Black Cohosh and the protective effects on bone metabolism as measured by computer tomography (qCT) in ovariectomized (ovx) rats

Osteoporosis is a major disease in postmenopausal women. There is compelling evidence that the special extract from Cimicifuga racemosa (L.) Nutt. (CR) BNO 1055 influences positively bone metabolism and prevents induced osteoporosis by ovariectomy (ovx).

Aim of the study was the investigation of CR BNO 1055 extracts and their protective effects on bone metabolism. Via liquid-liquid extraction, extracts were separated into two groups, i.e. a lipophilic rich in saponins and a hydrophilic rich in sugars and phenylpropanoids.

Preparative fractions were characterized by TLC and by HPLC-UV-ELSD and HPLC-MS. Analytical data clearly prove the presence of triterpene glycosides in the lipophilic fraction and the presence of carbohydrates and phenylpropanic acid derivatives in the hydrophilic fraction.

To investigate the activity on bone metabolism of CR, ovx rats received either nutrition containing CR, 17ß-estradiol or food without any active component. All types of food were soy-free food. QCTs were performed at the level of the metaphysis of the tibia and the trabecular density measured prior to the ovariectomy and at the end of the four weeks lasting application of the extracts.

Within these four weeks the bones of the ovx rodents lost nearly half of their cancellous density. This effect did not appear by rats fed with nutrition including 17ß-estradiol and CR. The lipophilic fraction shows a significant high activity on bone metabolism while the hydrophilic fraction was inactive. The qCt results demonstrate that the prevention effect of CR BNO 1055 on bone is up to the lipophilic compounds of the extract.

Keywords: Black Cohosh, Cimicifuga racemosa, bone metabolism

Acknowledgement: This work was funded by the Bayerische Forschungsstiftung AZ-838–08, Germany