Efficacy of supportive therapy of allergic rhinitis by stinging nettle (Urtica dioica) root extract: A randomized,double-blind,placebo-controlled,clinical trial

The aim of this study was to survey the exact benefit of this herb in the management of clinical and laboratory signs and symptoms of allergic rhinitis. in a randomized double blind clinical trial,74 patients with the signs and symptoms of allergic rhinitis and a positive skin prick test were selected and randomly divided into 2 groups who were taken urtica dioica 150-mg,urtidin® f.c tablet) or placebo for one month. their signs and symptoms,eosinophil percentage on nasal smear,serum ige,and interleukin il-4,il-5,interferon- γ) levels were recorded. forty patients completed the trial. based on the sino- nasal outcome test 22 snot-22),a significant improvement in clinical symptom severity was observed in both groups p < .001). furthermore,a statistically significant reduction in mean nasal smear eosinophil count was observed after treatment with nettle p < .01). however,the mean ige and il4 and il5 levels in the study group before and after treatment with nettle saw no significant changes p > .1). intergroup pre- and post-treatment laboratory findings suggested that there was a significant difference in post-treatment changes of mean ifn γ levels between the study and placebo group p = 0.017). although the current study showed certain positive effects of nettle in the management of allergic rhinitis on controlling the symptoms based on the snot-22,similar effects were demonstrated by placebo as well. we believe that our limitations underscore the need for larger,longer term studies of nettle for the treatment of allergic rhinitis. © 2017 by school of pharmacy.