Butterbur, an herbal remedy, confers complementary anti-inflammatory activity in asthmatic patients receiving inhaled corticosteroids

We evaluated the effects of butterbur (BB), a herbal remedy, given as add-on therapy to asthmatics maintained on inhaled corticosteroids (ICS), assessing adenosine monophosphate (AMP) bronchoprovocation (primary outcome variable) along with other surrogate inflammatory markers such as exhaled nitric oxide (NO), serum eosinophil cationic protein (ECP) and peripheral blood eosinophil count (EOS). 16 atopic asthmatics with mean (SEM) FEV 1 of 78 (4) % predicted, maintained on their constant ICS dose throughout the study, received for 1 week either BB 25 mg bid or placebo (PL) bid, in a double-blind, cross-over fashion, with a 1-week washout period prior to each randomized treatment. Measurements were made at baselines prior to each randomized treatment and following the randomized treatment period. Baseline values for the primary and secondary outcomes were not significantly different prior to BB and PL. AMP PC 20 as doubling dilution change from baseline, significantly improved ( p