Quercetin   n 0.1 0.3 1 3 10 30 100 µM Control 10 1.7±0.5 3.6±0.91) 6.9±0.91) 12.4±1.12) 32.0±5.72) 54.1±8.4 97.8±3.7 Endothelium-denuded 5 1.5±1.3 3.1±1.6 6.9±1.8 11.2±2.4 30.8±4.9 44.1±4.2a) 77.9±2.3a) L-NAME 100 µM 5 1.9±0.9 3.6±1.1 7.1±2.1 13.2±3.7 21.1±4.6 33.0±5.3a) 69.5±6.1a) L-NMMA 100 µM 5 1.9±0.6 4.1±1.3 7.3±1.8 12.0±2.4 25.4±4.8 38.7±6.0a) 78.0±11.6a) L-NMMA 100 µM + Indomethacin 10 µM 5 1.9±0.8 4.1±1.3 6.8±1.3 11.0±2.0 18.2±4.7 30.4±6.2a) 65.2±6.6a)

Values (%) represent mean ± S.E.M. 1) anda) : p<0.05, 2) : p<0.01, 3) : p<0.001. Symbols of1), 2) and3) mean significant differences in comparison between the effects of quercetin itself at each concentration and the maximal constriction induced by NE. Symbol of a) indicates significant difference as compared with control (quercetin alone) values.

Table 2: Endothelium-dependent vasodilatation induced by quercetin in rat aorta