The effects of Rosae Multiflorae fructus extract on allergic rhinitis: animal experiments and clinical trials

Background: Allergic rhinitis (AR) causes itching, sneezing, watery rhinorrhea, and nasal congestion. However, there is no medication to cure AR. In previous study, we found a candidate, Rosae Multiflorae fructus, has potent anti-oxidative, anti-allergic, and anti-inflammatory properties. Aims and Objectives: Therefore, we investigated the effect of Rosae Multiflorae fructus extract (RMFE) on AR symptoms in a mouse model and a randomized double blind control trial. Methods: The effects of RMFE were evaluated by criteria in AR mice challenged with ovalbumin, such as symptoms, Th1/Th2-related cytokines, and histopathologic analysis. In clinical trial, fifty one patients with AR were received two tablets of RMFE (200 mg/tablet) or placebo, twice every day, for four weeks. Nasal symptom score related with AR were monitored to evaluate the effect of RMFE. Results: Oral administration of RMFE inhibited the accumulation of eosinophils in nasal lavage fluid (NALF) and the nasal mucosa, goblet cells in the nasal epithelium, and mast cells in the respiratory region of the nasal cavity. Furthermore, the RMFE suppressed Th2-related cytokines, such as IL-4, IL-5, and IL-13 in NALF, nasal-associated lymphoid tissue, and splenocytes, whereas the Th1-associated cytokine IL-12 was up-regulated by RMFE. In human study, the RMFE showed significant improvements in symptoms related with AR (total nasal symptom score and watery rhinorrhea) over placebo on 2 and 6 weeks. Conclusions: RMFE was proved to be helpful in treating AR symptoms by modulating the relationships between Th1/Th2 responses without noticeable side effects.