Effect of microencapsulation on Saccharomyces cerevisiae var. boulardii viability in the gastrointestinal tract and level of some blood biochemical factors in wistar rats.

BACKGROUND AND OBJECTIVES: Probiotics are live microorganisms that, when administered in an adequate amount, confer a health benefit on the host through the gut. Saccharomyces cerevisiae is a widespread yeast found in nature. This microorganism has been used as a probiotic agent in recent years. In this study, the effect of microencapsulation on survival rate of S. cerevisiae var. boulardii in the simulated gastrointestinal tract medium and the impact of microencapsulated S. cerevisiae var. boulardii on some serum biochemical factors in a rat model was evaluated. MATERIALS AND METHODS: 30 male wistar rats were divided into three groups (control, rats receiving microencapsulated S. cerevisiae var. boulardii, and rats receiving S. cerevisiae var. boulardii alone). The probiotic was gavaged at a dosage of 2 gr/kg BW for 8 weeks. Blood was collected from rats at the end of the treatment period and biochemical factors were measured using Mancompany kits. RESULTS: The results showed a significant increase in viability of microencapsulated S. cerevisiae var. boulardii in comparison with free S. cerevisiae var. boulardii (p<0.05). Weight of rats in probiotic treated groups was significantly higher in comparison with the control group (p<0.05). Moreover, probiotic treatment reduced mean levels of triglycerides, cholesterol, free blood sugar and liver enzymes in rats. CONCLUSION: Microencapsulation could increase the survival rate of yeast probiotics in the gastrointestinal tract; however, more studies are needed for better understanding of the exact effect of microencapsulation on probiotics' function.

Staphylococcus aureus Enterotoxin B Down-Regulates the Expression of Transforming Growth Factor-Beta (TGF-ß) Signaling Transducers in Human Glioblastoma.

BACKGROUND: It has been revealed that Staphylococcus aureus enterotoxin B (SEB) may feature anti-cancer and anti-metastatic advantages due to its ability to modify cell immunity processes and signaling pathways. Glioblastoma is one of the most aggressive human cancers; it has a high mortality nature, which makes it an attractive area for the development of novel therapies. OBJECTIVES: We examined whether the SEB could exert its growth inhibitory effects on glioblastoma cells partially through the manipulation of a key tumor growth factor termed transforming growth factor-beta (TGF-ß). MATERIALS AND METHODS: A human primary glioblastoma cell line, U87, was treated with different concentrations of SEB. The cell quantity was measured by the MTT assay at different exposure times. For molecular assessments, total ribonucleic acid (RNA) was extracted from either non-treated or SEB-treated cells. Subsequently, the gene expression of TGF-ß transducers, smad2/3, at the messenger RNA (mRNA) level, was analyzed via a quantitative real-time polymerase chain reaction (qPCR) using the SYBR Green method. Significant differences between cell viability and gene expression levels were determined (Prism 5.0 software) using one-way analyses of variance (ANOVA) test. RESULTS: We reported that SEB could effectively down-regulate smad2/3 expression in glioblastoma cells at concentrations as quantity as 1 µg/mL and 2 µg/mL (P < 0.05 and P < 0.01, respectively). The SEB concentrations effective at regulating smad2/3 expression were correlated with those used to inhibit the proliferation of glioblastoma cells. Our results also showed that SEB was able to decrease smad2/3 expression at the mRNA level in a concentration- and time-dependent manner. CONCLUSIONS: We suggested that SEB could represent an agent that can significantly decrease smad2/3 expression in glioblastoma cells, leading to moderate TGF-ß growth signaling and the reduction of tumor cell proliferation.

Antifungal effect of Echinophora platyloba on expression of CDR1 and CDR2 genes in fluconazole-resistant Candida albicans.

BACKGROUND: Several studies examined the effect of the Echinophora platyloba extract in treatment of azole-resistant Candida albicans clinical isolates. OBJECTIVE: We investigated the effect of E. platyloba extract on expression of CDR1 and CDR2 genes in fluconazole-resistant clinical isolates of C. albicans using real-time PCR. MATERIALS AND METHODS: The crude extract of E. platyloba was obtained using percolation method. Using serial dilution method, different concentrations of extract were achieved. Two hundred microlitres of fungal suspension (10(6) CFU/ml) was added to the media and cultured with different concentrations and then incubated at 37 °C for 48 h. The concentration of extract in the first tube, which inhibited the growth of C. albicans, was recorded as the Minimal Inhibitory Concentration (MIC). In order to analyse the expression of CDR1 and CDR2 genes, RNA was extracted from C. albicans isolates before and after treatment with MIC of E. platyloba using glass beads and the denaturing buffer agents in an RNase-free environment and then the cDNA was synthesised and used for real-time PCR assay. RESULTS: Twenty of total of 148 isolates were resistant to fluconazole. The MIC and MFC for the alcoholic extract of E. Platyloba were 64 mg/ml and 128 mg/ml, respectively. Real-time PCR results revealed that the mRNA levels of CDR1 and CDR2 genes significantly declined after incubation with E. Platyloba (both p values < 0.001). CONCLUSION: E. Platyloba is effective in reducing CDR1 and CDR2 expression which in turn plays an important role in fluconazole resistance in Candida species.

Modulation of transforming growth factor­ß signaling transducers in colon adenocarcinoma cells induced by staphylococcal enterotoxin B.

Colorectal cancer (CRC) is a notable cause of cancer­associated mortality worldwide, making it a pertinent topic for the study of cancer and its treatment. Staphylococcal enterotoxin B (SEB), an enterotoxin produced by Staphylococcus aureus, has been demonstrated to exert anticancer and antimetastatic effects due to its ability to modify cell immunity and cellular signaling pathways. In the current study, SEB was investigated, including whether it exerts its growth inhibitory effects on colon adenocarcinoma cells. This may occur through the manipulation of a key tumor growth factor, termed transforming growth factor­ß (TGF­ß), and its signaling pathway transducer, Smad2/3. The human colon adenocarcinoma HCT116 cell line was treated with different concentrations of SEB, and cell number was measured using MTT assay at different treatment times. Smad2/3 RNA expression level was analyzed in untreated or SEB­treated cells using quantitative polymerase chain reaction, which indicated significant differences between cell viability and Smad2/3 expression levels. SEB effectively downregulated Smad2/3 expression in the HCT116 cells at concentrations of 1 and 2 µg/ml (P=0.0021 and P=0.0017, respectively). SEB concentrations that were effective at inhibiting Smad2/3 expression were correlated with those able to inhibit the proliferation of the cancer cells. SEB inhibited Smad2/3 expression at the mRNA level in a concentration­ and time­dependent manner. The present study thus proposed SEB as an agent able to significantly reduce Smad2/3 expression in colon cancer cells, provoking moderate TGF­ß growth signaling and the reduction of tumor cell proliferation.

Immunomodulatory effects of Aloe vera and its fractions on response of macrophages against Candida albicans.

Natural products are important resources in traditional medicine and have been long used for prevention and treatment of many diseases. Medicinal plants have immunomodulatory properties. Aloe is one of the herbal medicines widely used in natural treatment and alternative therapy for various types of diseases. Aloe vera has been shown to modulate the immune response. Macrophages have been shown to play an essential role as the first line of defense against invading pathogen. Candida albicans is a communal and opportunistic pathogen in humans. In this study, we investigated the effect of A. vera extract and its fractions on infected macrophages with C. albicans. Viability of intraperitoneal macrophages was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test. Cell viability of infected macrophages was increased by the extract and dose of some isolated fractions dependently. The extract as well as R100, R50, R30, and R10 fractions of A. vera significantly increased cell viability of macrophages in most doses. R5 and F5 fractions showed no significant difference in comparison with control group. Further studies in animal models and human are necessary to clarify the modulatory effects of A. vera on macrophage function. Isolation and purification of A. vera components are also needed to find out the effective molecules.