Antitumor effects of Scutellariae radix and its components baicalein, baicalin, and wogonin on bladder cancer cell lines

Objectives. To investigate the antitumor effects of Scutellariae radix and its components baicalein, baicalin, and wogonin on human bladder cancer cell lines (KU-1 and EJ-1) and a murine bladder cancer cell line (MBT-2). Methods. Bladder cancer cells were incubated with various concentrations of the agents. Antiproliferative activity against the bladder cancer cell lines was examined by 3-(4,5-dimethylthianol-2-yl)-2,5-diplenyl tetrazolium bromide assay. In an in vivo experiment, the mice were subcutaneously injected with MBT-2 cells, and Scutellariae radix was orally administered at a dose of 2 or 10 mg per mouse one time daily for 10 days from day 11 to day 20. Results. All the drugs inhibited cell proliferation in a dose-dependent manner, but baicalin exhibited the greatest antiproliferative activity. The concentration of baicalin necessary to obtain 50% inhibition was 3.4 mu g/mL for KU-1, 4.4 mu g/mL for EJ-1, and 0.93 mu g/mL for MBT-2. For KU-1 and MBT-2, the percentage of cell survival significantly decreased (P <0.05) at a baicalin concentration of 1 mu g/mL. In an in vivo experiment, antitumor effects of Scutellariae radix on C3H/HeN mice implanted with MBT-2 were investigated. All the control mice showed a progressive increase in tumor volume, reaching 2.81 +/- 0.18 cm(3) on day 20 and 5.36 +/- 0.44 cm(3) on day 25. However, when Scutellariae radix was orally administered at a dose of 10 mg per mouse one time daily for 10 days from day 11 to day 20, the tumor volume was 1.99 +/- 0.19 cm(3) on day 20 and 3.86 +/- 0.26 cm3 on day 25, a significant inhibition of tumor growth (P <0.05). Conclusions. These results suggest that Chinese herbal medicines may become an attractive and promising treatment for bladder cancer. UROLOGY 55: 951-955, 2000. (C) 2000, Elsevier Science Inc.