Inducible nitric oxide synthase involvement in the mechanism of action of Saccharomyces boulardii in castor oil-induced diarrhoea in rats

Antidiarrheal Effect of DLBS1Y62, a Bioactive Fraction of Uncaria gambir Roxb. Dried Sap Extract, in Wistar Rats

Background

Diarrhea is a common health problem worldwide, especially in developing countries. It is the second leading cause of mortality for children. Uncaria gambir Roxb. extract has been used to treat diarrhea and dysentery, and as an astringent medicine, in Asian countries. Here, we investigated the antidiarrheal effect of DLBS1Y62, which is the bioactive fraction of dried sap extract from U. gambir, using castor oil-induced diarrhea and castor oil-induced enteropooling in rats.

Methods

DLBS1Y62 was obtained by crushing and milling the dried sap extract of U. gambir leaves. Male Wistar rats, 2–3 months old, weighing 200–250 g (n=30), were used for this study. Negative controls received 0.05 mL purified water. Positive controls were treated with 2 mg/kg BW loperamide orally as a suspension. Groups I, II, and III received 6.25, 12.5, and 25 mg/kg BW DLBS1Y62, respectively. Group IV received a combination of 6.25 mg/kg BW DLBS1Y62 and 20 mg/kg BW attapulgite. Diarrheal onset and frequency were observed; then, the weight and volume of intestinal contents were measured.

Results

DLBS1Y62 at all dose levels and in combination with attapulgite could inhibit the formation of further fecal forms of diarrhea, without delaying the onset of diarrhea. The rats that received DLBS1Y62 25 mg/kg BW had the lowest frequency of diarrhea and average intestinal contents compared with the treatment and negative control groups. DLBS1Y62 at a dose of 25 mg/kg BW also gave similar results to 2 mg/kg BW loperamide as a positive control in reducing diarrheal frequency and intestinal content.

Conclusion

The results of this study suggest that DLBS1Y62, particularly at a dose of 25 mg/kg BW, containing tannin as a compound, may become an alternative treatment for diarrhea.

Saccharomyces cerevisiae Fermentation Product Did Not Attenuate Clinical Signs, but Psyllium Husk Has Protective Effects in a Murine Dextran Sulfate Sodium-Induced Colitis Model

BACKGROUND

Yeast products and psyllium husk may provide relief from clinical signs of colitis due to their ability to promote gut integrity, modulate gut microbiota, or positively affect immune responses, which have been demonstrated in several species.

OBJECTIVE

The objective of this study was to investigate the effects of a Saccharomyces cerevisiae fermentation product (SCFP) and psyllium husk (PH) on cecal and fecal microbiota, colonic gene expression and histopathology, and mesenteric lymph node (MLN) immune cells in a dextran sulfate sodium (DSS)-induced colitis model.

METHODS

Male C57BL/6J mice (n = 54) were assigned to a control, 5% SCFP, or 5% PH diet. After 2 wk of diet adaptation, mice were provided distilled water or 3% (wt:vol) DSS for 5 d ad libitum. Body weight, food and water intakes, and disease activity index (DAI) were recorded daily during the treatment period. Fresh fecal samples were collected before and during treatment for microbial analyses. After treatment, mice were killed, followed by tissue collection. Tissues were stored in proper solutions until further analyses. Data were analyzed using the Mixed Models procedure of SAS 9.4 (SAS Institute).

RESULTS

Consumption of SCFP increased (P < 0.05) species richness of the gut microbiota and relative abundance of Butyricicoccus in fecal and cecal samples compared with control or PH mice. PH mice had greater (P < 0.05) gene expression of claudin (Cldn) 2, Cldn3, Cldn8, and occludin(Ocln) compared with control mice. DAI, MLN immune cell populations, colonic histopathology, and colonic gene expression were not affected (P > 0.05) by SCFP in DSS mice. DSS mice consuming PH had lower (P < 0.05) DAI compared with control or SCFP mice.

CONCLUSIONS

Results suggest that, despite the modest changes it had on cecal and fecal microbiota, SCFP did not attenuate clinical signs associated with DSS-induced colitis in mice, while PH showed protective effects.

Saccharomyces boulardii inhibits the expression of pro-inflammatory cytokines and inducible nitric oxide synthase genes in the colonic mucosa of rats experimentally-infected with Blastocystis subtype-3 cysts

Blastocystis spp. is the most frequent infectious unicellular, luminal parasite in all species of animals and humans. It has been linked to diarrhoea and irritable bowel syndrome. Saccharomyces boulardii (Sb) is a widely used probiotic that previously showed efficacy against several intestinal pathogens. The aim of this study was to investigate the therapeutic role of Sb on Blastocystis spp. Methods: Five groups of Blastocystis subtype-3 infected rats were treated with either live Sb alone, metronidazole (MTZ) alone, Sb extract, both Sb and MTZ, or placebo-treated besides the noninfected control group. Assessment of treatment effectiveness was done by study of parasitological cure rate, histopathological effect and analysis of the colonic mucosal level of mRNAs expressions for the proinflammatory cytokines interleukin-6 (IL-6), IL-8, tumour necrosis factor alpha (TNF-α) and Inducible nitric oxide synthase (iNOS) by real-time reverse transcription-polymerase chain reaction (real-time RT-PCR). Results showed that live Sb significantly improved the histological characteristics and decreased the cytokines and iNOS in the colonic mucosa. Co-administration of live Sb together with MTZ gave a better effect than other treatments and had early efficacy and revealed a 100% reduction of the parasite stages from both the stool and intestinal wash fluid.

Antidiarrheal Action of Bacillus subtilis CU1 CNCM I-2745 and Lactobacillus plantarum CNCM I-4547 in Mice

Preventive actions of probiotics as antidiarrheal agents are well documented, but their mechanisms are poorly understood. Two selected probiotics, Bacillus subtilis CU1 and Lactobacillus plantarum CNCM I-4547, were tested in mouse experimental models of diarrhea and the possible mechanisms of action were investigated. Diarrhea was induced in mice by oral castor oil administration or by i.v. injection of lipopolysaccharide (LPS) of Salmonella enteritis. The antidiarrheal drug loperamide was used as control. Fecal water excretion was quantified for 2 h and paracellular permeability and electrical parameters of the colon were assessed in Ussing chambers. The expression of colonic exchangers or channels and of Toll-like receptor 4 (TLR4) was assessed by immunohistochemistry. Prophylactic treatment with B. subtilis CU1 or with L. plantarum CNCM I-4547 reduced LPS-induced diarrhea. The reduction of water excretion was in the same range as those induced by loperamide. In the castor oil model, this effect was only observed with B. subtilis CU1. The two probiotic treatments abolished the increase in paracellular permeability induced by LPS, but not by castor oil. However, only L. plantarum CNCM I-4547 treatment decreased the colonic expression of TLR-4. After B. subtilis CU1, colonic expression of cystic fibrosis transmembrane conductance regulator (CFTR) was reduced and that of Na⁺/H⁺ exchanger 3 (NHE3) increased. B. subtilis CU1 may increase the capacity of the colon to absorb excess of water in diarrheic conditions by acting on CFTR and NHE3 expression. The two probiotics strains showed an impact on diarrhea through limitation of water excretion that may involve paracellular permeability or electrolyte transport for L. plantarum CNCM I-4547 and B. subtilis CU1 respectively.

Gleaning Insights from Fecal Microbiota Transplantation and Probiotic Studies for the Rational Design of Combination Microbial Therapies

Beneficial microorganisms hold promise for the treatment of numerous gastrointestinal diseases. The transfer of whole microbiota via fecal transplantation has already been shown to ameliorate the severity of diseases such as Clostridium difficile infection, inflammatory bowel disease, and others. However, the exact mechanisms of fecal microbiota transplant efficacy and the particular strains conferring this benefit are still unclear. Rationally designed combinations of microbial preparations may enable more efficient and effective treatment approaches tailored to particular diseases. Here we use an infectious disease, C. difficile infection, and an inflammatory disorder, the inflammatory bowel disease ulcerative colitis, as examples to facilitate the discussion of how microbial therapy might be rationally designed for specific gastrointestinal diseases. Fecal microbiota transplantation has already shown some efficacy in the treatment of both these disorders; detailed comparisons of studies evaluating commensal and probiotic organisms in the context of these disparate gastrointestinal diseases may shed light on potential protective mechanisms and elucidate how future microbial therapies can be tailored to particular diseases.

Influence of Saccharomyces boulardii CNCM I-745on the gut-associated immune system

Background

The probiotic Saccharomyces boulardii CNCM I-745 (also known as Saccharomyces cerevisiae HANSEN CBS 5926; in the following S. boulardii) has proven its effectiveness in preventive and therapeutic treatment of many gastrointestinal diseases, especially diseases associated with acute diarrhea. In particular, antibiotic-associated diarrhea, Clostridium difficile-associated diarrhea, traveller’s diarrhea, as well as acute diarrhea due to common viral and bacterial infections in children and adults.

Aim

The aim of this review is to summarize the experimental studies elucidating the molecular and immunological mechanisms by which these clinically proven effects are archived, with an emphasis on the gut-associated immune system. The main focus is laid on anti-inflammatory and immune-modulatory action of S. boulardii involved in bacterial or enterotoxin-mediated diarrhea and inflammation. An attempt is made to differentiate between the effects associated with cellular versus soluble factors and between prophylactic and therapeutic effects.

Methods

A literature search was performed in PubMed/PubMed Central for the effects of S. boulardii on the gut-associated immune system (focus acute diarrhea).

Results and conclusion

S. boulardii exhibits its positive effect by the direct effects on pathogens or their toxins as well as by influencing the host’s infection-induced signaling cascades and its innate and adaptive immune system. The combination of these mechanisms results in a reduction of the pathogens’ ability for adhesion or colonization and an attenuation of the overreacting inflammatory immune response. Thereby, the integrity of the intestinal epithelial cell layer is preserved or restored, and the diarrheic leakage of fluids into the intestinal lumen is attenuated.

Cellular and molecular effects of yeast probiotics on cancer

The cancer is one of the main causes of human deaths worldwide. The exact mechanisms of initiation and progression of malignancies are not clear yet, but there is a common agreement about the role of colonic microbiota in the etiology of different cancers. Probiotics have been examined for their anti-cancer effects, and different mechanisms have been suggested about their antitumor functions. Nonpathogenic yeasts, as members of probiotics family, can be effective on gut microbiota dysbiosis. Generally safe yeasts have shown so many beneficial effects on human health. Probiotic yeasts influence physiology, metabolism, and immune homeostasis in the colon and contribute to cancer treatment due to possessing anti-inflammatory, anti-proliferative and anti-cancer properties. This study reviews some of the health-beneficial effects of probiotic yeasts and their biological substances like folic acid and β-glucan on cancer and focuses on the possible cellular and molecular mechanisms of probiotic yeasts such as influencing pathogenic bacteria, inactivation of carcinogenic compounds, especially those derived from food, improvement of intestinal barrier function, modulation of immune responses, antitoxic function, apoptosis, and anti-proliferative effects.

A novel synergistic galactomannan-based unit dosage form for sustained release of acarbose

In the current study, the potential of a novel combination of a galactomannan with acarbose (100 mg) was evaluated for attaining a desired hypoglycaemic effect over a prolonged period of time. Three major antidiabetic galactomannans viz., fenugreek gum, Boswellia gum, and locust bean gum were selected in order to achieve a synergistic effect in the treatment along with retardation in drug release. In vitro studies indicated that batches containing various proportions of fenugreek gum (AF40-60) were able to control drug release for a longer duration of approximately 10-12 h. In contrast, the matrices prepared using Boswellia and locust bean gum were able to sustain the release for relatively shorter durations. Drug release mainly followed first-order release kinetics owing to the highly soluble nature of the drug. In vivo study depicted a significant reduction (p < 0.001) in the postprandial blood glucose and triglyceride levels in the diabetic rats on treatment with formulation AF40. Thus, the developed system provides a better control of the postprandial glycaemic levels and it also obviates the need of conventional multiple dosing of acarbose. Furthermore, it also reduces the occurrence of side effects like diarrhea and loss of appetite.

Efficacy and safety of the probiotic Saccharomyces boulardii for the prevention and therapy of gastrointestinal disorders

Several clinical trials and experimental studies strongly suggest a place for Saccharomyces boulardii as a biotherapeutic agent for the prevention and treatment of several gastrointestinal diseases. S. boulardii mediates responses resembling the protective effects of the normal healthy gut flora. The multiple mechanisms of action of S. boulardii and its properties may explain its efficacy and beneficial effects in acute and chronic gastrointestinal diseases that have been confirmed by clinical trials. Caution should be taken in patients with risk factors for adverse events. This review discusses the evidence for efficacy and safety of S. boulardii as a probiotic for the prevention and therapy of gastrointestinal disorders in humans.

Anti-inflammatory effects of Saccharomyces boulardii mediated by myeloid dendritic cells from patients with Crohn's disease and ulcerative colitis

Saccharomyces boulardii (Sb) is a probiotic yeast that has demonstrated efficacy in pilot studies in patients with inflammatory bowel disease (IBD). Microbial antigen handling by dendritic cells (DC) is believed to be of critical importance for immunity and tolerance in IBD. The aim was to characterize the effects of Sb on DC from IBD patients. Highly purified (>95%), lipopolysaccharide-stimulated CD1c(+)CD11c(+)CD123(-) myeloid DC (mDC) from patients with ulcerative colitis (UC; n = 36), Crohn's disease (CD; n = 26), or infectious controls (IC; n = 4) were cultured in the presence or absence of fungal supernatant from Sb (SbS). Phenotype and cytokine production and/or secretion of IBD mDC were measured by flow cytometry and cytometric bead arrays, respectively. T cell phenotype and proliferation were assessed in a mixed lymphocyte reaction (MLR) with allogenic CD4(+)CD45RA(+) naïve T cells from healthy donors. Mucosal healing was investigated in epithelial wounding and migration assays with IEC-6 cells. SbS significantly decreased the frequency of CD40-, CD80-, and CD197 (CCR7; chemokine receptor-7)-expressing IBD mDC and reduced their secretion of tumor necrosis factor (TNF)-α and interleukin (IL)-6 while increasing IL-8. In the MLR, SbS significantly inhibited T cell proliferation induced by IBD mDC. Moreover, SbS inhibited T(H)1 (TNF-α and interferon-γ) polarization induced by UC mDC and promoted IL-8 and transforming growth factor-β-dependent mucosal healing. In summary, we provide novel evidence of synergistic mechanisms how Sb controls inflammation (inhibition of T cell costimulation and inflammation-associated migration and mobilization of DC) and promotes epithelial restitution relevant in IBD.

Beneficial effects of probiotic and food borne yeasts on human health

Besides being important in the fermentation of foods and beverages, yeasts have shown numerous beneficial effects on human health. Among these, probiotic effects are the most well known health effects including prevention and treatment of intestinal diseases and immunomodulatory effects. Other beneficial functions of yeasts are improvement of bioavailability of minerals through the hydrolysis of phytate, folate biofortification and detoxification of mycotoxins due to surface binding to the yeast cell wall.

[Saccharomyces boulardii reduced intestinal inflammation in mice model of 2,4,6-trinitrobencene sulfonic acid induced colitis: based on microarray]

BACKGROUND/AIMS

Saccharomyces boulardii has been reported to be beneficial in the treatment of inflammatory bowel disease. The aim of this work was to evaluate the effect of S. boulardii in a mice model of 2,4,6-trinitrobencene sulfonic acid (TNBS) induced colitis and analyze the expression of genes in S. boulardii treated mice by microarray.

METHODS

BALB/c mice received TNBS or TNBS and S. boulardii treatment for 4 days. Microarray was performed on total mRNA form colon, and histologic evaluation was also performed.

RESULTS

In mice treated with S. boulardii, the histological appearance and mortality rate were significantly restored compared with rats receiving only TNBS. Among 330 genes which were altered by both S. boulardii and TNBS (>2 folds), 193 genes were down-regulated by S. boulardii in microarray. Most of genes which were down-regulated by S. bouardii were functionally classified as inflammatory and immune response related genes.

CONCLUSIONS

S. boulardii may reduce colonic inflammation along with regulation of inflammatory and immune responsive genes in TNBS-induced colitis.

Arginine, citrulline and nitrate concentrations in the cerebrospinal fluid from patients with acute hydrocephalus

Citrulline and nitric oxide (NO) are synthesized by NO synthase (NOS) in a 1:1-stoichiometry. In this study, we determined by HPLC arginine and citrulline concentrations by fluorescence detection and nitrate levels by UV absorbance detection in the cerebrospinal fluid (CSF) from patients with acute hydrocephalus that underwent ventricular drainage. We found increased citrulline concentration (50.6+/-17.2 versus 20.9+/-2.0 microM) and decreased arginine/citrulline molar ratio (0.42+/-0.11 versus 1.12+/-0.16) in hydrocephalus patients, while arginine and nitrate concentrations and citrulline/nitrate molar ratio remained with little change. Citrulline has been determined as a marker of NOS activity in some studies, but it remains to be determined the extent at which this statement holds true, since other biochemical pathways also regulate the concentration of this amino acid. Our results suggest that citrulline is primarily synthesized from NOS in acute hydrocephalus. The evaluation of sample deproteinization by addition of methanol for the analysis of amino acids in CSF is also reported.