Byrsonima intermedia A. Juss partitions promote gastroprotection against peptic ulcers and improve healing through antioxidant and anti-inflammatory activities

Aqueous extract of the bark of Uncaria tomentosa, an amazonian medicinal plant, promotes gastroprotection and accelerates gastric healing in rats

ETHNOPHARMACOLOGICAL IMPORTANCE

Uncaria tomentosa Willd. DC., is used in the Amazonian region of South America, wherein ethnic groups use the plant to treat diseases, including gastric disorders. However, despite its widespread popular use, this species has yet to be assessed for its anti-ulcer effects.

AIM OF THE STUDY

In this study, we aimed to evaluate the in vivo gastroprotective and gastric healing activities of an aqueous extract of the bark of Uncaria tomentosa (AEUt) and sought to gain an understanding of the pharmacological mechanisms underlying these biological effects.

MATERIALS AND METHODS

To verify the gastroprotective properties rats were treated with AEUt (30, 60, or 120 mg/kg) prior to inducing gastric ulceration with ethanol or piroxicam. Additionally, the involvement of nitric oxide, non-protein sulfhydryl compounds (NP-SH), α-2 adrenergic receptors, and prostaglandins was investigated. Furthermore, a pylorus ligature model was employed to investigate the antisecretory activity of AEUt. The gastric healing effects of AEUt (60 mg/kg) were examined in rats in which ulceration had been induced with 80% acetic acid, whereas the quality of healing was evaluated in mice with interleukin-induced recurrent ulcers. We also evaluated the in vivo thickness of the gastric wall using ultrasonography. Moreover, the levels of reduced glutathione (GSH) and malondialdehyde (MDA) were evaluated in ulcerated mucosa, and we determined the activities of the enzymes myeloperoxidase (MPO), N-acetyl-β-D-glycosaminidase, superoxide dismutase, catalase, and glutathione S-transferase. In addition, we assessed the effects of AEUt on cell viability and subjected the AEUt to phytochemical analyses.

RESULTS

Administration of the AEUt (60 or 120 mg/kg) prevented ethanol- and piroxicam-induced ulceration, which was also confirmed histologically. Moreover, we observed that pre-treatment with NEM and indomethacin abolished the gastroprotective effects of AEUt, thereby indicating the involvement of NP-SH and prostaglandins in these protective effects. In addition, we found that the administration of AEUt had no appreciable effects on the volume, acidity, or peptic activity of gastric juice. Furthermore, the AEUt (60 mg/kg) accelerated the gastric healing of acetic acid-induced ulcers by 46.2% and ultrasonographic findings revealed a reduction in the gastric wall thickness in this group. The gastric healing effect of AEUt was also accompanied by a reduction in MPO activity. The AEUt (60 mg/kg) also minimized ulcer recurrence in mice exposed to IL-1β and was associated with the maintenance of GSH levels and a reduction in MDA contents. We deduce that the biological effects of AEUt could be associated with the activities of polyphenols and the alkaloids isomitraphylline and mitraphylline, identified as predominant constituents of the AEUt. Furthermore, we found no evidence to indicate that AEUt would have any cytotoxic effects.

CONCLUSION

Collectively, our findings provide compelling evidence indicating the therapeutic efficacy of U. tomentosa. Our data indicate that compounds in AEUt confer gastroprotection and that this preventive effect of AEUt was accompanied by gastric healing and a reduction in gastric ulcer recurrence. Moreover, we provide evidence to indicate that the gastroprotective and gastric healing effects involve the antioxidant system and anti-inflammatory responses that contribute to preserving the gastric mucosa.

Use of Callistemon citrinus as a gastroprotective and anti-inflammatory agent on indomethacin-induced gastric ulcers in obese rats

Background

Obesity leads to an elevated risk of developing gastrointestinal disease such as gastric ulcers. Callistemon citrinus leaf extract has shown antioxidant, antimicrobial, hepatoprotective, and chemoprotective effects against colon cancer. The aim of this study is to evaluate the gastroprotective effect of C. citrinus leaf extract on indomethacin-induced gastric ulcers in obese rats.

Methods

Gastric ulcers were induced in female obese Wistar rats using a single oral dose of indomethacin (IND). In the first stage, the rats were fed with a high fat sugar diet (HFSD) for 15 weeks to induce obesity and, at the same time, the diet of the other group of animals included daily administration of ethanolic C. citrinus leaf extract (250 mg/kg) in addition to HFSD. In the second stage, gastric ulcers were induced with IND (30 mg/kg). The gastroprotective activity of C. citrinus, the inflammatory enzyme activities, and cytokines in the stomach were determined.

Results

C. citrinus produced a reduction of gastric lesions caused by IND. Myeloperoxidase (MPO), cyclooxygenase-2 (COX-2), and 5-lipoxygenase (5-LOX) activities also decreased. Although inflammatory biomarkers such as TNFα, IL-6, AOPP, and leptin were significantly decreased by C. citrinus, adiponectin levels increased. Moreover, C. citrinus decreased weight gain and morphological and biochemical parameters.

Conclusion

The use of indomethacin in rats fed with a high fat-sugar diet increased gastric ulcers. Gastroprotective effect of C. citrinus in obese rats is attributed to the reduction of pro-inflammatory cytokines and the inflammatory enzymes.

The Potential of Alternative Therapies and Vaccine Candidates against Helicobacter pylori

Alternative therapies and vaccination are essential to combat the emergence of multidrug-resistant Helicobacter pylori and to prevent the development of gastroduodenal diseases. This review aimed to systematically review recent studies on alternative therapies, i.e., probiotics, nanoparticles, and natural products from plants, as well as recent progress in H. pylori vaccines at the preclinical stage. Articles published from January 2018 to August 2022 were systematically searched using PubMed, Scopus, Web of Science, and Medline. After the screening process, 45 articles were eligible for inclusion in this review. Probiotics (n = 9 studies) and natural products from plants (n = 28 studies) were observed to inhibit the growth of H. pylori, improve immune response, reduce inflammation, and reduce the pathogenic effects of H. pylori virulence factors. Natural products from plants also showed anti-biofilm activity against H. pylori. However, clinical trials of natural products from plants and probiotics are still lacking. A paucity of data assessing the nanoparticle activity of N-acylhomoserine lactonase-stabilized silver against H. pylori was observed. Nonetheless, one nanoparticle study showed anti-biofilm activity against H. pylori. Promising results of H. pylori vaccine candidates (n = 7) were observed at preclinical stage, including elicitation of a humoral and mucosal immune response. Furthermore, the application of new vaccine technology including multi-epitope and vector-based vaccines using bacteria was investigated at the preclinical stage. Taken together, probiotics, natural products from plants, and nanoparticles exhibited antibacterial activity against H. pylori. New vaccine technology shows promising results against H. pylori.

Chemical characterization of Brazilian savannah Byrsonima species (muricis) and their impact on genomic instability and chemopreventive effects

The identification of new drugs with few or no adverse effects is of great interest worldwide. In cancer therapy, natural products have been used as chemopreventive and chemotherapeutic agents. Plants from the Brazilian savannah belonging to the Byrsonima genus are popularly known as muricis and have attracted much attention due to their various pharmacological activities. However, there are currently no data on these plants concerning their use as chemopreventive or chemotherapeutic agents in human cell lines. The present study assessed the potential of B. correifolia, B. verbascifolia, B. crassifolia, and B. intermedia extracts as natural alternatives in the prevention and/or treatment of cancer. The chemical constituents present in each extract were analyzed by electrospray ionization-mass spectrometry (ESI-MSN). The mutagenic/antimutagenic (micronucleus assay), genotoxic/antigenotoxic (comet assay), apoptotic/necrotic (acridine orange/ethidium bromide uptake), and oxidative/antioxidative (CM-H₂DCFDA) effects of the extracts and their influence on gene expression (RTqPCR) were investigated in nonmetabolizing gastric (MNP01) and metabolizing hepatocarcinoma (HepG2) epithelial cells to evaluate the effects of metabolism on the biological activities of the extracts. The genotoxicity, mutagenicity, and apoptotic effects observed in HepG2 cells with B. correifolia and B. verbascifolia extracts are probably associated with the presence of proanthocyanidins and amentoflavone. In MNP01 cells, none of the four extracts showed mutagenic effects. B. crassifolia and B. intermedia extracts exhibited strong antimutagenicity and enhanced detoxification in HepG2 cells and antioxidant capacities in both types of cells, possibly due to the presence of gallic and quinic acids, which possess chemopreventive properties. This study identifies for the first time B. correifolia and B. verbascifolia extracts as potential agents against hepatocarcinoma and B. crassifolia and B. intermedia extracts as putative chemopreventive agents.

Flavonoids-Rich Plant Extracts Against Helicobacter pylori Infection as Prevention to Gastric Cancer

Gastric cancer is the fifth most common and fourth type to cause the highest mortality rates worldwide. The leading cause is related to Helicobacter pylori (H. pylori) infection. Unfortunately, current treatments have low success rates, highlighting the need for alternative treatments against carcinogenic agents, specifically H. pylori. Noteworthy, natural origin products contain pharmacologically active metabolites such as flavonoids, with potential antimicrobial applications.

Objective: This article overviews flavonoid-rich extracts’ biological and pharmacological activities. It focuses on using these substances against Helicobacter pylori infection to prevent gastric cancer. For this, PubMed and Science Direct databases were searched for studies that reported the activity of flavonoids against H. pylori, published within a 10-year time frame (2010 to August 2020). It resulted in 1,773 publications, of which 44 were selected according to the search criteria. The plant family primarily found in publications was Fabaceae (9.61%). Among the flavonoids identified after extraction, the most prevalent were quercetin (19.61%), catechin (13.72), epicatechin (11.76), and rutin (11.76). The potential mechanisms associated with anti-H. pylori activity to the extracts were: inhibition of urease, damage to genetic material, inhibition of protein synthesis, and adhesion of the microorganism to host cells.

Conclusion: Plant extracts rich in flavonoids with anti-H. pylori potential proved to be a promising alternative therapy source, reinforcing the relevance of studies with natural products.

Intelligent Algorithm-Based Gastrointestinal X-Ray Examination in Evaluating the Therapeutic Effect of Probiotics Combined with Triple Therapy on Children with Helicobacter Infection

In this study, gastrointestinal X-ray imaging was processed based on the Ncut algorithm, the gastric signs of the children after probiotics combined with triple therapy were examined, the therapeutic effect of probiotics combined with triple therapy was evaluated, and the correlation between Helicobacter pylori (HP) infection and gastric disease was analyzed. The included children were randomly divided into group A (treated with standard triple therapy) and group B (pretreated with probiotics on the basis of the treatment method of group A) with 48 cases in each group. The gastrointestinal angiography results of children were observed. The accuracy of the gastrointestinal angiography based on intelligent algorithms was evaluated by taking the results of the urea breath test (UBT) as the gold standard. The results were as follows: first, gastrointestinal X-ray imaging before and after treatment showed that the recovery of the gastric body and gastric antral mucosa for children in group B was better than that of group A (P < 0.05); second, the incidence of gastrointestinal diseases in HP-positive patients was 78% and the incidence of HP-negative patients was 32%; third, the sensitivity, specificity, and accuracy of gastrointestinal X-ray imaging based on intelligent algorithm were 76.47%, 93.67%, and 90.63%, respectively. After treatment, tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) in group B were much lower than those in group A (P < 0.05), and the incidence of adverse reactions in group B was lower than that in group A (P < 0.05). In summary, gastrointestinal X-ray imaging based on intelligent algorithm had a reliable reference value for the judgment of gastrointestinal HP infection and probiotics combined with triple therapy was more effective for HP infection, which was worthy of clinical application.

Dietary proanthocyanidins on gastrointestinal health and the interactions with gut microbiota

Many epidemiological and experimental studies have consistently reported the beneficial effects of dietary proanthocyanidins (PAC) on improving gastrointestinal physiological functions. This review aims to present a comprehensive perspective by focusing on structural properties, interactions and gastrointestinal protection of PAC. In brief, the main findings of this review are summarized as follows: (1) Structural features are critical factors in determining the bioavailability and subsequent pharmacology of PAC; (2) PAC and/or their bacterial metabolites can play a direct role in the gastrointestinal tract through their antioxidant, antibacterial, anti-inflammatory, and anti-proliferative properties; (3) PAC can reduce the digestion, absorption, and bioavailability of carbohydrates, proteins, and lipids by interacting with them or their according enzymes and transporters in the gastrointestinal tract; (4). PAC showed a prebiotic-like effect by interacting with the microflora in the intestinal tract, and the enhancement of PAC on a variety of probiotics, such as Bifidobacterium spp. and Lactobacillus spp. could be associated with potential benefits to human health. In conclusion, the potential effects of PAC in prevention and alleviation of gastrointestinal diseases are remarkable but clinical evidence is urgently needed.

The role of toll-like receptors in peptic ulcer disease

Helicobacter pylori (HP) is the primary etiologic factor that induces events in the immune system that lead to peptic ulcers. Toll-like receptors (TLRs) are an important part of the innate immune system, as they play pivotal roles in pathogen-associated molecular pattern (PAMP) recognition of HP as well host-associated damage-associated molecular patterns (DAMPs). Recent advancements such as COX-2 production, LPS recognition through TLR2, CagL, and CagY protein of HP activating TLR5, TLR9 activation via type IV secretion system (T4SS) using DNA transfer, TLR polymorphisms, their adaptor molecules, cytokines, and other factors play a significant role in PUD. Thus, some novel PUD treatments including Chuyou Yuyang granules, function by TLR4/NF-κB signaling pathway suppression and TNF-α and IL-18 inhibition also rely on TLR signaling. Similarly glycyrrhetinic acid (GA) treatment activates TLR-4 in Ana-1 cells not via TRIF, but via MYD88 expression, which is significantly upregulated to cure PUD. Therefore, understanding TLR signaling complexity and its resultant immune modulation after host-pathogen interactions is pivotal to drug and vaccine development for other diseases as well including cancer and recent pandemic COVID-19. In this review, we summarize the TLRs and HP interaction; its pathophysiology-related signaling pathways, polymorphisms, and pharmaceutical approaches toward PUD.

UHPLC-(ESI)-HRMS and NMR-Based Metabolomics Approach to Access the Seasonality of Byrsonima intermedia and Serjania marginata From Brazilian Cerrado Flora Diversity

Seasonality is one of the major environmental factors that exert influence over the synthesis and accumulation of secondary metabolites in medicinal plants. The application of the metabolomics approach for quality control of plant extracts is essentially important because it helps one to establish a standard metabolite profile and to analyze factors that affect the effectiveness of the medicinal plants. The Brazilian Cerrado flora is characterized by a rich diversity of native plant species, and a number of these plant species have been found to have suitable medicinal properties. Some of these plant species include Byrsonima intermedia and Serjania marginata. To better understand the chemical composition of these plant species, we conducted a study using the state-of-the-art techniques including the HPLC system coupled to an Exactive-Orbitrap high resolution mass spectrometer with electrospray ionization interface UHPLC-(ESI)-HRMS and by NMR being performed 2D J-resolved and proton NMR spectroscopy. For the analysis, samples were harvested bimonthly during two consecutive years. UHPLC-(ESI)-HRMS data were preprocessed and the output data uploaded into an in-house Excel macro for peak dereplication. MS and NMR data were concatenated using the data fusion method and submitted to multivariate statistical analysis. The dereplication of LC-HRMS data helped in the annotation of the major compounds present in the extracts of the three plant species investigated allowing the annotation of 68 compounds in the extracts of B. intermedia (cinnamic acids, phenolic acids derived from galloyl quinic and shikimic acid, proanthocyanidins, glycosylated flavonoids, triterpenes and other phenols) and 81 compounds in the extracts of S. marginata (phenolic acids, saponins, proanthocyanidins, glycosylated flavonoids among other compounds). For a better assessment of the great number of responses, the significance of the chemical variables for the differentiation and correlation of the seasons was determined using the variable importance on projection (VIP) technique and through the application of the false discovery rate (FDR) estimation. The statistical data obtained showed that seasonal factors played an important role on the production of metabolites in each plant species. Temperature conditions, drought and solar radiation were found to be the main factors that affected the variability of phenolic compounds in each species.

The essential oil from Baccharis trimera (Less.) DC improves gastric ulcer healing in rats through modulation of VEGF and MMP-2 activity

ETHNOPHARMACOLOGICAL RELEVANCE

Baccharis trimera (Less.) DC known as "carqueja" in Brazil has been acknowledged as a medicinal plant in folk medicine for the treatment of stomach aches and gastrointestinal disorders.

AIM OF THE STUDY

The present study aimed to evaluate the gastroprotective and healing effects of essential oil from B. trimera (EOBT) against gastric ulcer lesions caused by absolute ethanol and acetic acid, respectively, and to identify the mechanism of action of this essential oil in male Wistar rats.

MATERIALS AND METHODS

The plant material used to obtain EOBT was collected in the southern region of Brazil and was analyzed by chromatography-mass spectrometry (GCMS) demonstrate its characteristic chemical composition, with carquejyl acetate as its main component. Different doses of EOBT (50, 100, and 200 mg/kg) were administered orally in male Wistar rats as an acute treatment against absolute ethanol-induced gastric lesions. The gastric healing effect of EOBT (100 mg/kg) was evaluated once a day after 7, 10, and 14 days of treatment. After treatment, the stomachs of rats from all groups were collected to measure the lesion area (mm2), the activity of myeloperoxidase (MPO), and the relative expression of caspases -3, -8, -9, cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF). The zymography method was used to elucidate the activity of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) in the healing action of EOBT. We also analyzed toxicological parameters (body weight evolution and biochemical parameters) that could result after treatment with this essential oil for 14 days.

RESULTS

Pretreatment with EOBT (100 and 200 mg/kg) significantly decreased the severity of gastric damage induced by absolute ethanol and decreased MPO activity in gastric tissue. After 10 and 14 days of treatment with EOBT (100 mg/kg) once a day, the lesion area was significantly reduced by 61% and 65.5%, respectively, compared to the negative control group. The gastric healing effect of EOBT was followed by a decrease in the expression of COX-1 compared to that in the negative control group. Notably, treatment with EOBT for 14 days increased the expression of VEGF compared to that using an anti-ulcer drug (lansoprazole). Additionally, analyses of MMP-2 and MMP-9 activities in the gastric mucosa confirmed the accelerated gastric healing effect of EOBT, with a significant decrease in the activity of pro-MMP-2. No sign of toxicity was observed after treatment with EOBT for 14 consecutive days.

CONCLUSION

These findings indicated that EOBT was effective in preventing and accelerating ulcer healing by decreasing MPO activity, increasing VEGF expression, and decreasing MMP-2 activity. These actions collectively contribute to the rapid recovery of gastric mucosa following treatment with EOBT, without any observed toxicity.

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.

Review: Helicobacter pylori and non-malignant upper gastrointestinal diseases

This review covers recent publications investigating the relationship between Helicobacter pylori infection and gastroesophageal reflux disease, Barrett's esophagus, eosinophilic esophagitis, peptic ulcer disease (PUD), H pylori gastritis, and functional dyspepsia. In the area of gastroesophageal reflux disease, new data suggest that reflux may have a role in the transmission of H pylori infection. In addition to several observational studies, data on alterations in esophageal physiology in patients with H pylori infection are presented. Further evidence for the inverse relationship between H pylori infection and Barrett's esophagus is available in the form of a meta-analysis from the North American Barrett's and Esophageal Carcinoma Consortium. The relationship between H pylori infection and eosinophilic esophagitis remains uncertain. Although new data do not indicate a significantly lower prevalence of H pylori among patients with eosinophilic esophagitis, a meta-analysis showed a 37% reduced risk of eosinophilic esophagitis among H pylori-infected patients. Novel data are presented on the genetic variability of bacterial virulence factors and their relationship with PUD. We also report data on plasma biomarkers, which may detect progression to gastric cancer in H pylori-associated PUD. A new meta-analysis was published, which assessed the risk of PUD in low-dose aspirin users with H pylori infection. Finally, we report on the ongoing attempts to stratify patients with gastritis using endoscopic methods when compared to standard biopsy examination.