Radiation protection of sodium alginate and its regulatory effect on intestinal microflora in mice.

Prolonged or high-dose exposure to ionizing radiation (IR) can cause damage to normal tissues of the body. Therefore, it is imperative to find effective radiation protective agents to mitigate IR-induced damage. This study evaluated the effects of sodium alginate (SA) on the radiation protection and modulatory effects of gut microorganisms using a Coγ-induced damage model in mice. Results showed that SA could reduce the damage of hematopoietic system; and alleviate the oxidative damage in irradiated mice by inhibiting the content of malondialdehyde (MDA) and increasing the activities of superoxide dismutase (SOD) and glutathione (GSH) in serum, spleen, jejunum and liver. Moreover, SA treatment ameliorated IR-induced small intestine lesions and alleviated liver injury. This was consistent with decreased levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and tumor necrosis factor-α (TNF-α), and increased levels of interferon-γ (IFN-γ) and interleukin-2 (IL-2) after SA treatment. Furthermore, SA treatment reversed IR-induced gut dysbiosis, elevated the Firmicutes/Bacteroidetes ratio, increased the beneficial bacteria and reduced the pathogenic bacteria in the small intestine. In conclusion, the present study demonstrated that SA exerted good radioprotective effect by improving hematopoietic system, alleviating oxidative stress, attenuating liver injury and inflammatory response, and modulating the intestinal microbiota in irradiated mice.