Podophyllotoxin and rutin in combination prevents oxidative stress mediated cell death and advances revival of mice gastrointestine following lethal radiation injury.

Intestinal injury is inevitable during exposure to high radiation doses and is a common side effect observed during abdominal/pelvic radiotherapy. Yet, no radiation countermeasures are available for gastrointestine (GI) injury management. The aim of this study is to determine the effects of podophyllotoxin and rutin in combination (G-003M) on ionising radiation induced GI injury. We prophylactically administered G-003M to C57BL/6J mice exposed to 9 Gy total body radiation (TBI) and assessed for morphological changes, loss in absorption, fluid retention, biochemical alterations, immunohistochemical analysis to study cPARP, caspase-3, PCNA expression, and TUNEL staining. The irradiated intestine demonstrated extensive loss in crypts and villi, disrupted mucosal lining with reduced xylose uptake and enhanced fluid level post 7-day radiation. Mice receiving G-003M before radiation showed significant protection to intestinal epithelium, better allocation of secretory goblet cells, recovery in absorption, and reduced intestinal oedema. Additionally, G-003M administration also prevented radiation induced ROS generation, lipid peroxidation (MDA levels) and maintained the intestinal glutathione pool compared to the irradiated animals. G-003M supplementation also resulted in restoration of intestinal mitochondrial membrane potential, which was otherwise depolarised by radiation treatment. Immunohistochemical analysis demonstrated decrease in c-PARP and caspase-3 expression in jejuna cross sections and upregulation of PCNA in G-003M treated crypt cells as compared to 9 Gy irradiated mice. Our findings show that G-003M augment survival of mice against lethal radiation by promoting structural and functional regeneration in intestinal tissue. This combination therefore can be effectively explored for preventing radiation induced GI toxicity.