The cytotoxicity of compounds derived from the aerial parts of Saururus chinensis towards 24
cancer model and six normal cell lines was examined by MTT assay and compared with those of the
anticancer agents cisplatin and
doxorubicin. The active principles were characterized as the
neolignans manassantin A, and its erythro, erythro- and threo, erythro-epimers by spectroscopic analysis.
Manassantin A was isolated from S. chinensis as a new cytotoxic principle. Its two epimers were isolated for the first time in nature. The
neolignans were more active than
cisplatin and
doxorubicin, with IC50 values of the
neolignans,
cisplatin, and
doxorubicin against SK-Hep-1, PC-3, DU-145, BT-20, SK-BR-3, T-47D, Hela, T98G, and SK-MEL-28
cancer cell lines, in the ranges 0.018-0.423, 1.175-7.922, and 0.131- >50 microg/mL, respectively.
Manassantin A and its threo, erythro-epimer were equicytotoxic towards model
cancer cell lines. threo, erythro-
Manassantin A was more active than erythro, erythro-
manassantin A. Additionally, these three
neolignans (IC50 > 10 microg/mL) had very low cytotoxicity towards six normal cell lines, whereas
cisplatin (IC50 2.846-0.825 microg/mL) and
doxorubicin (IC50 5.222-0.008 microg/mL) exhibited potent cytotoxic effects. Structure-activity relationships indicate that the hydroxy moiety appears to be essential for cytotoxicity. These
neolignans merit further study as potential
anticancer agents or as leads.