Effect of carbenoxolone sodium on human gastric acid secretion

Glass box machine learning for retrospective cohort studies using many patient records. The complex example of bleeding peptic ulcer

Glass Box Machine Learning is, in this study, a type of partially supervised data mining and prediction technique, like a neural network in which each weight or pattern of mutually relevant weights is now replaced by a meaningful "probabilistic knowledge element." We apply it to retrospective cohort studies using large numbers of structured medical records to help select candidate patients for future cohort studies and similar clinical trials. Here it is applied to aid analysis of approaches to aid Deep Learning, but the method lends itself well to direct computation of odds with "explainability" in study design that can complement "Black Box" Deep Learning. Cohort studies and clinical trials traditionally involved at least one 2 × 2 contingency table, but in the age of emerging personalized medicine and the use of machine learning to discover and incorporate further relevant factors, these tables can extend into many extra dimensions as a 2 × 2 x 2 × 2 x ….data structure by considering different conditional demographic and clinical factors of a patient or group, as well as variations in treatment. We consider this in terms of multiple 2 × 2 x 2 data substructures where each one is summarized by an appropriate measure of risk and success called DOR*. This is the diagnostic odds ratio DOR for a specified disease conditional on a favorable outcome divided by the corresponding DOR conditional on an unfavorable outcome. Bleeding peptic ulcer was chosen as a complex disease with many influencing factors, one that is still subject to controversy and that highlights the challenges of using Real World Data.

What is the possible therapeutic effect of Ginkgo biloba on gastric ulcer induced by ammonia in albino rats?

Gastric ulcer is a worldwide disease. Helicobacter pylori is one of the most common chronic bacterial infections that induce chronic inflammation in the gastric mucosa, mediated by an array of pro-and inflammatory cytokines. The aim of this study was to investigate the possible therapeutic effects of Ginkgo biloba extract on gastric ulcer induced by ammonium hydroxide in rats and the potential underlying mechanisms. The study was done on 32 adult male Wistar albino rats, divided equally into 4 groups: normal control, gastric ulcer-induced group using 1 ml of 1% NH₄OH orally, ulcer control group; rats received 1% carboxymethyl cellulose daily for 14 days after induction of ulcer and treated rats received orally 200 mg/kg Ginkgo biloba once daily for 14 days after induction of ulcer. The study revealed administration of ammonia showed multiple gastric lesions; edema, hyperemia, hemorrhage, and ulcers with a significant increase in ulcer score, myeloperoxidase (MPO), and interleukin-1β (IL-1β) and a significant decrease in reduced glutathione (GSH), mucus amount, and gastric pH. After the administration of Ginkgo biloba, there was an improvement in gastric lesions, with a significant reduction of ulcer score, MPO, and IL-1β and a significant increase in GSH, mucus content, and gastric pH. Moreover, collagen types I and IV were gradually increased in the treated group.

Ulcer healing and mechanism(s) of action involved in the gastroprotective activity of fractions obtained from Syngonanthus arthrotrichus and Syngonanthus bisulcatus

Background

Syngonanthus arthrotrichus and Syngonanthus bisulcatus, currently known for Comanthera aciphylla (Bong.) L.R.Parra & Giul. and Comanthera bisulcata (Koern.) L.R. Parra & Giul, popularly known in Brazil as “sempre-vivas,” are plants from the family Eriocaulaceae. They are found in the states of Minas Gerais and Bahia. The species are known to be rich in flavonoids to which their gastroprotective activity has been attributed. In this research, experimental protocols were performed to elucidate the associated mechanisms of action.

Methods

The activity was evaluated using induced gastric ulcer models (acetic acid and ethanol-induced gastric lesions in NEM or L-NAME pre-treated mice, and by ischemia/reperfusion). Antioxidant enzymes, serum somatostatin, and gastrin were also evaluated.

Results

In chronic gastric ulcers, a single daily oral dose of Sa-FRF or Sb-FRF (100 mg/kg body wt.) for 14 consecutive days accelerated ulcer healing to an extent similar to that seen with an equal dose of cimetidine. The pre-treatment of mice with NEM (N-ethylmaleimide) or L-NAME (N-nitro-L-arginine) abolished the protective activity of Sa-FRF, Sa-FDF, Sb-FDF and Sb-FRF or Sa-FRF and Sb-FRF, respectively, which indicates that antioxidant compounds and nitric oxide synthase activity are involved in the gastroprotective. Sa-FRF and Sb-FRF (100 mg/kg p.o) protected the gastric mucosa against ulceration that was induced by ischemia/reperfusion (72 and 76 %, respectively). It also decreased lipid peroxidation and restored total thiols in the gastric wall of mice that had been treated with ethanol. When administered to rats submitted to ethanol-induced gastric lesions, Sa-FRF and Sb-FRF (100 mg/kg, p.o.) increased the somatostatin serum levels, while the gastrin serum levels were proportionally decreased.

Conclusions

The results indicate significant healing effects and gastroprotective activity for the Sa-FRF and Sb-FRF, which probably involves the participation of SH groups, nitric oxide (NO), the antioxidant system, somatostatin, and gastrin. All are integral parts of the gastrointestinal mucosa’s cytoprotective mechanisms against aggressive factors.

Assessment of some Herbal Drugs for Prophylaxis of Peptic Ulcer

Aqueous (hydrophilic) and chloroform (Lipophilic) extracts of nine medicinal plants currently used in Egyptian traditional medicine to treat some gastrointestinal tract (GIT) disorders were tested for their gastro-protective effect against the incidence of peptic ulcer. Indomethacin-induced ulcer in a rat model was used for this testing. Mentha microphylla, Brassica oleracea Capitata (Cabbage), B. oleracea Botrytis (cauliflower) aqueous fraction, Portolaca oleracea polysaccharide fraction, Oreganum marjoranum, Matricaria recutita, Solanum nigrum hydrophilic and lipophilic fractions, in addition to the chloroform fraction of Portolaca oleracea and Cicorium intybus afforded high protection against the incidence of gastric ulcer (~95%). O. syriacum hydrophilic and lipophilic fractions and gum arabic afforded moderate prophylactic effect. L. sicerarea, C. intybus hydrophilic fractions and M. microphylla lipophilic fraction were inactive. Herbs represent excellent resources for cost-effective and readily available gastro-protective remedies without side effects.

Antiulcerogenic activity of chlorogenic acid in different models of gastric ulcer

Chlorogenic acid (CGA) is found in many foods, including coffee, berries, potatoes, carrots, wine, apples, and various herbs, and has anti-inflammatory, antidiabetic, and antitumoral actions. The CGA is well absorbed orally, and its effects on gastric ulcer have not been previously reported. The present manuscript evaluated the effect of oral administration of CGA on ethanol/HCl (Et/HCl) or nonsteroidal anti-inflammatory drug (NSAID)-induced gastric ulcer model in male Swiss mice. Animals were pretreated with 0.2 % carboxymethylcellulose (vehicle, p.o.), omeprazole (positive control, 30 mg/kg, p.o.), carbenoxolone (antioxidant positive control, 100 mg/kg, p.o.), or CGA (5, 25, or 50 mg/kg, p.o.). One hour later, the gastric ulcer was induced by injecting Et/HCl solution (100 μL/10 g body weight; Et 60 % + HCl 0.03 M) or piroxicam (100 mg/kg, p.o). After another hour or 4 h later, gastric tissues were collected from Et/HCl or piroxicam-treated animals, respectively, to evaluate the size of the lesion, histological alterations, secretion of gastric acid, neutrophil migration, oxidative/antioxidative enzymes, markers of lipid peroxidation, or concentrations of inflammatory mediators. CGA treatment had a gastroprotective effect in both models, reducing the percentage of lesioned area. CGA treatment did not alter the secretion of gastric action but inhibited neutrophil migration and restored the levels of catalase, superoxide dismutase, glutathione peroxidase, glutathione, and thiobarbituric acid reactive substances in mice treated with Et/HCl. Additionally, CGA treatment blocked the increase of tumor necrosis factor alpha and leukotriene B4 but did not restore the reduced prostaglandin levels in the NSAID-induced ulcer. Together, the data presented herein show that CGA may be a suitable natural compound for the prevention and treatment of gastric lesions caused by a different etiology.

The plant kingdom as a source of anti-ulcer remedies

Phytogenic agents have traditionally been used by herbalists and indigenous healers for the prevention and treatment of peptic ulcer. This article reviews the anti-acid/anti-peptic, gastro-protective and/or anti-ulcer properties of the most commonly employed herbal medicines and their identified active constituents. Botanical compounds with anti-ulcer activity include flavonoids (i.e. quercetin, naringin, silymarin, anthocyanosides, sophoradin derivatives) saponins (i.e. from Panax japonicus and Kochia scoparia), tannins (i.e. from Linderae umbellatae), gums and mucilages (i.e. gum guar and myrrh). Among herbal drugs, liquorice, aloe gel and capsicum (chilli) have been used extensively and their clinical efficacy documented. Also, ethnomedical systems employ several plant extracts for the treatment of peptic ulcer. Despite progress in conventional chemistry and pharmacology in producing effective drugs, the plant kingdom might provide a useful source of new anti-ulcer compounds for development as pharmaceutical entities or, alternatively, as simple dietary adjuncts to existing therapies.

Effect of carbenoxolone on the biological activity of nitric oxide: relation to gastroprotection

1. The interactions between carbenoxolone and nitric oxide (NO) were examined by investigating their effects on human platelet aggregation, on rat aortic strips precontracted by phenylephrine and on protection of rat gastric mucosa against ethanol-induced injury. 2. Carbenoxolone (100-300 microM) caused a significant and concentration-dependent potentiation of rat peritoneal neutrophil (RPN)- 3-morpholino-syndnonimine (SIN-1)- or iloprost-induced inhibition of platelet aggregation. Higher concentrations (500 microM) of carbenoxolone alone markedly inhibited platelet aggregation. Pretreatment with carbenoxolone (100-300 microM) antagonized the reversal of the RPN- or SIN-1-induced antiaggregatory effect by oxyhaemoglobin (10 microM). 3. Rat aortic strips with intact endothelium precontracted by phenylephrine (0.1-0.3 microM) were relaxed by carbenoxolone (100-300 microM) in a concentration-dependent manner. Relaxations were abolished by mechanical removal of the endothelium or by incubation with methylene blue (10 microM) or NG-nitro-L-arginine (L-NNA, 100 microM). Sodium nitroprusside (10 nM)-induced relaxations of endothelium-denuded rat aortic strips were potentiated by carbenoxolone (100 microM). . The carbenoxolone (200 mg kg-1, p.o.)-induced gastroprotection against ethanol was antagonized by L-NNA (5-40 mg kg-1) in a dose-dependent manner. Pretreatment of rats with indomethacin (10 mg kg-1, s.c.) increased the effect of L-NNA. 5. The results suggest that the activity of carbenoxolone in the experimental systems tested is due to phosphodiesterase inhibition, although radical scavenging properties of the drug could contribute to some of the effects observed. In the rat gastric mucosa both increased prostaglandin levels and effects on the NO system could contribute to the protective action of carbenoxolone.

Mucosal coating agents and other nonantisecretory agents. Are they cytoprotective?

Gastric cytoprotection is protection against gross and histological gastric mucosal injury by a mechanism other than inhibition of neutralization of gastric acid secretion. Animal studies have shown that a variety of agents afford such a protective effect. With some of these agents, a similar protective effect has been shown in man. This protective effect must be distinguished from an action that enhances healing of an already established mucosal lesion as an ulcer. It is yet to be established that the cytoprotective effect of an agent enhances ulcer healing. Agents other than prostaglandins that have been shown to possess such a cytoprotective effect in animals are reviewed. Some, such as sucralfate, act via stimulation of endogenous prostaglandin synthesis, while others, such as DeNol, neomycin, and meciadanol, do not. Investigation of the mechanism through which these agents enhance gastric mucosal defense is a fertile field for investigation.

Acid, pepsin, and mucus secretion in patients with gastric and duodenal ulcer before and after colloidal bismuth subcitrate (De-Nol)

Basal and pentagastrin stimulated gastric secretion was measured in seven patients with duodenal, and six with gastric ulcers before and after four weeks' treatment with colloidal bismuth subcitrate (as De-Nol), one tablet four times a day. Each duodenal and all but one of the gastric ulcers healed. After De-Nol there were no significant changes in basal, or pentagastrin stimulated volume, acid output, or primary parietal component. There were marked decreases in basal (duodenal ulcer -25%; gastric ulcer -16%) and pentagastrin stimulated total pepsin outputs, (duodenal ulcer -42%, gastric ulcer -36%). There were insignificant decreases in basal output of mucus, but postpentagastrin stimulated mucus output was significantly inhibited (p less than 0.05) in patients with duodenal (-16%) and with gastric ulcer (-27%). The drop in gastric proteolysis after De-Nol is unlikely to be because of the healing of the ulcers and is more likely to be because of the drug. The ulcer healing efficacy of De-Nol may be related to this decline in the proteolytic action of gastric juice, but is unlikely to be because of a quantitative change in mucus, or in acid secretion.

Carbenoxolone and prostaglandin E2 and F2 alpha gastric juice levels in man

The purpose of the present study is to evaluate the effect of carbenoxolone after a non-oral administration on the levels of prostaglandins E2 and F2 alpha in gastric juice. The gastric secretion of 6 healthy volunteers (in basal conditions and after administration of a stimulus of 6 micrograms/kg weight of pentagastrin i.m.) was studied before and after seven days of treatment with 150 mg b.i.d. of carbenoxolone suppository. Concentration and output of prostaglandins E2 and F2 alpha (measured by radioimmunoassay), hydrochloric acid, pepsin and N-acetylneuraminic acid in gastric juice were determined. Compared to control values, no statistically significant difference in acid, pepsin or prostaglandin F2 alpha content, or in gastric juice volume, was observed after treatment. However a significant increase was observed in the concentration and output of prostaglandin E2 after administration of pentagastrin. The concentration and output of N-acetyl-neuraminic acid increased significantly only in basal conditions in carbenoxolone-treated subjects. The present study suggests that the cytoprotective action of carbenoxolone on gastric mucosa in man could be due to an increased prostaglandin E2 activity. This effect is observed after rectal administration, therefore suggesting that carbenoxolone also has a systemic action.

Effect of carbenoxolone on gastric prostaglandin E2 levels in patients with peptic ulcer disease following vagal and pentagastrin stimulation

The influence of oral carbenoxolone sodium (50 mg X 3 daily) on prostaglandin E2 release into gastric juice has been examined in nine peptic ulcer patients (duodenal ulcer, n = 6; prepyloric ulcer, n = 1; gastric ulcer, n = 2) during modified sham feeding and following bolus stimulation of acid secretion by pentagastrin (6 micrograms/kg). Carbenoxolone increased the overall mean of prostaglandin E2 concentrations in gastric juice following modified sham feeding by 32 +/- 9% (mean +/- SEM; P less than 0.02) and decreased the acidity slightly but significantly (P less than 0.05). A marked rise in prostaglandin E2 levels (46 +/- 11%; n = 5; P less than 0.02) was observed in for duodenal ulcer patients and the patient with a prepyloric ulcer responding to therapy (i.e., pain relief and ulcer healing within 4 weeks of treatment). A significant peak (P less than 0.05) related to modified sham feeding was observed only during medication, while a late gradual increase in prostaglandin E2 levels--not associated with vagal stimulation--occurred both in control and carbenoxolone experiments. No significant differences were observed following pentagastrin stimulation. The initial peak in prostaglandin E2 levels observed during medication favours the notion that the mechanism of drug action relies on inhibition of enzymatic degradation while the late increase in prostaglandin E2 levels may be explained by artificial prostaglandin formation during the aspiration procedure.

Effect of carbenoxolone on alkaline secretion by isolated amphibian gastric and duodenal mucosa

The influence of carbenoxolone sodium on HCO-3 transport has been examined in spontaneously alkalinizing amphibian antral (Necturus and Rana catesbeiana) and proximal duodenal (Rana catesbeiana) mucosa and in cimetidine-treated fundic mucosa (Rana temporaria) in vivo. Low concentrations of carbenoxolone (10(-6)-10(-4) mol/l, serosal side and 10(-5) mol/l, luminal side) did not affect the secretory rate or electrical properties of these tissues. In the stomach a higher concentration of carbenoxolone (10(-3) mol/l, serosal side) caused an immediate fall in transmucosal potential difference (PD) and electrical resistance. There was an initial decrease in the rate of HCO-3 transport followed by an increase in titratable alkalinization due to passive permeation of base from the serosal bathing solution. The non-steroidal anti-inflammatory agent ibuprofen (3 x 10(-3) mol/l, serosal side) inhibited alkaline secretion while the bile salt sodium taurocholate (10(-4) mol/l, luminal side) converted net alkaline secretion to a titratable acidity in cimetidine-treated fundus. Pretreatment of the mucosa with carbenoxolone (10(-4) mol/l) did not influence the response to taurocholate but when added with ibuprofen it potentiated the inhibitory effect of this drug on fundic alkaline secretion. In contrast, prostaglandin E2 (10(-6) mol/l) markedly reduced the inhibition of fundic alkaline secretion caused by ibuprofen. The anti-ulcer properties of carbenoxolone do not appear to be related to effects on gastroduodenal HCO-3 transport.