Antileukemic activity of Bidens pilosa L. var. minor (Blume) Sherff and Houttuynia cordata Thunb.

To evaluate the anti-leukemic activity of Bidens pilosa L. var. minor (Blume) Sherff and Houttuynia cordata Thunb., cytotoxicity tests with an XTT-based colorimetric assay were used. Five leukemic cell lines, namely L1210, U937, K562, Raji and P3HR1, were cultured with hot water extracts of B. pilosa var. minor or H. cordata. Hot water extracts of B. pilosa var. minor inhibited these five leukemic cells with IC50s between 145 microg/ml and 586 microg/ml. The effect was greatest on four cell lines, namely L1210, P3MR1, Raji and K562, with IC50s below 200 microg/ml and a selective index of more than 5. Hot water extract of H. cordata inhibited these five leukemic cells with IC50s between 478 microg/ml and 662 microg/ml. The selective index was between 1.5 and 2.1. B. pilosa var. minor was more effective than H. cordata in inhibiting most of the leukemic cells in our study. We suggest that B. pilosa L. var. minor (Blume) Sherff may prove to be a useful medicinal plant for treating leukemia.