title: Antioxidant and anti-hyperglycemic activity of polysaccharide isolated from Dendrobium chrysotoxum Lindl.
abstract: Although polysaccharide is believed to play an important role in the medicinal effect of Dendrobium chrysotoxum Lindl (DCL), its role as an antioxidant and in anti-hyperglycemic induction was not reported. In this study, polysaccharide with molecular weight of approximately 150 kDa, herein named DCLP, was isolated from the stem of DCL, and its antioxidative, hypoglycemic and immune stimulating effects were evaluated using various in vitro and in vivo assay systems. DCLP inhibited hydroxyl radicals (*OH)-mediated deoxyribose degradation by scavenging hydroxyl radicals directly as well as by chelating iron ions. DCLP also showed dose-dependent scavenging activity on superoxide anions (O2*) and offered significant protection (p < 0.001) against glucose oxidasemediated cytotoxicity in Jurkat cells. DCLP had immune stimulating effects, as evidenced by the DCLP-mediated increases in the level of DNA synthesis, viability, and cytokine secretion in mouse lymphocytes. Moreover, oral administration of DCLP produced a significant reduction in blood glucose level in alloxan-induced diabetic mice. These findings suggest that DCLP has a potential utility in treating patients who require enhanced antioxidation, immune function and/or hypoglycemic activity.
authors.affiliation: Research Center of Bioactive Materials, Chonbuk National University, Chonju 561-756, Korea.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Zhao
authors.forename: Young-Ok
authors.initials: YO
authors.lastname: Son
authors.forename: So-Soon
authors.initials: SS
authors.lastname: Kim
authors.forename: Yong-Suk
authors.initials: YS
authors.lastname: Jang
authors.forename: Jeong-Chae
authors.initials: JC
authors.lastname: Lee
mesh_terms: D000496:Alloxan / Q000633:toxicity; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D002474:Cell-Free System / Q000737:chemistry / Q000187:drug effects; D016207:Cytokines / Q000378:metabolism; D031667:Dendrobium / Q000737:chemistry*; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000139:chemically induced / Q000517:prevention & control; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D017665:Hydroxyl Radical / Q000037:antagonists & inhibitors / Q000737:chemistry; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D019169:Jurkat Cells; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D011134:Polysaccharides / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared; D013481:Superoxides / Q000037:antagonists & inhibitors / Q000737:chemistry
chemical_list: D000975:Antioxidants; D016207:Cytokines; D016166:Free Radical Scavengers; D007004:Hypoglycemic Agents; D010936:Plant Extracts; D011134:Polysaccharides; D013481:Superoxides; D017665:Hydroxyl Radical; D000496:Alloxan