[Comparative study on effect of 8-prenlynaringenin and narigenin on activity of osteoclasts cultured in vitro].
OBJECTIVE
To compare the effects of 8-prenylnaringenin (PNG) and naringenin (NG) on the activity and apoptosis of osteoclasts cultured in vitro, in order to study physiological activity of 8-prenyl perssad.


METHODS
Osteoclasts were separated from long-limb bones of newly born rabbits, cultured in alpha-MEM containing 10% FBS, and then added with PNG and NG with the concentration of 1 x 10(-5) mol x L(-1). They were stained with TRAP and determined for enzymatic activity with TRAP after 4 d, and analyzed by toluidine blue staining after 7 d. The apoptotic osteoclasts were analyzed by Annexin V-FITC staining after 2, 4, 8, 12, 24, 36, and 48 hours, to observe their apoptosis. Their total RNAs were extracted, and analyzed for TRAP and Cathepsin K expressions by Real-time RT-PCR.


RESULTS
Compared with the control group, both of the PNG group and the NG group showed much less osteoclasts (TRAP positive cells), lower TRAP activity and TRAP and Cathepin K (CTSK) expression, and smaller number of bone resorption pits and areas. The PNG group show lower indexes than the NG group. Additionally, the PNG group reached the apoptotic peak of osteoclasts at 12 h after drug administration, whereas the NG group reached after 24 h. And the former had more apoptotic cells than the latter.


CONCLUSIONS
8-PNG is much more active than NG in inhibiting the resorption of osteoclasts and inducing apoptosis of osteoclasts. Their only difference lies in 8-prenyl perssad, which is proved to be able to enhance the anti-bone resorption activity of 8-prenylnarigenin.
Institute of Orthopaedics, Lanzhou General Hospital, Lanzhou Command, PLA, Lanzhou 730050, China. 05lvxiang@163.com
Xiang
X
Lv
Ke-Ming
KM
Chen
Bao-Feng
BF
Ge
Hui-Ping
HP
Ma
Peng
P
Song
Kui
K
Cheng
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D001862:Bone Resorption / Q000517:prevention & control; D056657:Cathepsin K / Q000378:metabolism; D002478:Cells, Cultured; D044950:Flavanones / Q000494:pharmacology*; D010010:Osteoclasts / Q000187:drug effects*; D011817:Rabbits
C119737:8-prenylnaringenin; D044950:Flavanones; D000135:Acid Phosphatase; D056657:Cathepsin K; C005273:naringenin