Further study on the effects of motherwort (Leonurus sibiricus L) on preneoplastic and neoplastic mammary gland growth in multiparous GR/A mice.

To evaluate further the chemopreventive role of motherwort (Leonurus sibiricus L; MW) in lesions of the mammary gland and uterus of GR/A mice, the effects on these lesions of the adsorbed (MW1) and unadsorbed (MW2) fractions of MW separated by ion-exchange resins were studied. The incidence of palpable mammary tumours was suppressed and their growth was retarded by both MW1 and MW2, between whose effects no apparent difference was seen. However, neither of them showed effects on pregnancy-dependent mammary tumours (PDMT), mammary hyperplastic alveolar nodules (HAN) or uterine adenomyosis, whereas MW promoted PDMT and inhibited HAN and adenomyosis. All these findings indicate the importance of the synergistic action of several components, specified and unspecified, for the full manifestation of the effects of Chinese medicine.