The aim of the study is to investigate the radioprotective effect of polysaccharide extract from Sipunculus nudus (SNP). Beagle dogs were randomly divided into the following six groups. Group-1: Un-treated and un-irradiated controls. Group-2: Exposed to a single acute dose of 2 Gy γ-radiation alone. Groups-3, 4 and 5: Oral administration of SNP at 50, 100 or 200 mg/kg body weight once a day for...