Immunomodulating Activity of Hochu-ekki-to against Mouse Model for Enterohemorrhagic Escherichia coli Infection / 日本東洋医学雑誌

ABSTRACT

Risk factors for developing hemolytic uremic syndrome among patients with enterohemorrhagic <i>Escherichia coli</i> O157: H7 (EHEC) infection include age. The young, especially those under the age of five, face an increased risk, as do the elderly. In the present study, we evaluated the protective effects of Hochu-ekki-to (HET) on intraperitoneal infection with EHEC, using immunosuppressant, dexamethasone (Dex)-treated mice.<br>It was found that HET induced improvement of Dex-induced leukopenia. Similarly, the IgM-plaque forming cell responses to sheep red blood cell (SRBC) were restored by the administration of HET to the normal-mice level in Dex-treated mice. Consequently, HET was administered orally into the Dex-treated mice before infection with EHEC to observe the therapeutic effect. With the oral administration of 500mg/kg/head of HET into the Dex-treated mice, prolonged survival was shown: the 50% survival time in the HET-administered mice was four days, compared with one day in the non-administered controls. In addition, the number of bacteria in the liver was reduced by the administration of HET in the Dex-treated mice.<br>The results indicate that orally administered-HET protects against EHEC infection in Dex-treated mice, and such protective effects appear to be due to the restorative effects of HET against the Dex-induced immunosuppression.