Abstract
Rhizopus oryzae U-1 water extract (ROU-we) was administered orally to rats at 10mg/kg body weight for 9 days. Salmonella enteritidis was inoculated at a dose of 109CFU/animal. The following protective effects of ROU-we against infection were examined: cell counts of Salmonella in organs of infected rats (liver, spleen, and mesenteric lymph nodes); phagocytic capacity of collected peripheral monocytes and peritoneal macrophages; cell counts of respective helper T-cell subclasses (Th0, Th1, and Th2); and the leukocyte percentage in peripheral blood. The Salmonella cell count in the liver of the ROU-we group decreased significantly compared to that of the control group and the peripheral monocytes' phagocytic capacity increased 4.5-fold. Moreover, the ROU-we group's Th1 response was higher than the infected control group. However, the healthy control group and the ROU-we group showed similar Th1/Th2 balance and cell count tendencies. These results suggest that ROU-we activated peripheral monocytes and improved Th1/Th2 balance, thereby strengthening immunity against Salmonella infection.