Leading structures of plant origin for drug development.

This review summarizes the most important results of a plant screening program performed in the author's laboratory during the last 10 years. The screening program was initiated to search for new plant constituents with potential pharmacological activity in the field of inflammation in general, allergic asthma, immunodeficiencies and cardiovascular diseases. The test program mainly utilised in vitro assays, and particular attention was given to the key enzymes of the prostaglandin metabolism, cellular and humoral targets of the unspecific immune system, an in vitro ACE-inhibition test system, and an in vivo plethysmographic system as an inhibitory model of bronchial obstruction. The results of structure-activity relationship studies are also described.