Effect of quercetin on platelet aggregation induced by oxyradicals.
OBJECTIVE
To study the action of quercetin (Que) on inhibiting platelet aggregation.


METHODS
Active oxygen free radicals produced by xanthine/xanthine oxidase (Xan/XO) reaction was used, platelet aggregation was determined by the turbidimetric method, and the Xan/XO oxyradicals generating reaction by luminol-dependent chemiluminescence (Che) method.


RESULTS
Active oxygen free radicals enhanced the platelet aggregation induced by ADP 1.6 mumol.L-1. The rate of maximal aggregation increased from 29%-38% for ADP to 59%-70% for ADP + Xan/XO. The enhancement was abolished by the treatment of platelet-rich plasma (PRP) with Que 650 mumol.L-1 or hydrocortisone (Hyd) 900 mg.L-1. Both Que and Hyd scavenged the active oxyradicals in vitro. The Che was decreased by 75.7% (Que 4 mumol.L-1) and 79.0% (Hyd 900 mg.L-1) as compared with control.


CONCLUSIONS
Active oxygen free radicals participated in the platelet aggregation, and scavenging oxyradicals by Que was one of mechanisms of inhibiting platelet aggregation.
Xie
M L
ML
Department of Pharmacology, Suzhou Medical College, China.
Lu
Q
Q
Gu
Z L
ZL
D000818:Animals; D016166:Free Radical Scavengers / Q000494:pharmacology; D005609:Free Radicals; D066298:In Vitro Techniques; D008297:Male; D010100:Oxygen / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D011794:Quercetin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D016166:Free Radical Scavengers; D005609:Free Radicals; D010975:Platelet Aggregation Inhibitors; D011794:Quercetin; D010100:Oxygen