Rice Bran Extract Alleviates Inflammation and Promotes Wound Healing in Radiation Dermatitis

Radiation dermatitis is a common side effect of radiotherapy, affecting up to 95% of cancer patients receiving radiation therapy and often leading to skin damage, inflammation, and ulceration. The pathogenesis of radiation dermatitis involves complex mechanisms, such as the production of reactive oxygen species (ROS) and sustained inflammatory responses. Current treatments, including topical steroids, moisturisers, and non-steroidal anti-inflammatory drugs (NSAIDs), often provide limited efficacy, primarily addressing symptoms rather than the underlying pathophysiological processes. In this study, we evaluated the therapeutic potential of rice bran extract (RBE) in mitigating radiation-induced skin injury. High-performance liquid chromatography (HPLC) analysis revealed that RBE is rich in bioactive compounds, including pyrogallol, gallic acid, and ferulic acid, known for their antioxidant and anti-inflammatory properties. In vitro assays demonstrated that RBE exhibited fair biocompatibility, reduced IL-6 production, enhanced 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, stimulated procollagen synthesis, and promoted fibroblast migration. In a murine dorsal skin irradiation model, topical RBE application alleviated dermatitis severity, reduced skin ulceration, minimised histological signs of inflammation and fibrosis, and promoted epithelial regeneration. Bulk RNA sequencing revealed that RBE modulated key pathways related to inflammation resolution, epidermal repair, and metabolic adaptation, with Pparg identified as a central upstream regulator. Overall, RBE demonstrates antioxidant, anti-inflammatory, and pro-regenerative activities that support its potential for preventing and treating radiation dermatitis.