[Exogenous H2O2 regulated secondary metabolism of Scutellaria baicalensis and enhanced drug quality].

ABSTRACT

The increasing demand of Chinese materia medica could not be supplied by wild resource, and the cultivated medicinal materials become popular, which led to decreased quality of many medicinal materials due to the difference of the circumstance between the wild and the cultivated. How to improve quality becomes key points of Chinese medicine resource. The leaves of Scutellaria baicalensis were sprayed with H2O2, the activities of superoxide dismutase (SOD) and catalase (CAT) changed little, but there had been a marked decrease of peroxidase (POD) and ascorbic oxidase (APX), which showed that the antioxidase system declined. Meanwhile, H2O2, as enhanced the expression of phenylalnine ammonialyase (PAL) and ß-glucuronidase (GUS) as well as activity of PAL, promoted the biosynthesis and biotransformation of flavonoids. At the day 2 after treated, H2O2 of 0.004 µmol·L⁻¹ the contents of the baicalin and the wogonoside decreased slightly, but the contents of the baicalein and the wogonin increased significantly, the baicalein from 0.094% to 0.324%, the wogonin from 0.060% to 0.110%, i. e. increased 246% and 83.3%, respectively.