Inhibition of mast cell histamine release by 2,6-dimethoxy-p-benzoquinone isolated from Berchemia racemosa.

Abstract
The MeOH extract of Berchemia racemosa has an inhibitory activity on histamine release from rat mast cells. From the active fraction of the extract, 2,6-dimethoxy-p-benzoquinone was isolated. It shows strong inhibition of histamine release from rat mast cells induced by compound 48/80 and by concanavalin A, with IC50 values of 6 and 8 .mu.M, respectively.