Radioprotection to small intestine of the mice against ionizing radiation by semiquinone glucoside derivative (SQGD) isolated from Bacillus sp. INM-1.

Ionizing irradiation induces severe damage to the intestinal crypt cells which are responsible for renovation and maintenance of the intestinal cellular architecture. Therefore, protection of intestinal cells and tissue against lethal irradiation using a semiquinone glucoside derivative (SQGD) isolated from radioresistant bacterium Bacillus sp. INM-1 is the prime focus of the present investigation. BALB/c mice were administered by SQGD (50 mg/kg.b.wt. i.p.) 2 h before whole body irradiation (10 Gy), and histological analysis of the jejunum section was carried out and compared to the irradiated mice. Significant (p < 0.0001) increase in villus length, number of cells per villus, crypts numbers per villus section, total cells counts and mitotic cell counts per crypt and low goblet cells per villus section, and low apoptotic index per crypt section were observed in the irradiated mice pre-treated by SQGD at 48-168 h. Significant induction in NF-kβ at 24 h and Bcl-2/Bax ratio was observed in irradiated mice pre-treated by SQGD compared to only irradiated animals. SQGD pre-treatment before irradiation was found instrumental to reverse the radiation-induced degenerative changes by replenishment of the damaged cells by enhancing mitotic, proliferating, pro-survival, and apoptosis inhibitory activities probably through modulation of cell cycle arrest in G(1)/S phase in the intestinal cellular milieu.