title: Polysaccharides from Astragalus membranaceus promote phagocytosis and superoxide anion (O2-) production by coelomocytes from sea cucumber Apostichopus japonicus in vitro.
abstract: The potential immunostimulatory effects of Astralagus membranaceus polysaccharides (APS) on sea cucumber, Apostichopus japonicus (Selenka), were investigated in vitro. Phagocytosis and superoxide anion (O(2)(-)) production by phagocytic amoebocytes (PA) from A. japonicus coelomic fluid were measured during incubation at 18 degrees C, 22 degrees C, or 25 degrees C with APS at 0, 10, 20, or 40 microg mL(-1) (n=3). Phagocytic activity against yeast cells was quantified by direct visualization, and O(2)(-) production by nitroblue tetrazolium (NBT) reduction assay. Compared with controls, including APS at 20 microg mL(-1) significantly increased (P<0.05) the percentage of phagocytic capacity (PC) and phagocytic index (PI) at 18 degrees C and 22 degrees C, but no significant enhancement was observed at 25 degrees C. In contrast, the coelmocytes of A. japonicus can have an obvious generation of O(2)(-) after the stimulation. The concentration of 20 microg mL(-1) APS resulted in a significant increase in nitroblue tetrazolium (NBT) positive cells (P<0.05) at different temperature and even 10 microg mL(-1) APS could increase O(2)(-) generation significantly at 18 degrees C and 22 degrees C. Both phagocytosing and O(2)(-) production increased with the increase of APS concentration from 0 to 20 microg mL(-1) at different temperature, and when APS at 40 microg mL(-1), they were decreased. It suggested that immunocytes activity in A. japonicus decreased with the temperature increasing from 18 degrees C to 25 degrees C, and APS could be an effective immunostimulant to enhance phagocytic activity and O(2)(-) production.
authors.affiliation: Department of Bioscience and Biotechnology, Dalian University of Technology, Dalian, 116024, People's Republic of China.
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Sun
authors.forename: Liji
authors.initials: L
authors.lastname: Jin
authors.forename: Tingting
authors.initials: T
authors.lastname: Wang
authors.forename: Jipeng
authors.initials: J
authors.lastname: Xue
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Li
authors.forename: Jiansong
authors.initials: J
authors.lastname: You
authors.forename: Shuying
authors.initials: S
authors.lastname: Li
authors.forename: Yongping
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000276:Adjuvants, Immunologic / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D027885:Astragalus propinquus / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D010586:Phagocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure; D010587:Phagocytosis / Q000187:drug effects*; D011134:Polysaccharides / Q000302:isolation & purification / Q000494:pharmacology*; D012616:Sea Cucumbers / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure; D013481:Superoxides / Q000378:metabolism*; D013696:Temperature; D015003:Yeasts / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D011134:Polysaccharides; D013481:Superoxides