxidant compounds and alkaloids present in the plant, also considering the question of the seasonal period that directly interferes in the production of these compounds. In the immunological analysis, the extracts did not stimulate the spontaneous production of oxygen peroxide (H2O2) and nitric oxide (NO•). CONCLUSIONS: Other studies, such as the variation of the chemical composition of the plant by local seasonality, hypoglycemic and antilipemic action, should be carried out to better delineate the biological action present in this plant.

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.

Gastroprotective activity of the methanol extract from peels of Plinia edulis (Vell.) Sobral fruits and its isolated triterpenes: maslinic and ursolic acids

According to the Brazilian folk medicine, the leaves of Plinia edulis (Vell.) Sobral (Myrtaceae), known as cambuca, are indicated in the treatment of gastric disorders. Infusions of P. edulis leaves were previously demonstrated to contain both maslinic (MA) and ursolic acids (UA). Both triterpenes have also been identified in the methanolic extract of peels from P. edulis fruit (MEPPE); however, the antiulcer effects of MEPPE have not yet been studied. This study therefore evaluates the gastroprotective potential of MEPPE, MA, and UA using ethanol/HCl- and indomethacin-induced gastric ulcers in mice. In addition, the in vitro effects of these compounds on the H+, K+-ATPase activity and on the free radical DPPH were measured. When used at concentration of 100 μg/mL, both MEPPE and UA were found to reduce the DPPH radical levels by 78.66 and 60.14%, respectively. However, MA did not reduce DPPH radical levels. Our results illustrated the antiulcer effects of MEPPE, MA, and UA against experimental ulcer models when administered by either the oral or the intraperitoneal routes. In addition, MEPPE reduced the size of ethanol/HCl-induced ulcers in a dose-dependent manner (log half-maximal effective oral dose, LogED50 = 1.09). Interestingly, UA promoted gastroprotection at lower doses than MA by increasing the production of mucin levels at 692%; however, it does not alter the activity of H+, K+-ATPase. In contrast, both MEPPE and MA, when incubated at concentrations of 10 and 100 μg/mL, inhibited H+, K+-ATPase activity in 61.81, 68.37, 54.04, and 70.45%, respectively. These results confirm that MEPPE, MA, and UA display gastroprotective activity through different modes of action; MA inhibits H+, K+-ATPase activity, whereas UA favour the mucus barrier.

Chrysophyllum cainito (apple-star): a fruit with gastroprotective activity in experimental ulcer models

The gastroprotective potential of the methanolic extracts from peels (MEPe), seeds (MESe) and pulp (MEPu) of Chrysophyllum cainito L. (Sapotaceae) fruits was evaluated in mice using ethanol/HCl- and indomethacin-induced ulcer, as well as the antiulcer effect of the juice and flour from this fruit. The lowest oral gastroprotective dose of MEPe, MESe and MEPu against ethanol/HCl was 3, 3 and 10 mg/kg, respectively. Moreover, all extracts increased mucin secretion at 176, 198 and 193%. Intraperitoneal administration of MEPe (0.3 mg/kg), MESe (0.3 mg/kg) and MEPu (1 mg/kg) also promoted gastroprotection against ethanol/HCl. In addition, MEPe (3 mg/kg, p.o), MESe (3 mg/kg, p.o) and MEPu (10 mg/kg, p.o) reduced indomethacin-induced gastric ulcer in mice by 78, 70 and 50%, respectively. Regarding the mode of action, the gastroprotective effect of MEPe was decreased by the pre-administration of N-ethylmaleimide (NEM, a sulfhydryl group chelator, 10 mg/kg, i.p), glibenclamide (a potassium channel blocker, 10 mg/kg, i.p), yohimbine (10 mg/kg, i.p, an alpha-adrenergic receptor antagonist, 10 mg/kg, i.p) and indomethacin (a cyclooxygenase inhibitor, 10 mg/kg, i.p). The gastroprotective effect of MESe was reduced by the pre-administration of NEM, glibenclamide, N-Nitro-L-arginine methyl ester (L-NAME, a nitric oxide synthase inhibitor, 70 mg/kg, i.p) and yohimbine, while MEPu had the gastroprotective effect decreased in animals pretreated with NEM and L-NAME. However, the extracts did not reduce gastric acid secretion. The supplementation with the flour from C. cainito fruit at 10% by 7 days, but not the juice intake, displayed gastroprotective potential, evidencing the fruit as a promising functional food. Together, the antiulcer effect of extracts of the C. cainito fruit in different experimental models was confirmed by the favoring of mucosal protective mechanisms among different, but complementary, modes of action. In parallel, the gastroprotective effects of the flour from C. cainito fruit were also described.

Gastroprotective Value of Berries: Evidences from Methanolic Extracts of Morus nigra and Rubus niveus Fruits

This study evaluated the gastroprotective value of the methanol extracts from fruits of Morus nigra L. (black mulberry (MEMN)) and Rubus niveus Thunb (raspberry (MERN)). The total phenolic compounds and flavonoids were measured, as well as the in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenger activity. The gastroprotective effects of the extracts against 60% ethanol/0.3 M HCl were evaluated in mice. After that, the lipid hydroperoxides and reduced glutathione levels at ulcerated tissue were determined. The effects of extracts on H⁺/K⁺-ATPase activity were also verified. The extracts exhibited high contents of polyphenols; however, MERN presented 1.5-fold higher levels. The presence of flavonoids also was confirmed. In addition, MEMN (IC₅₀ = 13.74 μg/mL) and MERN (IC₅₀ = 14.97 μg/mL) scavenged DPPH radical. The MEMN reduced the ulcer area only at 300 mg/kg (p.o.) by 64.06%. Interestingly, MERN decreased the ulcer area in a superior potency (ED₅₀ = 20.88 mg/kg), reducing the ulcer area by 81.86% at 300 mg/kg, and increased the gastric mucin levels. The antioxidant effects of extracts were evidenced by reduced lipoperoxides and increased reduction of glutathione amount in the gastric mucosa. However, MEMN or MERN did not change the H⁺/K⁺-ATPase activity. These results confirm that M. nigra and R. niveus are berries with a gastroprotective value by strengthening of gastric protective factors.