Cimicifuga and Melbrosia lack oestrogenic effects in mice and rats

Objectives: The natural medicines, Cimicifuga and Melbrosia, are widely sold. Cimicifuga is an extract of Cimicifuga racemosa (L.), and Melbrosia is a mixture of Gelée Royale, perga-pollen and pollen. Cimicifuga and Melbrosia are used through self-medication to relieve symptoms of hot flushes and other menstrual or menopausal discomfort in many of the Danish women consulting private gynaecologists. A gynaecologist tends to treat these symptoms with oestrogen, so the present experiments were therefore made to investigate whether Cimicifuga and Melbrosia have oestrogenic effects as defined by the classical biological methods: uterine growth in immature mice and vaginal cornification in ovariectomized rats. Methods: Vehicle, 6, 60 or 600 mg/kg Cimicifuga or 30, 300 or 3000 mg/kg Melbrosia was administered orally for 3 days to groups of 10 immature mice and the uterus weight measured on the fourth day. Similarly, vehicle, 6, 60, 600 mg/kg Cimicifuga or 3, 30, 300 mg/kg Melbrosia was injected subcutaneously in groups of 12 ovariectomized rats for 3 days and vaginal smears investigated for signs of cornified cells. All experiments were repeated once. Results: No signs of an oestrogenic effect connected with the preparations were found in any of the experiments. Conclusions: It can be concluded that the eventual beneficial effects on menstrual or menopausal discomfort connected with Cimicifuga and Melbrosia self-medication cannot be explained as a traditional oestrogenic effect as measured in biological experiments.