Polysaccharide isolated from Parmelia tinctorum ameliorates ionizing irradiation-induced damage in mice

In this study,wpt-a,a type of water-soluble homogeneous lichen polysaccharide,was isolated and purified from parmelia tinctorum. we investigated whether wpt-a has radioprotective effects when administered before total-body irradiation (tbi). mice were treated with wpt-a via intraperitoneal injection (i.p.) once per day for three consecutive days prior to 7,7.5,8.5,10 or 10.5-gy tbi. our results indicated that the survival rate was enhanced at a range of levels of tbi. the calculated dose reduction factor (drf) was 1.2. white blood cell (wbc) counts,spleen colony forming units (cfu-s) and bone marrow nucleated cell (bmnc) counts were used to investigate the radioprotective effects of wpt-a on the hematopoietic system. the treatment groups received wpt-a at 20,50 and 80 mg/kg b.w. doses before 6.5-gy tbi and showed significantly higher bmnc and wbc counts compared with the radiation-only group. the groups administered 50 and 80 mg/kg b.w. wpt-a showed a significant increase in cfu-s compared with the radiation-only group. we also carried out a single cell gel electrophoresis assay to explore the radioprotective effects of wpt-a on dna damage. the results from single-cell gel electrophoresis of peripheral blood leukocytes showed that wpt-a attenuated radiation-induced dna damage. these results indicate a potential use for wpt-a as a radioprotector. © 2014 the author.