Protective effect and mechanism of rebamipide on NSAIDs associated small bowel injury

Berberine mitigates diclofenac-induced intestinal mucosal mechanical barrier dysfunction through the restoration of autophagy by inhibiting exosome-mediated lncRNA H19

Small intestine damage caused by diclofenac is called diclofenac enteropathy. Berberine (BBR), a class of isoquinoline alkaloids derived from Berberis vulgaris and Phellodendron amurense, is widely used in intestinal diseases. The present study evaluated the protective effect of BBR on the intestinal mucosal mechanical barrier in diclofenac enteropathy and its possible action mechanism. The in vitro animal experiment revealed that BBR downregulated the expression of long non-coding RNA H19 (lncRNA H19) in the small intestine and exosomes. In the co-culture experiment involving exosomes and intestinal epithelial cell-6 (IEC-6) cells, the results of qRT-PCR, western blotting, and immunofluorescence assays demonstrated that the elevated expression of lncRNA H19 in the small intestine, conveyed via exosomes derived from the diclofenac group, suppressed the expression levels of autophagy-associated protein 5 (Atg 5) and light chain 3 (LC 3), as well as and the tight junction (TJ) proteins zonula occludens-1 (ZO-1), claudin-1, and occluding, relative to the control group. BBR treatment attenuated exosomal lncRNA H19 levels, upregulated the expression of Atg5 and LC3 expression, enhanced TJ protein expression, and increased the light chain 3 (LC3)-II/LC3-I ratio. These findings significantly elucidated that BBR promoted the restoration of autophagy in IECs by inhibiting exosomal lncRNA H19, thereby mitigating the impairment of the intestinal mucosal mechanical barrier function in diclofenac enteropathy. The process involving exosomal lncRNA H19 regulating autophagy, thereby affecting the intestinal mucosal mechanical barrier, offers a novel perspective for the application of BBR in the treatment of diclofenac enteropathy.

Wheat peptides inhibit the activation of MAPK and NF-κB inflammatory pathways and maintain epithelial barrier integrity in NSAID-induced intestinal epithelial injury

The use of non-steroidal anti-inflammatory drugs (NSAIDs) has negative effects on the gastrointestinal tract, but the proton pump inhibitors currently in use only protect against gastrointestinal disease and may even make NSAID-induced enteropathy worse. Therefore, new approaches to treating enteropathy are required. This study aimed to investigate the protective effect of wheat peptides (WPs) against NSAID-induced intestinal damage in mice and their mechanism. Here, an in vivo mouse model was built to investigate the protective and reparative effects of different concentrations of WPs on NSAID-induced intestinal injury. WPs ameliorated NSAID-induced weight loss and small intestinal tissue damage in mice. WP treatment inhibited NSAID-induced injury leading to increased levels of oxidative stress and expression levels of inflammatory factors. WPs protected and repaired the integrity and permeability injury of the intestinal tight junction induced by NSAIDs. An in vitro Caco-2 cell model was built with lipopolysaccharide (LPS). WP pretreatment inhibited LPS-induced changes in the Caco-2 cell permeability and elevated the levels of oxidative stress. WPs inhibited LPS-induced phosphorylation of NF-κB p65 and mitogen-activated protein kinase (MAPK) signaling pathways and reduced the expression of inflammatory factors. In addition, WPs increased tight junction protein expression, which contributed to improved intestinal epithelial dysfunction. Our results suggest that WPs can ameliorate NSAID-induced impairment of intestinal barrier functional integrity by improving intestinal oxidative stress levels and reducing inflammatory factor expression through inhibition of NF-κB p65 and MAPK signaling pathway activation. WPs can therefore be used as potential dietary supplements to reduce NSAID-induced injury of the intestine.

Further insights into the impact of rebamipide on gentamicin-induced nephrotoxicity in rats: modulation of SIRT1 and β-catenin/cyclin D1 pathways

Gentamicin (GM) is an effective antibiotic administered to treat acute Gram-negative infections. Nevertheless, its clinical application is limited due to nephrotoxicity. Therefore, our research aimed to investigate the potential renoprotective impact of rebamipide (RBM), a gastroprotective drug, on GM-induced kidney damage in rats, as well as putative nephroprotective pathways. RBM was orally administered (100 mg/kg/d for 14 d) commencing 7 d before the administration of GM (100 mg/kg/d, intraperitoneally). Nephrotoxicity was elucidated, and the silent information regulator 1 (SIRT1) and β-catenin/cyclin D1 pathways were assessed. GM induced a significant elevation in the serum levels of creatinine, blood urea nitrogen (BUN), and kidney injury molecule-1 (KIM-1), as well as the relative kidney index. In addition, GM increased lipid peroxidation and lowered total antioxidant capacity (TAC) level and superoxide dismutase (SOD) activity. GM administration also demonstrated a significant amplification in tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), nuclear factor-κappa B p65 (NF-κB p65), p38 mitogen-activated protein kinase (p38 MAPK), and caspase-3 kidney levels, as well as B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax)/Bcl-2 ratio. Notably, RBM treatment amended all these changes induced by GM. Furthermore, the potential role of SIRT1 and β-catenin-dependent signaling pathways in GM-induced renal injury was assessed. Our findings showed that GM-treated rats demonstrated a substantial decrease in SIRT1, nuclear factor E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) along with an increase in β-catenin, forkhead box O-3a (FOXO-3a), and cyclin D1 protein expressions. RMB treatment markedly attenuated the deterioration caused by GM on these pathways. Additionally, RBM alleviated the GM-induced deleterious kidney tissue histopathology. In conclusion, our findings have verified that RBM can halt GM-induced renal injury by partly modulating SIRT1 and β-catenin pathways.

Carnosic Acid Ameliorates Indomethacin-Induced Gastric Ulceration in Rats by Alleviating Oxidative Stress and Inflammation

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and indomethacin (IND) are the most commonly prescribed for inflammation or pain. However, widespread use causes several adverse effects, such as gastric ulcers, upper gastric system bleeding, and erosions. Carnosic acid (CA) is an important natural antioxidant found in rosemary (Rosmarinus essentials) and exhibits a protective effect by suppressing oxidative stress and inflammation. This study aimed to investigate the impact of CA on IND-induced gastric ulceration. Wistar male rats received CA (100 mg/kg) or esomeprazole (ESP) (20 mg/kg, standard drug) by oral gavage for 14 days, after that gastric ulceration was induced by oral administration of 100 mg/kg IND. CA pretreatment attenuated both gross morphological lesions and histopathological alterations. CA strongly reduced IND-induced oxidative stress, verified by a decrease in MDA (p < 0.001) and TOS levels (p < 0.05). Furthermore, an IND-dependent increase in CAT (p < 0.001) and GPx (p < 0.01) activities, as well as a reduction in GSH levels (p < 0.01), were ameliorated by CA pretreatment. CA also attenuated inflammatory damage by suppressing IL-1β (p < 0.01), IL-6 (p < 0.01), and TNFα (p < 0.001) production and increasing Nrf2/HO-1 (p < 0.05) expressions. In conclusion, CA shows a gastroprotective effect by reducing oxidative stress and attenuating inflammation.

Ibuprofen Increases Markers of Intestinal Barrier Injury But Suppresses Inflammation at Rest and After Exercise in Hypoxia

PURPOSE

The purpose of this study was to evaluate the effects of acute ibuprofen consumption (2 × 600-mg doses) on markers of enterocyte injury, intestinal barrier dysfunction, inflammation, and symptoms of gastrointestinal (GI) distress at rest and after exercise in hypobaric hypoxia.

METHODS

Using a randomized double-blind placebo-controlled crossover design, nine men (age, 28 ± 3 yr; weight, 75.4 ± 10.5 kg; height, 175 ± 7 cm; body fat, 12.9% ± 5%; V̇O 2 peak at 440 torr, 3.11 ± 0.65 L·min -1 ) completed a total of three visits including baseline testing and two experimental trials (placebo and ibuprofen) in a hypobaric chamber simulating an altitude of 4300 m. Preexercise and postexercise blood samples were assayed for intestinal fatty acid binding protein (I-FABP), ileal bile acid binding protein, soluble cluster of differentiation 14, lipopolysaccharide binding protein, monocyte chemoattractant protein-1, tumor necrosis factor α (TNF-α), interleukin-1β, and interleukin-10. Intestinal permeability was assessed using a dual sugar absorption test (urine lactulose-to-rhamnose ratio).

RESULTS

Resting I-FABP (906 ± 395 vs 1168 ± 581 pg·mL -1 ; P = 0.008) and soluble cluster of differentiation 14 (1512 ± 297 vs 1642 ± 313 ng·mL -1 ; P = 0.014) were elevated in the ibuprofen trial. Likewise, the urine lactulose-to-rhamnose ratio (0.217 vs 0.295; P = 0.047) and the preexercise to postexercise change in I-FABP (277 ± 308 vs 498 ± 479 pg·mL -1 ; P = 0.021) were greater in the ibuprofen trial. Participants also reported greater upper GI symptoms in the ibuprofen trial ( P = 0.031). However, monocyte chemoattractant protein-1 ( P = 0.007) and TNF-α ( P = 0.047) were lower throughout the ibuprofen trial compared with placebo (main effect of condition).

CONCLUSIONS

These data demonstrate that acute ibuprofen ingestion aggravates markers of enterocyte injury and intestinal barrier dysfunction at rest and after exercise in hypoxia. However, ibuprofen seems to suppress circulating markers of inflammation.

NLRP3 inflammasome inhibitor MCC950 can reduce the damage of pancreatic and intestinal barrier function in mice with acute pancreatitis

PURPOSE

Abnormal activation of NOD-like receptor protein 3 (NLRP3) inflammasome can lead to the occurrence and progression of acute pancreatitis. This study investigated the protective effect of MCC950 on pancreatitis mice.

METHODS

Eighteen mice were randomly divided into control group, severe acute pancreatitis (SAP) group and SAP+MCC950 group. Serum interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) were measured by ELISA. Hematoxylin and eosin (HE) staining was used to evaluate the pathological damage. Western blotting was used to detect the expression of NLRP3 inflammasome and tight junction proteins in the small intestine and pancreas.

RESULTS

MCC950 could reduce the levels of IL-6 and IL-1β in SAP mice. After treatment with MCC950, the expression levels of NLRP3 inflammasome in the pancreas of SAP mice were significantly reduced and the pathological damage to the pancreas and intestine was alleviated. Compared with the control group, the expression of tight junction protein (ZO-1,occludin and claudin-4) in the intestinal mucosa of SAP mice was decreased, and the expression of claudin-4 and occludin were upregulated after MCC950 treatment.

CONCLUSIONS

MCC950 can inhibit NLRP3 inflammasome activation and significantly reduce the inflammatory response and delay the process of pancreatitis. It has therapeutic potential in the treatment of acute pancreatitis.

Epithelial protective therapy in comorbid diseases. Practical Guidelines for Physicians

In 2021 the first multidisciplinary National Consensus on the pathophysiological and clinical aspects of Increased Epithelial Permeability Syndrome was published. The proposed guidelines are developed on the basis of this Consensus, by the same team of experts. Twenty-eight Practical Guidelines for Physicians statements were adopted by the Expert Council using the "delphic" method. Such main groups of epithelial protective drugs as proton pump inhibitors, bismuth drugs and probiotics are discussed in these Guidelines from the positions of evidence-based medicine. The clinical and pharmacological characteristics of such a universal epithelial protector as rebamipide, acting at the preepithelial, epithelial and subepithelial levels, throughout gastrointestinal tract, are presented in detail.

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.

Engineering a Remedy to Modulate and Optimize Biopharmaceutical Properties of Rebamipide by Synthesizing New Cocrystal: In Silico and Experimental Studies

PURPOSE

Rebamipide (REB) a potent anti-ulcer agent, has not been exploited to its full potential, owing to it extremely poor solubility, leading to highly diminutive bioavailability (<10%). The purpose is to carry out its solid-state modification.

METHOD

Cocrystallisation was done with three GRAS coformers namely citric acid (CA), 3,4-dihydroxybenzoic acid (DHBA) and oxalic acid (OXA) employing the liquid-assisted grinding method. Cocrystal formation was based upon amide-carboxyl and amide-hydroxyl supramolecular synthons. Characterization of novel cocrystals i.e. RCA, RDHBA and ROXA was carried out by DSC, PXRD and additionally by FT-IR spectroscopy. Chemical structures have been determined utilizing the PXRD pattern by Material Studio®. Furthermore, cocrystals were subjected to solubility and intrinsic dissolution rate (IDR) evaluation. Also, pharmacodynamic and pharmacokinetic studies were performed and compared with pure rebamipide.

RESULT

The appearances of a single sharp melting endotherm in DSC, along with novel characteristic peaks in PXRD infer the existence of a new crystalline form. Shifting in characteristic vibrations in FT-IR spectroscopy supports the establishment of distinct hydrogen-bonded networks. Structural determination revealed that RCA crystallizes in 'Bb2b' space groups whereas RDHBA in 'P1' and ROXA crystallize out in the 'P-1' space group. All the cocrystals exhibited superior apparent solubility and almost 7-13 folds increase in IDR. Furthermore, 1.6-2.5 folds enhancement in relative bioavailability and remarkable amplification in anti-ulcer, anti-inflammatory and the antioxidant potential of these cocrystals were observed.

CONCLUSION

The study ascertains the advantages of cocrystallization, with RCA showing greatest potential and suggests a viable alternative approach for improved formulation of rebamipide.