Citrus Tachibana Leaf Extract Mitigates Symptoms of Food Allergy by Inhibiting Th2‐Associated Responses

The objective of this study was to determine whether Citrus tachibana (fruit body with peel, leaves, and branch) can protect against the development of food allergy and the mechanism behind it, and to identify the active compound(s) responsible. We found that C. tachibana leaf extract (CLE) mitigated ovalbumin (OVA)‐induced food allergy symptoms including increased rectal temperature, diarrhea, and anaphylaxis. This mitigation was likely due to CLE‐mediated decreases in cytokine release from T‐helper 2 cells (Th2 cells) in mesenteric lymph nodes. Moreover, higher levels of CLE attenuated systemic Th2 cell–mediated responses in mouse splenocytes sensitized with OVA+Alum. This was evidenced by CLE‐mediated reductions in Th2 cytokine release, including interleukin (IL)‐4, IL‐5, and IL‐13, but not the Th1 cytokines IL‐12 and interferon (IFN)‐γ, which was attributable to decreased gene expression levels. We also identified kaempferol as the most potent compound for reducing Th2‐associated responses in splenocytes. The findings of this study suggest that CLE suppresses Th2‐cell–mediated immune responses, contributing to alleviation of food allergy symptoms, and that kaempferol is a flavonoid with potential antiallergenic activity that targets Th2 cell–induced responses. Practical Application Citrus tachibana leaf extract (CLE) exhibits protective effect against OVA‐mediated food allergy, which is likely to occur by attenuating Th2‐associated respon...
Source: Journal of Food Science - Category: Food Science Authors: Tags: H: Health, Nutrition & Food Source Type: research