title: Inhibitory effect of quercetin on tumor necrosis factor and interleukin-1 beta pro-osteoclastic activities.
abstract: OBJECTIVE
  To study the effects of quercetin on tumor necrosis factor (TNF) and interleukin-1 beta (IL-1 beta) pro-osteoclastic activities.
  
  
  METHODS
  [3H] TdR uptake by osteoblasts was used to measure cell proliferation, microspectrophotometer for cellular AIP activity using p-nitrophenyl phosphate as enzyme substrate, and radioimmunoassay for prostaglandin E2.
  
  
  RESULTS
  Quercetin 5-40 mumol.L-1 reduced the inhibition of cell proliferation and AIP activity induced by TNF or IL-1 beta in a concentration-dependent manner. PGE2 production stimulated by either cytokines was also reduced by quercetin at 20 and 40 mumol.L-1.
  
  
  CONCLUSIONS
  quercetin exerted a marked inhibitory effect on TNF and IL-1 activities, related to their pro-osteoclastic function.
authors.affiliation: Research Laboratory of Natural and Synthetic Drugs, School of Pharmacy, Second Military Medical University, Shanghai, China.
authors.forename: J P
authors.initials: JP
authors.lastname: Zhang
authors.forename: T M
authors.initials: TM
authors.lastname: Wu
authors.forename: Z L
authors.initials: ZL
authors.lastname: Hu
authors.forename: D H
authors.initials: DH
authors.lastname: Qian
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001862:Bone Resorption; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D015232:Dinoprostone / Q000378:metabolism; D007375:Interleukin-1 / Q000037:antagonists & inhibitors*; D053583:Interleukin-1beta; D051379:Mice; D008813:Mice, Inbred ICR; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010446:Peptide Fragments / Q000037:antagonists & inhibitors*; D011794:Quercetin / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D007375:Interleukin-1; D053583:Interleukin-1beta; D010446:Peptide Fragments; D014409:Tumor Necrosis Factor-alpha; C052994:interleukin-1beta (163-171); D011794:Quercetin; D000469:Alkaline Phosphatase; D015232:Dinoprostone