Histomorphometric analysis of bone marrow constituents in ovariectomized Cimicifuga racemosa (L.) Nutt. (CR) treated animals

Following ovariectomy (ovx) rats lose trabecular bone and hematopoietic tissue whereas the amount of fat tissue increases. These fat cells secrete cytotoxic cytokines which cause local inflammation in the bone marrow which augments development of osteoporosis. Whether this can be prevented by estradiol-17ß (E2) or CR BNO 1055 was tested.

Rats (3 months old) were ovx and fed with E2 (0.156mg/animal/day, positive controls) or with CR BNO 1055 (8.22mg/animal/day) which was shown in previous experiments to prevent osteoporosis. The surface of trabecles and their 3-dimensional structure was determined histomorphometrically. In addition, the amount of fat tissue was quantified.

The trabecular surface and the 3-dimensional integrity of the trabecular apparatus in the metaphysis of the tibia was severely disturbed following ovx and this was almost totally prevented by E2 and CR BNO 1055. In addition ovx animals had high fat load in the bone marrow which was largely prevented by E2 and the BNO 1055 extract.

These results indicate that the high amount of fat tissue in the bone marrow correlates with decreased trabecular integrity. This can be largely prevented by E2 and by compounds present in CR BNO 1055. Hence, E2 and CR BNO 1055 (which is devoid of estrogenic compounds) protect against the development of osteoporosis in part by decreasing the bone marrow fat load.

Keywords: Cimicifuga racemosa, osteoarthritis, osteoporosis

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