Effect of Eriobotrya japonica Leaf Supplements on Allergic Rhinitis Symptoms and Skin Conditions in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Study

Abstract

Eriobotrya japonica (E. japonica) leaves have been used as an herbal traditional medicine in China and Japan owing to their anti-inflammatory and protective effects against skin conditions and allergy symptoms. These beneficial effects are likely mediated by the various triterpenoids present in E. japonica leaves. However, the efficacy of E. japonica leaves in the treatment of allergic rhinitis has not been evaluated in humans. Therefore, in the present study, a randomized, controlled, double-blind trial was performed on healthy adults of age >20 (n = 27) who were randomly assigned to receive either 2.5 g of placebo or E. japonica leaf supplements once daily for 4 weeks. The Japanese Allergic Rhinitis Quality of Life Standard Questionnaire (JRQLQ), dermatological allergy symptoms, Dermatology Life Quality Index, and skin condition parameters were assessed at baseline and after 4 weeks. Significant differences were observed in the variability of the itchy nose, itchy eyes, and eye symptoms between the E. japonica supplementation and placebo groups after 4 weeks. Arm skin transepidermal water loss was improved only in the E. japonica supplementation group. This study suggests that E. japonica leaves can be used as a functional food ingredient to relieve allergic symptoms.