Investigation of phenolic leaf extract of Heimia myrtifolia (Lythraceae): Pharmacological properties (stimulation of mineralization of SaOS-2 osteosarcoma cells) and identification of polyphenols.

Evaluation of the activity of an aqueous alcoholic extract obtained from the leaves of Heimia myrtifolia (Lythraceae) by determining its stimulating effect on two human osteoblastic cell lines HOS58 and SaOS-2 indicated its potential for use in the prevention and treatment of osteoporosis. In addition, the extract was found to significantly increase the mineralization of cultivated human bone cell SaOS-2, in which a strong dose-dependent increase was observed. A phytochemical investigation of the extract also confirmed that H. myrtifolia is capable of synthesizing and accumulating appreciable amounts of several phenolics, thus leading to the isolation and characterization of sixteen of these constituents. Identified among these isolates were a new natural product, 1,6-di-O-dehydrotrigalloyl-β-D-(4)C(1)-glucopyranose, and a rare natural product (this marks its second report), 5,7,4'-trihydroxy-3-methoxyflavanone (dihydrokaempferol-3-O-methyl ether). Structures of these isolates were fully elucidated on the basis of conventional methods of analysis and confirmed by ESI/MS and (1)H and (13)C-NMR analysis.