Gastroprotective and anti-oxidative properties of ascorbic acid on indomethacin-induced gastric injuries in rats

The Effect of Corn and Wheat Glutens Fed to Lambs on Some Microbial and Chemical Properties of Musculus Longismus Dorsi and Determination of Intramuscular and Tail Fatty Acid Profile

This study examined the effects of wheat and corn gluten added to lamb diets as a unilateral protein source on some microbial and chemical properties of Musculus Longismus dorsi (LD), determination of intramuscular and tail fat profile. It was found that TBARS levels in LD muscle on the days of storage were highest in the wheat gluten-treated groups (p<0.01). It was found that the changes in pH values in LD muscle were different on days (p<0.05). It was found that the change of L*, a ve b values on days differed between groups during the storage period (p<0.05). It was found that the numbers of TMAB, Enterobacteriaceae, Lactobacillus spp., Pseudomonas spp. and TPAB changed significantly (p<0.05) during the storage process. While a significant difference was found between the MUFA levels of dorsal muscle intramuscular adipose tissue of the groups (p<0.05). As a result, it was determined that the metabolic differences of the one-way protein sources fed to the lambs in the digestive system and other organs had an effect on the meat quality, intramuscular fat and fatty acid profile of the tail.

Association between the consumption of ultra-processed foods and the incidence of peptic ulcer disease in the SUN project: a Spanish prospective cohort study

PURPOSE

Consumption of ultra-processed foods (UPF) has increased despite potential adverse health effects. Recent studies showed an association between UPF consumption and some gastrointestinal disorders. We evaluated the association between UPF consumption and peptic ulcer disease (PUD) in a large Spanish cohort.

METHODS

We conducted a prospective analysis of 18,066 participants in the SUN cohort, followed every two years. UPF was assessed at baseline and 10 years after. Cases of PUD were identified among participants reporting a physician-made diagnosis of PUD during follow-ups. Cases were only partially validated against medical records. Cox regression was used to assess the association between baseline UPF consumption and PUD risk. Based on previous findings and biological plausibility, socio-demographic and lifestyle variables, BMI, energy intake, Helicobacter pylori infection, gastrointestinal disorders, aspirin and analgesic use, and alcohol and coffee consumption were included as confounders.We fitted GEE with repeated dietary measurements at baseline and after 10 years of follow-up. Vanderweele's proposed E value was calculated to assess the sensitivity of observed associations to uncontrolled confounding.

RESULTS

During a median follow-up of 12.2 years, we recorded 322 new PUD cases (1.56 cases/1000 person-years). Participants in the highest baseline tertile of UPF consumption had an increased PUD risk compared to participants in the lowest tertile (HR = 1.52, 95% CI: 1.15, 2.00, Ptrend=0.002). The E-values for the point estimate supported the observed association. The OR using repeated measurements of UPF intake was 1.39 (95% CI: 1.03, 1.87) when comparing extreme tertiles.

CONCLUSION

The consumption of UPF is associated with an increased PUD risk.

Concomitant Effects of Metformin and Vitamin C on Indomethacin-Induced Gastric Ulcer in Rats: Biochemical and Histopathological Approach

INTRODUCTION

Gastric ulcer is one of the most common and serious conditions in the gastrointestinal tract. One of the main causes of gastric ulcers is using of non-steroidal anti-inflammatory drugs (NSAIDs) which have limited their use in clinical practice. Several studies have revealed that metformin and Vitamin C (Vit C) exhibit protective effects against gastric mucosal damage in different animal models. However, no studies indicate their combination's effect on gastric ulcer models. Therefore, this study aims to investigate the protective effects of metformin and Vit C combination on indomethacin-induced gastric ulcers.

MATERIAL AND METHODS

In total, thirty rats were divided into six groups, including the control group, rats received indomethacin (50 mg/kg, i.p.), rats received indomethacin and pretreated with ranitidine (100 mg/kg), metformin (100 mg/kg, i.p.), Vit C (100 mg/kg), or metformin combined with Vit C. Four hours after indomethacin administration, rats were euthanized, and gastric tissues were removed for macroscopic, histopathologic, and biochemical examinations.

RESULTS

All therapeutics used in this study were found to alleviate gastric mucosal injury caused by indomethacin, as observed in histopathologic and macroscopic evaluations. Both Vit C and metformin were observed to significantly decrease lipid peroxidation and enhance the activity of anti-oxidative enzymes, SOD, GPx, and catalase. However, a more significant effectiveness was observed in catalase and GPx activities when Vit C was co-administered with metformin.

CONCLUSIONS

In conclusion, the present study revealed that metformin and Vit C combination therapy could potentially treat gastric ulcers associated with indomethacin.

Research on the mechanism of Guanyu Zhixie Granule in intervening gastric ulcers in rats based on network pharmacology and multi-omics

Objective

Guanyu Zhixie Granule (GYZXG) is a traditional Chinese medicine compound with definite efficacy in intervening in gastric ulcers (GUs). However, the effect mechanisms on GU are still unclear. This study aimed to explore its mechanism against GU based on amalgamated strategies.

Methods

The comprehensive chemical characterization of the active compounds of GYZXG was conducted using UHPLC-Q/TOF-MS. Based on these results, key targets and action mechanisms were predicted through network pharmacology. GU was then induced in rats using anhydrous ethanol (1 mL/200 g). The intervention effects of GYZXG on GU were evaluated by measuring the inhibition rate of GU, conducting HE staining, and assessing the levels of IL-6, TNF-α, IL-10, IL-4, Pepsin (PP), and epidermal growth factor (EGF). Real-time quantitative PCR (RT-qPCR) was used to verify the mRNA levels of key targets and pathways. Metabolomics, combined with 16S rRNA sequencing, was used to investigate and confirm the action mechanism of GYZXG on GU. The correlation analysis between differential gut microbiota and differential metabolites was conducted using the spearman method.

Results

For the first time, the results showed that nine active ingredients and sixteen targets were confirmed to intervene in GU when using GYZXG. Compared with the model group, GYZXG was found to increase the ulcer inhibition rate in the GYZXG-M group (p < 0.05), reduce the levels of IL-6, TNF-α, PP in gastric tissue, and increase the levels of IL-10, IL-4, and EGF. GYZXG could intervene in GU by regulating serum metabolites such as Glycocholic acid, Epinephrine, Ascorbic acid, and Linoleic acid, and by influencing bile secretion, the HIF-1 signaling pathway, and adipocyte catabolism. Additionally, GYZXG could intervene in GU by altering the gut microbiota diversity and modulating the relative abundance of Bacteroidetes, Bacteroides, Verrucomicrobia, Akkermansia, and Ruminococcus. The differential gut microbiota was strongly associated with serum differential metabolites. KEGG enrichment analysis indicated a significant role of the HIF-1 signaling pathway in GYZXG's intervention on GU. The changes in metabolites within metabolic pathways and the alterations in RELA, HIF1A, and EGF mRNA levels in RT-qPCR experiments provide further confirmation of this result.

Conclusion

GYZXG can intervene in GU induced by anhydrous ethanol in rats by regulating gut microbiota and metabolic disorders, providing a theoretical basis for its use in GU intervention.

Antioxidant Activity, Stability in Aqueous Medium and Molecular Docking/Dynamics Study of 6-Amino- and N-Methyl-6-amino-L-ascorbic Acid

The antioxidant activity and chemical stability of 6-amino-6-deoxy-L-ascorbic acid (D1) and N-methyl-6-amino-6-deoxy-L-ascorbic acid (D2) were examined with ABTS and DPPH assays and compared with the reference L-ascorbic acid (AA). In addition, the optimal storing conditions, as well as the pH at which the amino derivatives maintain stability, were determined using mass spectrometry. Comparable antioxidant activities were observed for NH-bioisosteres and AA. Moreover, D1 showed higher stability in an acidic medium than the parent AA. In addition, AA, D1, and D2 share the same docking profile, with wild-type human peroxiredoxin as a model system. Their docking scores are similar to those of dithiothreitol (DTT). This suggests a similar binding affinity to the human peroxiredoxin binding site.

Ascorbic acid as antioxidant

Ascorbic acid, as one of the basic exogenous vitamins, is known for its tremendous antioxidant properties. This review has been prepared to show not only the importance of ascorbic acid as a free radical scavenger, but also to summarize its antioxidant action based on other mechanisms, including activation of intracellular antioxidant systems. Ascorbic acid interacts with small molecule antioxidants, including tocopherol, glutathione and thioredoxin, but also can stimulate the biosynthesis and activation of antioxidant enzymes, such as superoxide dismutase, catalase or glutathione peroxidase. Moreover, ascorbic acid promotes the activity of several transcription factors (Nrf2, Ref-1, AP-1), which enables the expression of genes encoding antioxidant proteins. Additionally, it supports the action of other exogenous antioxidants, mainly polyphenols. In this connection, both DNA, protein and lipids are protected against oxidation. Although ascorbic acid has strong antioxidant properties, it can also have pro-oxidant effects in the presence of free transition metals. However, its role in prevention of DNA mutation and cellular apoptosis, especially in relation to cancer cells is controversial.

Antioxidative and Anti-Inflammatory Activity of Ascorbic Acid

Ascorbic acid, as a one of the basic exogenous vitamins, occurs in the body in the form of ascorbate, known for its strong antioxidant and anti-inflammatory properties. The presented review shows not only the importance of ascorbate as a free radical scavenger but also summarizes its antioxidant action based on other mechanisms, including the activation of intracellular antioxidant systems and its effect on the NFκB/TNFα pathway and apoptosis. Ascorbate interacts with small-molecule antioxidants, including tocopherol, glutathione, and thioredoxin; it can also stimulate biosynthesis and the activation of antioxidant enzymes, such as superoxide dismutase, catalase, or glutathione peroxidase. Moreover, ascorbate promotes the activity of transcription factors (Nrf2, Ref-1, AP-1), which enables the expression of genes encoding antioxidant proteins. Additionally, it supports the action of other exogenous antioxidants, mainly polyphenols. In this regard, both DNA, proteins, and lipids are protected against oxidation, leading to an inflammatory reaction and even cell death. Although ascorbate has strong antioxidant properties, it can also have pro-oxidant effects in the presence of free transition metals. However, its role in the prevention of DNA mutation, inflammation, and cell apoptosis, especially in relation to cancer cells, is controversial.

Profiling of secondary metabolites and DNA typing of three different Annona cultivars grown in Egypt

OBJECTIVES

Natural products are often efficacious and safe alternatives to synthetic drugs. This study explored secondary leaves and bark metabolites profiles in extracts of a new Egyptian hybrid, Annona cherimola × Annona squamosa, known as Abdel Razek. This hybrid exhibited 100% similarity with A. cherimola as evidenced by random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) analyses.

METHODS

Primary constituents in methanol extracts of different plant organs were identified. Extracts richest in alkaloids and polyphenolics were assessed for in vitro antioxidant activity and the most potent were further studied in vivo for treating gastric ulcer in rats. The latter activity was assessed histopathologically.

RESULTS

Structural analysis with HPLC/ESI-MSⁿ, and UPLC/HESI-MS/MS identified 63 metabolites, including seven amino acids, 20 alkaloids, 16 flavonoids, eight phenolics and other compounds. Severe stomach alteration was observed after ethanol induction in rats. Ulcer score, oxidative stress biomarkers, cell organelles biomarker enzymes, and gastrointestinal histological features improved to variable degrees after treatment with Annona Abdel Razek hybrid leaves and bark methanol extracts.

CONCLUSION

Extracts of Annona Abdel Razek had showed in vitro antioxidant effect and may be promising for the treatment of gastric ulcers.

Dietary Pomegranate By-Product Alleviated the Oxidative Stress Induced by Dexamethasone in Laying Hens in the Pre-Peak Period

Simple Summary

The present work was designed to maximize an agro-industrial by-products’ benefits in an environmentally safe manner. This study explores the antioxidative effects of pomegranate peels as dietary additives on the performance of laying hens in the pre-peak period under oxidative stress induced by dexamethasone. Pomegranate peel powder was included at 2% and 4% in the diets of laying hens exposed to oxidative stress induced by dexamethasone compared with negative and positive control groups for 12 weeks. Based on the obtained results, the current study recommends the possibility of using dietary pomegranate peels up to 4% not only for alleviating the adverse effects of oxidative stress in the pre-peak laying period but also as a sustainable and economical approach for agricultural development.

Abstract

This experiment was conducted to assess the inclusion of the by-products of pomegranate peels to ameliorate the harmful impacts of oxidative stress in the pre-peak period of laying hens. For this, 120 local Egyptian strain hens (Inshas hens) aged 24 weeks old were used in four treatments. Pomegranate peel powder was included at 2% and 4% in the diets of laying hens subjected to oxidative injuries induced by dexamethasone compared with negative and positive control groups for 12 weeks. The addition of pomegranate peel powder (PPP) reduced the adverse effects of oxidative stress induced by dexamethasone on body weight (p = 0.006) and egg production (p = 0.010) comparing to the positive control. Additionally, pomegranate peel powder had a significant positive lowering effect on plasma cholesterol (p < 0.001) and triglyceride contents (p = 0.005) compared to control groups. The lipid peroxidation indicators (MDA) were reduced, but the antioxidative enzymes (SOD, CAT, and GPx) and total antioxidant blood capacity were improved with PPP. Based on the obtained data, the present research recommends using dietary PPP up to 4% to mitigate adverse oxidative stress effects in the pre-peak laying period and as a sustainable and economical approach for agricultural development.

Therapeutic and Preventive Effects of Olea europaea Extract on Indomethacin-Induced Small Intestinal Injury Model in Rats

Background

Olea europaea (known as olive fruit) has anti-inflammatory and antioxidant activities and many potential health benefits including gastric inflammation reduction has been shown previously. This study aimed to investigate the preventive and therapeutic effects of O. europaea extract on the early histological changes in indomethacin-induced small intestinal injury model with the plasma D-lactate concentration being measured as a tool for determination of intestinal permeability.

Methods

In this experimental study, two separate protective and therapeutic protocols were designed. In both experiments, male Wistar rats were randomly divided into 4 groups and either pretreated with 0, 100, 200, or 400 mg/kg/day of O. europaea extract or received the treatment after administration of indomethacin. Their small intestines were examined to compare the histological changes. The intestinal injury severity was evaluated according to the presence of eosinophils, plasma cell infiltration, edema, congestion, and hyperplasia of the crypt using a histological scoring system. Also, measured were the presence of neutrophils, decreased villus length-to-crypt depth ratio, and destructed villus architecture. The plasma concentration of D-lactate was measured as well.

Results

The therapeutic use of O. europaea decreased the eosinophil, edema, congestion, and crypt hyperplasia scores compared to the control group. Although no significant difference was seen between groups of the preventive experiment in plasma cell infiltration score, villus length-to-crypt depth ratio, neutrophil infiltration, and percentage of destructed villus architecture, treatment with O. europaea caused a reduction in edema, eosinophil, congestion, and crypt hyperplasia score. In both experiments, no significant difference was seen between groups for villus length-to-crypt depth ratio, neutrophil infiltration, and percentage of destructed villus architecture. Plasma D-lactate concentration was decreased in all O. europaea-treated groups compared to the control group in the therapeutic and preventive experiments (p < 0.01, one-way ANOVA followed by the Dunnett test).

Conclusion

O. europaea extract can be used to decrease some side effects of indomethacin on intestinal tissue and enhances the gastrointestinal function. O. europaea extract could be considered as a potential herbal supplement in the treatment of intestinal morphological injuries.

Evaluation of the antiulcer activity of the aqueous stem bark extract of Balanites aegyptiaca L Delile in Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Balanites aegyptiaca L. Delile (Zygophyllaceae) is a perennial tree that is mostly found in Africa, south Asia and most desert environments. Decoctions of its stem barks are used in northern Nigeria for the treatment of ulcers and stomach issues. Other folkloric uses include treatment of wounds, malaria, dysentery, asthma, and fever.

AIM OF THE STUDY

The present study evaluated the antiulcer activity of the aqueous stem bark extract of Balanites aegyptiaca in Wistar rats.

MATERIALS AND METHODS

The antiulcer activity of the aqueous stem bark extract of Balanites aegyptiaca (125, 250 and 500 mg/kg, p.o.) was evaluated in ethanol, indomethacin, pylorus ligation and acetic acid-induced ulcer models in rats. Parameters such as mean ulcer indices and percentage ulcer inhibition were assessed in ethanol, indomethacin and acetic acid-induced ulcer models while gastric volume, pH, and titratable acidity were evaluated in the pylorus ligation ulcer model.

RESULTS

The extract at the doses of 125, 250 and 500 mg/kg caused a significant (p < 0.01), dose dependent reduction in mean ulcer indices in the ethanol and indomethacin ulcer models. A significant dose dependent reduction in mean ulcer indices were also observed after three (p < 0.01) and seven (p < 0.001) days of treatment with the extract in acetic acid-induced ulcer model. In pylorus ligation model, the gastric secretion parameters (gastric volume, pH, and titratable acidity) showed no alteration in the different doses of the extract when compared to the control.

CONCLUSION

Our study showed that the aqueous stem bark extract of Balanites aegyptiaca possesses gastroprotective and ulcer healing properties and therefore not only provides scientific evidence for its folkloric use in the treatment of ulcers but also showed evidence that it may be used in the development of a new phytotherapeutic formulation for the treatment of peptic ulcer.

The effects of vitamins and selenium mixture or ranitidine against small intestinal injury induced by indomethacin in adult rats

This study was aimed at investigating morphological and biochemical efficacies of antioxidants on indomethacin-induced small intestinal damage in rats. Group I: control animals (negative control) given only placebo, Group II: (positive control) are animals orally given combination of antioxidants [vitamin C (Vit C), vitamin E (Vit E), β-carotene and sodium selenite (Se)] daily for 3 days, Group III: Rats were given only indomethacin, Group IV: animals were given of antioxidants combination for 3 days, last dose was given 2 hr before the administration of indomethacin. Group V: Animals receiving ranitidine for 3 days (second positive control). Group VI: Animals received ranitidine for 3 days, last dose was given 2 hr before to indomethacin administration. Indomethacin caused degenerative morphological and biochemical changes, which were reversed on antioxidants administration. As a result, we propose that antioxidants combination would be therapeutically beneficial for treating indomethacin-induced lesions of small intestine. PRACTICAL APPLICATIONS: Indomethacin is a widely preferred nonsteroidal anti-inflammatory drug (NSAID) but its side effects on gastrointestinal system are well known. Indomethacin also causes production of reactive oxygen species. Antioxidants and selenium has protective effects. According to the results of this study, antioxidants and selenium can be used as a food supplement for preventing NSAID-induced side effects and toxicity.

Chemical composition and protective role of Pulicaria undulata (L.) C.A. Mey. subsp. undulata against gastric ulcer induced by ethanol in rats

Pulicaria undulata subsp. undulata (Family; Asteraceae) is a medicinal plant used to treat inflammation. The objective of this study is to explore the protective effect of the ethanol extract of P. undulata subsp. undulata aerial parts against ethanol induced gastric ulcer in rats. The chemical composition of plant extract, the unsaponifiable matter and the fatty acid methyl esters were analyzed. The biological evaluation was carried out through measuring ulcer indices, oxidative stress markers, certain marker enzymes, inflammatory index and the histopathological assessment of the stomach in rats. The total unsaponifiable matter (94.29%) and the fatty acid methyl ester (82.96%) content were identified. Gastric ulcer recorded significant increase in gastric volume and lesion counts (p < 0.0001). Drastic changes in all biochemical parameters under investigation were observed. Protection with plant extract reversed the action of ethanol by variable degrees of improvement in comparison with the reference drug. The presence of carbohydrates and proteins that acted as a mucilage lining the stomach inner wall give its protective action. In conclusion, P. undulata subsp. undulata succeeded to have anti-ulcerative protective effect. The measured biomarkers served as a good mirror to predict gastric ulcer and the presence of carbohydrates, protein and fibers present in the plant extract acted as a mucilage lining the inner intestinal wall and protect against ethanol induced gastric ulcer. Future study will be carried out to identify the biologically active compounds responsible for plant protection against the gastric ulcer.

Apple Polyphenol Suppresses Indomethacin-Induced Gastric Damage in Experimental Animals by Lowering Oxidative Stress Status and Modulating the MAPK Signaling Pathway

Indomethacin is a nonsteroid anti-inflammatory drug (NSAID) that is used to alleviate pain and inflammation in clinical medicine. Previous studies indicated that NSAIDs can cause gastrointestinal mucosal complications, and it is associated with mucosal lipid peroxidation and oxidative damage. Based on the evidences, decreasing oxidative stress may be an ideal therapeutic strategy for preventing gastrointestinal ulcer. Apple (Rosaceae Malus sp.) is one of the most commonly consumed fruits worldwide. The abundant polyphenolic constituents have received increasing attention for decades. In both in vivo and in vitro studies, the reports showed that apple polyphenol (AP) seems to provide an indirect antioxidant protection by activating cellular antioxidant enzymes to defend against oxidative stress. To address this issue and develop AP into a healthy improvement supplement, we studied the effect and potential mechanisms of AP in indomethacin-treated animal. The results showed AP can decelerate the gastric lesion, significantly suppress lipid peroxidation, increase the level of glutathione and the activity of catalase, and regulate the MAPK signaling proteins. These findings imply that AP protects the gastric mucosa from indomethacin-caused lesions and the protection is at least partially attributable to its antioxidative properties. This alternative medical function of AP may be a safe and effective intervention for preventing indomethacin-induced gastric complications.

The aqueous extract from Artemisia capillaris inhibits acute gastric mucosal injury by inhibition of ROS and NF-kB

Artemisia capillaris, also called "InJin" in Korean, has been used as traditional oriental medicine in Korea because of its various pharmacological activities. These include hepatoprotective, analgesic, and antipyretic activities. The present study was designed to validate the beneficial effects of the aqueous extract of A. capillaris (AEAC) against acute gastric mucosal injury and investigate the underlying molecular mechanisms. The pharmacological efficacy of AEAC was evaluated using the gastric ulcer index and histological examination. AEAC decreased gastric mucosal lesions mediated by HCl/ethanol in vivo in a dose-dependent manner. Interestingly, the mucosal damage was almost prevented by pretreatment with 200 or 400?mg/kg AEAC. However, AEAC did not have acid-neutralizing activity in vitro and did not prevent histamine secretion in HMC-1 mast cells. In the gastric mucosa, AEAC also significantly inhibited lipid peroxide formation through superoxide dismutase (SOD) activation. Moreover, AEAC strongly reduced the generation of pro-inflammatory cytokines, such as interleukin-6 (IL-6) and interleukin-1? (IL-1?), through nuclear factor kappa B (NF-?B) downregulation. Taken together, our findings suggest that AEAC inhibits inflammation and maintains oxidant/antioxidant homeostasis, resulting in a gastro-protective effect against HCl/ethanol-induced gastric damage. Therefore, AEAC might be a promising drug or useful neutraceutical for treatment of gastritis and gastric ulcer.

Evaluation of the antioxidant and gastroprotective activity and HPLC analysis of the hydroalcoholic extract of Tocoyena formosa leaves (Cham. & Schlecht) K. Schum

The peptic ulcer is a gastric disorder that affects millions of people and yet they cause many side effects. In this sense, natural products represent an important alternative to the discovery of compounds with gastroprotective activity. The present work has as its objective to evaluate the antioxidant and gastroprotective activity of the Hydroalcoholic Extract of Leaves from Tocoyena formosa (Cham. & Schlecht.) K. Schum (HELTF), this being much emphasized in traditional medicine for inflammatory morbidities and gastric symptoms. For the evaluation of the antioxidant activity, FRAP and DPPH tests were carried out, and for the evaluation of the gastroprotective activity, gastric lesion induction by ethanol, acidified ethanol, indomethacin and physical barrier tests were used. Antioxidant assay of HELTF revealed an EC50 of 558.66 μM FeSO4/g and IC50 of 189.78 μg/ml for FRAP and DPPH respectively. In gastroprotective, in ethanol model, all the doses presented significant activity in comparison to controls, however, in the gastric lesion induction test by acidified ethanol and indomethacin, only the dose of 200 mg/kg presented with significance. In the physical barrier test presented evidence that protection by the formation of a protective layer associated with mucus. Concluded, therefore, that HELTF possesses antioxidant and significate gastroprotective activity.

Evidence of gastric ulcer healing activity of Maytenus robusta Reissek: In vitro and in vivo studies

ETHNOPHARMACOLOGICAL RELEVANCE

Maytenus robusta Reissek (Celastraceae) is traditionally used in Brazilian folk medicine to treat gastric ulcer, as a substitute for M. ilicifolia, which is almost extinct. The gastroprotective properties of M. robusta were demonstrated previously using only preventive approaches, such as acute gastric ulcer models. However, the healing effect of M. robusta in gastric ulcers remains unclear.

AIM OF THE STUDY

The current study was carried out to investigate the healing effectiveness of M. robusta hydroalcoholic extract (HEMR) from aerial parts in the acetic acid-induced chronic ulcer model and to determine its effect on cell proliferation, scavenging free radicals, and inflammatory and oxidative damage.

MATERIAL AND METHODS

To evaluate the healing properties of HEMR in vivo, chronic gastric ulcer was induced in rats by 80% acid acetic. Next, different groups of animals (n=6) were treated orally with vehicle (water plus 1% tween, 1 ml/kg), omeprazole (20mg/kg), or HEMR (1-10mg/kg), twice daily for 7 days. At the end of the treatment, the total ulcer area (mm(2)) was measured and a sample of gastric tissue was taken for histological and histochemical analysis. Evaluation of GSH and LOOH levels, GST, SOD, CAT and MPO activity was also performed at the site of the lesion. In parallel, radical scavenging activity, cytoprotective effect, and cell proliferation activity in fibroblasts (L929 cells) were determined by in vitro trials. The antisecretory properties were evaluated using the pylorus ligature model in rats, and the anti-Helicobacter pylori activity was determined in vitro. Acute toxicity was evaluated by relative organ weight and biochemical parameters in serum. The prokinetic properties were also evaluated in mice.

RESULTS

Oral administration of HEMR (10mg/kg) reduced the gastric ulcer area by 53%, compared to the vehicle group (120.0 ± 8.3mm(2)), the regeneration of gastric mucosa was evidenced in histological analysis. Moreover, HEMR treatment increased gastric mucin content and reduced oxidative stress and inflammatory parameters at the site of the ulcer. In vitro, HEMR (1-1000 µg/ml) was able to scavenge free radical DPPH and promote cytoprotection against H2O2 in fibroblasts at 0.1-100 µg/ml. Moreover, HEMR healing properties also were confirmed by enhancement of proliferation and coverage of scratched wounds in fibroblast monolayer. However, HEMR (10mg/kg) by the intraduodenal route did not promote changes in volume, pH, total acidity or pepsin activity in the pylorus ligature model, and HEMR up to 2000 µg/ml also did not present considerable activity against H. pylori. In relation to gastrointestinal motility, HEMR (10mg/kg, p.o) did not provoke alterations. It is also important to mention that oral administration of HEMR did not produce any sign of acute toxicity in animals.

CONCLUSIONS

The data here obtained show that M. robusta has evident ulcer healing potential, mainly through the strengthening of protective factors of gastric mucosa, such as mucus layer, antioxidant defenses and cell proliferation. Taking into account the advantages of cultivation and harvesting of M. robusta compared to M. ilicifolia, and the evidence presented here, it is plausible to conclude that hydroalcoholic extract obtained from aerial parts of M. robusta is an interesting source for the development of a phytotherapeutic formulation to treat gastric ulcer.

Melatonin is more effective than ascorbic acid and β-carotene in improvement of gastric mucosal damage induced by intensive stress

INTRODUCTION

Oxidative stress has been considered to play a primary role in the pathogenesis of stress-induced gastric damage. The aim of this study was to investigate the effects of melatonin, ascorbic acid and β-carotene on stress-induced gastric mucosal damage.

MATERIAL AND METHODS

Fifty-six male Wistar albino rats were divided into control, stress, stress + standard diet, stress + saline, stress + melatonin, stress + ascorbic acid and stress + β-carotene groups. The rats from stress groups were exposed to starvation, immobilization and cold by immobilizing for 8 h at +4°C following 72-hour food restriction. Following stress application, melatonin, ascorbic acid and β-carotene were administered for 7 days. Specimens of gastric tissue were prepared for microscopic and biochemical examinations.

RESULTS

Mean histopathological damage scores and mean tissue malondialdehyde levels were significantly decreased but mean tissue glutathione levels and glutathione peroxidase and superoxide dismutase activities were increased in treatment groups vs. stress groups in general. Mean histopathological damage scores of the stress + Mel group was lower than those of stress + D, stress + S, stress + β-car (p < 0.05) and stress + Asc groups (p < 0.005). Additionally, mean tissue catalase activity of the stress + Mel group was higher than that of stress + S (p < 0.005), stress + D (p < 0.05) and stress + β-car groups (p < 0.05).

CONCLUSIONS

Melatonin is more effective than ascorbic acid and β-carotene in improvement of gastric damage induced by intensive stress. We suggest that as well as the direct antioxidant and free radical scavenging potency of melatonin, its indirect effect via the brain-gut axis might account for its greater beneficial action against stress-induced gastric damage.

Evaluation of combined famotidine with quercetin for the treatment of peptic ulcer: in vivo animal study

The aim of this work was to prepare a combined drug dosage form of famotidine (FAM) and quercetin (QRT) to augment treatment of gastric ulcer. FAM was prepared as freeze-dried floating alginate beads using ion gelation method and then coated with Eudragit RL100 to sustain FAM release. QRT was prepared as solid dispersion with polyvinyl pyrrolidone K30 to improve its solubility. Photo images and scanning electron microscope images of the prepared beads were carried out to detect floating behavior and to reveal surface and core shape of the prepared beads. Anti-ulcerogenic effect and histopathological examination of gastric tissues were carried out to investigate the effect of the combined drug formulation compared with commercial FAM tablets and FAM beads. Gastric glutathione (GSH), superoxide dismutase, catalase, tissue myeloperoxidase, and lipid peroxidation enzyme activities and levels in rat stomach tissues were also determined. Results revealed that spherical beads were formed with an average diameter of 1.64±0.33 mm. They floated immediately with no lag time before floating, and remained buoyant throughout the test period. Treatment with a combination of FAM beads plus QRT showed the absence of any signs of inflammation or hemorrhage, and significantly prevented the indomethacin-induced decrease in GSH levels (P<0.05) with regain of normal GSH gastric tissue levels. Also, there was a significant difference in the decrease of malondialdehyde level compared to FAM commercial tablets or beads alone (P<0.05). The combined formula significantly improved the myeloperoxidase level compared to both the disease control group and commercial FAM tablet-treated group (P<0.05). Formulation of FAM as floating beads in combination with solid dispersion of QRT improved the anti-ulcer activity compared to commercially available tablets, which reveals a promising application for treatment of peptic ulcer.

Water-soluble vitamin deficiencies in complicated peptic ulcer patients soon after ulcer onset in Japan

We investigated over time whether contemporary Japanese patients with complicated peptic ulcers have any water-soluble vitamin deficiencies soon after the onset of the complicated peptic ulcers. In this prospective cohort study, fasting serum levels of water-soluble vitamins (vitamins B1, B2, B6, B12, C, and folic acid) and homocysteine were measured at 3 time points (at admission, hospital discharge, and 3 mo after hospital discharge). Among the 20 patients who were enrolled in the study, 10 consecutive patients who completed measurements at all 3 time points were analyzed. The proportion of patients in whom any of the serum water-soluble vitamins that we examined were deficient was as high as 80% at admission, and remained at 70% at discharge. The proportion of patients with vitamin B6 deficiency was significantly higher at admission and discharge (50% and 60%, respectively, p<0.05) than at 3 mo after discharge (10%). In conclusion, most patients with complicated peptic ulcers may have a deficiency of one or more water-soluble vitamins in the early phase of the disease after the onset of ulcer complications, even in a contemporary Japanese population.

Meat quality of heat stress exposed broilers and effect of protein and vitamin E

1. This study was designed to determine the effects of heat stress exposure on broiler fattening performance, meat quality and microbial counts. 2. Six groups were established: CHP (24°C+210 g/kg crude protein (CP)), SHP (34°C+210 g/kg CP), CLP (24°C+190 g/kg CP), SLP (34°C+190 g/kg CP), SHPVE (34°C+210 g/kg CP+Vitamin E) and SLPVE (34°C+190 g/kg CP+Vitamin E) groups. 3. It was determined that the body weights of the male animals included in Group CHP displayed statistically significant differences in comparison to those of Groups SHP, CLP and SLP. Furthermore, it was ascertained that the values of Group CLP also displayed statistically significant differences in comparison to those of Groups CHP, SHP and SLP. The feed consumptions in Groups CHP and CLP were significantly different from those of the remaining groups, excluding Group SHP. The highest feed conversion rate was determined in Group SHPVE. 4. When evaluated for chicken drumstick TBA values, Group CHP differed significantly from Groups SHP, SHPVE, CLP and SLP, whilst Group CLP differed significantly from Groups SHP, SHPVE and SLP. On the other hand, when evaluated for breast meat TBA values, Group CHP displayed statistically significant differences in comparison to Groups SHP, SLP and SLPVE, whilst Group CLP differed significantly from Groups CHP, SHP, SLP and SLPVE. 5. The sensitivity of breast meat to colour susceptibility was greater than that of chicken drumsticks. While storage period affected the TBA values and microbial counts of meat significantly, its effect on colour parameters was found to be variable. Trial groups significantly affected total aerobic mesophilic bacteria counts in chicken drumsticks, and Enterobacteriaceae and total aerobic mesophilic bacteria counts in breast meat. 6. In conclusion, heat stress adversely affected final body weights and the lipid oxidation of meat, whilst vitamin E alleviated these adverse effects.

Alpha-lipoic acid protects against indomethacin-induced gastric oxidative toxicity by modulating antioxidant system

Gastroprotective effects of α-lipoic acid (ALA) against oxidative gastric damage induced by indomethacin (IND) have been investigated. All doses (50, 75, 100, 150, 200, and 300 mg/kg body weight) of ALA reduced the ulcer index with 88.2% to 96.1% inhibition ratio. In biochemical analyses of stomach tissues, ALA administration decreased the level of lipid peroxidation (LPO) and activities of myeloperoxidase (MPO) and catalase (CAT) in gastric tissues, which were increased after IND application. ALA also increased the level of glutathione (GSH) and activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) that were decreased in gastric damaged stomach tissues. In conclusion, the gastroprotective effect of ALA could be attributed to its ameliorating effect on the antioxidant defense systems.

Gastric ulceration in diabetes mellitus: protective role of vitamin C

The effect of vitamin C administration on gastric acid secretion and ulcer in diabetic rats was studied. Vitamin C (200 mg/kg b.w.) was administered to both streptozotocin-induced diabetic and control groups orally for 28 days. Gastric acid secretion was measured and ulcer was induced using ethanol. Histological changes were observed in the stomach. Basal and stimulated acid secretion in diabetic control rat was significantly (P < 0.01) decreased when compared to vitamin C-treated diabetic group and control. Administration of vitamin C significantly (P < 0.05) increased the histamine-stimulated gastric acid secretion in diabetics than control while reduction in gastric secretion by ranitidine was similar compared with control. Vitamin C treatment significantly (P < 0.05) reduced ulcer index in diabetic group and increased mucus weight when compared with diabetic group which was also confirmed with photomicrographs. The mean body weight of diabetic rats treated with vitamin C was comparable to the control. The blood glucose level was significantly (P < 0.01) reduced in diabetic group given vitamin C (8.9 ± 1.8 mMol/L) compared to the diabetic control (32.2 ± 2.1 g). It is concluded that vitamin C is beneficial in improving gastric acid secretion and protects against ulceration in streptozotocin-induced diabetes mellitus in rats due to its antioxidant potential.

2,3-Dimercaptopropanol, a thiol chelator, alleviates gastroduodenal ulcers in rats

Earlier studies have implicated reactive oxygen species and transitional metals in the pathogenesis of gastric lesions. In this study, we have evaluated the effect of 2,3-dimercaptopropanol (DMP), a thiol compound and metal chelator, on chemically induced gastroduodenal ulcers in rats. Acid secretion studies were undertaken using pylorus-ligated rats pretreated with DMP (3-100 mg/kg, i.p.). The effect of orally administered DMP on cysteamine-induced duodenal ulcers and ethanol-induced gastric ulcers was also tested. The level of nonprotein sulfhydryls (NP-SH) and gastric wall mucus was measured in the glandular stomach of rats treated with ethanol. None of the dose of DMP affected the volume or acidity of gastric secretion. Low doses of DMP (3 and 10 mg/kg) significantly reduced cysteamine-induced duodenal ulcers, whereas the high doses (30 and 100 mg/kg) were ineffective in this model. All the doses of DMP significantly and dose dependently attenuated ethanol-induced gastric lesions. The adverse effects of ethanol on gastric wall mucus and NP-SH were significantly and dose dependently reversed by DMP. In conclusion, the protective effects of DMP appear to be independent of gastric acid secretion and may be associated with counteracting the oxidative stress by replenishing glutathione and reducing the pool of transition metals.

Protective effect of a cysteine prodrug and antioxidant, L-2-oxothiazolidine-4-carboxylate, against ethanol-induced gastric lesions in rats

Earlier studies have suggested an important role of glutathione (GSH) in cytoprotection against free radicals induced oxidative damage. This study reports gastroprotective effects of a cysteine precursor, L-2-oxothiazolidine-4-carboxylate (OTC), in experimental models of gastric secretion and ulceration. Acid secretion studies (volume and acidity) were undertaken in pylorus-ligated rats whereas the gastric lesions were induced by ethanol. Different groups of animals were treated with OTC (0, 100, 200 and 400 mg/kg). The levels of gastric wall mucus, nonprotein sulfhydryls (NP-SH) and myeloperoxidase (MPO) were measured in the glandular stomach of rats following ethanol-induced gastric lesions. Both medium and high doses of OTC significantly reduced the volume and acidity of gastric secretion in pylorus-ligated rats. Pretreatment with OTC significantly and dose-dependently attenuated the formation of ethanol-induced gastric lesion. OTC significantly protected the gastric mucosa against ethanol-induced depletion of gastric wall mucus, NP-SH and MPO. The gastroprotective effects of OTC may be attributed to its ability to inhibit neutrophils activity and replenish GSH demand.

Mammary carcinogen-protein binding potentials: novel and biologically relevant structure-activity relationship model descriptors

Previously, SAR models for carcinogenesis used descriptors that are essentially chemical descriptors. Herein we report the development of models with the cat-SAR expert system using biological descriptors (i.e., ligand-receptor interactions) rat mammary carcinogens. These new descriptors are derived from the virtual screening for ligand-receptor interactions of carcinogens, non-carcinogens, and mammary carcinogens to a set of 5494 target proteins. Leave-one-out validations of the ligand mammary carcinogen-non-carcinogen model had a concordance between experimental and predicted results of 71%, and the mammary carcinogen-non-mammary carcinogen model was 72% concordant. The development of a hybrid fragment-ligand model improved the concordances to 85 and 83%, respectively. In a separate external validation exercise, hybrid fragment-ligand models had concordances of 81 and 76%. Analyses of example rat mammary carcinogens including the food mutagen and oestrogenic compound PhIP, the herbicide atrazine, and the drug indomethacin; the ligand model identified a number of proteins associated with each compound that had previously been referenced in Medline in conjunction with the test chemical and separately with association to breast cancer. This new modelling approach can enhance model predictivity and help bridge the gap between chemical structure and carcinogenic activity by descriptors that are related to biological targets.

Gastroprotective and antioxidant effects of opipramol on indomethacin-induced ulcers in rats

Tricyclic antidepressants are particularly useful in the treatment of endogenous depression. Since the 1950s, tricyclic antidepressants (TCAs) have also been used for the treatment of gastric ulcer disease. Many TCAs have been evaluated for their antiulcer effects, but there are presently no data in the literature specifically concerning the antidepressant opipramol. This study aimed to investigate the antiulcer effects of opipramol and to determine its potential relationship with oxidant and antioxidant systems. The antiulcer activities of 25, 50 and 100 mg/kg opipramol have been investigated on indomethacin-induced ulcers in rats. Compared with a control group (indomethacin alone), opipramol decreased indomethacin-induced ulcers significantly at all doses used (52%, 71% and 76% respectively). Opipramol also significantly increased the glutathione (GSH), superoxide dismutase (SOD) and nitric oxide (NO) levels in the stomach tissue, all of which were decreased in the control group given only indomethacin. All doses of opipramol also significantly decreased myeloperoxidase (MPO), malondialdehyde (MDA) and catalase (CAT) levels in stomach tissue compared to the control. In conclusion, the activation of enzymatic and non-enzymatic antioxidant mechanisms, as well as the inhibition of some toxic oxidant mechanisms, appear to play a role in the antiulcer effect of opipramol. This new indication for opipramol prompts a rethinking about the possible clinical application of opipramol, particularly for peptic ulcer patients also presenting depression.