Immediate effects of acute Mars mission equivalent doses of SEP and GCR radiation on the murine gastrointestinal system-protective effects of curcumin-loaded nanolipoprotein particles (cNLPs)

Introduction: Missions beyond low Earth orbit (LEO) will expose astronauts to ionizing radiation (IR) in the form of solar energetic particles (SEP) and galactic cosmic rays (GCR) including high atomic number energy (HZE) nuclei. The gastrointestinal (GI) system is documented be highly radiosensitive with even relatively dose IR exposures capable inducing mucosal lesions disrupting epithelial barrier function. also an established risk factor for colorectal cancer (CRC) several studies examining long-term GI effects SEP/GCR exposure using tumor-prone APC mouse models. Studies acute short-term modeled space wildtype models are more limited necessary better define charged particle- induced pathologies test novel medical countermeasures (MCMs) promote astronaut safety. Methods: In this study, we performed ground-based where male female C57BL/6J mice were exposed γ-rays, 50 MeV protons, or 1 GeV/n Fe-56 ions at NASA Space Radiation Laboratory (NSRL) histology immunohistochemistry endpoints measured first 24 h post-irradiation immediate SEP/GCR-induced alterations. Results: Our data show that unlike matched γ-ray controls, protons iron disrupts intestinal function induces lesions, vascular congestion, breakdown, marked enlargement mucosa-associated lymphoid tissue. We kinetics DNA double-strand break (DSB) repair gamma-H2AX- specific antibodies apoptosis via TUNEL labeling, noting induction disappearance extranuclear cytoplasmic by gamma-H2AX only particle-irradiated samples. 18 pre-treatment curcumin-loaded nanolipoprotein (cNLPs) delivered IV injection reduces DSB-associated foci levels restore crypt villi lengths. Discussion: These improve our understanding physiological alterations tract immediately following radiations demonstrates effectiveness a promising MCM.