Quality evaluation of guidelines for the diagnosis and treatment of radiation enteritis

Pharmacological potential of natural medicine Astragali Radix in treating intestinal diseases

Due to changes in diet and lifestyle, the prevalence of intestinal diseases has been increasing annually. Current treatment methods exhibit several limitations, including adverse reactions and drug resistance, necessitating the development of new, safe, and effective therapies. Astragali Radix, a natural medicine utilized for over two millennia, offers unique advantages in treating intestinal ailments due to its multi-component and multi-target properties. This study aims to review the effective components of Astragali Radix that provide intestinal protection and to explore its pharmacological effects and molecular mechanisms across various intestinal diseases. This will provide a comprehensive foundation for using Astragali Radix in treating intestinal diseases and serve as a reference for future research directions. The active components of Astragali Radix with protective effects on the intestines include astragaloside (AS)-IV, AS-III, AS-II, astragalus polysaccharide (APS), cycloastagenol, calycosin, formononetin, and ononin. Astragali Radix and its active components primarily address intestinal diseases such as colorectal cancer (CRC), inflammatory bowel disease (IBD), and enterocolitis through mechanisms including anti-inflammatory actions, antioxidative stress responses, anti-proliferation and invasion activities, regulation of programmed cell death, immunoregulation, restoration of the intestinal epithelial barrier, and modulation of the intestinal microbiota and its metabolites. Consequently, Astragali Radix demonstrates significant intestinal protective activity and represents a promising natural treatment for intestinal diseases. However, the pharmacological actions and mechanisms of some active components in Astragali Radix remain unexplored. Moreover, further comprehensive toxicological and clinical studies are required to ascertain its safety and clinical effectiveness.

Pathways regulating intestinal stem cells and potential therapeutic targets for radiation enteropathy

Radiotherapy is a pivotal intervention for cancer patients, significantly impacting their treatment outcomes and survival prospects. Nevertheless, in the course of treating those with abdominal, pelvic, or retroperitoneal malignant tumors, the procedure inadvertently exposes adjacent intestinal tissues to radiation, posing risks of radiation-induced enteropathy upon reaching threshold doses. Stem cells within the intestinal crypts, through their controlled proliferation and differentiation, support the critical functions of the intestinal epithelium, ensuring efficient nutrient absorption while upholding its protective barrier properties. Intestinal stem cells (ISCs) regulation is intricately orchestrated by diverse signaling pathways, among which are the WNT, BMP, NOTCH, EGF, Hippo, Hedgehog and NF-κB, each contributing to the complex control of these cells' behavior. Complementing these pathways are additional regulators such as nutrient metabolic states, and the intestinal microbiota, all of which contribute to the fine-tuning of ISCs behavior in the intestinal crypts. It is the harmonious interplay among these signaling cascades and modulating elements that preserves the homeostasis of intestinal epithelial cells (IECs), thereby ensuring the gut's overall health and function. This review delves into the molecular underpinnings of how stem cells respond in the context of radiation enteropathy, aiming to illuminate potential biological targets for therapeutic intervention. Furthermore, we have compiled a summary of several current treatment methodologies. By unraveling these mechanisms and treatment methods, we aspire to furnish a roadmap for the development of novel therapeutics, advancing our capabilities in mitigating radiation-induced intestinal damage.

Intravenous immunoglobulin protects the integrity of the intestinal epithelial barrier and inhibits ferroptosis induced by radiation exposure by activating the mTOR pathway

Radiation exposure often leads to serious health problems in humans. The intestinal epithelium is sensitive to radiation damage, and radiation causes destruction of the intestinal epithelial barrier, which leads to radiation enteritis (RE), the loss of fluids, and the translocation of intestinal bacteria and toxins; radiation can even threaten survival. In this study, we aimed to explore the influence of IVIg on the integrity of the intestinal epithelial barrier after RE. Using a RE mouse model, we investigated the protective effects of intravenous immunoglobulin (IVIg) on the epithelial junctions of RE mice and validated these findings with intestinal organoids cultured in vitro. In addition, transmission electron microscopy (TEM), western blotting (WB) and immunostaining were used to further investigate changes in intestinal epithelial ferroptosis and related signaling pathways. When RE occurs, the intestinal epithelial barrier is severely damaged. IVIg treatment significantly ameliorated this damage to epithelial tight junctions both in vivo and in vitro. Notably, IVIg alleviated RE by inhibiting intestinal epithelial ferroptosis in RE mice. Mechanistically, IVIg promoted activation of the mTOR pathway and inhibited ferroptosis in the intestinal epithelium of mice. Rapamycin, which is a potent inhibitor of the mTOR protein, significantly abolished the protective effect of IVIg against radiation-induced damage to intestinal epithelial tight junctions. Overall, IVIg can prevent RE-induced damage to the intestinal epithelial barrier and inhibit ferroptosis by activating the mTOR pathway; this study provides a new treatment strategy for patients with RE caused by radiotherapy or accidental nuclear exposure.