Flavones Contents in Extracts from Oroxylum indicum Seeds and Plant Tissue Cultures

Oroxylum indicum (L.) Benth. ex Kurz or Pheka, is a plant in the Bignoniaceae family with various traditional uses. The mature fruits promote anti-helminthic and stomachic effects, while the seeds have been used as a purgative and for the relief of tonsil pain. The young fruits are popularly consumed as vegetables, while the seeds are one of the components in traditional drink formulations. To develop new plant raw material sources, a plant tissue culture technique was used to generate plant tissue cultured samples from the seeds of O. indicum. Plant tissue cultured samples were collected from three different growth stages; 4 days, then at 3 and 9 weeks, and prepared as crude extracts by maceration with ethanol, along with the seed raw material sample. A high performance liquid chromatographic (HPLC) method was used for quantitative analysis of the contents of the three major flavones; baicalin, baicalein, and chrysin in the extracts from the seeds and plant tissue cultured samples of this plant. Baicalin was found in the highest amount among these three flavones in all extracts. The seed extract contained the highest baicalin content (24.24% w/w in the extract), followed by the shoot extract from tissue-cultured plant at week 3 (14.78% w/w of the extract). The amounts of chrysin in all O. indicum showed the same trend as the contents of baicalin, but the amounts were lower, while baicalein was accumulated at the lowest amount among three flavonoids and the amounts were quite stable in all O. indicum extracts. From the results, O. indicum seed and plant tissue cultured extracts have potential as sources of flavones, which could be further developed as health products in the future.