Difference of growth-inhibitory effect of Scutellaria baicalensis-producing flavonoid wogonin among human cancer cells and normal diploid cell.

Methanol extract from cultured Scutellaria baicalensis cells inhibited the proliferation of human monocytic leukemia cell line THP-1 and human osteogenic sarcoma cell line HOS. The inhibitory effects of baicalin, baicalein and wogonin, the three major flavonoids contained in the extract, were studied. It should be noted that wogonin did not show the inhibitory effect on human fetal lung normal diploid cell line TIG-1, as compared to the inhibition observed in cancer cells. Physiological analyses in THP-1 cells showed that wogonin induced cell cycle arrest at G(2)/M phase and apoptosis. This is the first report discovering a cancer-specific apoptosis-inducing activity of wogonin.

High-yield production of scutellaria radix flavonoids (baicalein, baicalin and wogonin) by liquid-culture of Scutellaria baicalensis root-derived cells

Production of baicalein, baicalin and wogonin by liquid culture of Scutellaria baicalensis cells derived from the plant root was studied. The maximum production obtained were 119 mg/L of baicalein at two week, 1372 mg/L of baicalin at eight week, and 14 mg/L of wogonin at two week. In addition, the production of baicalin was drastically increased to 1000 mg/L level at 3-week culture, and the extremely high production rate (339 mg/L•week) was obtained. In the comparison of total antioxidative activities among baicalein, baicalin and wogonin, evaluated by thiocyanate method, it was suggested that the location of hydroxyl groups both at 5- and 6-position contributed to enhancement of radical scavenging activity, and/or methoxylation at 8-position diminished the activity. The possibility of utilizing these flavonoids for natural antioxidants and medicine is also discussed.