Hisako Yasui

Effect of intranasal administration of Lactobacillus pentosus S-PT84 on influenza virus infection in mice

Lactobacillus pentosus strain S-PT84 isolated from Kyoto pickles enhances splenic natural killer (NK) cell activity and exhibit anti-allergic effects by modulating the Th1/Th2 (T-helper1/T-helper2) balance. In the present study, we investigated whether the immune response could be activated by intranasal administration of S-PT84 in the respiratory immune system and protected against influenza virus infection in mice. When BALB/c mice received intranasal administration of S-PT84 once daily for 3 consecutive days, S-PT84 strongly induced interleukin-12 (IL-12) and gamma interferon (IFN-gamma) production in mediastinal lymph node (MLN) cells. At intranasal infection with influenza virus PR8 (a mouse-adapted H1N1 strain) after S-PT84 treatment, the survival rates of mice improved in a dose-dependent manner, and the titer of influenza virus in bronchoalveolar lavage fluids (BALF) was significantly decreased by S-PT84 administration. Production of IL-12 and alpha-interferon (IFN-alpha) in BALF were significantly higher in mice treated with S-PT84 compared to the control mice. Lung NK activity was also significantly augmented in S-PT84-treated mice. These results suggested that the L. pentosus strain S-PT84 showed inhibitory activity against influenza virus infection.

Effect of an Oral Administration of Lactobacillus casei Strain Shirota on the Natural Killer Activity of Blood Mononuclear Cells in Aged Mice

The natural killer (NK) activity of blood mononuclear cells and splenocytes in aged mice fed on a diet containing Lactobacillus casei strain Shirota (LcS group) was significantly (P<0.01) higher than that in mice fed on a diet without LcS. In the LcS group, there was a significant positive correlation (r=0.63, P<0.01) between the NK activity of blood mononuclear cells and the NK activity of splenocytes.

Reddish Coloration of Chinese Quince (Pseudocydonia sinensis) Procyanidins during Heat Treatment and Effect on Antioxidant and Antiinfluenza Viral Activities

To investigate the effects of processing Chinese quince fruit on the denaturation of phenolics and their food functions, fruit phenolic extracts were heated together with organic acid for up to 12 h. Chinese quince phenolic (mostly procyanidins) solution subjected to heat treatment changed from almost colorless, pale yellow, to a reddish color. Before heat treatment, the absorption spectra of polymeric procyanidins were observed only around 280 nm; after heat treatment, absorption occurred between 400 and 600 nm, which is related to the reddish color appearance. Thioacidolysis of denatured reddish phenolics showed that (-)-epicatechin subunits decreased during heat treatment and, in contrast, cyanidin increased. In addition, novel substances that could not be degraded by thioacidolysis were formed. Meanwhile, antioxidant activities, assessed by linoleic acid peroxidation, 1,1-diphenyl-2-picrylhydrazyl (DPPH), Folin-Ciocalteu, and FRAP methods, increased during heat treatment. The antiinfluenza viral activity of denatured reddish phenolics was inferior to that of intact fruit phenolics; however, they retained moderate activity. These results indicate that red coloration of fruit products of Chinese quince was mainly due to the spectral (i.e. structural) changes of procyanidins accompanied with formation of cyanidin. Increasing the length of heat treatment increased the antioxidant capacity of phenolics, and the resultant reddish phenolics retained moderate antiinfluenza viral activity.

Anti-atopic dermatitis effects and the mechanism of lactic acid bacteria isolated from Mongolian fermented milk.

We investigated the anti-allergic effects of one strain (T120) of a lactic acid bacteria (LAB) isolated from Mongolian fermented milk using atopic dermatitis (AD) model mice (NC/Nga mice). Strain T120 has already been identified as Enterococcus faecium and shown to induce strong production of IL-12 (Kimura et al. 2006). In in vitro studies, strain T120 suppressed total IgE production and induced IL-12 and IFN-gamma production by splenocytes of NC/Nga mice. The additional examination of various neutralization antibodies was performed to elucidate in detail the mechanism of depressed IgE production by strain T120. As a result, it became clear that IL-12 induced by strain T120 increased production of IFN-gamma and total IgE production was mainly controlled by the IFN-gamma. In order to define the cells which produce IL-12 powerfully by this strain, antigen-presenting cells (APCs) such as macrophages and dendritic cells (DCs) were removed from the splenocytes, and the reactivity of these cells to the strain was examined. Induction of IL-12 and IFN-gamma by strain T120 became significantly very low by removal of APCs from splenocytes. Therefore, it was clear that strain T120 acted on APCs and induced production of IL-12. Further, this strain enhanced the production of IL-10 by splenocytes. In in vivo studies, intraperitoneal injection of strain T120 inhibited serum IgE elevation and atopic dermatitis symptoms in NC/Nga mice. These results suggest that an anti-allergic effect of strain T120 depends on the increased production of IL-12 by APCs activated by the strain and following the increased production of IFN-gamma. Further, activation of regulatory T cells by strain T120 may inhibit atopic disease.

Pediococcus pentosaceus Sn26 Inhibits IgE Production and the Occurrence of Ovalbumin-Induced Allergic Diarrhea in Mice

We investigated the anti-allergic effect of a new strain (Pediococcus pentosaceus Sn26, the Sn26 strain) among 59 strains isolated from Japanese fermented vegetable pickles, the Sunki pickle. The Sn26 strain increased Th1 type cytokine (IL-12 and IFN-γ) production of Peyer’s patch (PP) cells in BALB/c mice, improved the Th1/Th2 balance, and inhibited IgE production of splenocytes of ovalbumin (OVA)-induced allergic diarrheic mice. Next we demonstrated, by neutralizing IL-12 and IFN-γ, that the Sn26 strain first induced IL-12, that IL-12 induced IFN-γ, and that decreases in IL-4 and IgE production followed. Furthermore, oral administration of the Sn26 strain decreased serum OVA-specific IgE levels and ameliorated the appearance of diarrhea in OVA-induced allergic diarrheic mice. Based on these results, it was assumed that oral administration of the Sn26 strain ameliorated type-1 allergies through improvement of the Th1/Th2 balance and decreases in IgE production.

Augmentation of cellular immunity and protection against influenza virus infection by bovine late colostrum in mice.

OBJECTIVE We investigated whether oral administration of skimmed and concentrated bovine late colostrum (SCBLC) activates the immune system and protects against influenza virus (Flu) infection. METHODS Murine Peyers patch (PP) cells (2.5 105) were cultured in 0.1 ml RPMI-1640 supplemented with SCBLC at a concentration of 0, 0.1 or 1.0 mg/ml. To determine the levels of IL-12 and IFN-, supernatants were collected on day 3. Mice were orally administered sterile saline solution (control group), or 400 g/g body weight (SCBLC 400 group) or 2,000 g/g body weight (SCBLC 2,000 group) of SCBLC for three weeks. These mice were measured for natural killer (NK) cells activity on PP cells, splenocytes and lung cells. Also, these mice in the control and SCBLC 2,000 groups were infected with Flu and were measured for the accumulated symptom rate. RESULTS In PP cells cultured with SCBLC, the levels of IL-12 and IFN- were significantly increased in vitro. Oral administration of SCBLC to mice significantly increased NK cell activity of PP cells, splenocytes and lung cells. The accumulated symptom rate of the SCBLC 2,000 group was significantly lower than that of the control group in a mouse model of Flu infection. CONCLUSION These results indicate that oral administration of SCBLC activates not only systemic cellular immunity but also local cellular immunity, such as in the respiratory tract, and that activation of cellular immunity is one of the mechanisms of amelioration of Flu infection.

Inhibitory Effect of a Hot-Water Extract of Leaves of Japanese Big-Leaf Magnolia (Magnolia obovata) on Rotavirus-Induced Diarrhea in Mouse Pups

The leaf of Japanese big-leaf magnolia (Magnolia obovata Thunb.) has long been used as a natural packaging material for traditional foods in Japan. However, many of the physiological functions of the leaves against oral infection and resultant illness remain unclear. The aim of the present study was to investigate the effects of a hot-water extract of the leaves of Magnolia obovata on diarrhea induced by rotavirus (RV), a major cause of acute diarrhea. RV strain SA11 was mixed with the M. obovata leaf extract and inoculated orally to neonatal BALB/c mouse pups. Simultaneous inoculation of SA11 with the extract significantly decreased the incidence of diarrhea. In addition, the extract significantly inhibited cytopathic effects and mRNA expression of viral proteins in SA11-infected MA104 cells. Two flavonoid glycosides, quercitrin and rutin, were strongly suggested to be major anti-RV agents in the extract by serial solvent extraction and reversed-phase HPLC-ESI-MS analysis. Our results suggest that the hot-water extract of M. obovata leaves can be used as a medicine or food additive to prevent and ameliorate RV-induced diarrhea in individuals that may have difficulty in benefitting from the RV vaccines.