Insights into the Structure of Sucralfate by Advanced Solid- and Liquid-State NMR

Sucralfate, which is a sucrose octasulfate aluminum complex, is an active pharmaceutical ingredient (API) falling in the category of cytoprotective agents which are very effective for gastric and duodenal ulcers. On interaction with stomach acid, it ionizes into aluminum and sucrose octasulfate ions to form a protective layer over the ulcerated region inhibiting further attack from acid. The mechanism of action of sucralfate in the context of its structure is not well understood. Considering that at least two forms of this API are available in the market, there are no reports on the various forms of sucralfate and differences in their pharmacological action. We characterized the two forms of sucralfate using multinuclear, multidimensional solid-state NMR, and the results show significant structural differences between them arising from variation in the aluminum environment and the level of hydration. The impact of structural differences on pharmacological action was examined by studying acid-induced Al release by 27Al liquid-state NMR. The sucralfate, European pharmaceutical standard, Form I, undergoes faster disruption in acid compared to Form II. The difference is explained on the basis of structural differences in the two forms which gives significant insights into the action of sucralfate in relation to its structure.

Mucin levels in glands of the colonic mucosa of rats with diversion colitis subjected to enemas containing sucralfate and n-acetylcysteine alone or in combination

PURPOSE

To evaluate the tissue content of neutral and acidic mucins, sulfomucins and sialomucins in colonic glands devoid of intestinal transit after enemas containing sucralfate and n-acetylcysteine alone or in combination.

METHODS

Sixty-four rats underwent intestinal transit bypass. A colonic segment was collected to compose the white group (without intervention). After derivation, the animals were divided into two groups according to whether enemas were performed daily for two or four weeks. Each group was subdivided into four subgroups according to the substance used: control group: saline 0.9%; sucralfate group (SCF): SCF 2 g/kg/day; n-acetylcysteine group (NAC): NAC 100 mg/kg/day; and SCF+NAC group: SCF 2 g/kg/day + NAC 100 mg/kg/day.Neutral and acidic mucins were stained by periodic acid-Schiff and alcian-blue techniques, respectively. The distinction between sulfomucins and sialomucin was made by the high alcian-blue iron diamine technique. The content of mucins in the colonic glands was measured by computerized morphometry. The inflammatory score was assessed using a validated scale. The results between the groups were compared by the Mann-Whitney's test, while the variation according to time by the Kruskal-Wallis' test (Dunn's post-test). A significance level of 5% was adopted.

RESULTS

There was reduction in the inflammatory score regardless of the application of isolated or associated substances. Intervention with SCF+NAC increased the content of all mucin subtypes regardless of intervention time.

CONCLUSIONS

The application of SCF+NAC reduced the inflammatory process of the colonic mucosa and increased the content of different types of mucins in the colonic glands of segments excluded from fecal transit.

Design Strategy for a Hydroxide-Triggered pH-Responsive Hydrogel as a Mucoadhesive Barrier to Prevent Metabolism Disorders

Excess nutrient uptake is one of the main factors of complications related to metabolism disorders. Therefore, efforts have emerged to modulate nutrient transport in the intestine. However, current approaches are mainly invasive interventions with various side effects. Here, a pH-responsive hydrogel is formulated by acidifying the hydroxide compounds within sucralfate to allow electrostatic interactions between pectin and aluminum ions. The pH responsiveness relies on the alternation of cations and hydroxide species, providing reversible shifting from a hydrogel to a complex coacervate system. It acts as a transient physical barrier coating to inhibit intestinal absorption and changes the viscosity and barrier function in different parts of the gastrointestinal tract, showing enhanced mucoadhesive properties. The therapeutic hydrogel remarkably lowers the immediate blood glucose response by modulating nutrient contact with bowel mucosa, suggesting potential in treating diabetes. In addition, it significantly reduces weight gain, fat accumulation, and hepatic lipid deposition in rodent models. This study provides a novel strategy for fabricating pH-responsive hydrogels, which may serve as a competent candidate for metabolism disorder management.

Effectiveness of the polyphenols-rich Sedum dendroideum infusion on gastric ulcer healing in rats: Roles of protective endogenous factors and antioxidant and anti-inflammatory mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Peptic ulcer is an inflammatory disease that therapeutic options are mainly focused in antisecretory drugs. Sedum dendroideum Moc & Sessé ex DC (Crassulaceae) is employed in folk medicine for the treatment of gastric ulcers. Recently, our group demonstrated that Sedum dendroideum infusion (SDI) is rich in polyphenols (flavonol glycosides, myricetin, quercetin and kaempferol) and promoted gastroprotection against acute ulcer models, without changes gastric acid secretion.

AIM OF THE STUDY

Here, we follow the investigation of the healing effects of SDI (ED₅₀ = 191 mg/kg) in the chronic gastric ulcer model induced by 80% acetic acid in rats, elucidating underlying mechanisms.

MATERIAL AND METHODS

Rats were orally treated with vehicle (water, 1 mL/kg), SDI (191 mg/kg), omeprazole (40 mg/kg) or sucralfate (100 mg/kg) twice daily for 5 days after ulcer induction. Following treatments, toxicological effects, macroscopic ulcer appearance, microscopic histological (HE, mucin PAS-staining) and immunohistochemical (PCNA and HSP70) analysis, inflammatory (MPO and NAG activity, cytokine levels measurements) and antioxidant (SOD and CAT) parameters were investigated in gastric ulcer tissues.

RESULTS

Oral treatment with SDI accelerated gastric ulcer healing, maintained mucin content and promoted epithelial cell proliferation. SDI also reduced neutrophil and mononuclear leukocyte infiltration, TNF-α and IL-1β levels and the oxidative stress, restoring SOD and CAT activities in the ulcer tissue.

CONCLUSIONS

The gastric healing effect of SDI was mediated through endogenous protective events as well as due to the anti-inflammatory and antioxidant actions. Our observations support and reinforce the traditional utilize of Sedum dendroideum as a natural nontoxic therapeutic alternative for the treatment of gastric ulcers.

Efficacy of Sucralfate-Combined Quadruple Therapy on Gastric Mucosal Injury Induced by Helicobacter pylori and Its Effect on Gastrointestinal Flora

BACKGROUND

This study explored the therapeutic efficacy of standard triple therapy combined with sucralfate suspension gel as well as the mechanisms of action in mouse models of H. pylori infection.

MATERIALS AND METHODS

C57BL/6J mice were randomly divided into 5 groups: NC (natural control), HP (H. pylori infection), RAC (rabeprazole, amoxicillin, and clarithromycin), RACS (RAC and sucralfate suspension gel), and RACB (RAC and bismuth potassium citrate). HE staining and electron microscopy were performed to estimate histological and ultrastructural damages. The IL-8, IL-10, and TNF-α of gastric antrum tissues were measured by immunohistochemistry and qRT-PCR. ZO-1 and Occludin were also detected with immunohistochemistry. The genomes of gastric and fecal microbiota were sequenced.

RESULTS

The eradication rate of H. pylori in the RACS group was higher than the RAC group. RACS therapy had protective effects on H. pylori-induced histological and ultrastructural damages, which were superior to the RAC group. RACS therapy reduced the protein and mRNA levels of IL-8 compared with the RAC group. The expression of Occludin in the RACS group was significantly higher than that of the RAC group. The composition of gastric and fecal microbiota for RACS was similar to the RACB group according to PCA.

CONCLUSIONS

The RACS regimen eradicated H. pylori infection effectively and showed RACS had protective effects against H. pylori-induced histological and ultrastructural damage. The mechanisms of RACS effects included decreasing IL-8, enhancing Occludin, and transforming gastric microbiota. Moreover, RACS and RACB have a similar effect on gastrointestinal flora.

A Controlled Study to Examine the Effect of Topical Sucralfate on Radiofrequency-induced Burn Wounds in Rats

Several preclinical studies have shown topical sucralfate facilitates wound repair.

PURPOSE

This study aimed to evaluate the effect of 10% topical sucralfate on healing radiofrequency-induced burn wounds in rats.

METHODS

Twenty (20) male rats were divided into 2 equal groups. Using radiofrequency, 4 full-thickness, 1 cm in diameter round burns were created on the backs of the rats that then were randomized to receive twice-daily treatment for 30 days with 10% sucralfate or neutral cream. Biopsies were taken on days 4, 7, 14, and 21 to analyze fibrin-leukocyte crut, edema density, epidermal-dermal cell infiltration, amount of fibroblast and collagen fibers, amount of elastic fibers, neovascularization-angiogenesis, and reepithelialization-granulation tissue. Data were collected to a spreadsheet and entered into statistical software for analysis. Histopathological features were classified as categorical variables and compared using the χ2 test and Fisher's exact test. When χ2 was used, Yates' correction for continuity was performed. All reported P values were 2-tailed; P less than .05 was considered statistically significant.

RESULTS

On day 4, improvement in edema density (P = .034), epidermal detachment (P = .020), epidermal-dermal cell infiltration (P = .007), and polymorphonuclear leukocyte infiltration (P = .021) were statistically more significant in the sucralfate than control group. On day 7, epidermal-dermal cell infiltration (P = .007) and elastic fibers P = .050) were statistically more significant in the sucralfate group. On day 14, angiogenesis (P = .029), reepithelialization (P = .035), and granulation tissue (P = .003) were statistically more significant in the sucralfate group. By the end of the study (day 30), angiogenesis (P = .010), reepithelialization (P <.001), fibroblast density (P = .016), granulation tissue (P = .035), and collagen density (P = .002) were significantly improved in the sucralfate group versus the control group.

CONCLUSION

In a rat wound model, 10% topical sucralfate was found to histopathologically facilitate the healing process compared to the control group. Controlled clinical studies are needed to elucidate the effect of this treatment in human wounds.

Oral Viscous Sucralfate Gel for Post-procedural Treatment of Barrett's Esophagus

Barrett's esophagus refers to an abnormal change in the cells of the lower portion of the esophagus. It is characterized by the replacement of the normal stratified squamous epithelium lining of the esophagus by columnar epithelium cells which are usually found lower in the gastrointestinal tract. The medical significance of this pathology is approximately 0.5% risk to develop esophageal adenocarcinoma (per patient diagnosed with Barrett's esophagus per year). Diagnosis requires endoscopy and biopsy. In general, high-grade dysplasia and early stages of adenocarcinoma can be treated by endoscopic resection and/or endoscopic ablative therapy, whereas advanced stages (submucosal) are generally advised to undergo surgical treatment. Patients who undergo endoscopic resection and/or endoscopic ablative therapy might suffer from retrosternal discomfort and transient dysphagia, adverse effects that sometimes accompanies these procedures. One of the common post-procedural treatments is sucralfate 1 g 3 to 4 times daily for two weeks after the procedure. The rational for this treatment is to enhance the wound-healing process in the esophagus tissues and to coat the wounded tissues with a cytoprotective agent. As no clinical trials have been performed in order to prove the efficacy of sucralfate in the postprocedural treatment of Barrett's esophagus, this article summarizes the clinical experience accumulated from the treatment with sucralfate as a wound-healing enhancer. In addition, the article deals with the hypothesized mechanism of action of sucralfate and gives one option for compounding sucralfate oral viscous gel.

Effect of sucralfate on gastric permeability in an ex vivo model of stress-related mucosal disease in dogs

BACKGROUND

Sucralfate is a gastroprotectant with no known systemic effects. The efficacy of sucralfate for prevention and treatment of stress-related mucosal diseases (SRMD) in dogs is unknown.

HYPOTHESIS/OBJECTIVES

To develop a canine ex vivo model of SRMD and to determine the effect of sucralfate on mucosal barrier function in this model.

ANIMALS

Gastric antral mucosa was collected immediately postmortem from 29 random-source apparently healthy dogs euthanized at a local animal control facility.

METHODS

Randomized experimental trial. Sucralfate (100 mg/mL) was applied to ex vivo canine gastric mucosa concurrent with and after acid injury. Barrier function was assessed by measurement of transepithelial electrical resistance (TER) and radiolabeled mannitol flux.

RESULTS

Application of acidified Ringers solution to the mucosal side of gastric antrum caused a reduction in gastric barrier function, and washout of acidified Ringers solution allowed recovery of barrier function (TER: 34.0 ± 2.8% of control at maximum injury, 71.3 ± 5.5% at recovery, P < .001). Sucralfate application at the time of injury or after injury significantly hastened recovery of barrier function (TER: 118.0 ± 15.2% of control at maximum injury, P < .001 and 111.0 ± 15.5% at recovery, P = .35).

CONCLUSIONS AND CLINICAL IMPORTANCE

Sucralfate appeared effective at restoring defects in gastric barrier function induced by acid and accelerating repair of tissues subjected to acid in this model, suggesting that sucralfate could have utility for the treatment and prevention of SRMD in dogs.

[Effects of sucralfate and acid-suppressive drugs on preventing ventilator- associated pneumonia of mechanically ventilated patients: a meta-analysis]

OBJECTIVE

To evaluate the effect of sucralfate and acid-suppressive drugs on preventing ventilator-associated pneumonia (VAP) in mechanically ventilated patients.

METHODS

All randomized controlled trials (RCTs), which studied the effect of sucralfate and acid-suppressive drugs on the incidence of VAP in mechanically ventilated patients, were searched from PubMed, Embase and the Cochrane Library during January 1966 to March 2013 via manual and computer retrieval. All related data were extracted. Meta analysis was conducted using the statistical software RevMan 5.2 and the quality of the RCTs was strictly evaluated with the methods recommended by the Cochrane Collaboration.

RESULTS

A total of 15 RCTs involving 1315 patients in the sucralfate group and 1568 patients in the acid-suppressive drug group were included in this study. The incidence of VAP was significantly reduced in the sucralfate group (RR = 0.81, 95%CI 0.7-0.95, P = 0.008), while no difference was found between the two groups in the incidence of stress-related gastrointestinal bleeding (RR = 0.96, 95%CI 0.59-1.58, P = 0.88). No statistical difference was found in the days on ventilator, duration of ICU stay and ICU mortality in the two groups (all P values > 0.05).

CONCLUSION

In patients with mechanical ventilation, sucralfate could decrease the incidence of VAP, while has no such effect on the stress-related gastrointestinal bleeding, the days on ventilator, duration of ICU stay and ICU mortality.

Anti-secretory and cyto-protective effects of peganine hydrochloride isolated from the seeds of Peganum harmala on gastric ulcers

Gastroprotective mechanism of peganine hydrochloride isolated from Peganum harmala seeds was investigated. Peganine hydrochloride was evaluated against cold restraint (CRU), aspirin (AS), alcohol (AL) and pyloric ligation (PL) induced gastric ulcer models in rats. Potential anti-ulcer activity of peganine was observed against CRU (50.0%), AS (58.5%), AL (89.41%) and PL (62.50%) induced ulcer models. The reference drug omeprazole (10mg/kg, p.o.) showed 77.45% protection against CRU, 49.97% against AS and 69.42% against PL model. Sucralfate, another reference drug (500mg/kg, p.o.) showed 62.50% protection in AL induced ulcer model. Peganine significantly reduced free acidity (33.38%), total acidity (38.09%) and upregulated mucin secretion by 67.91%, respectively. Further, peagnine significantly inhibited H(+) K(+)-ATPase activity in vitro with IC50 of 73.47μg/ml as compared to the IC50 value of omeprazole (30.24μg/ml) confirming its anti-secretory activity.

Anti-secretory and cyto-protective effects of chebulinic acid isolated from the fruits of Terminalia chebula on gastric ulcers

In continuation of our drug discovery program on Indian medicinal plants, the gastro protective mechanism of chebulinic acid isolated from Terminalia chebula fruit was investigated. Chebulinic acid was evaluated against cold restraint (CRU), aspirin (AS), alcohol (AL) and pyloric ligation (PL) induced gastric ulcer models in rats. Potential anti-ulcer activity of chebulinic acid was observed against CRU (62.9%), AS (55.3%), AL (80.67%) and PL (66.63%) induced ulcer models. The reference drug omeprazole (10 mg/kg, p.o.) showed 77.73% protection against CRU, 58.30% against AS and 70.80% against PL model. Sucralfate, another reference drug (500 mg/kg, p.o.) showed 65.67% protection in AL induced ulcer model. Chebulinic acid significantly reduced free acidity (48.82%), total acidity (38.29%) and upregulated mucin secretion by 59.75% respectively. Further, chebulinic acid significantly inhibited H(+) K(+)-ATPase activity in vitro with IC50 of 65.01 μg/ml as compared to the IC50 value of omeprazole (30.24 μg/ml) confirming its anti-secretory activity.

Gastroprotective activity of Trichosanthes cucumerina in rats

AIM OF THE STUDY

The aim of the present study was to scientifically investigate whether Trichosanthes cucumerina Linn (Family: Cucurbitaceae) has gastroprotective activity.

MATERIALS AND METHODS

All the experiments were conducted using Wistar strain rats (weight: 200-220 g). The food and water given to rats was withdrawn for 36 and 12h respectively, before the commencement of the experiment. These rats were randomly divided into 6 groups (n=8 rats/group; 4 males+4 females) and groups 1-3 were orally administrated with hot water extract (HWE) at a dose of 375, 500 and 750 mg/kg, respectively. Group 4 was orally treated with equal volume of distilled water (1 mL; control), group 5 was orally treated with a reference drug, cimetidine (100mg/kg) while the group 6 was orally treated with another reference drug, sucralfate (400mg/kg). In the indomethacin experiment, only one dose of HWE (750 mg/kg) was tested, as this was found to have the maximum effect in the alcohol model also.

RESULTS

Results show that the HWE of Trichosanthes cucumerina possesses significant (P<or=0.05) and dose dependent gastroprotective effects in the alcohol model in terms of the length and number of gastric lesions mediated by alcohol, with a maximum effect at 750 mg/kg (inhibition of lesion length by 92%; number of gastric lesions by 88%). The same dose also mediated a significant (P<or=0.05) gastroprotective activity in the indomethacine model (inhibition of lesion length by 88%; number of gastric lesions by 84%). In both models, the protective effect demonstrated by the HWE was comparable with that produced by cimetidine. The HWE significantly (P<or=0.05) increased the amount of mucus produced by the rat gastro mucosa (by 39%) and reduced the gastric acidity (total acidity by 36%; free acidity by 40%). pH of the gastric juice increased from 4.1 to 6.0. However, no change in the volume of gastric juice was observed. Further, HWE showed potent antihistamine activity.

CONCLUSION

It may be concluded that HWE of Trichosanthes cucumerina exerts a significant protection against ethanol or indomethacin induced gastric damage. Increasing the protective mucus layer, decreasing the acidity of the gastric juice and antihistamine activity are probable mechanisms by which the HWE of Trichosanthes cucumerina mediates its gastroprotective actions.

Topical treatment of chronic venous ulcers with sucralfate: a placebo controlled randomized study

Venous leg ulcers are an important medical issue due to their high incidence in the elderly and the lack of a standard curative approach. Apart from surgical therapy, different medical treatments to effect ulcer wound repair and regeneration are currently being investigated. Sucralfate is a cytoprotective agent employed to prevent or treat several gastrointestinal diseases such as gastroesophageal reflux, gastritis, peptic ulcer, stress ulcer and dyspepsia. In this study we evaluated the efficacy, safety and tolerability of topical sucralfate (SUC-LIS 95) on the healing of chronic venous leg ulcers in 50 patients by a double-blind, placebo-controlled, randomized study. Our results indicated that the daily application of SUC-LIS 95 to non-infected post-phlebitis/vascular ulcers, for a median period of 42.0 days, led to complete healing in 95.6% of patients, against only 10.9% of cases with a matched placebo. A significant improvement was obtained in the SUC-LIS 95-treated patient group with regard to local tissue inflammation as well as pain and burning, and consequently, in ulcer size and the evolution of granulation tissue. Our findings were corroborated for selected patients by the morphological analysis of biopsies obtained before and after treatment. Using ultrastructural analysis we demonstrated that the topical use of SUC-LIS 95 was able to affect neoangiogenesis, increase wound contraction, promote re-epithelialization of the wound area and diminish the inflammatory reaction. Overall, our results indicated that patients with chronic venous ulcers show improvement after the use of topical sucralfate.

Protein and non-protein sulfhydryls and disulfides in gastric mucosa and liver after gastrotoxic chemicals and sucralfate: Possible new targets of pharmacologic agents

AIM: To investigate the role of major non-protein and protein sulfhydryls and disulfides in chemically induced gastric hemorrhagic mucosal lesions (HML) and the mechanism of gastroprotective effect of sucralfate.

METHODS: Rats were given 1 mL of 75% ethanol, 25% NaCl, 0.6 mol/L HCl, 0.2 mol/L NaOH or 1% ammonia solutions intragastrically (i.g.) and sacrificed 1, 3, 6 or 12 min later. Total (reduced and oxidized) glutathione (GSH + GSSG), glutathione disulfide (GSSG), protein free sulfhydryls (PSH), protein-glutathione mixed disulfides (PSSG) and protein cystine disulfides (PSSP) were measured in gastric mucosa and liver.

RESULTS: Reduced glutathione (GSH) was depleted in the gastric mucosa after ethanol, HCl or NaCl exposure, while oxidized glutathione (GSSG) concentrations increased, except by HCl and NaOH exposure. Decreased levels of PSH after exposure to ethanol were observed, NaCl or NaOH while the total protein disulfides were increased. Ratios of reduced to oxidized glutathione or sulfhydrils to disulfides were decreased by all chemicals. No changes in thiol homeostasis were detected in the liver after i.g. abbreviation should be spelled out the first time here administration of ethanol. Sucralfate increased the concentrations of GSH and PSH and prevented the ethanol-induced changes in gastric mucosal thiol concentrations.

CONCLUSION: Our modified methods are now suitable for direct measurements of major protein and non-protein thiols/disulfides in the gastric mucosa or liver. A common element in the pathogenesis of chemically induced HML and in the mechanism of gastroprotective drugs seems to be the decreased ratios of reduced and oxidized glutathione as well as protein sulfhydryls and disulfides.

Promotion of cutaneous wound healing by famotidine in Wistar rats

BACKGROUND & OBJECTIVE

Drugs like famotidine, omeprazole and sucralfate which have been reported to promote the healing of gastric ulcers, may have the same effect on cutaneous wounds. Due to paucity of information in this regard, the present study was planned to investigate the effect of these drugs on resutured incision, excision and dead space wounds in Wistar rats.

METHODS

Resutured incision, excision and dead space wounds were inflicted under light ether anaesthesia aseptically. Control animals received vehicle and other groups received famotidine, omeprazole and sucralfate orally for a period of 10 days in the incision and dead space wounds, whereas in excision wounds till complete closure. On the 11th day after estimating breaking strength of the resutured incision wounds, animals were sacrificed and granulation tissue removed from dead space wounds to estimate the breaking strength and hydroxyproline content. Quantification of granulation tissue and histological studies were also carried out. Wound closure rate, epithelization time and scar features were studied in the excision wound models from the day of famotidine till complete closure of the wound.

RESULTS

Only famotidine significantly promoted the healing process in all the three wound models studied. Histopathological studies revealed increased collagen content and granulation tissue in famotidine treated group compared to control.

INTERPRETATION & CONCLUSION

In all the three wound models studied famotidine promoted wound healing whereas omeprazole and sucralfate did not do so. The pro healing effect of famotidine needs to be explored clinically.

Sucralfate protects blood clots from peptic digestion by gastric juice in vitro

OBJECTIVE

To test in vitro the ability of sucralfate to protect a blood clot from peptic digestion by gastric juice.

MATERIAL AND METHODS

Blood clots adhering to the bottom of plastic tubes were exposed to native acidic gastric juice or gastric juice to which Al-Mg antacids, sucralfate or alkali had been added. The tubes were tilted regularly at room temperature and clot digestion monitored by measuring the diameters of the clots. After 15 h, the liquids, but not the adherent clots, were poured out and the tubes refilled with native acidic gastric juice. Further clot digestion was measured, as before.

RESULTS

Native gastric juice digested the clots completely during approximately 7 h, while in neutralized gastric juice or in gastric juice containing antacids or sucralfate no digestion was seen. In the second experiment, native gastric juice completely digested all remaining clots, except those previously exposed to sucralfate. A dose-response study indicated that gastric juice containing 3% or more of sucralfate had this long-lasting, clot-protective effect.

CONCLUSIONS

In vitro, sucralfate adheres to and protects blood clots from digestion by gastric juice pepsin. This unique effect of sucralfate may be of clinical relevance in the treatment of bleeding peptic ulcers.

EFFECTS OF SUCRALFATE, CIMETIDINE AND RABEPRAZOLE ON MUCOSAL HYDROXYPROLINE CONTENT IN HEALING OF ETHANOL-HCL-INDUCED GASTRIC LESIONS

1. No general consensus has been reached on the treatment of acute gastric lesions. The aims of the present study were to clarify the effects of sucralfate, cimetidine and rabeprazole monotherapies and combination therapies on acute gastric lesions from the viewpoint of connective tissue regeneration. 2. Gastric lesions were experimentally created by the oral administration of 50% ethanol-0.15 mol/L HCl to rats. After 30 min, the anti-ulcer agents sucralfate (100 mg/kg), cimetidine (20 mg/kg) and rabeprazole (2 mg/kg) were administered separately or in combination and the stomach was excised at different times to measure the level of hydroxyproline in the gastric mucosa and determine lesion index. Immunostaining against prolylhydroxylase was performed on some specimens. 3. In the control group, lesion index decreased linearly from 30 min after ethanol-HCl administration and the level of mucosal hydroxyproline peaked between 2 and 4 h later. Although sucralfate significantly promoted lesion healing, it had no effect on mucosal hydroxyproline level. Cimetidine suppressed increases in mucosal hydroxyproline and prolonged lesion healing, but these findings were reversed by combining cimetidine and sucralfate. Rabeprazole had no significant effect on lesion healing, but promoted lesion healing in combination with sucralfate. Immunohistochemical analysis showed that prolylhydroxylase was expressed in spindle cells that lined the glandular cells in a boundary area between normal and injured tissues. 4. Under conditions in which the effects of intragastric pH are minimal, sucralfate is superior to antisecretory agents in promoting the healing of acute gastric lesions.

Sucralfate prevents the delay of wound repair in intestinal epithelial cells by hydrogen peroxide through NF-kappaB pathway

BACKGROUND

Recent studies have shown that sucralfate (SF) has therapeutic effects on colonic inflammation in ulcerative colitis. The aim of this study was to clarify the function of SF for wound repair in intestinal epithelial cells (IEC).

METHODS

(1) Activation of signal proteins [ERK1/2 mitogen-activated protein kinase (MAPK), IkappaB-alpha] in IEC-6 cells after stimulation with 10(-4) M potassium sucrose octasulfate (SOS), which is the functional element of SF, was assessed by Western blot. (2) Induction of transforming growth factor (TGF)-beta1, TGF-alpha, EGF, and cyclooxygenase-2 (COX-2) mRNA after stimulation of IEC-6 cells with SOS was assessed by reverse transcriptase-polymerase chain reaction. (3) IEC-6 cells were wounded and cultured for 24 h with various concentrations of SOS in the absence or presence of 20 microM H(2)O(2). Epithelial migration or proliferation was assessed by counting migrating cells or bromodeoxyuridine (BrdU)-positive cells across the wound border.

RESULTS

(1) SOS activated IkappaB-alpha, but it did not activate ERK1/2 MAPK. (2) SOS enhanced the expression of COX-2 mRNA, but it did not change the mRNA expression of other growth factors. (3) SOS did not enhance wound repair in IEC-6 cells, but it decreased the number of dead cells (maximum, 74%) (P < 0.01) in a dose-dependent manner and prevented the diminishment of epithelial migration (maximum, 61%) (P < 0.01) and proliferation (maximum, 37%) (P < 0.05) induced by H(2)O(2). These functions of SOS were suppressed by the NF-kappaB and COX-2 inhibitors.

CONCLUSIONS

SOS prevented the delay of wound repair in IEC-6 cells induced by H(2)O(2), probably through induction of COX-2 and an anti-apoptotic mechanism. These effects of SOS might be given through the activation of the NF-kappaB pathway.

[Preventive effects of teprenone on gastric mucosal lesions induced by Helicobacter pylori in mice]

OBJECTIVE

To determine the preventive effect of teprenone on gastric mucosal injury induced with Helicobacter pylori concentrated culture supernatant (CCS) in Balb/c mice.

METHODS

Gastric mucosa lesions were induced with intragastrical administration of Helicobacter pylori CCS. Sixty Balb/c mice were divided into control group, injury group, sucralfate protective group and teprenone protective group. Mice of two protective groups were pretreated with sucralfate or teprenone respectively before induction of gastric mucosa lesions. Mucosal changes were assessed by microscopic examination, quantitative histology and electron microscopy.

RESULTS

Histologic and ultrastructural lesions in protective groups were less severe than those in injury group. Epithelial damage scoring (EDS) of teprenone protective group (1.68 +/- 0.69) and sucralfate protective group (1.72 +/- 0.73) were significantly decreased than injury group (2.47 +/- 0.58, P < 0.05).

CONCLUSION

Teprenone as well as sucralfate reduces gastric mucosal lesions induced by Helicobacter pylori CCS in mice.

Effects of Aloe vera and sucralfate on gastric microcirculatory changes, cytokine levels and gastric ulcer healing in rats

AIM: To compare the effects of Aloe vera and sucralfate on gastric microcirculatory changes, cytokine levels and gastric ulcer healing.

METHODS: Male Spraque-Dawley rats (n= 48) were divided into four groups. Group1 served as control group, group 2 as gastric ulcer group without treatment, groups 3 and 4 as gastric ulcer treatment groups with sucralfate and Aloe vera. The rats from each group were divided into 2 subgroups for study of leukocyte adherence, TNF-α and IL-10 levels and gastric ulcer healing on days 1 and 8 after induction of gastric ulcer by 20 % acetic acid.

RESULTS: On day 1 after induction of gastric ulcer, the leukocyte adherence in postcapillary venule was significantly (P< 0.05) increased in the ulcer groups when compared to the control group. The level of TNF-α was elevated and the level of IL-10 was reduced. In the ulcer groups treated with sucralfate and Aloe vera, leukocyte adherence was reduced in postcapillary venule. The level of IL-10 was elevated, but the level of TNF-α had no significant difference. On day 8, the leukocyte adherence in postcapillary venule and the level of TNF-α were still increased and the level of IL-10 was reduced in the ulcer group without treatment. The ulcer treated with sucralfate and Aloe vera had lower leukocyte adherence in postcapillary venule and TNF-α level. The level of IL-10 was still elevated compared to the ulcer group without treatment. Furthermore, histopathological examination of stomach on days 1 and 8 after induction of gastric ulcer showed that gastric tissue was damaged with inflammation. In the ulcer groups treated with sucralfate and Aloe vera on days 1 and 8, gastric inflammation was reduced, epithelial cell proliferation was enhanced and gastric glands became elongated. The ulcer sizes were also reduced compared to the ulcer group without treatment.

CONCLUSION: Administration of 20 % acetic acid can induce gastric inflammation, increase leukocyte adherence in postcapillary venule and TNF-α level and reduce IL-10 level. Aloe vera treatment can reduce leukocyte adherence and TNF-α level, elevate IL-10 level and promote gastric ulcer healing.

The effect of residual water on antacid properties of sucralfate gel dried by microwaves

The aim of this work was to study the acid neutralization characteristics of microwave-dried sucralfate gel in relation to the water content and physical structure of the substance. Several dried sucralfate gels were compared with humid sucralfate gel and sucralfate nongel powder in terms of neutralization rate and buffering capacity. Humid sucralfate gel and microwave-dried gel exhibited antacid effectiveness. In particular, the neutralization rate of dried gel powders was inversely related to the water content: as the water content of dried powders decreased, the acid reaction rate linearly increased. The relationship was due to the different morphology of dried sucralfate gels. In fact, the porosity of the dried samples increased with the water reduction. However, the acid neutralization equivalent revealed that the dried sucralfate gel became more resistant to acid attack in the case of water content below 42%. Then, the microwave drying procedure had the opposite effect on the reactivity of the aluminum hydroxide component of dried sucralfate gel powders, since the rate of the reaction increased whereas the buffering capacity decreased as the amount of water was reduced.

[The effect of selective bowel decontamination and mechanical bowel preparation on bacterial translocation due to intraabdominal hypertension]

BACKGROUND

The objective of our study is to evaluate the preventive effects of selective digestive decontamination (SDD) and mechanical bowel preparation in rats with experimentally induced bacterial translocation.

METHODS

Fourty adult male Sprague Dowley rats weighing 250-300 g. were divided equally into four groups as Group 1 (sham [control]), Group 2 (experimentally induced IAH at 19 mmHg), Group 3 ( SDD group) and Group 4 (SDD and mechanical bowel preparation with 19 mmHg intraabdominal pressure). Group 3 and 4 were treated at 12 hours intervals with oral gentamycine 5 mg/kg and IM sefotaxime 100mg/kg Mechanical bowel preparation was performed by oral administration of sodium phosphate. After 24 hours all rats were sacrified; mesenteric lymph nodes, spleen and liver biopsy specimens were harvested aseptically. Specimens were diluted and cultured in McConkey medium and the colony-forming units (CFU/gr ) were calculated.

RESULTS

In Kruskal Wallis tests there were no significant differences between Group 1 and 3 or 4, and also Group 3 and 4 (p>0.05, p=0.872 respectively), while differences between Group 1 and 2, and also Group 3 and 4 were statistically significant (p<0.001) with respect to CFU/g estimates.

CONCLUSION

These data indicate that selective intestinal decontamination and mechanical bowel preparation prevent bacterial translocation due to intraabdominal hypertension.

Desmodium gangeticum: a potent anti-ulcer agent

The present study was designed to investigate anti-ulcerogenic property of ethanolic extract of Desmodium gangeticum (DG) against cold restraint (CRU, 2 hr cold restraint stress), aspirin (ASP, 150 mg/kg orally), alcohol (AL, absolute alcohol 1 ml/200gm) and pyloric ligation (PL, 4 hr pylorus ligation) induced gastric ulcer models in Sprague Dawley rats, and histamine (HST, 0.25 mg/kg) induced duodenal ulcer in guinea pigs. We found that DG at a dose of 200mg/kg, (orally), markedly decreased the incidence of ulcers in all the above models. DG showed significant protection against CRU (68.37%), AL (88.87%), ASP (38.2%), PL (40.63%) and HST (63.15%) induced ulcer models, whereas standard drug omeprazole (OMZ) showed protection index of 83.86, 56.35, 70.31 and 84.21%, respectively in CRU, ASP, PL and HST models. Sucralfate as standard drug showed 92.64% protection in AL model. DG significantly reduced acid secretion 41.61%, whereas OMZ produced 43.13% reduction. Treatment with DG showed increase in mucin secretion by 56.17%, whereas OMZ showed 12.45% increase. Anti-ulcer effect of DG may be due to its cytoprotective effect along with antisecretory activity and could act as a potent therapeutic agent against peptic ulcer disease.

Effect of Cissus quadrangularis on gastric mucosal defensive factors in experimentally induced gastric ulcer-a comparative study with sucralfate

Cissus quadrangularis is an indigenous plant commonly mentioned in Ayurveda for treatment of gastric ulcers. The ulcer-protective effect of a methanolic extract of C. quadrangularis (CQE) was comparable to that of the reference drug sucralfate. Further, gastric juice and mucosal studies showed that CQE at a dose of 500 mg/kg given for 10 days significantly increased the mucosal defensive factors like mucin secretion, mucosal cell proliferation, glycoproteins, and life span of cells. The present investigation suggests that CQE not only strengthens mucosal resistance against ulcerogens but also promotes healing by inducing cellular proliferation. Thus, CQE has potential usefulness for treatment of peptic ulcer disease.

The acidic complexation of tetracycline with sucralfate for its mucoadhesive preparation

The complex of antibiotics with sucralfate (SF) was prepared with acid. The mechanism of the complexation and some factors concerning the preparation, which influence the mucoadhering property, were studied. The complexation was confirmed by the change in color and instrumental analysis. The acidic complex appeared to be produced by reagglomeration of SF preliminary particles. It was suggested that the amide or amine groups of tetracycline (TC) and aluminum moieties of SF serve as the binding sites. The potential of multiple binding sites and a priority in them were suggested by the Scatchard plot analysis. The additional amounts of acid and the increase in the surface area increased the number of sites. The amount of the additional acid appeared to be the most important factor during the preparation of the acidic complex. The appropriate amount of acid added appeared to produce a complex rich in TC. However, an excess amount might cause the excess dissociation of aluminum moieties, which destroys the mucoadhesive paste-forming property.

Teprenone, but not H2-receptor blocker or sucralfate, suppresses corpus Helicobacter pylori colonization and gastritis in humans: teprenone inhibition of H. pylori-induced interleukin-8 in MKN28 gastric epithelial cell lines

BACKGROUND

The role of teprenone in Helicobacter pylori-associated gastritis has yet to be determined. To investigate the effect of teprenone on inflammatory cell infiltration, and on H. pylori colonization of the gastric mucosa in H. pylori-infected patients, we first compared the effect of teprenone with that of both histamine H2 receptor antagonists (H2-RA) and sucralfate on the histological scores of H. pylori gastritis. We then examined its in vitro effect on H. pylori-induced interleukin (IL)-8 production in MKN28 gastric epithelial cells.

MATERIALS AND METHODS

A total of 68 patients were divided into three groups, each group undergoing a 3-month treatment with either teprenone (150 mg/day), H2-RA (nizatidine, 300 mg/day), or sucralfate (3 g/day). All subjects underwent endoscopic examination of the stomach before and after treatment. IL-8 production in MKN28 gastric epithelial cells was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Following treatment, the teprenone group showed a significant decrease in both neutrophil infiltration and H. pylori density of the corpus (before vs. after: 2.49 +/- 0.22 vs. 2.15 +/- 0.23, p =.009; 2.36 +/- 0.25 vs. 2.00 +/- 0.24, p =.035, respectively), with no significant differences seen in either the sucralfate or H2-RA groups. Teprenone inhibited H. pylori-enhanced IL-8 production in MKN28 gastric epithelial cells in vitro, in a dose-dependent manner.

CONCLUSIONS

Teprenone may modify corpus H. pylori-associated gastritis through its effect on neutrophil infiltration and H. pylori density, in part by its inhibition of IL-8 production in the gastric mucosa.

Inhibitory effect of green tea catechins in combination with sucralfate on Helicobacter pylori infection in Mongolian gerbils

BACKGROUND

The occurrence of antibiotic-resistant Helicobacter pylori has been reported. It is desirable to develop an effective method to prevent the occurrence of resistant strains of Helicobacter pylori. Green tea catechins (GTCs) have been reported to have an antibacterial effect. Therefore, the possibility of eradicating Helicobacter pylori by the oral administration of GTCs was investigated.

METHODS

Solutions of GTCs and solutions of GTCs adsorbed to sucralfate (GTC-scf), at concentrations of 20 mg GTCs and/or 20 mg sucralfate/ml were prepared. Then 1 ml of the GTC-scf or the GTC solution was administered daily, for 10 days to Mongolian gerbils infected with Helicobacter pylori. Then the stomachs were extirpated and homogenized. The homogenate was spread on selective medium plates. After 5-day culture, colony-forming units (CFU) of Helicobacter pylori were counted.

RESULTS

The CFU of Helicobacter pylori was significantly decreased by GTC-scf.

CONCLUSIONS

GTC-scf may have a bactericidal effect on Helicobacter pylori infection.

Does sucralfate prevent apoptosis occurring in the ischemia/reperfusion-induced intestinal injury?

BACKGROUND/PURPOSE

We have shown in a previous study that sucralfate is beneficial in the prophylaxis and treatment of hypoxia/reoxygenation-induced intestinal injury. The aim of this study is to investigate whether sucralfate has any effect on the prevention of apoptosis in the ischemia/reperfusion (I/R)-induced intestinal injury.

METHODS

Rats were randomized into three groups. Group 1 and 2 were subjected to I/R. Group 1 (treatment group) received sucralfate while group 2 (treatment control group) did not. Group 3 served as a normal control group (sham group). The terminal ileum was harvested for histopathologic investigation by light microscopy. The presence of apoptotic enterocytes (DNA fragmentation in cell nuclei) was detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end-labeling (TUNEL) reaction.

RESULTS

In treatment control group, 3 of 7 rats had severe inflammation. None of the sucralfate-treated rats showed severe inflammation, 6 of them only showed mild inflammatory changes (p < 0.05). The apoptotic percentage was found to be 37.1 +/- 9.4 in the sucralfate-treated group (group 1), whereas it was 45.4 +/- 3.9 in the untreated group (group 2) (p < 0.05). The sham group had a completely normal intestinal architecture.

CONCLUSIONS

The present study shows that 1) the experimental model of I/R-induced intestinal injury induces enterocyte apoptosis; 2) sucralfate decreases enterocyte apoptosis in the experimental model of I/R-induced intestinal injury which may play a key role in the pathophysiological events leading to failure of the intrinsic gut barrier defense mechanisms.

[The effect of bFGF and sucralfate on cell proliferation during continuous tissue expansion]

OBJECTIVE

To investigate the effect of local application of bFGF combined with sucralfate on the cell proliferation during continuous tissue expansion (CTE).

METHODS

Nine white pigs were selected to undergo the continuous tissue expansion in this study and treated with bFGF and sucralfate, respectively as the following groups: group 1 with both bFGF and sucralfate, group 2 only with bFGF, group 3 with only sucralfate, and group 4 with saline as control. Fifteen samples were taken in each pig for immunohistochemistry analysis 1-14 days and 6 weeks after the operation.

RESULTS

In the group with both bFGF and sucralfate, the epidermic basal cells proliferated significantly after the operation and reached top level in 3 days, which was statistical higher than the control group, but the multiplication of basal cell was the lowest 14 days after the operation, still more than the control group. In dermal layer, proliferation of fibroblasts, vessel endothelial cells, hair follicles epidermic cells and sweat gland epicytes was also significant higher in the group with both bFGF and sucralfate than that the control group and reached top level 7 day after the operation, but the proliferation of cells decreased obviously 14 days after the operation, still higher than the control group. The mitotic activity of cells returned to the basal level in 42 days. There were no significant differences among the group 2, group 3 and group 4.

CONCLUSION

Local application of both bFGF and sucralfate could be more effect to induce cells multiplication during early skin expansion to facilitate the growth of neoformed skin soft tissue.

ABT-773: pharmacokinetics and interactions with ranitidine and sucralfate

We assessed the pharmacokinetics and interaction of ABT-773 in 12 volunteers receiving ABT-773 alone or concomitantly with ranitidine or sucralfate. Data for 150 mg of ABT-773 were as follows: the maximum concentration of the drug in plasma (C(max)) was 318 ng/ml, its half-life was 5.66 h, and its area under the plasma concentration-time curve from 0 h to infinity (AUC(0- infinity )) was 1,662 ng. h/ml. Coadministration of ranitidine, reduced the C(max) (-25.7%) and AUC(0- infinity ) (-15.8%) significantly. Sucralfate had no impact on the bioavailability of ABT-773.

Effects of the anti-ulcer agents ecabet sodium, cimetidine and sucralfate on acetylsalicylic acid-induced gastric mucosal damage deteriorated by renal failure in rats

Renal failure including post-renal transplantation increases the susceptibility of the upper gastrointestinal mucosa to injury. The aim of this study was to confirm the influence of renal failure on gastric mucosal barrier and the protective effect of various anti-ulcer agents in rats. Renal failure (RF) was induced by 45-min left renal artery clamping and right-uninephrectomy. Four days after surgery, gastric mucosal lesions were induced by intragastric administration of acetylsalicylic acid (ASA, CAS 50-78-2) (100 mg/kg). Anti-ulcer agents were given orally 30 min before ASA administration. RF induced moderate gastric mucosal damages, but significantly worsened the ASA-induced gastric lesions. Ecabet sodium (CAS 86408-72-2) and cimetidine (CAS 51481-61-9) significantly inhibited ASA-induced gastric lesions in RF rats, whereas sucralfate (CAS 54182-58-0) tended to inhibit it. ASA and all of these anti-ulcer agents had no effect on the serum creatinine and blood urea nitrogen levels increased by RF. The gastric mucosa of RF rats is more susceptible to damage induced by ASA. Ecabet and cimetidine potently inhibited gastric lesions in RF rats suggesting its utility for the gastric mucosal damage in patients with RF including post-renal transplant.

Effects of sucralfate on gastric irritant-induced necrosis and apoptosis in cultured guinea pig gastric mucosal cells

We previously reported that several gastric irritants, including ethanol, hydrogen peroxide, and hydrochloric acid, induced both necrosis and apoptosis in cultured gastric mucosal cells. In the present study, we examined the effects of sucralfate, a unique gastroprotective drug, on gastric irritant-induced necrosis and apoptosis produced in vitro. Sucralfate strongly inhibited ethanol-induced necrosis in primary cultures of guinea pig gastric mucosal cells. The preincubation of cells with sucralfate was not necessary for its cytoprotective effect to be observed, thus making its mechanism of action different from that of other gastroprotective drugs. Necrosis of gastric mucosal cells induced by hydrogen peroxide or indomethacin was also suppressed by sucralfate. On the other hand, sucralfate only weakly inhibited ethanol-induced apoptosis. These results suggest that the cytoprotective effect of sucralfate on gastric mucosa in vivo can be explained, at least in part, by its inhibitory effect on gastric irritant-induced necrosis.

Sucralfate mouthwash for prevention and treatment of 5-fluorouracil-induced mucositis: a randomized, placebo-controlled trial

A randomized, double-blind, placebo-controlled trial was conducted to evaluate the effectiveness of a sucralfate mouthwash in preventing and alleviating oral mucositis induced by 5-fluorouracil (5FU). A total of 81 patients with colorectal cancer were enrolled. Patients were studied during their first cycle of chemotherapy with 5FU and leucovorin (LV) daily for 5 days every 4 weeks (Mayo Clinic schedule). Patients were randomly allocated to receive either a sucralfate suspension or a placebo suspension that was identical in appearance. Patients were instructed to use the suspension as a mouthwash four times daily from the beginning of the chemotherapy cycle. All patients received oral cryotherapy. Patients graded the severity of their own symptoms on a daily basis, and this was the primary outcome measure. There was no difference in the frequency or severity of oral mucositis between the sucralfate- and the placebo-treated group. Some mucositis was reported by 79% of the patient group. Assessment of mucositis by trial staff underestimated the incidence of this problem. Results of this trial do not support the hypothesis that a sucralfate mouthwash can prevent or alleviate oral mucositis induced by 5FU. Patient reporting of mucositis is a more sensitive instrument for assessment of mucositis than review by medical staff.

[Local application of bFGF and sucralfate during continuous tissue expansion]

OBJECTIVE

To investigate the effect of local application of bFGF and sucralfate during continuous tissue expansion (CTE).

METHODS

CTE combined with local administration of bFGF and sucralfate was used in twelve patients with scar and nasal tip defects. Twenty three expanders were placed in the subcutaneous pockets through intralesion short incisions. Continuous expansion began at 1-3 days after expander implantation. The histomorphological changes and epidermal cell proliferation were observed. The clinical results were investigated.

RESULTS

The average inflation time was 8.9 days. The average interval of the two operations was 13.5 days. The average hospitalization was 28.4 days. The average immediate stretch-back rate of the expanded skin was 25.7%. The clinical results were satisfactory without any complications. Histological examinations showed that the epidermal, granular and spinous layer became thicker. The basal cells increased significantly. The dermis thinned slightly and the collagen fibers became thicker. The elastic fiber regenerated significantly. Fibroblast and capillary density increased obviously. The immunohistochemistry analysis showed that the proliferation of epidemic basal cells was significant postoperatively.

CONCLUSION

Local application of exogenous bFGF and sucralfate during CTE was feasible in patients. It could accelerate tissue expansion and improve the quality of expanded skin flap.

Tolerability of bolus versus continuous gastric feeding in brain-injured patients

Brain injured patients may exhibit altered gastric emptying; thus, some believe post-pyloric feeding to be tolerated better than gastric feeding. Reliable post-pylorus access can be difficult to obtain, so gastric feeding remains the preferred route for administering nutrition. Feeding intolerance may be associated with increased complications and costs. We sought to compare bolus (B) versus continuous (C) gastric feeding in brain injured patients. This retrospective cohort study was carried out at a neurological/neurosurgical intensive care unit at a Level 1 trauma and tertiary referral center. Our subjects were 152 consecutive patients over two years. Use of B or C feedings was based on clinicians' preferences. Abdominal examination and gastric residuals (> 75 mL over four hours) defined feeding intolerance (FI). Putative risks for FI were compared between the groups. Demographic characteristics were similar between groups B (n = 86) and C (n = 66). Feeding intolerance occurred more often in group B than in group C (60.5% vs. 37.9%, p = 0.009). Group C patients achieved 75% of nutritional goals faster than group B patients (median 3.3 vs. 4.6 days; p = 0.03). Prokinetic agent use was similar between the groups and did not reduce the time to achieve nutritional goals. There was a trend towards a reduction in the incidence of infections in group C (p = 0.05). Independent predictors of FI included: sucralfate (OR 2.3), propofol (OR 2.1), pentobarbital (OR 3.9) or paralytic (OR 3) use; older age (OR 5); days receiving mechanical ventilation (OR 1.2); and admission diagnosis of either intracerebral hemorrhage (OR 2.2) or ischemic stroke (OR 1.9). Continuous gastric feeding is better tolerated than B feedings in patients with acute brain injuries. Use of prokinetic agents did not affect time to achievement of nutritional goals. Use of common medications including sucralfate and propofol were associated with FI.

[Effect of local application of basic fibroblast growth factor and sucralfate on skin tissue structure after expansion]

OBJECTIVE

To investigate the effect of local application of basic fibroblast growth factor (bFGF) and sucralfate on the skin tissue structure after expansion.

METHODS

Continuous tissue expansion (CTE) experimental animal model was made with constant pressure pump in nine white pigs. The bFGF and sucralfate were perfused between tissue and tissue expander. Both bFGF and sucralfate were injected in group I, both bFGF and normal saline in group II, only sucralfate in group III, and normal saline in group IV as control group. The samples were took from each pig for histomorphological assessment on the 3rd day and 6th week after expansion.

RESULTS

Compared with control group, epidermal, granular spinous and basal cell thickness increased significantly (P < 0.05) in group I; in dermal layer, dermal thickened slightly and the collagen fibers became thicker and orderly; the elastic fiber regenerated significantly; the density of fibroblasts and capillaries significantly increased (P < 0.05) in group I. The collagen fibers were broken on the 3rd day and 6th week after expansion in control group. However, the thickness of the fibrous capsule layer was similar in each group.

CONCLUSION

Local application of exogenous bFGF and sucralfate combined with CTE can greatly promote the skin growth. It can accelerate the tissue expansion.

Lack of effect of sucralfate on the absorption and pharmacokinetics of rosiglitazone

The aim of the present study was to investigate the effect of sucralfate pretreatment on the pharmacokinetics of rosiglitazone following a single oral dose in healthy male volunteers. After an over night fast, and according to a randomized schedule, each volunteer (n = 9) received a single oral dose of rosiglitazone 8 mg (Avandia tablets, 4 mg x 2) with or without pretreatment of sucralfate 2 g (Recolfate tablets, 1 g x 2) in an open-label crossover study with a 2-week washout period. Plasma samples were collected over a period of 24 hours at regular intervals. Safety assessment included monitoring of the vital signs, blood parameters, and ECG. No statistically significant differences (p > 0.05) were observed for any of the calculated rosiglitazone pharmacokinetic parameters in the two treatment groups. The mean parameters, AUC0-infinity and Cmax, following rosiglitazone administration alone were 3825.02 ng x h/ml and 664.47 ng/ml, respectively, and for rosiglitazone administered after pretreatment with sucralfate were 4848.19 ng x h/ml and 624.88 ng/ml, respectively. The t(max) for rosiglitazone alone and for rosiglitazone after sucralfate treatments was 1.11 and 1.67 hours, respectively. The mean elimination half-life for rosiglitazone and rosiglitazone after sucralfate treatment was 4.35 and 4.51 hours, respectively. Fraction of rosiglitazone absorbed was calculated by the Wagner-Nelson method, and no statistically significant difference (p > 0.05) was observed for the two treatments. Since sucralfate pretreatment did not show any significant difference in the pharmacokinetics of rosiglitazone, no dose adjustment is warranted for rosiglitazone when it is administered with sucralfate.

The effects of cefephim, G-CSF, and sucralfate on bacterial translocation in experimentally induced acute pancreatitis

The preventive effects of granulocyte colony-stimulating factor, cefephim, and sucralfate on bacterial translocation in experimentally induced acute pancreatitis were investigated. Forty male Wistar albino rats were used in this study. For each rat, the pancreatobiliary ductus was ligated and hence acute pancreatitis was induced. In the control group, no further procedure was performed. Meanwhile, cefephim as an antibiotic, filgrastim, which is a colony-stimulating factor, and sucralfate were given to the other groups at the specified doses. To inhibit bacterial translocation by preserving the bowel barrier, sucralfate, which is known to have a cytoprotective effect on the gastrointestinal system, was used in high doses. Cefephim 30 mg/kg per day (intramuscularly) in group II, filgrastim 10 mg/kg per day (subcutaneously) in group III, and sucralfate 50 mg/kg per day by 8-F feeding tube gavage into the stomach in group IV were given. The number of bacteria translocated into the mesenteric lymph nodes, pancreas, liver, and spleen in the control group significantly increased in comparison with the other groups (P < 0.05). The average number of leukocytes (per mm3) in the control group was significantly higher than that of other groups (P < 0.0001). Regarding the average serum amylase levels, the values of all groups clearly decreased in comparison with the control group (P < 0.0001). Although in the cefephim, filgrastim, and sucralfate groups, (+) pancreatitis was generally seen, in the control group (+++) pancreatitis was detected. Bacterial translocation to the mesenteric lymph nodes and pancreas was partially prevented by filgrastim and sucralfate, and was completely prevented by cefephim. We conclude that in the management of acute pancreatitis, the use of the prophylactic antibiotics, sucralfate and filgrastim, may be advantageous.

Prophylactic and curative effects of Bacopa monniera in gastric ulcer models

Bacopa monniera Wettst. (BM, syn. Herpestis monniera L; Scrophulariaceae), is an Ayurvedic drug used as a rasayana. Its fresh juice was earlier reported to have significant antiulcerogenic activity. In continuation, methanolic extract of BM (BME) standardized to bacoside-A content (percentage-38.0 +/- 0.9), when given in the dose of 10-50 mg/kg, twice daily for 5 days, showed dose-dependent anti-ulcerogenic on various gastric ulcer models induced by ethanol, aspirin, 2 h cold restraint stress and 4 h pylorus ligation. BME in the dose of 20 mg/kg, given for 10 days, twice daily showed healing effects against 50% acetic acid-induced gastric ulcers. Further work was done to investigate the possible mechanisms of its action by studying its effect on various mucosal offensive acid-pepsin secretion and defensive factors like mucin secretion, mucosal cell shedding, cell proliferation and antioxidant activity in rats. BME 20 mg/kg showed no effect on acid-pepsin secretion, increased mucin secretion, while it decreased cell shedding with no effect on cell proliferation. BME showed significant antioxidant effect per se and in stressed animals. Thus, the gastric prophylactic and curative effects of BME may be due to its predominant effect on mucosal defensive factors.

Effects of Sucralfate on the Oral Bioavailability of Moxifloxacin, a Novel 8-Methoxyfluoroquinolone, in Healthy Volunteers

OBJECTIVE

To investigate the effect of concomitant Al3+ (sucralfate) administration on the pharmacokinetics and tolerability of moxifloxacin.

DESIGN

This was a single-centre, randomised, nonblinded, 2-way crossover study in healthy volunteers.

PARTICIPANTS

12 healthy men (age 21 to 41 years) were enrolled in the study.

METHODS

The plasma and urinary pharmacokinetics of moxifloxacin were characterised up to 72 hours after single doses of moxifloxacin 400mg administered orally either alone or together with 190mg of Al3+ (Sucralfat-Ratiopharm 1000) given immediately before and at 5, 10, 15 and 24 hours after the dose of moxifloxacin. There was a 2-week washout phase between the treatments.

RESULTS

The treatments were well tolerated. The concomitant administration of Al3+ reduced the bioavailability of moxifloxacin [geometric mean area under the concentration-time curve from zero to infinity (AUCinfinity) 12.9 versus 32.2 mg/L x h; relative bioavailability 40%, 90% confidence interval (CI) 33 to 49%] and slowed down the absorption rate [median time to maximum concentration (tmax) 3.5 versus 1.0 hours], with a reduction of the maximum plasma concentration (Cmax) fgeometric mean Cmax0.82 versus 2.83 mg/L; estimated true ratio of Cmax 29%, 90% CI 20 to 42%].

CONCLUSIONS

Concomitant ingestion with sucralfate and/or oral Al3+-containing antacids significantly reduces the bioavailability of moxifloxacin. This is compatible with reduced solubilisation as a consequence of a chelation reaction with polyvalent cations, a common finding for quinolones. Therefore, staggered administration of moxifloxacin and Al3+-containing or related cationic interactants should be considered to avoid a loss of therapeutic efficacy due to subtherapeutic plasma concentrations of the quinolone.

The effect of ferrous sulphate and sucralfate on the bioavailability of oral gemifloxacin in healthy volunteers

Sucralfate is a cytoprotectant with antacid properties and ferrous sulphate is commonly prescribed for iron-deficiency anaemia. This open, randomized, single-dose, five-way crossover study investigated the effect of sucralfate and ferrous sulphate on the bioavailability of gemifloxacin, a novel fluoroquinolone antimicrobial. Twenty-seven healthy male volunteers received gemifloxacin, 320 mg p.o., alone, 3 h after sucralfate (2 g) or ferrous sulphate (325 mg), or 2 h before sucralfate or ferrous sulphate. Each subject received all five dosing regimens in random order with at least 6 days between regimens. Plasma samples collected up to 48 h after dosing with gemifloxacin, were assayed for gemifloxacin to determine pharmacokinetic parameters. Administration of gemifloxacin 3 h after sucralfate produced a marked decrease of 53% in the area under the plasma concentration-time curve from time zero extrapolated to infinity (AUC0-infinity), and a decrease of 69% in the maximal plasma concentration (Cmax). Administration of gemifloxacin 3 h after ferrous sulphate resulted in only a modest reduction of 11% in AUC0-infinity and of 20% in Cmax, which was not considered to be clinically significant. In contrast, at the doses used neither sucralfate nor ferrous sulphate altered gemifloxacin bioavailability when it was administered 2 h before either of these agents. Gemifloxacin was well tolerated in all the regimens. The results of this study support the dosing recommendation that gemifloxacin can be safely administered at least 2 h before sucralfate or ferrous sulphate, or at least 3 h after ferrous sulphate.

Up-regulation of endothelin-1 in gastric mucosal inflammatory responses to Helicobacter pylori Lipopolysaccharide: effect of omeprazole and sucralfate

BACKGROUND

Helicobacter pylori is recognized as a primary etiologic factor in the development of gastric disease and the product of particular significance to the virulent action of the bacterium is its cell wall lipopolysaccharide. We applied the animal model of H. pylori lipopolysaccharide-induced acute gastritis to study the effect of antiulcer agents, omeprazole and sucralfate, on the course of mucosal inflammatory responses by analyzing the interplay between the extent of epithelial cell apoptosis and the mucosal expression of endothelin-1 (ET-1), tumor necrosis factor-alpha (TNF-alpha), and the activity of constitutive (cNOS) and inducible (NOS-2) nitric oxide synthase.

METHODS

Rats pretreated twice daily for 3 consecutive days with omeprazole at 40 mg/kg, sucralfate at 100 mg/kg or the vehicle, were subjected to intragastric application of H. pylori lipopolysaccharide at 50 microg/animal, and after 2, 4, and 10 additional days on the antiulcer drug or vehicle regimen their mucosal tissue used for histologic and biochemical assessment.

RESULTS

In the absence of antiulcer agents, H. pylori lipopolysaccharide elicited within 2 days a pattern of acute mucosal inflammatory responses accompanied by a massive epithelial cell apoptosis, a 2.9-fold increase in the mucosal expression of ET-1, an 11.7-fold enhancement in TNF-alpha, and a 9.3-fold increase in NOS-2, while cNOS activity showed a 5.5-fold decrease. The extent of mucosal inflammatory involvement reached a maximum by the 4th day and showed a decline by the 10th day. This was reflected in a marked reduction in epithelial cell apoptosis, decrease in the mucosal expression of ET-1, TNF-alpha and NOS-2, and the recovery in cNOS activity. Comparing to the vehicle controls, treatment with proton pump inhibitor, omeprazole, led at the end of a 10 day period to a 48.3% reduction in the extent of mucosal inflammatory involvement elicited by H. pylori lipopolysaccharide, while a 74.2% reduction in the mucosal inflammatory involvement was achieved with gastroprotective agent, sucralfate. Moreover, this advantage of sucralfate over omeprazole in countering the lipopolysaccharide-induced changes was reflected at the end of 10 day treatment period in a 20.4% greater decrease in apoptosis, a 47.5% greater reduction in TNF-alpha and a 50.7% greater reduction in ET-1. However, both agents exerted similar influence on the restoration of gastric mucosal cNOS activity and showed a comparable effect at the end of a 10 day treatment in countering the lipopolysaccharide-induced increase in the expression of NOS-2.

CONCLUSIONS

The findings suggest that an increase in the mucosal ET-1 level elicited by H. pylori lipopolysaccharide, combined with a decline in cNOS may be responsible for the induction of TNF-alpha and triggering the inflammatory process. We also show that sucralfate exhibits greater efficacy than omeprazole in suppressing the H. pylori-induced mucosal inflammatory responses. This property of sucralfate may well be due to its ability to suppress the mucosal rise in ET-1.

Anti-ulcer effects of chitin and chitosan, healthy foods, in rats

In this study, we compared the effects of low molecular weight (LMW) chitosan (MW: 25,000-50,000), high molecular weight (HMW) chitosan (MW: 500,000-1000,000) and chitin on ethanol-induced gastric mucosal injury and on the healing of acetic acid-induced gastric ulcers in rats. Oral administration of LMW chitosan (250, 500 and 1000 mg/kg) dose-dependently prevented ethanol-induced gastric mucosal injury. Repeated oral administration of LMW chitosan (100, 200 and 400 mg/kg twice daily) also dose-dependently accelerated the gastric ulcer healing. However, the effects of HMW chitosan and chitin on the gastric mucosal injury formation and the gastric ulcer healing were less potent than those of LMW chitosan. LMW chitosan (250 and 500 mg/kg, orally) was ineffective in inhibiting gastric acid secretion in pylorus-ligated rats, although it had a weak acid-neutralizing action. LMW-chitosan (250, 500 and 1000 mg/kg orally) dose-dependently prevented the decrease in gastric mucus content induced by ethanol. These results indicate that of the three compounds, LMW chitosan has the most potent gastric cytoprotective and ulcer healing-promoting actions. In addition, gastric mucus-increasing action of LMW-chitosan may be, at least in part, related to the anti-ulcer effect of this compound.

Role of interleukin-4 in down-regulation of endothelin-1 during gastric ulcer healing: effect of sucralfate

BACKGROUND

The course of events associaed with healing gastric mucosal injury involves an orderly interplay between the array of signaling molecules that exert their influence on the processes leading to the restoration of the mucosal integrity. In this study, we investigated the effect of antiulcer agent, sucralfate, on the mucosal apoptotic processes during gastric ulcer healing by analyzing the expression of interleukin-4 (IL:4), endothelin-1 (ET-1), tumor necrosis factor-alpha (TNF-alpha), and the mucosal activity of capase-3, and constitutive (cNOS) and inducible nitric oxide synthase (NOS-2).

METHODS

Rats with experimentally induced chronic gastric ulcers were administered twice daily for 14 days either sucralfate at 100 mg/kg or vehicle, and at different stages of treatment their stomachs were used for macroscopic and biochemical assessments.

RESULTS

The ulcer onset was characterized by a massive epithelial apoptosis associated with a 33-fold increase in caspase-3 activity, 5.7-fold increase in TNF-alpha, 17.5-fold increase in NOS-2 and a 3.9-fold increase in ET-1, while the mucosal expression of cNOS activity showed a 7.6-fold drop and IL-4 expression fell by 37.2%. The healing was reflected in a rapid recovery in IL-4, and a decrease in apoptosis, caspase-3, TNF-alpha, ET-1 and NOS-2, and a slow recovery in cNOS activity, and the process was accelerated in the sucralfate-treated group. While in the absence of sucralfate the expression of IL-4 returned to that of the normal mucosa by the 7th day of healing and that of ET-1 and TNF-alpha by the 14th day, an accelerated ulcer healing with sucralfate treatment was associated with IL-4 recovery by the 4th day and that of ET-1 and TNF-alpha by the 10th day when the ulcer heated, while recovery in cNOS activity required 14 days. Yet, in both groups of animals the apoptotic DNA fragmentation rate, caspase-3 and the expression of NOS-2 activity remained significantly elevated even after the ulcer healed.

CONCLUSIONS

The results suggest that a decrease in the mucosal expression of the regulatory cytokine IL-4 at the ulcer onset may well be a key factor causing dysregulation of ET-1 production, induction of TNF-alpha, and triggering the apoptotic events that affect the efficiency of mucosal repair process. We also show that accelerated ulcer healing by sucralfate may be the result of a rapid mucosal IL-4 generation that leads to the suppression of the mucosal apoptotic events.

The effect of staggered dosing of sucralfate on oral bioavailability of sparfloxacin

AIMS

To investigate the effect of sucralfate on sparfloxacin absorption when administered concurrently or at strategically spaced dosing times designed to avoid the potential interaction.

METHODS

The study was a four-way crossover design where eight healthy Japanese volunteers were randomized to one of four treatment sequences at entry. A 300 mg dose of sparfloxacin was administered alone for treatment A (control). Treatments B, C and D included sucralfate 1.5 g every 12 h for five doses. For treatment B, the fifth dose of sucralfate was administered concurrently with sparfloxacin 300 mg. For treatment C, 300 mg sparfloxacin was given 2 h prior to the fifth dose of sucralfate. Treatment D consisted of sparfloxacin 300 mg given 4 h prior to the fifth dose of sucralfate. Blood and urine samples were collected at predetermined time intervals for 72 h. Sparfloxacin concentrations in plasma and urine and the concentrations of sparfloxacin metabolite in urine were determined by high performance liquid chromatography assays.

RESULTS

Sucralfate administrated concurrently with sparfloxacin decreased the mean AUC(0,infinity) of sparfloxacin 2-fold (P<0.001) and the mean Cmax 2.1-fold (P<0.001) compared with sparfloxacin alone. When sucralfate was administrated 2 h after sparfloxacin, the mean AUC(0,infinity) was decreased 1.5-fold (P<0.01) and the mean Cmax 1.4-fold (P<0.01). Sucralfate did not alter the extent of absorption of sparfloxacin when it was given 4 h after the administration of sparfloxacin. The relative bioavailabilities for treatments B, C and D were 0.50 (95% CI: 0.35-0.65), 0.64 (95% CI: 0. 51-0.77), and 0.92 (95% CI: 0.81-1.03), respectively, relative to sparfloxacin alone. The mean percentage of the sparfloxacin dose recovered in urine was significantly lower after sparfloxacin was administered with sucralfate than after sparfloxacin was administered alone or 2 h before the sucralfate dose (P<0.001). Treatments B, C and D were demonstrated to be equivalent to treatment A in the rate of absorption. The tmax, CLr and t1/2 were not significantly affected by sucralfate. The metabolism of sparfloxacin was not altered in the presence of sucralfate.

CONCLUSIONS

Oral administration of sucralfate with sparfloxacin or 2 h after sparfloxacin, decreased the extent of sparfloxacin absorption. When both drugs are to be administered together, sucralfate should be administered 4 h after sparfloxacin, allowing thus sufficient time for sparfloxacin absorption prior to the sucralfate dose and thereby minimizing the chance of a significant interaction.

The effects of sucralfate and selective intestinal decontamination on bacterial translocation

Sucralfate is widely used as a cytoprotective agent in patients with peptic ulcer and other intestinal mucosal damage. In this study, the effects of sucralfate and/or selective intestinal decontamination with gentamycin on bacterial translocation (BT) in rats with experimentally-induced mechanical jaundice were investigated. Seventy-five adult male Wistar albino rats were divided into five groups of 15 each. In all except a sham group, we performed ligation of the common bile duct (CBD) via a vertical laparatomy. After surgery, the rats in group 1 were treated with oral sucralfate (5 mg/kg per day); those in group 2 underwent oral gentamycin therapy (5 mg/kg per day) for 5 days. Group 3 rats were treated with sucralfate and gentamycin for 5 days subsequent to the operation. The rats in group 4 served as controls, and received only 0.9% saline solution. Group 5 was a sham group. After 5 days of surgery, all rats were killed; the mesenteric lymph nodes (MLN), liver, and a segment of terminal ileum were harvested aseptically. The collected tissues were cultured in McCaunkey medium and chocolate agar. For each specimen, the colony-forming units (CFU) were calculated and the percentage of viable translocated micro-organisms was counted. In all rats who had ligation of the CBD, high numbers of bacteria were demonstrated in the liver, MLN, and ileum. In the liver of rats with sucralfate and/or gentamycin treatment, there was a marked reduction in CFU compared to the control group. Similarly, in the MLN measurements of CFU were higher in the control rats than the study groups. In both McCaunkey and chocolate media, the numbers of bacteria in control rats were significantly higher than in the study groups (P < 0.001). However, among the study groups themselves there was no significant difference in CFU in any of the specimens or culture media (P > 0.05). Experimentally-induced mechanical jaundice from ligation of the CBD causes significant BT in rats. Sucralfate and/or gentamycin may reduce the degree of BT from the bowel mucosa. We did not find any difference in protection from BT between sucralfate and gentamycin or both in rats with experimentally-induced mechanical jaundice.

Long-lasting cytoprotection after pentadecapeptide BPC 157, ranitidine, sucralfate or cholestyramine application in reflux oesophagitis in rats

Recently, the effectiveness of pentadecapeptide BPC 157 and other anti-ulcer agents, called 'direct cytoprotection', was evidenced in totally gastrectomized rats duodenum challenged with cysteamine 24 h after surgery, and sacrificed 24 h after ulcerogen application. The further focus was on the possibility that this effect could be seen over a more prolonged period (1, 2, 4 weeks), and in other parts of the gastrointestinal tract (i.e. oesophagus). After the removal of the stomach, the oesophagus and jejunum were joined by a termino-lateral anastomosis. The animals were euthanized 7, 14 or 28 d after surgery, when oesophagitis was blindly assessed both macroscopically (percentage of ulcerations areas) and microscopically (percentage of areas of ulcers, regeneration and hyperplasia; number of inflammatory cells - polymorphonuclear and mononuclear). Starting 24 h after surgery, the medication was continuously given in the drinking water, in a volume of 12.5 mL/rat daily, until euthanasia at the end of the observation period, i.e. 7, 14, 28 d following surgery. Based on previous experiments, the doses of agents were daily calculated per kg b.w. as follows: BPC 157 125 mg or 125 ng, cholestyramine 2.5 mg, ranitidine 125 mg, sucralfate 725 mg, whereas controls received 72.5 mL x kg(-1) water. In support of these initial findings, and considering gastrectomized acid-free rats as an ideal model for long-term cytoprotective studies as well, pentadecapeptide BPC 157 markedly attenuated termino-lateral oesophagojejunal anastomosis-reflux oesophagitis also over a quite prolonged period. This efficacy was only partly shared by other anti-ulcer agents. After 1-week-old oesophagitis (microscopical assessment), but not after 2 or 4 weeks, less damaged mucosa was noted in rats drinking ranitidine or sucralfate compared to controls. Similar effectiveness was noted for cholestyramine. The obtained results were supported also by inflammatory cell assessment. Compared with control values, BPC 157-treated groups consistently presented less polymorphonuclears and less mononuclears in all assessed periods. Interestingly, the values obtained in other treated groups showed no difference compared with control values. Thus, despite limitations, a generalization supporting a direct importance of a common cytoprotective approach, could be clearly provided. A useful, long-lasting cytoprotective activity (apparently more prominent in BPC 157 rats, than in reference agents, ranitidine, sucralfate, as well as cholestyramine) may be a likely suitable therapy in otherwise resistant reflux oesophagitis conditions.