Tropomyosin (TM) is the predominant allergenic protein in shrimp, which has induced IgE-mediated food allergy reactions. In this study, Lit v 1 was purified from Penaeus vannamei muscles, which were glycosylated by pectic oligosaccharides. The results showed that Di-Galacturonic acid (DGA) and galacturonic acid (GA) induced the unfolding of the primary protein structure of TM, and changed alpha-helical structure, and IgE binding capacity. In addition, compared with TM-sensitized BALB/c mice, galacturonic acid-modified TM (GA-TM) and Di-Galacturonic acid-modified TM (DGA-TM) were insufficient to stimulate sensitization, and significantly reduced the hypersecretion of IgE, IgG1, HIS, and IL-4, up-regulated IgG2a and IFN-γ levels to improve imbalanced Th1/Th2, Treg/Th17 immunity, and promoted mRNA expression of tight junction proteins. Together, this study confirmed that glycosylation modification alleviated sensitization by altering TM structure, reducing IgE binding allergic inflammatory response, and regulating cytokine immune balance. Overall, these results indicated that glycosylation modification was a promising method for decreasing the allergenic reactivity of allergic proteins.

Tropomyosin (TM) in shrimp is one of the predominant causes of food allergy around the world. In the present study, the effect of seabuckthorn juice against TM -induced shrimp allergy was investigated in BALB/c mice. Allergic symptoms, spleen index, intestinal section and diarrhea were measured in shrimp allergy mice. As the results, seabuckthorn juice suppressed the lesions in jejunum tissue, diarrhea and allergic symptoms in shrimp allergy mice. Seabuckthorn juice also reduced serum concentrations of tumor necrosis factor-α (TNF-α) as well as immunoglobulin E (IgE) and stimulated the secretion of interleukin-10 (IL-10) in mice with shrimp allergy. Taken together, our findings suggest that increased IL-10 by seabuckthorn juice inhibits Th2 cytokine production to suppress shrimp allergic symptoms. Furthermore, seabuckthorn juice also regulates shrimp allergy by reducing jejunum lesions, inhibiting levels of TNF-α and IgE.

Jujube contains abundant cyclic adenosine monophosphate (cAMP) and the ultrasonic-assisted pectinase extraction (UAPE) conditions for obtaining the maximum cAMP yield from jujube were optimized. Orthogonal array design was applied to evaluate the effects of 4 variables by UAPE on cAMP yield. The results showed that the optimal cAMP yield (783.0 μg/g) was derived at ratio of liquid to solid 5 mL/g, ratio of pectinase to raw material 1.5%, time 60 min and temperature 40 ℃. Moreover, the effect of cAMP on the anti-allergic function of action induced by immunoglobulin E (IgE) and its meschanism was investigated through establishing the sensitized cell model in rat basophilic leukemia (RBL-2H3) cells using dinitrophenylated (DNP)-bovine serum albumin (BSA)-IgE. The results showed that cAMP interfered with sensitized cells, effectively inhibited the occurrence of basophil degranulation in dose dependence, and significantly reduced the activity of β-hexosamindase (β-hex), at the optimal concentration of 50 μg/mL. The level of anti-inflammatory factor interleukin-10 (IL-10) was promoted and the content of pro-inflammatory factor tumor necrosis factor-α (TNF-α) was suppressed by cAMP. In addition, influx of intracellular Ca²⁺ was repressed effectively. Our results demonstrate that jujube cAMP regulated the cytokine balance in the allergy pathway through blocking the influx of extracellular Ca²⁺, with the prevention of allergy symptoms.