Anti-stress effect of the Lactobacillus pentosus strain S-PT84 in mice.

We investigated if the orally administered Lactobacillus pentosus strain S-PT84 (S-PT84) might show anti-stress activity and ameliorate stress-induced immune suppression in mice. Stress of mice induced an increase in serum corticosterone and a decrease in splenic natural killer activity and in the number of splenocytes versus control mice. However, these changes were not observed in stressed mice that had been administered S-PT84. Furthermore, interleukin (IL)-12 and IL-10 production, which was downregulated in lipopolysaccharide-activated macrophages from stressed mice, was maintained at control levels in the macrophages of stressed mice that had been fed S-PT84. Interferon-γ production, which was downregulated in concanavalin A-activated splenocytes from stressed mice, tended to be maintained at control levels in stressed mice that had been fed S-PT84, although IL-4 production by these cells was not influenced by S-PT84 administration. Additionally, reduced glutathione (GSH) levels were decreased in serum and peritoneal macrophages from stressed mice versus controls, but these GSH levels were significantly higher in stressed animals that had been administered S-PT84 compared with those that had not. These results suggest that S-PT84 exerts anti-stress activity through immune modulation and/or antioxidative activity.

Prophylactic Effect of Lactobacillus pentosus strain S-PT84 on Candida Infection and Gastric Inflammation in a Murine Gastrointestinal Candidiasis Model.

We previously showed a prophylactic effect of Lactobacillus pentosus strain S-PT84 against oral candidiasis in mice. In the present study, we evaluated the protective effect of S-PT84 against Candida infection of the gastrointestinal tract. As the first step, we used an in vitro assay to compare the inhibitory effects of several lactobacilli (S-PT84 and Lactobacillus pentosus type strain JCM1558T, Lactobacillus gasseri type strain JCM1131T and Lactobacillus casei type strain JCM1134T) on mycelial growth of Candida albicans. S-PT84 directly adhered to Candida cells and showed the strongest growth-inhibitory activity among the tested Lactobacillus strains. In the second experiment, we used an in vivo assay to evaluate the effect of S-PT84 ingestion on severity score of stomach lesion and gastric inflammation in a mouse model of gastrointestinal candidiasis. The severity scores were significantly improved by oral administration of S-PT84 (6 mg/ 200 µL), consistent with decreased coverage of stomach lesions by patchy whitish plaques. The attenuation of stomach lesion severity by S-PT84 was more pronounced than that obtained with L. gasseri type strain JCM1131T, consistent with the results of the above in vitro study. Histological analysis also indicated that S-PT84 prevented the adhesion of C. albicans to the stomach surface and suppressed stomach inflammation caused by neutrophil infiltration. Furthermore, S-PT84 also suppressed the vascular permeability observed in Candida-infected stomach. These results suggest that oral administration of S-PT84 might be effective not only in inhibiting Candida infection but also in preventing gastric inflammation induced by Candida infection.

Prophylactic Effect of Lactobacillus pentosus strain S-PT84 on Candida Infection and Gastric Inflammation in a Murine Gastrointestinal Candidiasis Model [Errata].

We previously showed a prophylactic effect of Lactobacillus pentosus strain S-PT84 against oral candidiasis in mice. In the present study, we evaluated the protective effect of S-PT84 against Candida infection of the gastrointestinal tract. As the first step, we used an in vitro assay to compare the inhibitory effects of several lactobacilli (S-PT84 and Lactobacillus pentosus type strain JCM1558T, Lactobacillus gasseri type strain JCM1131T and Lactobacillus casei type strain JCM1134T) on mycelial growth of Candida albicans. S-PT84 directly adhered to Candida cells and showed the strongest growth-inhibitory activity among the tested Lactobacillus strains. In the second experiment, we used an in vivo assay to evaluate the effect of S-PT84 ingestion on severity score of stomach lesion and gastric inflammation in a mouse model of gastrointestinal candidiasis. The severity scores were significantly improved by oral administration of S-PT84 (6 mg/ 200 µL), consistent with decreased coverage of stomach lesions by patchy whitish plaques. The attenuation of stomach lesion severity by S-PT84 was more pronounced than that obtained with L. gasseri type strain JCM1131T, consistent with the results of the above in vitro study. Histological analysis also indicated that S-PT84 prevented the adhesion of C. albicans to the stomach surface and suppressed stomach inflammation caused by neutrophil infiltration. Furthermore, S-PT84 also suppressed the vascular permeability observed in Candida-infected stomach. These results suggest that oral administration of S-PT84 might be effective not only in inhibiting Candida infection but also in preventing gastric inflammation induced by Candida infection.

The effect of the sympathetic nervous system on splenic natural killer cell activity in mice administered the Lactobacillus pentosus strain S-PT84.

Splenic sympathetic nerve activity (SNA) modulates cellular immune functions such as splenic natural killer cell activity. Lactobacillus pentosus strain S-PT84 enhances splenic natural killer cell activity. Here, we examined whether S-PT84 affects splenic natural killer activity through splenic SNA in BALB/c mice. Splenic SNA was significantly decreased following the administration of S-PT84. This phenomenon was inhibited by pretreatment with thioperamide (histamine H3 receptor antagonist), suggesting that S-PT84 directly affected splenic SNA. Thioperamide also inhibited the increase in splenic natural killer activity by S-PT84. Thus, the change in splenic natural killer activity by S-PT84 may be partially modulated through SNA.

Effects of heat-killed Lactobacillus pentosus S-PT84 on postprandial hypertriacylglycerolemia in rats.

The effect of Lactobacillus pentosus strain S-PT84 (S-PT84) on postprandial hypertriacylglycerolemia was investigated in rats. S-PT84 dose-dependently inhibited the hydrolysis of triacylglycerols by pancreatic lipase in vitro. Intragastric administration of S-PT84 significantly reduced the lymphatic recovery of (3)H-trioleoylglycerol up to 8 h. The oral administration of a fat emulsion, with or without S-PT84, resulted in the concentration of plasma triacylglycerol 2 h and 3 h after administration being significantly lower in the S-PT84 group than in the group without S-PT84 (control group). These results suggest that S-PT84 alleviated postprandial hypertriacylglycerolemia by delaying triacylglycerol absorption in the intestine through the inhibition of pancreatic lipase.

Effect of Lactobacillus pentosus S-PT84 ingestion on IFN-α production from plasmacytoid dendritic cells by virus stimulation.

We investigated the effect of ingesting Lactobacillus pentosus S-PT84 on the interferon-α (IFN-α) production from splenocytes and plasmacytoid dendritic cells by virus stimulation. IFN-α production by the Lactobacillus pentosus S-PT84 ingestion group was significantly greater under the virus-infected condition than that by the control group. Lactobacillus pentosus S-PT84 could enhance the production of IFN-α which is known as an important cytokine for preventing virus infection. It may therefore become a prophylactic tool against such virus infection.

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.

Cholecystokinin secretion induced by beta-conglycinin peptone depends on Galphaq-mediated pathways in enteroendocrine cells.

BACKGROUND: Intraduodenal administration of peptone prepared from soybean beta-conglycinin (BconP) stimulates cholecystokinin (CCK) secretion from enteroendocrine cells, and suppresses food intake in rats. However, the sensing mechanism of BconP by CCK-producing cells is unknown. AIM OF THE STUDY: We investigated signal transduction pathways mediating CCK secretion in response to BconP in the murine CCK-producing cell line, STC-1. METHODS: STC-1 cells were seeded in 48-well culture plates until sub-confluent and CCK secretion was examined under various conditions. CCK concentration was determined by the enzyme immunoassay. RESULTS: BconP dose-dependently induced CCK secretion in STC-1 cells. Treatment with BAPTA-AM, an intracellular Ca2+ chelator, reduced BconP-induced CCK secretion, however, removal of extracellular Ca2+ did not affect the secretory response. Treatment with 2-amino borate (2-APB) reduced CCK releasing responses, suggesting the involvement of IP(3). In addition, BconP failed to induce CCK secretion after treatment with the Galphaq protein inhibitor (YM-254890). CONCLUSION: These results indicate that Galphaq pathway is responsible for BconP-induced CCK secretion in STC-1 cells, and suggest the involvement of a Galphaq-coupled GPCR(s) in dietary peptide sensing in enteroendocrine cells.

Antiallergic effects of Lactobacillus pentosus strain S-PT84 mediated by modulation of Th1/Th2 immunobalance and induction of IL-10 production.

BACKGROUND: Many types of fermented food are consumed in Japan. Although some are produced by plant-origin lactic-acid bacteria (LAB) fermentation, the physiological functions of such bacteria remain unclear. We therefore isolated LAB of plant origin from Kyoto pickles and determined the immunological activity of heat-killed preparations of plant-origin LAB. METHODS: The Lactobacillus pentosus strain S-PT84 was selected from among 16 LAB of plant origin as the strongest interleukin (IL)-12-inducing strain. IL-12- and IL-10-inducing activities were determined with macrophages from BALB/c mice. The in vivo immunomodulating effect of S-PT84was determined with BALB/c mice fed S-PT84. The antiallergic activity of S-PT84 was examined in ovalbumin (OVA)/alum-administered BALB/c mice. RESULTS: The L. pentosus strain S-PT84 induced production of both IL-12 and IL-10 in vitro. S-PT84 enhanced splenic natural-killer activity and modulated the T helper (Th) type 1/type 2 balance toward a Th1-dominant state. In the OVA-induced allergy model, orally administered S-PT84 lowered serum IgE levels and suppressed active cutaneous anaphylaxis reaction and splenic IL-4 production. IL-10 production from splenocytes of OVA-immunized mice was upregulated by feeding S-PT84. CONCLUSIONS: Despite heat-killing, S-PT84 exhibited antiallergic effects by modulating the Th1/Th2 balance and inducing regulatory T cells. The L. pentosus strain S-PT84, which is of plant origin and isolated from a traditional Japanese food, is expected to be useful for treatment of many immune diseases including allergies, tumors, infectious diseases and auto-immune diseases.