Antimutagenic activity against trp-p-1 of the edible Thai plant, Oroxylum indicum Vent

A methanolic extract of Oroxylum indicum strongly inhibited the mutagenicity of Trp-P-1 in an Ames test. The major antimutagenic constituent was identified as baicalein with an IC sub50 value of 2.78+-0.15microM. The potent antimutagenicity of the extract was correlated with the high content (3.95+-0.43%, dry weight) of baicalein. Baicalein acted as a desmutagen since it inhibited the N-hydroxylation of Trp-P-2.