wogonin and thiazolyl-blue

The molecular mechanisms of wogonin-induced apoptosis of human hepatoma SMMC-7721 cells are reported. Wogonin treatment resulted in significant inhibition of SMMC-7721 cells in a time-dependent and concentration-dependent manner. Typical morphological changes and apoptotic blebbing in SMMC-7721 cells were observed after treatment with 1x10(-4) mol/l wogonin for a period of 0-48 h. Flow cytometry and Annexin-V/propidium iodide double-staining experiments revealed a dramatic increase in the number of apoptotic and G0/G1 phase cells after wogonin treatment. The proapoptotic activity of wogonin is attributed to its ability to modulate the expression of bcl-2 and bax proteins. It is observed that the expression of bax protein is dramatically increased whereas the synthesis of bc1-2 protein is significantly decreased when cells are treated with wogonin. The results presented in this paper suggested an important relationship between gene regulation and wogonin-induced apoptosis, and indicated the possibility of developing naturally occurring monoflavonoids as novel anticancer agents for better management of human cancers.

Topics: Annexin A5; Apoptosis; bcl-2-Associated X Protein; Blotting, Western; Carcinoma, Hepatocellular; Cell Cycle; Cell Line, Tumor; Cell Shape; Colorimetry; DNA Fragmentation; DNA, Neoplasm; Flavanones; Humans; Propidium; Proto-Oncogene Proteins c-bcl-2; Reverse Transcriptase Polymerase Chain Reaction; Tetrazolium Salts; Thiazoles

The effects of the flavonoids from Scutellaria baicalensis Georgi (baicalein, baicalin and wogonin) in cultured human hepatoma cells (Hep G2, Hep 3B and SK-Hep1) were compared by MTT assay and flow cytometry. All three flavonoids dose-dependently decreased the cell viabilities accompanying the collapse of mitochondrial membrane potential and the depletion of glutathione content. However, the influence of baicalein, baicalin or wogonin on cell cycle progression was different. All three flavonoids resulted in prominent increase of G2/M population in Hep G2 cells, whereas an accumulation of sub G1 (hypoploid) peak in Hep 3B cells was observed. In SK-Hep1 cells, baicalein and baicalin resulted in dramatic boost in hypoploid peak, but wogonin made mainly in G1 phase accumulation. These data, together with the previous findings in other hepatoma cell lines, suggest that baicalein, baicalin and wogonin might be effective candidates for inducing apoptosis or inhibiting proliferation in various human hepatoma cell lines.

Topics: Apoptosis; Carcinoma, Hepatocellular; Cell Cycle; DNA, Neoplasm; Drugs, Chinese Herbal; Flavanones; Flavonoids; Flow Cytometry; Glutathione; Humans; Lamiaceae; Medicine, Chinese Traditional; Mitochondria; Molecular Structure; Tetrazolium Salts; Thiazoles; Tumor Cells, Cultured