Ailanthus altissima, commonly known as the 'tree of heaven,' is used in traditional medicine in many parts of Asia including China to treat cold and gastric diseases. Extracts of A. altissima, have demonstrated anti-proliferative 1) and central nervous depressant activities.2) Among the bioactive compounds isolated from A. altissima, [3][4][5][6] quassinoids have various biological activities such as anti-tumor, anti-viral, and anti-inflammatory effects. 7) Asthma is one of the most common diseases characterized by airway hyper-responsiveness (AHR) associated with elevated serum IgE and bronchial inflammation. In bronchial asthma, various factors result in infiltration of mast cells, eosionphils and T H 2 lymphocytes into the lesions with a downstream mediator.8) Measurements of eicosanoids and their metabolites in bronchoalveolar lavage fluid (BALF) after inhaled allergen challenge of asthmatics suggest that resident mast cells, infiltrating eosinophils, basophils and macrophages are responsible for leukotrienes (LTs) and prostaglandins (PGs) in the early and late bronchoconstrictor responses. 9,10) Eicosanoids are inflammatory mediators that are biosynthesized in many cell types by cyclooxygenases (COX) and lipoxygenases (LOX). They are strongly associated with inflammatory disorders, acute as well as chronic inflammation. The inhibition of eicosanoid production is one of the important therapeutic strategies in various inflammatory diseases. Among the eicosanoid generating enzymes, COX-2 was found to be essential for the production of PGs in inflammatory sites. 11) LTs produced by 5-LOX also have biological properties that would be expected for molecules that participate in the pathogenesis of bronchial asthma.12) Therefore, the dual inhibition of COX-2/5-LOX is believed to be the ideal treatment for allergic diseases and asthma.
13)Although many biological activities of A. altissima were reported, the anti-asthmatic activity of A. altissima has not been reported. In the present study, we describe a new biological function of A. altissima for the arachidonic cascade metabolism enzymes such as COX-2 and 5-LOX along with the potential for use in the treatment of asthma.
MATERIALS AND METHODS
Plant MaterialThe leaf and branch of A. altissima were collected in July 2004 in Daejeon, Korea. This plant material was authenticated by one of the authors (KH Bae) and a voucher specimen has been deposited in the Herbarium of College of Pharmacy, Chungnam National University under the registration number CNU 923. The dried sample (1 kg) was extracted in ethanol (5 l) by refluxing for 24 h twice to give 212 g of an extract and used throughout this study.Preparation of Bone Marrow-Derived Mast Cells (BMMC) Bone marrow cells from male BALB/c mice (Hyochang Science, Daegu, Korea) were cultured for up to 10 weeks in 50% enriched medium (RPMI 1640 containing 100 U/ml penicillin, 100 mg/ml streptomycin, 2 mM L-glutamine, 0.1 mM nonessential amino acids, and 10% fetal calf serum) and 50% WEHI-3 cell conditioned medium as a source ...