3-(3-Hydroxyphenyl)propionic Acid (m-Hydroxyphenylpropionic acid) is one of the major metabolites of ingested caffeic acid.it inhibited osteoclastogenesis and bone osteoclastic resorptive activity.

3-(3-hydroxyphenyl) propionic acid (3-3-PPA) and hippuric acid (HA), had dose-dependent suppressive effects on osteoclastogenesis and osteoclast resorptive activity in Corning osteo-assay plates.?Signaling pathway analysis showed that after pretreatment with HA or 3-3-PPA, RANKL-stimulated increase of osteoclastogenic markers, such as nuclear factor of activated T-cells, cytoplasmic 1 and matrix metallopeptidase 9 gene/protein expression were blunted.?Inhibitory effects of HA and 3-3-PPA on osteoclastogenesis utilized RANKL/RANK independent mediators[1].

RAW264.7 cells or nonadherent bone marrow cells were cultured in 96‐well plates (2?×?10^4cells/well) in the presence or absence of 50?ng/ml of RANKL.?Cells were treated with HA at four different concentrations, 0.01×, 0.1×, 1×, and 10×, with 1× equivalent to concentration of 60?μg/dl of HA free form appeared in blood after 10% BB supplemental diet in rats.?Four different concentrations of 3‐3‐PPA or 3‐(4‐hydroxyphenyl) propionic acid (3–4‐PPA), 0.1×, 1×, 10×, and 100×, with 1× equivalent to concentration of 10?μg/dl of 3‐3‐PPA or 3–4‐PPA free form appeared in blood after 10% BB supplemental diet in rats.?After 4 days for RAW264.7 cell cultures and 5 days for bone marrow cell cultures, the cells were ?xed with 4% paraformaldehyde and stained for tartrate‐resistant acid phosphatase (TRAPase) activity using a TRAPase Staining Kit .?TRAP‐positive cells containing >3 nuclei in each well were counted as osteoclasts under an epifluorescent microscope[1]