bismuth-subsalicylate and Disease-Models--Animal

The study of pharmacological interactions between herbal remedies and conventional drugs is important because consuming traditional herbal remedies as supplements or alternative medicine is fairly common and their concomitant administration with prescribed drugs could either have a favorable or unfavorable effect. Therefore, this work aims to determine the pharmacological interactions of a turmeric acetone extract (TAE) and its main metabolite (curcumin) with common anti-ulcer drugs (ranitidine and bismuth subsalicylate), using an ethanol-induced ulcer model in Wistar rats. The analysis of the interactions was carried out via the Combination Index-Isobologram Equation method. The combination index (CI) calculated at 0.5 of the affected fraction (fa) indicated that the TAE or curcumin in combination with ranitidine had a subadditive interaction. The results suggest that this antagonistic mechanism is associated to the mucoadhesion of curcumin and the TAE, determined by rheological measurements. Contrastingly, both the TAE and curcumin combined with bismuth subsalicylate had an additive relationship, which means that there is no pharmacological interaction. This agrees with the normalized isobolograms obtained for each combination. The results of this study suggest that mucoadhesion of curcumin and the TAE could interfere in the effectiveness of ranitidine, and even other drugs.

Topics: Animals; Anti-Ulcer Agents; Bismuth; Curcuma; Curcumin; Disease Models, Animal; Drug Interactions; Ethanol; Gastric Mucosa; Herb-Drug Interactions; Male; Organometallic Compounds; Plant Extracts; Ranitidine; Rats; Rats, Wistar; Salicylates; Stomach Ulcer

We evaluated the effect of optimized doses and dosing schedules of metronidazole, tetracycline, and bismuth-metronidazole-tetracycline (BMT) triple therapy with only 1 day of dosing on Helicobacter pylori SS1 titers in a mouse model. A reduction of bacterial titers was observable with 22.5 and 112.5 mg of metronidazole per kg of body weight (as well as BMT) given twice daily and four times daily (QID). Two hundred milligrams of tetracycline per kilogram, given QID, resulted in only a slight reduction of H. pylori titers in the stomach. We argue that optimization of doses based on antimicrobial drug levels in the animal and shortened (1 or 2 days) drug administration can be used to facilitate early evaluation of putative anti-H. pylori drug candidates in lieu of using human doses and extended schedules (7 to 14 days), as can be deduced from the results seen with these antimicrobial agents.

Topics: Animals; Bismuth; Disease Models, Animal; Drug Therapy, Combination; Female; Helicobacter Infections; Helicobacter pylori; Humans; Metronidazole; Mice; Mice, Inbred C57BL; Organometallic Compounds; Salicylates; Tetracycline

Helicobacter pylori can be eradicated by administration of antimicrobials, but resistant strains have emerged, and there is a need for novel therapeutic approaches against this infection. This study aimed to determine the safety and efficacy of 3'-sialyllactose sodium salt (3'SL), an oligosaccharide that occurs naturally in human and bovine milk and that can inhibit the adhesion of H. pylori to human epithelial cells in vitro.. Twelve H. pylori-positive rhesus monkeys were given 3'SL, either alone (regimens 1 and 2; n = 6) or in combination with omeprazole (regimen 3; n = 4), or bismuth subsalicylate (regimen 4; n = 6). Videogastroscopies were performed before, during, and after treatment, and gastric biopsy specimens were obtained for quantitative cultures and histology. The H. pylori strains colonizing the animals were genotyped.. After regimen 1 or 2, 2 of 6 animals were cured permanently, and a third animal was transiently cleared. The 3 other animals remained persistently colonized and did not respond to regimen 3. Regimen 4 resulted in transient decreases in colony counts in 3 of 6 other animals. Gastritis was suppressed only in the 2 animals who became persistently H. pylori negative. There was no apparent relation between 3'SL efficacy and any of the H. pylori tested genotypes. No side effects were observed in any of the animals receiving 3'SL.. Antiadhesive therapy is safe; it can cure or decrease H. pylori colonization in some rhesus monkeys, but the addition of a proton pump inhibitor or bismuth subsalicylate does not increase cure rate.

Topics: Animals; Anti-Bacterial Agents; Anti-Ulcer Agents; Bismuth; Disease Models, Animal; Drug Therapy, Combination; Genotype; Helicobacter Infections; Helicobacter pylori; Humans; Lactose; Liver Function Tests; Macaca mulatta; Organometallic Compounds; Proton Pump Inhibitors; Salicylates; Sialic Acids

Bismuth subsalicylate was tested in an in vivo perfused rabbit model of oesophagitis for its ability to prevent the mucosal injury caused by pepsin. Treatment efficacy was assessed under both a treatment-before-injury protocol and a treatment-after-injury protocol. Oesophageal mucosal barrier function was evaluated by measuring flux rates of H+, K+, and glucose. The degree of oesophagitis was determined by gross and microscopic examination of the mucosa by several independent observers. Results showed that under both treatment protocols, bismuth subsalicylate significantly reduced the pepsin induced disruption of the mucosal barrier, as well as the morphologic changes. Bismuth subsalicylate when given after exposure to pepsin was also found to protect against the morphologic injury in a dose dependent manner. Experiments in vitro suggested that bismuth subsalicylate inhibits the proteolytic action of pepsin by interacting with pepsin, rather than with the pepsin substrate. We conclude that bismuth subsalicylate can protect the oesophageal mucosa against peptic injury, probably through inactivation of pepsin.

Topics: Animals; Bismuth; Disease Models, Animal; Dose-Response Relationship, Drug; Esophagitis; Esophagus; Mucous Membrane; Organometallic Compounds; Pepsin A; Rabbits; Salicylates