Effect of carbenoxolone on the synthesis of glycoproteins and DNA in rat gastric epithelial cells

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.

Synergistic effects of triterpenic compounds with prostaglandin A1 on vaccinia virus infected L929 cells

Triterpenic compounds, such as glycyrrhizic acid (GRa) and carbenoxolone (CBX), have a synergistic effect with prostaglandin A1 on the inhibition of vaccinia virus (VV) replication in L929 cells. The fractional inhibitory concentration (FIC) values for GRa and CBX were 0.5 and 0.25, respectively. In the supernatant of triterpene treated cells, increased production of some prostaglandins was shown, whilst cell-associated prostaglandins and prostaglandins of the A series were only slightly influenced by the presence of triterpenes. From these findings there is no evidence that prostaglandin production and metabolism could be involved in the antiviral activity of triterpenes.

A study on the cell kinetics of the canine gastric mucosa by the cytofluorometric method: an evaluation of chemically induced gastric cancer

The cell kinetic alteration in the background mucosa of canine gastric cancer induced by N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) was evaluated by cytofluorometry in which the rate of S and G2 + M phase cell in gastric mucosal cells could be calculated, and a triphasic alteration was demonstrated; an initial reduction phase, an increase phase and a plateau phase with a high value. The initial reduction phase was caused by non-specific toxicity of ENNG as observed in drug induced gastric mucosal lesions, and subsequent increase and plateau phases originated from the action of ENNG itself to activate the mucosal turn-over and from histological changes in the background mucosa such as regenerative hyperplastic change after mucosal erosion and atrophic changes, sometimes including intestinal metaplastic change. Further, in comparison to carcinogenesis in chemically induced gastric cancer with and without a surfactant (Tween 60), it was suggested that one of the promotion effects of Tween 60 was closely related with activation of the mucosal turn-over.

The effect of pentosanpolysulphate and carbenoxolone on bacterial adherence to the injured urothelium

The effect of the glycosaminoglycan (GAG) layer on the adherence of Escherichia coli to the bladder urothelium of rats has been studied. The study was performed by destroying the GAG layer and the changes were observed using the electron microscope. Bacterial adherence to the bladder with a destroyed GAG layer was much higher than to the normal bladder. Following the destruction of the GAG layer, the instillation of sodium pentosanpolysulphate significantly reduced the adhesion of bacteria. Prophylactic intramuscular administration of carbenoxolone increased the speed of regeneration of the destroyed GAG layer.

Cytoprotective drugs. Focus on essential fatty acids and sucralfate

Cytoprotection has been defined as an ability of prostaglandins to prevent gastric mucosal injury produced by a variety of ulcerogenic and necrotizing agents without inhibition of gastric acid secretion or without neutralizing intragastric acidity. Since the first demonstration of cytoprotection by prostaglandins many other agents have been claimed to be cytoprotective. Essential fatty acids: arachidonic and linoleic, licorice products, sucralfate, antacids and sulfhydryl compounds all possess cytoprotective properties. All of these compounds are able to prevent or reduce gastric mucosal necrosis produced by absolute ethanol, a necrotizing agent which injures mucosa independently of the luminal pH. Gastric mucosal protection by essential fatty acids is mediated by their conversion by the gastric mucosa to protective prostaglandins. Sucralfate and antacids are also cytoprotective compounds which stimulate release of endogenous prostaglandins from the gastric mucosa.

Protective drugs in the treatment of gastroduodenal ulcer disease

Reduction of gastric acidity by the inhibition of secretion or neutralization is the therapeutic principle most widely used in peptic ulcer disease. From a pathophysiological standpoint, this does not appear logical, because in a majority of patients gastric acid secretion is not increased. In addition, there is some concern about the consequences of a reduction in gastric acidity, especially in the long term. And finally, all available inhibitors of gastric acid secretion have a systemic action and may thus cause systemic side effects. Carbenoxolone, sucralfate, and tri-potassium dicitrato bismuthate have been shown to accelerate healing of ulcers without appreciable acid inhibition. Despite an apparently different mode of action, the healing rates are similar to those of commonly used acid inhibitors. Several possible mechanisms of action have been claimed for each of these agents, but none has been convincingly demonstrated to be essential in ulcer healing. This may reflect ignorance of the relevant events rather than an action by a combined principle.

Cytoprotective action of carbenoxolone sodium on ethanol-induced gastric lesions in rats and its inhibition by indomethacin

Carbenoxolone produced a marked and dose-related inhibition of ethanol-induced gastric lesions in rats. This cytoprotective action was inhibited progressively and significantly by increasing doses of indomethacin. The evidence presented confirms previous suggestions that prostaglandin(s) are involved in the cytoprotective action of carbenoxolone.

A quantitative morphological study of the effects of carbenoxolone sodium on duodenal goblet-cells of the rat

A direct microscopic and microdensitometric examination was carried out on duodenal goblet-cells of non-fasted and fasted rats with and without carbenoxolone sodium treatment. The results of microdensitometric examination revealed a marked and significant increase of mucus production in the non-fasted and fasted rats pretreated for 2 hr with a single oral dose of carbenoxolone sodium at 100 mg/kg. Fasting alone also increased mucus production. On microscopic examination, the number of duodenal goblet-cells full of mucosubstances in the non-fasted and fasted rats receiving carbenoxolone sodium treatment was approximately 20% higher than in the controls.

Enhancement of the bladder defense mechanism by an exogenous agent

The mucopolysaccharide layer produced by the transitional cells coating the bladder plays an important role in the defense mechanism of the lower urinary tract. Carbenoxolone, a drug derived from licorice, has been shown to be beneficial to patients with peptic ulcer disease by stimulating increased mucous production in the stomach. Since the bladder epithelium has an endodermal derivation, the question of whether carbenoxolone has an effect on the mucopolysaccharide layer in the bladder was put forth. Carbenoxolone was shown to provide a protective effect to laboratory-induced lower urinary tract infections in the rabbit model.

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.