Red algal extracts from Plocamium lyngbyanum and Ceramium secundatum stimulate osteogenic activities in vitro and bone growth in zebrafish larvae

Through the current trend for bioprospecting, marine organisms - particularly algae - are becoming increasingly known for their osteogenic potential. Such organisms may provide novel treatment options for osteoporosis and other musculoskeletal conditions, helping to address their large healthcare burden and the limitations of current therapies. In this study, extracts from two red algae – Plocamium lyngbyanum and Ceramium secundatum – were tested in vitro and in vivo for their osteogenic potential. In vitro , the growth of human bone marrow stromal cells (hBMSCs) was significantly greater in the presence of the extracts, particularly with P . lyngbyanum treatment. Osteogenic differentiation was promoted more by C . secundatum (70 µg/ml), though P . lyngbyanum had greater in vitro mineralisation potential. Both species caused a marked and dose-dependent increase in the opercular bone area of zebrafish larvae. Our findings therefore indicate the presence of bioactive components in P . lyngbyanum and C . secundatum extracts, which can promote both in vitro and in vivo osteogenic activity.