Studies on the storage stability of betacyanins from fermented red dragon fruit (Hylocereus polyrhizus) drink imparted by xanthan gum and carboxymethyl cellulose.

Red dragon fruit is rich in health-benefited betacyanins that are susceptible to degradation. The present study was to improve the fermented red dragon fruit drink (FRDFD) betacyanins stability by incorporating hydrocolloids solution of xanthan gum (XG, 0.15-0.30%, w/v) and carboxymethyl cellulose (CMC, 0.3-0.5%, w/v) to produce Improved-FRDFD-dH2O. Results revealed the viscosities of all samples were significantly increased as the hydrocolloids concentration increased. All the samples' pH, aw, total soluble solids (TSS) and betacyanins content were not significantly affected by the hydrocolloids solution added. After four-week storage (25 °C), the formulation of 0.3% XG and 0.5% CMC had significantly reduced the betacyanins degradation from 60.55% to 30.66%. Meanwhile, all samples added with 0.3% XG and 0.3-0.5% CMC remained no significant change in viscosity, pH, aw and TSS after storage. These conclude the hydrocolloids solution of 0.3% XG and 0.5% CMC successfully stabilise the betacyanins in the FRDFD at 25 °C over four-week storage.

The effects of heat-killed wild-type Lactobacillus casei Shirota on allergic immune responses in an allergy mouse model.

BACKGROUND: Probiotics are used as a management strategy for allergic diseases, but their effects on allergic responses in sensitized allergic individuals remain unclear. This study explored the immunomodulatory effects of probiotics on allergen-specific allergic reactions in an allergy mouse model. METHODS: C57BL/6 mice were presensitized by epicutaneous patching with recombinant Der p 2, and were subsequently administered orally with either heat-killed wild-type Lactobacillus casei or NaHCO(3) buffer for 5 weeks (n=6 per group). All mice then received 2 subcutaneous immunizations of Der p 2 to mimic allergen immunotherapy, followed by aerosol challenge with Der p 2 a week later. RESULTS: The Der p 2-sensitized mice fed L. casei showed significantly lower Der p 2-specific IgE and IgG1 after subcutaneous immunizations and airway challenge with Der p 2 compared to the control, unfed group. Splenic T cells of mice fed L. casei showed suppression of Th-2 (IL-5, IL-13, IL-10 and IL-4) and proinflammatory (TNF-alpha, IFN-gamma) cytokines. Following airway allergen challenge, the mice fed L. casei showed histological evidence of attenuation of lung inflammation, as well as reductions in the total cell count and Th2 and proinflammatory cytokines in bronchoalveolar lavage fluid, compared to controls. Taken together, these results suggest that the oral administration of heat-killed L. casei could effectively downregulate the pre-existing Th-2 allergic responses and pulmonary inflammatory responses upon subcutaneous and airway allergen challenge. CONCLUSIONS: L. casei has intrinsic adjuvant and immunomodulatory properties that could potentially be exploited for secondary prevention or treatment of allergic respiratory diseases.

Efficacy evaluation of Der p 1 DNA vaccine for allergic asthma in an experimental mouse model.

Der p 1 is a major allergen that reacts with IgE in more than 70% allergic sera, hence a good candidate for DNA vaccine development. Previous study demonstrated that intramuscular injection of plasmid DNA containing wild type Der p 1 gene induced specific Th1 skewed immune response. The aim of this study is to further optimize the DNA construct to achieve preventive and therapeutic efficacies. An optimized construct, containing mouse Igkappa light chain leader sequence followed by codon optimized mature Der p 1 gene, was generated and used to prevent or treat Der p1 induced allergic asthma in an experimental model. Results showed that this optimized construct was effective in the inhibition of Der p 1 specific IgE levels, attenuation of Th2 response and reduction of airway hyperresponsiveness in terms of prophylactic efficacy. It also showed therapeutic efficacy in IgE inhibition and up-regulation of IgG2a and IFN-gamma. The information obtained here could facilitate the design of DNA vaccines for allergy in general.