Screening of flavonoids for effective osteoclastogenesis suppression.
Flavonoids are natural compounds derived from plants and some of them have been shown to inhibit osteoclast formation, implicating their potential use for the treatment of osteoporosis. Conventionally, the screening of antiosteoclastic agents is a tedious process that requires visual counting of the number of osteoclasts produced. The purpose of this study was to establish an easier and faster method for screening the antiosteoclastogenic flavonoids by using an enzyme assay. Tartrate-resistant acid phosphatase (TRAP) is a marker enzyme of the osteoclast. Results obtained demonstrated that cellular TRAP activity tended to correlate with the number of osteoclasts formed. However, the secreted TRAP activity was actually responsible for the resorption activities of the functional osteoclasts. Consequently, the effectiveness of antiosteoclastogenic agents was screened for by assessing their inhibition on receptor activator of NF-κB ligand (RANKL)-induced TRAP secretion. The half-inhibitory concentrations of flavonoids on TRAP secretion were employed as indices to compare the effectiveness of various flavonoids. The effective flavonoids also exhibited similar inhibitory potencies in the pit-formation analysis. This protocol provides a rapid analysis to screen for effective antiosteoclastogenic agents.
Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
Yu-Wei
YW
Wu
Shih-Ching
SC
Chen
Wen-Fu Thomas
WF
Lai
Yen-Chou
YC
Chen
Yu-Hui
YH
Tsai
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D002452:Cell Count; D002460:Cell Line; D048429:Cell Size / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D005260:Female; D005419:Flavonoids / Q000494:pharmacology*; D007527:Isoenzymes / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D053245:RANK Ligand / Q000494:pharmacology; D000071681:Tartrate-Resistant Acid Phosphatase
D005419:Flavonoids; D007527:Isoenzymes; D053245:RANK Ligand; D000135:Acid Phosphatase; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase