Radioprotective effect of Hohenbuehelia serotina polysaccharides through mediation of ER apoptosis pathway in vivo.

Exposure to ionizing radiation would induce human body to serious oxidative damage, leading to production of various diseases. In present study, the radioprotective effect based on endoplasmic reticulum (ER) apoptosis pathway of neutral polysaccharides from Hohenbuehelia serotina (NTHSP) was systematically investigated through establishment of radiation damage model in mice. Toxicological analyses showed that NTHSP did not possess any acute or chronic toxic on mice within experimental concentration range. In order to elucidate the radioprotective mechanism, immunohistochemical and RT-qPCR methods were respectively performed. The results suggested that the mice administrated with NTHSP could significantly prevent the splenocytes apoptosis induced by gamma-radiation through block of three major types in ER apoptosis pathway: PERK-ATF4-CHOP, IRE1α-XBP1-CHOP, as well as ATF6-XBP1-CHOP, compared with the mice in radiation group. Moreover, NTHSP could also inhibit the activation of Caspase-12 in ER, induced by gamma-radiation. Taken together, our results indicated that H. serotina polysaccharides possessed the excellent potential to serve as natural radioprotector for human body against the damage induced by radiation.