Int J Med Sci 2006; 3(3):112-116. doi:10.7150/ijms.3.112 This issue

Research Paper

In vitro bactericidal activities of Japanese rice-fluid against Helicobacter pylori strains

Yoshiyuki Kawakami1, Kozue Oana1, Masayoshi Hayama1, Hiroyoshi Ota1, Masahiko Takeuchi2, Kazuhiro Miyashita2, Tsunetomo Matsuzawa2, Kiyomi Kanaya3

1. Department of Biomedical Laboratory Sciences, School of Health Sciences, Shinshu University School of Medicine, Matsumoto, 390-8621, Japan
2. Agricultural Technology Institute, Nagano Farmers' Federation, Suzaka, 382-0084, Japan
3. Nagano Kohno Co. Ltd. 3, Nagano, 380-0948, Japan

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Kawakami Y, Oana K, Hayama M, Ota H, Takeuchi M, Miyashita K, Matsuzawa T, Kanaya K. In vitro bactericidal activities of Japanese rice-fluid against Helicobacter pylori strains. Int J Med Sci 2006; 3(3):112-116. doi:10.7150/ijms.3.112. Available from

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Background: Helicobacter pylori has now been widely recognized as a causative agent of gastroduodenal diseases. The development of safer anti- H. pylori compounds is desirable due to the antibiotic-resistant strains emerged to date.

Methods: We successfully developed the compounds of Rice-fluid derived from unpolished, polished, and usually cooked Japanese rice, and investigated their in vitro antibacterial activities by means of the Time-Kill-Curve methods against various species of bacteria including H. pylori strains.

Results: All of the compounds revealed keen bactericidal activities against H. pylori, followed by Streptococcus pneumoniae and Campylobacter jejuni strains, but failed to affect the viability of other bacterial species investigated including staphylococci, enterococci, Pseudomonas aeruginosa, and other gram-negative rods belonging to the family Enterobacteraceae. The bactericidal activities were demonstrated to be time- and concentration-dependent.

Conclusions: The compounds of Rice-fluid are considered to be potentially new and safe therapeutic regimens against H. pylori infections. The mechanism of their bactericidal activities against H. pylori strains remains to be elucidated.

Keywords: Helicobacter pylori, bactericidal activity, antibacterial activity, Japanese Rice-fluid.