ABSTRACT
<p><b>OBJECTIVE</b>To investigate the anti-thrombosis effect and its mechanism of Qingkailing injection (QKL).</p><p><b>METHOD</b>SD rats were randomly divided into control group, model group and QKL 2.5, 5.0, 10 groups. QKL were given (i.p.) to rats once a day for successively 4 days. The rats in all groups but control were pretreated with carrageenin (Ca) i.p. at 16 h before the last dose of QKL and followed by intravenous injection of endotoxin ( LPS fom E. coli O111:B4) 50 microg x kg(-1) 30 min after the last dosing of QKL. Thrombosis in rat tails were observed at 24 h after injection of LPS. The number of white blood cells and platelets, serum TNF-alpha, IL-6 level, CD11b/CD18 expression of white blood cells and platelet aggregation were analysed.</p><p><b>RESULT</b>QKL obviously inhibited the LPS/Ca-induced thrombosis as showed a reduced infarction range due to thrombosis in tails. The sera concentration of TNF-alpha and IL-6, expression of CD11b/CD18 in WBC and platelet coagulation rate were reduced after QKL treatment.</p><p><b>CONCLUSION</b>The anti-thrombosis action of QKL is associated with inhibition of WBC activation and adherence, reduction of inflammatory factor release and abating of platelet coagulation rate. The anti-thrombosis mechanism of QKL is consistent with its function of clearing away heat-evil and toxic materials.</p>