New method of inducing intestinal lesions in rats by intraduodenal administration of aspirin

NSAID-Associated Small Intestinal Injury: An Overview From Animal Model Development to Pathogenesis, Treatment, and Prevention

With the wide application of non-steroidal anti-inflammatory drugs (NSAIDs), their gastrointestinal side effects are an urgent health burden. There are currently sound preventive measures for upper gastrointestinal injury, however, there is a lack of effective defense against lower gastrointestinal damage. According to a large number of previous animal experiments, a variety of NSAIDs have been demonstrated to induce small intestinal mucosal injury in vivo. This article reviews the descriptive data on the administration dose, administration method, mucosal injury site, and morphological characteristics of inflammatory sites of various NSAIDs. The cells, cytokines, receptors and ligands, pathways, enzyme inhibition, bacteria, enterohepatic circulation, oxidative stress, and other potential pathogenic factors involved in NSAID-associated enteropathy are also reviewed. We point out the limitations of drug modeling at this stage and are also pleased to discover the application prospects of chemically modified NSAIDs, dietary therapy, and many natural products against intestinal mucosal injury.

The protective effect of Bifidobacterium bifidum G9-1 against mucus degradation by Akkermansia muciniphila following small intestine injury caused by a proton pump inhibitor and aspirin

Proton pump inhibitors (PPIs) can alleviate upper gastrointestinal injury but paradoxically exacerbate aspirin (ASA)-induced small intestine injury. In this study, our goal was to simulate this exacerbation by developing an appropriate animal model, which may help in establishing treatments. Methods: Male mice were fed a 60% fructose diet for 9 weeks, then administered 200 mg/kg ASA 3 h before sacrifice. The PPI omeprazole was administered intraperitoneally once daily for 9 weeks. Bifidobacterium bifidum G9-1 was administered orally for the last week. In addition, Akkermansia muciniphila was administered orally for 9 weeks instead of omeprazole. Results: ASA-induced small-intestine injury was observed in high-fructose fed mice. Omeprazole exacerbated ASA-induced intestinal damage, significantly decreased Bifidobacteria levels, and significantly increased A. muciniphila counts in the jejunum. The direct administration of A. muciniphila caused thinning of the jejunum mucus layer, which was also observed in mice that received ASA and omeprazole. On the other hand, the administration of Bifidobacterium bifidum G9-1 inhibited A. muciniphila growth and reduced thinning of the mucus layer. The number of goblet cells in the jejunum was reduced by the administration of ASA and omeprazole, while Bifidobacterium bifidum G9-1 prevented the reduction. Conclusions: These results suggest that omeprazole-induced gut dysbiosis promotes Akkermansia growth and inhibits Bifidobacterium growth, leading to a thinning of the mucus layer through a reduction in goblet cells in the small intestine. Probiotics are, therefore, a promising approach for the treatment of small intestine injury.

Study of the protective effect on intestinal mucosa of the hydrosoluble fiber Plantago ovata husk

Background

Several studies have indicated that dietary fiber may have a protective effect on gastrointestinal mucosa. The aim of this study was to evaluate the protective action of the soluble fiber Plantago ovata husk against intestinal damage.

Methods

To evaluate the anti-ulcerogenic effect on duodenal mucosa of the soluble fiber Plantago ovata husk, low-dose acetylsalicylic acid (10 mg/kg) was given orally to animals once daily for 14 or 28 days with and without Plantago ovata husk (100 mg/kg). 24 h after final dosing duodenal samples were removed for anatomopathological evaluation. Villi were examined by both light and scanning electron microscopy.

Results

Acetylsalicylic acid induced severe lesions in duodenal mucosa of rabbits, including erosions, epithelium disorganization, and cell vacuolization, increasing as well the amount of mononuclear and caliciform cells. Damage was much more severe in animals treated for 28 days. In groups receiving Plantago ovata husk, a significant attenuation of acetylsalicylic acid-induced lesions was already observed in group treated for 14 days, becoming more evident in those treated for 28 days, all of them with duodenal cytoarchitecture normal and similar to control animals.

Conclusions

These findings suggest that Plantago ovata husk may protect intestinal mucosa probably by limiting acetylsalicylic acid penetration into epithelial cells, although further studies are needed to confirm the same effect in other experimental models of induced mucosal damage and to elucidate the mechanisms of fiber protection.

The role of food for the formation and prevention of gastrointestinal lesions induced by aspirin in cats

BACKGROUND/AIMS

The effects of feeding conditions (fasted or fed) and dietary fiber (DF) in the diet on gastrointestinal (GI) damage induced by aspirin (ASA) were examined in cats.

METHODS

Plain ASA (P-ASA, 20 mg/kg) or one enteric-coated ASA tablet (EC-ASA, containing 100 mg ASA) was administered p.o. once daily for 3 or 7 days just after morning meal, 3 h after the evening meal, or in the morning without a morning meal (fasted). Several types of diet, dry food (DRY, DF: 2.8 %), canned food (CAN, DF: 0.4 %), and diets with added cellulose or pectin were provided twice daily.

RESULTS

P-ASA or EC-ASA administered just after feeding of DRY caused marked lesions in the GI tract, although EC-ASA did not produce any lesions in the stomach. GI damage was markedly decreased when ASA was administered 3 h after the evening meal. The induction of lesions by EC-ASA was markedly decreased in cats that ate CAN, but lesions were induced in cats fed CAN with added cellulose (6 %). The addition of pectin (6 %) to the DRY markedly decreased the induction of lesions by EC-ASA.

CONCLUSIONS

The results indicate that the induction of GI lesions by ASA was highly dependent on the feeding conditions and DF. To minimize the induction of GI damage, it would be better to take ASA 3 h after the evening meal, or after consuming diets that contain low amounts of insoluble DF and high amounts of soluble DF.