Therapeutic effects of β1, 4 mannobiose in a Balb/c mouse model of intranasally-induced pollen allergy

Inhibitory effect of Japanese black vinegar on IgE-mediated degranulation of RBL-2H3 cells and a murine model of Japanese cedar pollinosis

Japanese black vinegar (JBV) is a traditional vinegar manufactured with steamed unpolished rice. After screening, beneficial effects of JBV on IgE-mediated allergic responses were found. In this study, acetic acid-free JBV was used to evaluate its antiallergic effects. JBV suppressed degranulation of rat basophilic leukemia RBL-2H3 cells in a dose-dependent manner without cytotoxicity. The inhibitory effect of JBV on the degranulation seemed to be caused by the bioactive ingredients other than proteins, because the activity was not affected by heat treatment or protease digestion. JBV inhibited the elevation in the intracellular Ca²⁺ concentration induced by antigen. Immunoblot analysis revealed that JBV suppresses degranulation of RBL-2H3 cells by downregulated phosphorylation of PI3K, Akt, and PLCγ1. In addition, oral administration of JBV significantly suppressed passive cutaneous anaphylaxis reaction in mice and an allergic symptom in Cry j1-induced pollinosis model mice. Thus, JBV has a potential as a health-promoting food with the antiallergy effect.

Th17 response and its regulation in inflammatory upper airway diseases

Allergic rhinitis (AR) and chronic rhinosinusitis (CRS) are two widely prevalent inflammatory diseases in the upper airways. T cell immunity has been suggested to play an important pathogenic role in many chronic inflammatory diseases including inflammatory upper airway diseases. Inappropriate CD4(+) T cell responses, especially the dysregulation of the Th1/Th2 balance leading to excessive Th1 or Th2 cell activation, have been associated with allergic rhinitis and chronic rhinosinusitis. Nevertheless, recent studies suggest that IL-17A and IL-17A-producing Th17 cell subset, a distinct pro-inflammatory CD4(+) T cell lineage, may also play an important role in the pathophysiology of inflammatory upper airway diseases. Th17 cells may promote both eosinophilic and neutrophilic inflammation in AR and CRS. In addition, a few, but accumulating evidence shows that the Th17 responses can be tightly regulated by endogenous and exogenous substances in the context of AR and CRS. This review discusses recent advances in our understanding of the expression and function of the Th17 response and its regulation in inflammatory upper airway diseases, and the perspective for future investigation and clinical utility.

Recovery and purification of oligosaccharides from copra meal by recombinant endo-β-mannanase and deciphering molecular mechanism involved and its role as potent therapeutic agent

Production of manno-oligosaccharides (MOSs) from pretreated and defatted copra meal (dFCO) hydrolysis was achieved by endo-mannanase. Structural characterization of dFCO by FT-IR and NMR exhibited resemblance with galactomannan. The time-dependent hydrolysis of dFCO by recombinant endo-β-(1 → 4)-mannanase of Clostridium thermocellum by TLC and HPAEC displayed the release of mannose and MOSs mannobiose and mannotriose. Purified MOSs yielded 40 % mannobiose and 18 % mannotriose confirmed by mass spectroscopy which showed mannobiose (m/z = 365) and mannotriose (m/z = 527). The homology based structural analysis of catalytic endo-mannanase (CtManT) showed the catalytic core composed of Glu181 and Glu300 acting as acid/base and Glu288 as a nucleophile during galactomannan hydrolysis. Sub-site mapping of CtManT exhibited two aglycone and four glycone sites at cleavage sites existing on either side of β-(1 → 4)-linkage of galactomannan. Isolated MOSs displayed potential prebiotic characteristics and supported higher growth of probiotic Lactobacillus acidophilus and Bifidobacterium infantis than with standard inulin. Moreover, MOSs displayed over 97 % tolerance to simulated gastric juice, intestinal fluid, and α-amylase proving its potential as a stable prebiotic over inulin. In vitro cytotoxicity assay of MOSs (500 µg/mL) on human epithelial colorectal adenocarcinoma cell line (HT-29) demonstrated 60 % decreased viability of cells after 48 h displaying anti-tumorigenic property.