Initial Study Of Polysaccharide From Porphyra On Immunosuppressive Activity

PrefaceRecently,the wide study of component and value of health protection on Porphyra has discovered that Porphyra Polysaccharide and protein are ultimate constituent. Porphyra Polysaccharide is very important in polysaccharides domain, it is one of the sulfated polygalactans composed of galactose and 3, 6-anhydrogalactose units and sulfate. It is one of major component from Porphyra and usually accounts for 20%(?) 40% of the total mass.Porphyra Polysaccharide has been found to be able to reinforce immune system, but some scholar found that it is able to inhibit activity and generation of immunocell in vitro. In order to study Porphyra Polysaccharide effect on mouse of immune system in vivo, the article more study inhibition fraction on Porphyra Polysaccharide. Extracting Porphyra Polysaccharide and grading, inhibition fraction was peritoneal injection into mice. Observe the effect on natural killer cell and peritoneal macrophage and specific antibody of mouse. The result of this study will make an experimental basis for make clear Porphyra Polysaccharide positive and negative immune-modulating effects and exploitation and application.Materials and MethodsExtracting polysaccharide by routine, obtain Porphyra Polysaccharide F and grading fractions F,F and F. 96 Kunming mice were divided into 2 groups ,each group were divided into 8 groups of 6 mice/group. F and F in dosages(0．05g(?)kg,0．25 g(?)kg,0．5g(?)kg)were injected 6 groups, injection of Cyclophosphamide or physiological saline solution alon as controls. Another 2 mice were killed to get spleen cells. MTT, LDH, Griess and ELISA assay were adopted to study the effect on these polysaccharide and fractions on the activity of spleen cell, nature killer cell, peritoneal macrophage and the serum antigen-specific antibody level. The data obtained were analyzed statistically by Student`s t-test and ANOVA.ResultsPorphyra Polysaccharide and its fractions all showed significant inhibitory effect on the activity of spleen cells in vitro. The present results show that nature killer cell and peritoneal macrophage immune activity were inhibited by the F, on contrary that were promoted by F. The serum antigen-specific antibody level was not changed by F and F.DiscussionSome scholar found that Porphyra Polysaccharide is able to inhibit activity and generation of immunocell in vitro, it is concordant with this study. But Yashizawa thought porphyra might stimulate the macrophage activity. The difference is due to distinction on chemical composition and spatial structure. On the other hand, adopting to experiment method and immune cell is different.This text studied on F and F in vivo. The present results show that nature killer cell and peritoneal macrophage immune activity were inhibited by the F, on contrary that were promoted by F. The serum antigen-specific antibody level was not changed by F and F. By detecting NO level reflect indirectly peritoneal macrophage kill activity. Usually we considered that the mechanism of action is this: IFN-(?) is produced by Thl cell mainly. IFN-(?) has the strong activation of macrophage and NK cells, and the conjugation between the IFN-(?) and the receptor of Macrophage might recover and reinforce the producing levels of NO of Macrophage. In this study, result of inhibition is due to inhibit source head of mechanism. The serum antibody level seems to reflect the systemic immune status, and cytokine production seems to be an index of the local immune activity. We therefore speculate that positive and negtive immune-modulating effects are neutralized on Porphyra Polysaccharide.We may speculate that Porphyra Polysaccharide is multiplicity commixture .As whole, Porphyra Polysaccharide show immunologic enhancement, but may get the fraction of immune suppression by separation. On the other hand, positive and negtive immune-modulating effects are neutralized or showed result of ascendancy fraction on Porphyra Polysaccharide.ConclusionFraction of Porphyra Polysaccharide showed different extent inhibitory effect on the activity of spleen cells in vitro and nature killer cell and peritoneal macrophage, but the serum antigen-specific antibody level was not changed.