Black Cohosh and cancer

Black Cohosh (Cimicifuga racemosa) is a herb we mainly use in the treatment of menopause. (Indeed I wrote an article on the wonderful herb in newsletter no 55, November 2013.)

Black Cohosh is a native to the forests of eastern North America and its use in gynaecological conditions predates the settlement of the New World. By the mid-nineteenth century, the plant was commonly prescribed for the treatment of female reproductive tract conditions such as loss of periods, painful menstruation, heavy periods, endometriosis and severe after-birth pains. More recently, Black Cohosh has mainly and very successfully been used for the treatment of menopausal symptoms, particularly night sweat and hot flushes.

Black Cohosh has been investigated for its use in cancer and as an adjunctive treatment in tamoxifen-treated breast cancer patients. As well as displaying anti-inflammatory activities, this plant has shown cytotoxic and growth inhibitory properties against prostate and breast cancer cell lines.

In an animal model of mammary cancer, Black Cohosh extract demonstrated anti-proliferative activity and reduced the malignant potential of the tumours, and this chemoprotective activity persisted once the treatment had ceased.

There have been several clinical trials and preclinical studies investigating the synergistic effects of tamoxifen and Black Cohosh in relation to cytotoxic effects of the combined treatments and reduction in adverse effects of tamoxifen.
Black Cohosh has been found to be effective in treating the climacteric complaints in patients with breast cancer (hot flushes and night sweats) who are under tamoxifen treatment, and also enhance the cytotoxic and growth inhibitory effects of tamoxifen. A recent review paper stated that the use of Black Cohosh appears to be safe in patients with breast cancer.
Whilst the exact mechanisms of action, including its anticancer activities, remains inconclusive, the preclinical studies and clinical trials have demonstrated promising results for the use of Black Cohosh in the management of certain types of breast cancer lines.