RESTRICTION BY MOTHERWORT (Leonurus sibiricus L) OF LACTATION SUPPRESSED BY PREGNANCY-DEPENDENT MAMMARY TUMORS IN GR/A MICE

As a possible step to evaluate in the mammary gland the role of motherwort (Leonurus sibiricus L), a representative medicinal plant used traditionally for the therapy of gynecologic diseases, the effects of the agent on lactation which was suppressed by preganacy-dependent mammary tumors (PDMT) were studied in GR/A mice. Beginning the day of placing with males at 45-50 days of age, female mice were given 60% methanol-extract of the aerial part of motherwort as drinking water at the concentration of 0.5% throughout the experiment. Mice developing PDMT during pregnancy [PDMT(+)] and given motherwort were similar to mice developing no PDMT [PDMT(_)] with or without motherwort treatment and were significantly higher than PDMT(+) mice given tap water in litter growth and mammary RNA/DMA ratio on day 12 of the 2nd lactation. Mammary DNA and RNA contents were also elevated by motherwort in PDMT(+) mice. The results suggest that motherwort can ameliorate lactation suppressed by PDMT through its stimulation of both growth and function of the mammary glands.