INHIBITORY EFFECT OF QUERCETIN ON TUMOR-NECROSIS-FACTOR AND INTERLEUKIN-1-BETA PRO-OSTEOCLASTIC ACTIVITIES

AIM: To study the effects of quercetin on tumor necrosis factor (TNF) and interleukin-1 beta (IL-1 beta) pro-osteoclastic activities. METHOD S: [H-3]TdR uptake by osteoblasts was used to measure cell proliferati on, microspectrophotometer for cellular AIP activity using p-nitrophen yl phosphate as enzyme substrate, and radioimmunoassay for prostagland in E(2). RESULTS: Quercetin 5 - 40 mu mol . L(-1) reduced the inhibiti on of cell proliferation and AIP activity induced by TNF or IL-1 beta in a concentration-dependent manner. PGE(2) production stimulated by e ither cytokines was also reduced by quercetin at 20 and 40 mu mol . L( -1) CONCLUSION: quercetin exerted a marked inhibitory effect on TNF an d IL-1 activities, related to their pro-osteoclastic function.