Studies on the mechanism of action of Albizzia lebbeck, an Indian indigenous drug used in the treatment of atopic allergy.

Studies were conducted on the decoction of the bark of Albizzia lebbeck which has been in use by Ayurvedic physicians for bronchial asthma and eczema. The effect of A. lebbeck was studied on the degranulation rate of sensitized peritoneal mast cells of albino rats when challenged with antigen (horse serum). Triple vaccine was used as adjuvant. Disodium cromoglycate (DCG) and prednisolone were used for comparison. Drugs were given during the first or second week of sensitization and the mast cells studied at the end of the second or third week. Serum from these rats was used to passively sensitize recipient rats whose peritoneal mast cells were then studied. The in vitro effects of A. lebbeck and DCG on the degranulation rate of the sensitized mast cells were also studied. The results show that A. lebbeck has a significant cromoglycate-like action on the mast cells. In addition, it appears that it inhibits the early processes of sensitization and synthesis of reaginic-type antibodies. If A. lebbeck is given during the first week of sensitization it markedly inhibits the early sensitizing processes, while if given during the second week it suppresses antibody production during the period of drug administration. The active ingredients of the bark appear to be heat-stable and water-soluble.