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World J Gastroenterol. Oct 14, 2006; 12(38): 6178-6181
Published online Oct 14, 2006. doi: 10.3748/wjg.v12.i38.6178
Polaprezinc protects human colon cells from oxidative injury induced by hydrogen peroxide: Relevant to cytoprotective heat shock proteins
Tatsuya Ohkawara, Jun Nishihira, Rika Nagashima, Hiroshi Takeda, Masahiro Asaka
Tatsuya Ohkawara, Rika Nagashima, Hiroshi Takeda, Masahiro Asaka, Department of Gastroenterology and Hematology, Hokkaido University Graduate School of Medicine, Kita15, Nishi7, Kita-ku, Sapporo, 060-8678, Japan
Tatsuya Ohkawara, Jun Nishihira, Department of Research and Development, GeneticLab Co. Ltd., Kita9, Nishi15, Chuou-ku, Sapporo, 060-0009, Japan
Supported by the Grant-in-Aid for research, No.18590665 from the Ministry of Education, Science and Culture of Japan
Correspondence to: Tatsuya Ohkawara, MD, PhD, Department of Gastroenterology and Hematology, Hokkaido University Graduate School of Medicine, Kita15, Nishi7, Kita-ku, 060-8678, Sapporo, Japan. tokawara@med.hokudai.ac.jp
Telephone: +81-11-7161161 Fax: +81-11-7067867
Received: June 6, 2006
Revised: June 28, 2006
Accepted: July 7, 2006
Published online: October 14, 2006
Abstract

AIM: To investigate the effect of polaprezinc on cellular damage induced by hydrogen peroxide (H2O2) in human colon CaCo2 cells.

METHODS: CaCo2 cells were treated with polaprezinc (10-100 μmol/L) for 6 h. After polaprezinc treatment, the cells were incubated with H2O2 (20 μmol/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 μmol/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 H2O2, and up-regulated the expressions of HSP27 and HSP72 in the cells (10, 30 and 100 μmol/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 H2O2-caused injury in the cells.

CONCLUSION: Polaprezinc is a useful therapeutic agent for treatment of colitis and its effects depend on the function of cytoprotective HSP in colon.

Keywords: Heat shock protein; Oxidative injury; Polaprezinc