BONE MINERALIZATION ENHANCING ACTIVITY OF A METHOXYELLAGIC ACID GLUCOSIDE FROM A FEIJOA SELLOWIANA LEAF EXTRACT

Abstract

As part of an ongoing study to discover potential bioactive phenolics from terrestrial plant sources, the capability of an aqueous methanol extract obtained from the leaves of Feijoa sellowiana Berg. on possible prevention and treatment of osteoporosis has been examined by evaluating its stimulating effect on the two human osteoblastic cell lines HOS58 and SaOS-2. The extract was found to increase significantly the mineralization of cultivated human bone cell, whereby a clear increment (15.3 ± 2.7 %) in von Kossa positive area was determined when administering 25 g/ml leaf extract. Besides, a phytochemical investigation of the extract has led to the isolation and identification of twenty three phenolics, among which the new 3-methoxyellagic acid 4-O--glucopyranoside was fully identified. The new compound was shown to have a slight positive effect on in vitro mineralization of SaOS-2 human osteosarcoma cells. However, it showed a significant increase of mineralized area at 20µg/mL, while at lower concentrations the effect was not of significant value. It should be noted however that an increase of the number of mineralized spots (nodules) at all concentrations tested was observed. This can be taken as an evidence for increased cell maturation and osteoblasticity. This data give rise to the notion that the compound has a contribution to the significant effect exhibited by the Feijoa sellowiana crude extract.