Stimulatory effect of Shoyu polysaccharides from soy sauce on the intestinal immune system.

Soy sauce (Shoyu) is a traditional Japanese fermented seasoning and is available worldwide. We investigated the effect of Shoyu polysaccharides (SPS) prepared from soy sauce on the intestinal immune system of mice. SPS enhanced the production of immunoglobulin A (IgA) from Peyer's patch cells in vitro, and its oral administration to 7-week-old male BALB/c mice for 2 weeks at a dose of 1.5 mg per day significantly (p<0.01) increased the concentration of IgA in the intestine as compared to control mice. Furthermore, experiments on the intestinal transport of SPS in vitro using the human intestinal epithelial cell line Caco-2 confirmed the permeation of uronic acid to be time-dependent. In conclusion, SPS of soy sauce enhanced the production of IgA in vitro and in vivo, and the digested SPS might cross the enterocytic monolayer. Thus, soy sauce is a potentially promising food for enhancing host defenses.

Promotive effect of Shoyu polysaccharides from soy sauce on iron absorption in animals and humans.

Soy sauce (Shoyu) is a traditional fermented seasoning of Japan and is available throughout the world. We investigated the effect of Shoyu polysaccharides (SPS) prepared from soy sauce on iron absorption in vitro and in vivo. First, by measuring the iron-binding capacity of SPS, it was found that SPS stabilized the solubility of ferrous iron at neutral pH's by forming a complex, Fe-SPS. Second, in experiments with animals, it was found that SPS enhanced the absorption and/or pooling of iron in organs when anemic rats were fed iron-supplemented diets. Third, in a 4-week randomized, double-blind, placebo-controlled parallel group study, healthy women were treated with 600 mg of SPS (n = 22) or placebo (n = 23) each day. After the 4 weeks, serum levels of iron, hematocrit, and hemoglobin were significantly higher (P < 0.05) in the SPS-treated than in the placebo-treated group. In conclusion, SPS of soy sauce enhanced iron absorption, and soy sauce is a potentially promising seasoning for the treatment of anemia through food.

In vitro and in vivo immunomodulating activities of Shoyu polysaccharides from soy sauce.

We investigated the effects of Shoyu polysaccharides (SPS) prepared from soy sauce on immune functions in mice. SPS enhanced the consumption of glucose by peritoneal macrophages in vitro. In addition, oral administration of SPS to 6-week-old male BALB/c mice for 2 weeks at a dose of 3.0 mg/day increased the capacity of peritoneal macrophages to consume glucose as compared to control mice. We observed the regulatory effect of SPS on the balance of Th1/Th2 cell responses in mice. In splenic lymphocytes stimulated with Con A in vitro, SPS significantly suppressed the production of IL-4 and enhanced that of IFN-gamma. Furthermore, in mice treated with SPS at 3.0 mg per day for 2 weeks, the balance of Th1/Th2 cell responses was shifted to predominantly Th1 cell responses. These findings suggest that SPS effectively enhanced both macrophage and lymphocyte function in vitro and in vivo, and soy sauce would be a potentially promising food for enhancing host defenses.

Shoyu polysaccharides from soy sauce improve quality of life for patients with seasonal allergic rhinitis: a double-blind placebo-controlled clinical study.

Soy sauce (Shoyu) is a traditional fermented seasoning of East Asian countries and is available throughout the world. We obtained polysaccharides from raw soy sauce, and showed the anti-allergic activities of these Shoyu polysaccharides (SPS) in vitro and in vivo. The present study determined whether oral supplementation of SPS is an effective intervention for patients with seasonal allergic rhinitis. In an 8-week randomized, double-blind, placebo-controlled parallel group study, patients with mild seasonal allergic rhinitis were treated with 600 mg of SPS (n=25) or placebo (n=26) each day. After 4 weeks of treatment with SPS, symptom scores such as sneezing, nasal stuffiness, and hindrance of daily life were significantly different (P<0.05) from those in placebo-treated groups. The total symptom score, calculated from the sum of individual scores, showed a significant difference (P<0.05) between the 2 groups after 4-8 weeks. On nasal examination by the investigator, the color of the inferior turbinate in SPS-treated patients was significantly different (P<0.05) from that in placebo-treated patients between weeks 4 and 8, and the nasal symptom scores for color of inferior turbinate, watery discharge, and state of sniffles were also significantly different (P<0.05) from those in the placebo-treated group after 8 weeks. In conclusion, SPS of soy sauce improved the quality of life of patients with seasonal allergic rhinitis, and soy sauce would be useful in an anti-allergic therapy utilizing daily foods.

In vitro and in vivo anti-allergic activity of soy sauce.

Soy sauce (Shoyu) is a traditional fermented seasoning of Japan and available throughout the world. Polysaccharides were obtained from dialysate of Shoyu, and these Shoyu polysaccharides (SPS) were examined for anti-allergic activity in vitro and in vivo. The SPS originated from partially-degraded polysaccharides of soybeans by mold enzymatic hydrolyses, and Shoyu contained about 1% (w/v) SPS. First, the inhibitory effects of SPS on hyaluronidase, which is known to be related to inflammation and allergic responses, were as potent as those of an anti-allergic medicine, disodium cromoglycate. Second, SPS significantly inhibited the release of histamine from rat basophilic leukemia (RBL-2H3) cells, which had been induced by the antigen. Third, orally administered SPS had a significant suppressive effect on passive cutaneous anaphylaxis induced in the ears of mice. These results suggest that SPS may have anti-allergic activities, and soy sauce is a potentially promising seasoning for the treatment of allergic diseases through food.

Quality of life improvement with soy sauce ingredients, Shoyu polysaccharides, in perennial allergic rhinitis: a double-blind placebo-controlled clinical study.

Soy sauce (Shoyu) is a traditional fermented seasoning of East Asian countries and available throughout the world. We obtained polysaccharides from raw soy sauce, and showed the anti-allergic activities of these Shoyu polysaccharides (SPS) in vitro and in vivo. The present study determined whether oral supplementation of SPS is an effective intervention for patients with perennial allergic rhinitis. In a 4-week randomized, double-blind, placebo-controlled parallel group study, patients with mild perennial allergic rhinitis were treated with 600 mg of SPS (n=11) or placebo (n=10) each day. After 4 weeks of treatment with SPS, a reduction in symptom scores for runny nose, sore throat, and itchy eyes were significantly changed from the baseline within the group (p<0.05), but no change in these scores was observed over 4 weeks of treatment in the placebo group. However, differences in the symptom scores during the study period were not significantly different between the groups. The total symptom score, calculated from the sum of individual scores, showed a significant difference between the 2 groups after 4 weeks of treatment (p<0.05). The efficacy of global symptoms score, which was defined as the adjusted mean change from baseline during 4 weeks of treatment, also showed a significant improvement in the SPS group (p<0.05). An overall evaluation of the medication's effectiveness after 4 weeks treatment showed significant differences between the SPS- and placebo-treated groups (p<0.05). In conclusion, SPS of soy sauce improved the quality of life for patients with perennial allergic rhinitis, and soy sauce would be useful in an anti-allergic therapy utilizing everyday foods.

Antibacterial activity of licochalcone A against spore-forming bacteria.

Licochalcone A was isolated from the roots of licorice, Glycyrrhiza inflata, which has various uses in the food and pharmaceutical industries; isolation was followed by extraction with ethanol and column chromatography with silica gel. In this study, the activities of licochalcone A against some food contaminant microorganisms were evaluated in vitro. The vegetative cell growth of Bacillus subtilis was inhibited in a licochalcone A concentration-dependent manner and was completely prevented by 3 micrograms of licochalcone A/ml. Licochalcone A showed a high level of resistance to heating at 80 to 121 degrees C for 15 min. Licochalcone A did not inhibit the germination of heat-treated spores of B. subtilis induced by L-alanine. Licochalcone A showed effects against all gram-positive bacteria tested and especially was effective against all Bacillus spp. tested, with MICs of 2 to 3 micrograms/ml, but was not effective against gram-negative bacteria or eukaryotes at 50 micrograms/ml. Although the cationic antimicrobial peptides protamine and epsilon-poly-L-lysine resulted in the loss of antimicrobial activity in the presence of either 3% (wt/vol) NaCl or protease at 20 micrograms/ml, the antibacterial activity of licochalcone A was resistant to these conditions. Thus, licochalcone A could be a useful compound for the development of antibacterial agents for the preservation of foods containing high concentrations of salts and proteases, in which cationic peptides might be less effective.