Anti-Food Allergy Activity Of Porphyran And Gracilaria Lemaneiformis Oligosaccharide

Over the past few decades, the incidence of food allergy is increasing with years all over theworld. Food-induced allergic reactions are responsible for a variety of symptoms involving theskin, gastrointestinal tract, respiratory tract and may even lead to death. So nowadays novelanti-allergic agents from natural resources in the prevention or treatment of food allergy havereceived much attention. Porphyran is a sulfated polysaccharide from the porphyra and has manyphysiological activities including immunoregulatory, prevention and treatment of autoimmunedisease. Gracilaria lemaneiformis oligosaccharide was isolated from the co-culture systemcontained both Gracilaria lemaneiformis and bacterial strain. Until now, few study on theiranti-allergy activity was reported. So investigation of their anti-allergy and mechanisms will bemeaningful for the further development of novel anti-allergy drug or function food.The porphyran was isolated from porphyra haitanensis with hot-water extraction,evaporation under reduced pressure, precipitated by ethanol, then was purified byDEAE-cellulose52chromatographic column orderly. The carbohydrate,3,6-anhydrogalactose,SO42-, uronic acid and protein contents were98.85%,6.25%,14.26%,14.02%and1.2%. Themonosaccharide in porphyran is galactose though IC analysis, and its content was60.09%.The Gracilaria lemaneiformis oligosaccharide was obtained from Gracilaria lemaneiformiswith fermentation, ultra-filtration, then was purified by superdex peptide HR10/300chromatographic column orderly. The carbohydrate, reducting sugar and protein contents were78.85%,17.80%and0.2%. The oligosaccharide in Gracilaria lemaneiformis oligosaccharide ismainly tetrasccharide and hexaose through IC analysis, and the tetrasccharide and hexaosecontents were48.47%and25.69%respectively.The TM was extracted and purified from scylla paramamosain. This study investigated theanti-allergic potential of porphyran and Gracilaria lemaneiformis oligosaccharide using aTM-induced food allergy mouse model. The in vivo studies indicated that the mice of TM grouphad suffered from allergy as their serum IgE levels are4-9fold higher than that of PBS groupafter second intraperitoneal injection of TM. While intraperitoneal injection of porphyran orGracilaria lemaneiformis oligosaccharide significantly supressed serum IgE, IgG1level, andpromoted IgG2a level in mice. After last gavage, histamine content in feces of TM group miceincreased to187.48μg/mL, and the histamine content in faces of porphyran and Gracilarialemaneiformis oligosaccharide group went down to32.49μg/mL and133.52μg/mL respectively.The in vitro studies on mouse spleen cells indicated that the TM-induced Th2cytokines (IL-4, IL-5and IL-13) were reduced by porphyran or Gracilaria lemaneiformis oligosaccharide,however the Th1cytokine (IFN-γ, porphyran also can promote IL-10secretion) wereup-regulated in porphyran or Gracilaria lemaneiformis-treated cells. Moreover, they also canrepair the pathology in the jejunum. Porphyran induced IFN-γ secretion via JNK and JAK2signal pathway.In conclusion, porphyran and Gracilaria lemaneiformis oligosaccharide both can supressedTM-specific IgE and IgG1level, promoted IgG2a level, promoted Th1cykotines and supressedTh2cytokines. Moreover, they also can repair the pathology in the jejunum. These resultssuggesting that porphyran and Gracilaria lemaneiformis oligosaccharide have the capacity tocause the immune function of helper T cells to convert to the Th1, which modulate the imbalanceof Th1/Th2immune response, so as to inhibit the food allergies dominated by the Th2cells.