title: A potent sphingomyelinase inhibitor from Cordyceps mycelia contributes its cytoprotective effect against oxidative stress in macrophages.
abstract: A novel water-soluble polysaccharide fraction, CME-1, with a molecular mass of 27.6 kDa and containing mannose and galactose in a respective ratio of 4:6, was prepared from Cordyceps sinensis mycelia and identified by NMR and GC-MS. In the current study, we examined whether CME-1 has anti-inflammatory effects in RAW264.7 cells. The ability of CME-1 to inhibit H(2)O(2)-induced cell death in RAW264.7 cells was assessed by using an MTT assay and annexin V/propidium iodide double staining; we found that CME-1 protected cells against H(2)O(2)-induced injury. H(2)O(2)-induced intracellular oxidative stress and mitochondrial membrane depolarization were also diminished with CME-1 treatment. We evaluated the hydroxyl radical scavenging ability of CME-1 by using the DMPO-electron spin resonance technique, which indicated that CME-1 acts as an intracellular antioxidant in a concentration-dependent manner through a mechanism other than its scavenging activity. Activities of both neutral and acid sphingomyelinases (SMases) were assessed in vitro, and results showed that the CME-1 inhibited activities of both neutral and acid SMases in a concentration-dependent manner. CME-1 reduced H(2)O(2) treatment-elevated C16- and C18-ceramide levels measured by LC/MS/MS in RAW264.7 cells. Results suggest that CME-1 protects RAW264.7 cells against oxidative stress through inhibition of SMase activity and reduction of C16- and C18-ceramide levels.
authors.affiliation: Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan, Republic of China.
authors.forename: Shwu-Huey
authors.initials: SH
authors.lastname: Wang
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Yang
authors.forename: Yin-Chen
authors.initials: YC
authors.lastname: Liu
authors.forename: Yi-Hua
authors.initials: YH
authors.lastname: Chiu
authors.forename: Chien-Tsu
authors.initials: CT
authors.lastname: Chen
authors.forename: Pai-Feng
authors.initials: PF
authors.lastname: Kao
authors.forename: Chun-Mao
authors.initials: CM
authors.lastname: Lin
mesh_terms: D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D002518:Ceramides / Q000378:metabolism; D032661:Cordyceps / Q000737:chemistry* / Q000254:growth & development; D019610:Cytoprotection / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D051336:Mitochondrial Membranes / Q000187:drug effects; D025282:Mycelium / Q000737:chemistry* / Q000254:growth & development; D018384:Oxidative Stress / Q000187:drug effects*; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D012995:Solubility; D013108:Sphingomyelin Phosphodiesterase / Q000037:antagonists & inhibitors*; D014867:Water / Q000737:chemistry
chemical_list: C000599929:CME-1 polysaccharide, Cordyceps sinensis; D002518:Ceramides; D004791:Enzyme Inhibitors; D011134:Polysaccharides; D014867:Water; D006861:Hydrogen Peroxide; D013108:Sphingomyelin Phosphodiesterase