in a 4 day in vitro neonatal murine calvarial assay bones were incubated with the extracts for the entire 4 days bone formation was assessed by histology the ability of the extracts to inhibit il 1 10 u2212 10 m stimulated bone resorption was assessed in the neonatal bone resorption assay each extract was assessed for its capacity to inhibit bone resorption at 10 u03bcg ml the ability of the extracts prepared as in example 1 to inhibit il 1 10 u2212 10 m stimulated bone resorption was assessed in the neonatal bone resorption assay each extract was assessed for its capacity to inhibit bone resorption at 10 u03bcg ml the plants found positive for bmp 2 induction in example 1 were further tested in a human periosteal preosteoblast cell line hpob tert for their ability to induce the endogenous expression of bmp 2 this test in osteoblast cells confirmed the results shown in example 1 for example treatment of hpob tert cells with extracts of lindera benzoin extract 740 50 u03bcg ml and of cyperus rotundus extract 205 10 u03bcg ml for 48 h stimulated bmp 2 expression 3 8 and 2 8 fold of control see fig1 the validation of this assay has been performed with lovastatin 0 5 u03bcg ml as a positive control showing induction of bmp 2 by 2 5 fold at confluence cells were incubated with 0 05 u03bcg ml lovastatin or with the plant extracts total rna was extracted with trizol reagent gibco 10 u03bcg rna were reverse transcribed using the 1st strand cdna synthesis kit boehringer bmp 2 cdna sequences were amplified for 35 cycles at an annealing temperature of 55 u00b0 c using specific oligonucleotide primers 5.