Primary characterization and protective effect of polysaccharides from Hohenbuehelia serotina against γ-radiation induced damages in vitro

The primary structure and radioprotective activities of acid extracted polysaccharides (ACHSP), water extracted polysaccharides (WTHSP) and alkaline extracted polysaccharides (ALHSP) were investigated after isolating from the fruit bodies of Hohenbuehelia serotina. Results suggested that ACHSP and ALHSP were all composed of arabinose (Ara), xylose (Xyl), mannose (Man), glucose (Glu) and galactose (Gal), and WTHSP was composed of ribose (Rib), Ara, Man, Glu and Gal. The molecular weight distribution of ACHSP, WTHSP and ALHSP ranged from 4.62×10³ to 9.92×10⁶, 1.19×10³ to 1.55×10⁴ and 5.37×10³ to 1.82×10⁷, respectively. Biological activities experiments revealed that ACHSP, WTHSP and ALHSP possessed strong reducing power, immunomodulation and anti-radiation effects in a concentration-dependent manner. Among three polysaccharides, WTHSP exhibited the highest biological activities which could effectively increase the superoxide dismutase (SOD) and catalase (CAT) activities, and reduce the malonaldehyde (MDA) levels in splenocytes after radiation. WTHSP also possessed significant protective effect on DNA apoptosis induced by ionizing radiation. These results showed that WTHSP had potential biological applications to be exploited.