Immunotoxicity and allergenic properties of betulin-containing birch bark dry extract

Birch bark dry extract (BBDE) containing no less then 70% of betulin was studied in complex tests on mice and guinea pigs. Administered perorally in doses of 100 and 1000 mg/kg (p.o.), BBDE exhibited neither immunotoxic nor allergenic effects. In luminol-dependent chemiluminescence tests, BBDE administered in mice in a dose of 100 mg/kg (p.o.) during 14 days inhibited the production of reactive oxygen species by neutrophils. Upon a single administration in doses of 100 and 1000 mg/kg, BBDE suppressed a model inflammation induced by concanavalin A in mice. BBDE administered to guinea pigs in doses of 100 and 1000 mg/kg reduced the intensity of systemic anaphylaxis.