Abstract
The effect of hot water extract of Tabebuia avellanedae (Taheebo) in rat peritoneal mast cells during stimulation of histamine release was studied. Taheebo at concentrations of over 5 μg/ml caused an decrease in histamine release stimulated by C48/80 in a dosage-dependent manner. In the Ca2+ free medium, Taheebo caused a decrease in histamine release too. The effect of Taheebo was suppressed by high concentrations of C48/40 competitively. Taheebo at concentrations of over 10 μg/ml caused an decrease in histamine release stimulated by concanavalin A in a dosage-dependent manner, but the inhibition was non-competitive. These results suggested that Taheebo caused a decrease in the histamine release, which led to a decrease in the allergy symptoms.
