Study On Effects Of Phenolic Compounds On Immunoactivity Of Shrimp Allergen Extracts And Their Anti-allergic Activities

Shrimp is delicious, nutrient and deeply popular with consumers because of itsflavor. However, many allergic reports caused by shrimp and its products are frequent.It has a serious impact on people’s health and qualities of life. There are twoimprovements for food allergies. One is using certain technologies to reduce foodallergen’s activity. The other is adding anti-allergic active ingredients in food.Polyphenolic compounds, a small molecule substance with a wide range of biologicalactivity, widely exists in plants. This paper focuses on the effects of phenoliccompounds on immunoactivity of shrimp allergen extracts and the anti-allergicactivity of polyphenol-riched seaweed extracts. It also discusses the anti-allergicmechanism of polyphenol compounds.1. Tea polyphenol and ferulic acid have been selected to complex with shrimpallergen extracts and tested by immunoblotting, indirect enzyme-linkedimmunosorbent assay to detect the binding ability with IgE. The results showed thatferulic acid, tea polyphenols could react with shrimp allergen extracts. The immuneactivities of allergen extract solutions were reduced by97.1%and99.9%, separately.But the study also found that the immune activities of the ferulic acid-treatedprecipitate and tea polyphenol-treated precipitate were not significantly reduced. Theimmunoactivity of the ferulic acid-treated precipitate was reduced by29.4%, whilethe immunoactivity of tea polyphenol-treated precipitate was increased by15.8%.This may be due to the changes of the shrimp allergen’s epitope conformation bypolyphenolic compounds. Some of the original hidden epitope was exposed.2. Ethanol extracts of five commercial seaweeds were compared for theiranti-allergenic activity measured in terms of hyaluronidase inhibition. The resultsshow that scytosiphon had the lowest IC50(50%inhibitory concentration) of0.67mg/mL. Disodium cromoglycate (DSCG), an anti-allergic drug had an IC50=1.13mg/mL. Sscytosiphon possess potent anti-allergic components with a potential toreplace some commercially used compounds such as DSCG.3. Seven kinds of domestic and foreign common macroporous resins were chose to separate and purify the anti-allergic active ingredients of Scytosiphon. With thecomparison of adsorption and desorption rate, it was found that the XDA-1macroporous resin has good adsorption and desorption. The optimum adsorption anddesorption conditions were as follows: the concentration of extract solution(1.0mg/mL), pH value (5.83), adsorption speed (1.0mL/min), concentration of ethanol(80%), elution speed (1.0mL/min). The chromatographic process so optimized gave apurity of45.27%from the crude extracts. And the specific activity was increased1.94times.4. The allergic animal models were established in order to investigate theingredients’ inhibiting mechanism to allergic reaction. First the BALB/c mousemodels of shrimp were established. Scytosiphon extract was fed to the animaleveryday. The study confirmed that high-dose Scytosiphon extract could reduce thespecific IgE and IL-4levels of allergy serum, close to the medical group. The specificIgE and IL-4levels of high dose group for the prevention were decreased by60.05%and33.74%, compared to allergic model group. And the specific IgE and IL-4levelsof high dose group for the treatment were decreased by67.90%and34.83%,compared to allergic model group. The IL-4/IFN-γ ratio of allergy serum was alsodecreased. All the results suggest that the inhibiting mechanism of polyphenol-richedScytosiphon extract is reducing the excess of IL-4and inhibiting the increase ofTh2/Th1ratio. So that the generation of IgE is inhibited and the balance between Th1and Th2cells was recovered.To sum up, the complexation of polyphenol compounds and shrimp allergen cannot effectively reduce the immune activity of shrimp allergen. Thus, changing theconformation of allergen protein to reduce the immune activity of allergen bypolyphenol compounds remains to be further explored. On the other hand,polyphenol-riched Scytosiphon extract has a good anti-allergic effect. Itsanti-allergic activity is better than cromolyn sodium. It is an excellent naturalanti-allergic biological resource.