Medicinal plants for radiation enteritis: key bioactive compounds and relevant antioxidant mechanisms

Radiation enteritis, a complication following cancer radiotherapy, is caused by reactive oxygen species (ROS)-mediated oxidative damage, coupled with inflammatory dysregulation and disruption of the gut microbiota. Recent advancements in phytotherapy have highlighted the potential application of plant-derived bioactive compounds (e.g., curcumin from Curcuma longa, epigallocatechin gallate [EGCG], and resveratrol) as mitigators in treating radiation-induced intestinal injury. These compounds, characterized by potent ROS-scavenging activity, excellent biocompatibility, and minimal toxicity, exhibit promising attributes for therapeutic intervention. To better understand the botanical diversity and underlying mechanisms of radiation enteritis, this review systematically profiles the alkaloid-, flavonoid-, and polyphenol-rich medicinal plants, relevant bioactive constituents, and their associated therapeutic effects in synergistic modulation of oxidative, inflammatory, and apoptotic cascades. These natural compounds effectively leverage dual antioxidant mechanisms, including direct ROS scavenging via phenolic hydroxyl groups, indirect activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1), upregulation of endogenous antioxidants, suppression of pro-inflammatory cytokines, and enhancement of tight junction proteins for barrier repair. Despite their potential as adjuvant therapies, challenges remain in identifying exact antioxidant targets and translating these into clinical applications. To address this issue, we propose a framework that integrates phytochemistry, multi-omics profiling, and AI-enabled prediction of antioxidant targets. This review aims to facilitate the development of plant-based radioprotectants as next-generation adjuvant therapies.