Raloxifene (LY156758, Keoxifene) HCl a selective and orally activeestrogen receptormodulator (SERM), which inhibits human cytosolic aldehyde oxidase-catalyzed phthalazine oxidation activity withIC50of 5.7 nM. In vitro
Raloxifene, has been demonstrated as a potent uncompetitive inhibitor of human liver aldehyde oxidase-catalyzed oxidation of phthalazine, vanillin, and nicotine-Delta1\'(5\')-iminium ion, with Ki values of 0.87 nM, 1.2 nM and 1.4 nM. Raloxifene has also been shown to be a noncompetitive inhibitor of an aldehyde oxidase-catalyzed reduction reaction of a hydroxamic acid-containing compound, with a Ki of 51 nM. Raloxifene activates TGF beta 3 promoter as a full agonist at nanomolar concentrations, and raloxifene inhibits the estrogen response element-containing vitellogenin promoter expression as a pure estrogen antagonist in transient transfection assays.
In vivo
Raloxifene restores both bone mineral density and TGF beta 3 messenger RNA expression in the femur to levels measured in intact rats. Raloxifene (0.1 mg/kg-10 mg/kg, orally for 5 weeks) increases bone mineral density in the distal femur and proximal tibia in ovariectomized (OVX) rat. Raloxifene reduces serum cholesteroloral with ED50 of 0.2 mg/kg in ovariectomized (OVX) rat. Raloxifene diverges dramatically from estrogen in its lack of significant estrogenic effects on uterine tissue. Raloxifene prevents cancellous osteopenia as well as the changes in radial bone growth, bone resorption, and blood cholesterol, but is less effective in reducing cancellous bone formation and does not prevent uterine atrophy in ovariectomized (OVX) rats. Raloxifene (3 mg/kg/day) has potent estrogenic activity on bone resorption and serum cholesterol, a lesser effect on bone formation, and minimal activity on uterine wet weight in ovariectomized (OVX) rats. Cell Data
cell lines:182 solid and hematologic tumor cell lines