The cytotoxic effect of a herbal medicine Shosaiko-to (TJ-9) was exami
ned by the MTT assay on 7 human lung cancer cell lines (4 non-small ce
ll carcinomas, 3 small cell carcinomas) and on 5 hepatocellular carcin
oma cell lines. TJ-9 showed a dose-dependent cytotoxicity in all cell
lines except one (SBC-5). Of the seven herbs in TJ-9, Scutellaria root
showed the strongest cytotoxicity followed by the Glycyrrhiza root. A
mong baicalin, baicalein and wogonin from the Scutellaria root, cytoto
xicity was observed only with baicalin. The SBC-5 cell line which was
resistant to TJ-9 showed a lesser sensitivity to both Scutellaria root
and baicalin. TJ-9 showed almost equal cytotoxicity in cisplatin (CDD
P)-sensitive PC-10 and CDDP-resistant SBC-4 cell lines, and in H69 and
H69/CDDP cell lines. TJ-9, Scutellaria root and baicalin were all les
s cytotoxic for human lymphocytes and bone marrow cells than for a lun
g cancer cell line of SBC-4. These results suggest that TJ-9 and its c
omponents may be useful anticancer agents for the treatment of lung ca
ncer.