Discovering bioactive compounds for bone growth: bone stimulating properties of marine organism-derived extracts.

Background
An osteoporosis related fracture now occurs once every 3 seconds globally. Fractures have a significant detrimental impact on patient quality of life and present a large health care burden. As such, there is a need for effective treatments which can limit further bone loss, or ideally stimulate recovery of bone mineral density and structure.
Aims
•Screen for osteogenic activity from a wide extract range (hFOB cell line).
•Evaluate the activity of promising extracts using human derived bone marrow stromal cells.
•Test extracts in vivo, using a zebrafish bone growth model.
Methods
In vitro: assays included crystal violet for cell proliferation, alkaline phosphatase for differentiation and alizarin red-S for mineralisation.
In vivo: a model system investigating operculum size in juvenile zebrafish was used to assess mineralisation.
Results
Of the approximate 120 extracts screened to date, powdered red algaes were the most promising, particularly the epiphytic species Plocamium cartilagenum and Ceramium secundatum. Both were non-toxic and significantly stimulated hBMSC proliferation and differentiation. In vivo, larval zebrafish responded to extract inclusion favourably, showing limited mortality and significant, dose-dependent increases in operculum size.
Conclusions
Powdered algal extracts, particularly P. cartilagenum and C. secundatum, significantly stimulated both cell activity and in vivo bone formation.
Implications for practice
P. Cartilagenum and C. secundatum appear to contain osteogenic bioactives, which may be suitable for use in treating musculoskeletal conditions. Chemical analysis of the fractions now needs to be undertaken to identify active compounds.