Polaprezinc protects human colon cells from oxidative injury induced by hydrogen peroxide: relevant to cytoprotective heat shock proteins.
OBJECTIVE
To investigate the effect of polaprezinc on cellular damage induced by hydrogen peroxide (H(2)O(2)) in human colon CaCo2 cells.


METHODS
CaCo2 cells were treated with polaprezinc (10-100 micromol/L) for 6 h. After polaprezinc treatment, the cells were incubated with H(2)O(2) (20 micromol/L) for 1 h. Cell viability was measured by MTT assay. Western blot analysis for heat shock protein (HSP) 27 and HSP72 in the cells was performed. Moreover, cells were pretreated with quercetin (200 micromol/L), an inhibitor of HSP synthesis, 2 h before polaprezinc treatment, and cell viability and the expression of HSP27 and 72 were assessed in these cells.


RESULTS
Polaprezinc significantly protected CaCo2 cells from cell damage induced by H(2)O(2), and up-regulated the expressions of HSP27 and HSP72 in the cells (10, 30 and 100 micromol/L of polaprezinc; 35.0% +/- 7.7%, 58.3% +/- 14.6% and 64.2% +/- 8.2%, respectively. P < 0.01 versus polaprezinc-nontreated cells; 6.0% +/- 4.4%). Quercetin inhibited the up-regulation of HSP27 and HSP72 by polaprezinc and diminished the protective effect of polaprezinc against H(2)O(2)-caused injury in the cells.


CONCLUSIONS
Polaprezinc is a useful therapeutic agent for treatment of colitis and its effects depend on the function of cytoprotective HSP in colon.
Ohkawara
Tatsuya
T
Department of Gastroenterology and Hematology, Hokkaido University Graduate School of Medicine, Kita15, Nishi7, Kita-ku, 060-8678 Sapporo, Japan. tokawara@med.hokudai.ac.jp
Nishihira
Jun
J
Nagashima
Rika
R
Takeda
Hiroshi
H
Asaka
Masahiro
M
D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D018938:Caco-2 Cells; D002336:Carnosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003106:Colon / Q000187:drug effects*; D015870:Gene Expression; D055551:HSP27 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000187:drug effects; D006360:Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000187:drug effects*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000187:drug effects; D009942:Organometallic Compounds / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D011794:Quercetin / Q000494:pharmacology; D015854:Up-Regulation; D017967:Zinc Compounds / Q000494:pharmacology
D000897:Anti-Ulcer Agents; D055551:HSP27 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D009942:Organometallic Compounds; D017967:Zinc Compounds; C061957:polaprezinc; D002336:Carnosine; D011794:Quercetin; D006861:Hydrogen Peroxide