Effects of absorbed components of Saiboku-to on the release of leukotrienes from polymorphonuclear leukocytes of patients with bronchial asthma

Previous studies confirmed the efficacy of the Chinese herbal remedy Saibok u-to in patients with steroid-dependent asthma. We studied 8 phenolic compo unds, isolated from the urine of patients receiving Saiboku-to, with respec t to their effects on leukotriene (LT) release by polymorphonuclear leukocy tes (PMN) obtained from 6 patients with atopic asthma and 8 healthy subject s. The compounds (0.01-10 mug/ml) were incubated with Ca2+ ionophore (A2318 7)-stimulated PMN, and concentrations of leukotriene B-4 (LTB4) and leukotr eine C-4 (LTC4) in the supernatant were measured by EIA. Each compound supp ressed the release of LTB4 and LTC4 by PMN obtained from healthy and asthma tic subjects. In particular, baicalein and magnolol were 5-10 times more po tent than azelastine, an antiallergic drug, and significantly suppressed LT C4 release by PMN obtained from asthmatic patients, as compared with health y subjects. Suppression of LTC4 release by these compounds may play an impo rtant role in the clinical efficacy of Saiboku-to. (C) 2001 Prous Science. All rights reserved.