Osthole alleviates food allergy by blocking IL-33/ST2 pathway and targeting ILC2-CD4+T response

Osthole is widely used in medicine because of its anti-oxidative, anti-allergenic and anti-inflammatory. In this study, we explored the protective effects of osthole on food allergenic mice and investigated its potential mechanism of action. We first established a food allergic mouse model by intraperitoneal sensitization and OVA (ovalbumin) oral challenge. Osthole were orally administered before OVA challenge. Diarrhea and allergy scores were used to assess food allergy symptoms. The pathological changes of the intestine were examined by H&E staining and electron microscopy. OVA-IgE, mucosal mast cell protease-1 (mMCP-1), IL-33, ST2, group 2 innate lymphoid cell (ILC2), and regulatory T (Treg) related-cytokine levels were assessed.We found that the oral administration of osthole after OVA sensitization could improve food allergy symptoms and induce beneficial intestinal pathological changes in mice. Osthole reduce the levels of IgE and mMCP-1 and inhibited the IL33/ST2 signaling pathway, thereby blocking ILC2 response and improving Treg response.