Preparation And Investigation Of The Characteristics Of Ph-Sensitive Redox Nanoparticles (Rnps) For Aspirin-Induced Gastric Ulcer Treatment

Abstract

Multiple etiologies, including H. pylori infection, NSAIDs use, gastric bypass surgery, smoking, selective serotonin reuptake inhibitor use, stress, lifestyle choices, and genetic traits, have been identified as the primary risk factors for gastric ulcer (GU) disease. This project mainly focuses on Aspirin, a type of NSAIDs, often causes acute gastric mucosal damage that can be seen endoscopically or assessed indirectly (for example, by measuring increased gastrointestinal blood loss). The occurrence of most adverse effects is apparently related to the dose administered. This dose-response effect, evident in both endoscopic and microbleeding studies done after acute or short-term aspirin administration, is also associated with the risk of developing chronic gastric ulcer. This thesis carried out a variety of assay to investigate the characteristics and ROS scavenging activity of redox nanoparticles (RNPs). The pH sensitivity of RNP-N in acidic conditions is a premise to investigate the ability to protect the stomach from ulcers in Aspirin-induced peptic gastric ulcer (GU) mice model in this study. One oral dosing Aspirin (350 mg/kg) used to induce the gastric ulcer in mice, and treated by one oral dosing of RNPs (120mg/kg). According to the histological results, there was a significant difference of stomach mucosa between the untreated group and the pretreatment group with RNPs. In addition, while lipid peroxide level of the group pretreated with RNPs was 2 times less than of Aspirin-induced gastric ulcer group, MDA activity of mice treated with RNP-O was higher than with RNP-N. This proves that RNPs have good anti-inflammatory and ROS scavenging ability and that RNP-N has has well completed the task of an antioxidant and sensitive to acid environment.