The Radioprotection Of Polysaccharide From Tubers And Leaves Of Purple Sweet Potato In Vivo

The optimal extracting conditions of polysaccharide from purple sweet potato leaves were studied in this paper. We investigated the radioprotective activity of polysaccharide from purple sweet potato and purple sweet potato leaves in mice irradiated by a137Cs gamma (y) ray.Temperature, solid-liquid ratio, extraction time and the times of the extraction were selected as the single factor test conditions. The results of orthogonal test showed that the best process of polysaccharide extraction was that extraction temperature was70℃, extraction time was2h, the times of extraction was twice and the ratio of sample and solvent was1:30. The two different methods (the Sevage and the Polyamide) were compared that which one was better to remove protein from crude plysaccharides. The results indicate that the Polyamide was better. The optimal conditions:polyamide dosage was9g polyamide/0.1g crude plysaccharides, and the time was17.5h..Mice were randomly divided into five groups, namely the control group and four experimental groups which were given polysaccharide from purple sweet potato (modle group(0mg/kg Bw.d), low group(200mg/kg Bw.d), middle group (400mg/kg Bw.d), high group((800mg/kg Bw.d))for30days. The four experimental groups of mice were then exposed to the4Gy137Cs y-rays and were given polysaccharide from purple sweet potato for a further14days. Mice were randomly divided into another five groups. Four experimental groups were given polysaccharide from purple sweet potato leaves (modle group(0mg/kg Bw.d), low group(200mg/kg Bw.d), middle group (400mg/kg Bw.d), high group(800mg/kg Bw.d)for30days. The four experimental groups of mice were then exposed to the7.5Gy137Cs γ-rays and were given polysaccharide from purple sweet potato leaves for a further14days. The number of white blood cells, the number of micronuclei in polychromatophilic erythrocytes of bone marrow in mice and the number of spleen colony-forming cells (CFU-S) of all the ten groups were determined. The activity of superoxide dismutase, glutathione peroxidase and catalase, the level of malondialdehyde, spleen index and thymus index were also determined.Compared to the control group, daily administration of polysaccharides can increase the number of white blood cells, the number of micronuclei in polychromatophilic erythrocytes of bone marrow and the number of spleen colony-forming cells (CFU-S), which demonstrate the polysaccharides protected the hematopoietic system. The polysaccharides prevented the decline in the spleen index and thymus index in mice radiated by137Cs γ-rays, suggesting the two kinds of polysaccharide could at least partially restore immunological function. Further more, the activity of superoxide dismutase, glutathione peroxidase and catalase were restored, and the high level of malondialdehyde in mice radiated was reduced. All the results indicate that daily administration of the polysaccharide from purple sweet potato is radioprotective in mice irradiated by4Gy137Cs γ-rays in vivo and the polysaccharide from purple sweet potato leaves is radioprotective by7.5Gy137Cs y-rays, too.