The Protective Effect Of Rebamipide On The NSAIDs Enteropathy And Its Mechanism In Mice

Background: NSAIDs are widely used, NSAIDs gastrointestinal mucosal injury is a common adverse reactions. The gastric mucosal damage induced by NSAIDs has been extensively studied. The diagnosis and treatment of NSAIDs enteropathy have not been known clearly yet. The change of small intestinal permeability could directly reflect the small intestinal mucosa integrity and barrier function, help to identify early damage of intestinal mucosal. Therefore, the early small intestinal damage can be found by permeability detecting, which providing reference for NSAIDs enteropathy and assessment for the effect of mucosal pretective agent. Rebamipide is a mucosal protective agent, which can stimulate the production of endogenous prostaglandins in the gastric mucosa. In addition, rebamipide showed to have the healing effect for patients with corticosteroid resistant ulcerative colitis in a human case report. However, few researches have emphasized on the effect of rebamipide on NSAIDs enteropathy. The research was to investigate the protective effect of rebamipide for NSAIDs enteropathy and to explain its mechanism.Objective:To establish the Kunming mice model of NSAIDs enteropathy induced by diclofenac and investigate the effect of rebamipide on small intestinal injury and permeability in mice and its possible mechanism.Methods:1. NSAIDs enteropathy model(1) Comparison of different models NSAIDs enteropathy Aspirin, indomethacin, diclofenac sodium were used for preparation of NSAIDs enteropathy model, which aspirin 500mg/kg, indomethacin 5mg/kg, diclofenac sodium 10mg/kg administration intragastric for 3 days. Normal group fed with solvent. There days later, intestinal permeability was assessmented by EB and the number of ulcers were calculated.(2) Enteropathy models induced by different doses and times of diclofenacEnteropathy model were induced by different doses of diclofenac sodium (2.5mg/kg, 5mg/kg, 10mg/kg orally 3 days), and times (diclofenac were administered 10mg/kg for 1,2 and 3 days). Normal group fed with solvent. There days later, intestinal permeability was assessmented by EB and the number of ulcers were calculated.2. The protective effect of rebamipide on NSAIDs enteropathy and its mechanism.The model group was induced by intragastric administration with the diclofenac(2.5mg/kg) in mice. Normal group and model group were intragastric administrated with the solvent, glutamine group and rebamipide group were intragastric administrated with the glutamine (1000mg/kg) and rebamipide (100,200,400 mg/kg) respectively. At the end of the experiment, the small intestinal mucosa was collected for assessment of the pathologic change of intestinal mucosa and transmission electron microscope (TEM). The intestinal mucosal permeability was detected by Evans blue and FITC-dextran methods. The malondialdehyde(MDA) and myeloperoxidase(MPO) levels in small intestinal mucosal homogenate were determined. The parameters of mitochondrial function including the mitochondrial swelling and mitochondrial membrane protential, mitochondrial NADH levels, SDH and ATPase activities were measured.Results:1. NSAIDs enteropathy model(1) Comparison of different models NSAIDs enteropathy Compared with the normal group, aspirin group was not induced ulceration, the small intestinal permeability of EB was increased without statistically significant (621.1±114.2 vs 460.6±89.7 ug/g, P> 0.05). Indomethacin significantly induced the small intestinal damage, which showed ulcers significantly increased (8.2±1.9 vs 0, P <0.01), intestinal permeability of EB was significantly higher (2132.0±315.7 vs 460.6±89.7 ug / g, P <0.01). Diclofenac sodium (10mg/kg 3 days) was significantly induced intestinal injury.(2) Enteropathy models induced by different doses and times of diclofenacCompared with the normal group, diclofenac sodium 10mg/kg,1 days donot cause visible damage. the permeability of EB was not significant difference (567.5±80.2 vs 460.6±89.7 ug / g, P> 0.05). Other groups were induced the small intestinal damage significantly, and with the dosage increased and prolonged administration, the more obvious damage. According to our experimental results, and reference literature, we choose diclofenac sodium 2.5mg/kg for the next experiment.2. The protective effect of rebamipide on NSAIDs enteropathy and its mechanism.Compared with normal group, the permeability were increased significantly in model group (P<0.01). The pathologic score, MDA and MPO levels and the ulcers of intestinal mucosa were increased significantly. Intestinal mucosa showed a thinning of microvillous carpet,with decurtated and broaden junctional complex and enlarged intercellular space under TEM observations. The rebamipide can obviously reduce the intestinal mucosal permeability. The small intestinal villus morphology and intercellur space is near to be normal by TEM observations. The pathologic score,the MDA and MPO levels and the ulcers of intestinal mucosa were decreased significantly. At the mitochondrial level, rebamipide can evidently increase the SDH, ATPase activities and NADH levels, decrease the swelling extent of mitochondria. Conclusions:1. In different NSAIDs enteropathy model, diclofenac 2.5mg/kg orally 3 days induced the increased small intestinal permeability2. Rebamipide have a protective effect on NSAIDs enteropathy model, significantly improved intestinal permeability, the mechanism may be related to antioxidant and mitochondrial protection...