title: Mast cell degranulation induced by chlorogenic acid.
abstract: OBJECTIVE
  To investigate the mechanism of chlorogenic acid (CA)-induced anaphylactoid reactions.
  
  
  METHODS
  Degranulation of peritoneal mast cells was assayed by using alcian blue staining in guinea pigs, and the degranulation index (DI) was calculated. CA-induced degranulation of RBL-2H3 cells was also observed and assayed using light microscopy, transmission electron microscopy, flow cytometry, and beta-hexosaminidase release.
  
  
  RESULTS
  CA 0.2, 1.0, and 5.0 mmol/L was able to promote degranulation of peritoneal mast cells in guinea pigs in vitro, but it did not increase the degranulation of peritoneal mast cells in CA-sensitized guinea pigs compared with control (P>0.05). Treatment with CA 0.2, 1.0, and 5.0 mmol/L for 30, 60, and 120 min induced degranulation in RBL-2H3 cells in a dose- and time-dependent manner (P<0.01). Under transmission electron microscope typical characteristics of degranulation, including migration of granular vesicles toward the plasma membrane and integration combined with exocytosis, were observed, after CA or C48/80 treatment. Fluorescent microscopy and flow cytometric analysis showed that CA induced concentration-dependent translocation of phosphatidylserine in RBL-2H3 cells. beta-hexosaminidase release in RBL-2H3 cells was significantly increased after incubation with 1 mmol/L CA for 60 min and 5 mmol/L CA for 30 min (P<0.01).
  
  
  CONCLUSIONS
  CA induces degranulation of peritoneal mast cells and RBL-2H3 cells in guinea pigs, which might be one of the mechanisms of the generation of anaphylactoid reactions induced by CA.
authors.affiliation: National Drug Screening Center, China Pharmaceutical University, Nanjing, China.
authors.forename: Fang-hua
authors.initials: FH
authors.lastname: Huang
authors.forename: Xin-yue
authors.initials: XY
authors.lastname: Zhang
authors.forename: Lu-yong
authors.initials: LY
authors.lastname: Zhang
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Ni
authors.forename: Xiao-liang
authors.initials: XL
authors.lastname: Zheng
authors.forename: Ai-jun
authors.initials: AJ
authors.lastname: Chen
mesh_terms: D000707:Anaphylaxis / Q000139:chemically induced*; D000818:Animals; D015550:Cell Degranulation / Q000187:drug effects*; D045744:Cell Line, Tumor; D002726:Chlorogenic Acid / Q000008:administration & dosage / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D006168:Guinea Pigs; D008297:Male; D008407:Mast Cells / Q000378:metabolism / Q000502:physiology; D046529:Microscopy, Electron, Transmission; D010537:Peritoneum / Q000166:cytology / Q000378:metabolism; D051381:Rats; D013997:Time Factors; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism
chemical_list: D002726:Chlorogenic Acid; D001619:beta-N-Acetylhexosaminidases