Osteoprotective effect of the marine alkaloid norzoanthamine on an osteoporosis model in ovariectomized rat

Norzoanthamine (NZ), an alkaloid that has been isolated from the marine cnidiaria Zoanthus sp., has been shown an interesting anti-osteoporotic activity. Although its mechanism of action is not yet clear, it seems that it is different from those of currently used drugs making it particularly interesting. Previous studies have been carried out mostly in vitro. Herein, we present an in vivo study that allows to check the real potential of NZ as a protector substance by direct application into ovariectomized rat bone using a sustained deliver y system. Histological and histomorphometric results in ovariectomized rats showed higher bone quality as a result of greater number of trabeculae and osteogenic activity in the group implanted with NZ, compared to controls. In contrast with the untreated controls, NZ-treated groups showed a balanced osteoblast/osteoclast number ratio, similar to that found in the normal bone. These results suggest that NZ could be usef u l as adjunct to other osteoporosis treatments, but probably its main therapeutic role would be as preventive therapy against bone deterioration.

Automated summary

Norzoanthamine (NZ), an alkaloid isolated from marine cnidiaria Zoanthus sp., has shown interesting anti-osteoporotic activity. This in vivo study demonstrates that direct application of NZ into ovariectomized rat bone results in higher bone quality and balanced osteoblast/osteoclast ratio, similar to normal bone. NZ could be a useful adjunct to existing osteoporosis treatments or as a preventive therapy against bone deterioration.