Comparisons of Scutellaria baicalensis, Scutellaria lateriflora and Scutellaria racemosa: genome size, antioxidant potential and phytochemistry.

The genus Scutellaria in the family Lamiaceae has over 350 species, many of which are medicinally active. One species, Scutellaria baicalensis, is one of the most widely prescribed plants in Traditional Chinese Medicine, used for neurological disorders, cancer and inflammatory diseases and has been the subject of detailed scientific study but little is known about the phytochemistry of other Scutellaria. The current study was designed to compare the medicinal phytochemistry of 3 species of Scutellaria used to treat neurological disorders. To accomplish this objective, the specific objectives were (a) to establish an in vitro collection of the South American native; S. racemosa, (b) to botanically characterize S. racemosa and (c) to compare the phytochemistry of S. racemosa with S. baicalensis and S. lateriflora. S. racemosa was established in vitro from wild populations in Florida. Botanically, S. racemosa is diploid with 18 chromosomes, and flow cytometry data indicated that S. baicalensis and S. racemosa have small nuclei with estimated small genomes (377 mbp and 411 mbp respectively). Antioxidant potential studies showed that there were no significant differences in the 3 Scutellaria species. Phytochemical analyses detected and quantified the flavonoids baicalin, baicalein, scutellarin, and wogonin as well as the human neurohormones melatonin and serotonin in leaf and stem tissues from S. baicalensis, S. lateriflora, and S. racemosa. These findings represent the first phytochemical analysis of S. racemosa and establish S. racemosa as a model system for study of medicinal plant secondary metabolism and as a potential source of important phytopharmaceuticals for treatment of human disease.