Effects of motherwort (Leonurus sibiricus L) on preneoplastic and neoplastic mammary gland growth in multiparous GR/A mice

Chronic ingestion of methanol extract of the above-ground part of motherwort (Leonurus sibiricus L) in drinking water at the concentration of 0.5% enhanced the development of both pregnancy-dependent mammary tumours (PDMT) and mammary cancers originated from PDMT. By contrast, the treatment markedly suppressed the development of mammary cancers that originated from hyperplastic alveolar nodules (HAN) associated with the decreased formation of HAN. The incidence of uterine adenomyosis was also inhibited in mice given motherwort. The urinary excretion of allantoin, creatine and creatinine and glucose tolerance were stimulated by motherwort. The cause of discrepancy of the effects of motherwort on mammary cancers due to their origins is not clear at present. However, the stimulation by the agent of the excretion of any carcinogenic factors may at least partly contribute to its inhibition of mammary cancers originating from HAN.