Pueraria mirifica Exerts Estrogenic Effects in the Mammary Gland and Uterus and Promotes Mammary Carcinogenesis in Donryu Rats

Pueraria mirifica (PM), a plant whose dried and powdered tuberous roots are now widely used in rejuvenating preparations to promote youthfulness in both men and women, may have major estrogenic influence. In this study, we investigated modifying effects of PM at various doses on mammary and endometrial carcinogenesis in female Donryu rats. Firstly, PM administered to ovariectomized animals at doses of 0.03%, 0.3%, and 3% in a phytoestrogen-low diet for 2 weeks caused significant increase in uterus weight. Secondly, a 4 week PM application to non-operated rats at a dose of 3% after 7,12-dimethylbenz[a]anthracene (DMBA) initiation resulted in significant elevation of cell proliferation in the mammary glands. In a third experiment, postpubertal administration of 0.3% (200 mg/kg body weight (b.w.)/day) PM to 5-week-old non-operated animals for 36 weeks following initiation of mammary and endometrial carcinogenesis with DMBA and N-ethyl-N′-nitro-N-nitrosoguanidine (ENNG), respectively, resulted in significant increase of mammary adenocarcinoma incidence. A significant increase of endometrial atypical hyperplasia multiplicity was also observed. Furthermore, PM at doses of 0.3% and, more pronouncedly, of 1% induced dilatation, hemorrhage and inflammation of the uterine wall. In conclusion, postpubertal long-term PM administration to Donryu rats exerts estrogenic effects in the mammary gland and uterus, and at a dose of 200 mg/kg b.w./day was found to promote mammary carcinogenesis initiated by DMBA.

Pueraria mirifica Exerts Estrogenic Effect and Promotes Mammary and Endometrial

Pueraria mirifica (PM) is a plant which dried and powdered tuberous root is now widely used as a rejuvenating herb to promote youthfulness in both men and women. In this study, we investigated the modifying effects of PM at various doses on mammary and endometrial carcinogenesis in female Donryu rats. Firstly, PM administered to ovariectomized Donryu rats at doses of 0.03, 0.3 and 3% in phytoestrogen-low diet for 2 weeks induced the significant increases of uterus weight. Secondly, 4-week PM application to non-operated rats at a dose of 3% after the 7,12-dimethylbenz[a]anthracene (DMBA) initiation, resulted in significant elevation of cell proliferation in the mammary glands. In the third experiment, postpubertal administration of 0.3% (200 mg/kg b.w./day) PM to 5-week-old non-operated animals for 36 weeks following the initiation of mammary and endometrial carcinogenesis with DMBA and N-ethyl-N′-nitro-N-nitrosoguanidine (ENNG), respectively, caused significant increases of mammary adenocarcinoma incidence and multiplicity. A trend for increase of uterine adenocarcinomas and a significant increase of endometrial atypical hyperplasia multiplicity was observed at 0.3% PM. Furthermore, PM at doses of 0.3 and mostly 1% induced dilatation, hemorrhage and inflammation of the uterine wall. In conclusion, the postpubertal long-term PM administration to Donryu rats exerted estrogenic effect in the mammary gland and uterus, and at a dose of 200 mg/kg b.w./day promoted carcinogenesis initiated by DMBA and ENNG.