Abstract:

Objective To study the influence of Sedum aizoon L on hemostatic function of rats with gastrointestinal tract hemorrhage induced by aspirin,and to screen the optimal dose of Sedum aizoon L. Methods Rat gastric hemorrhage model was established using aspirin,which was judged by rat fecal occult blood test. The rats were treated with 3 doses of Sedum aizoon L [high dose 30 g/(kg·d), medium dose 1 g/(kg·d) and low dose 0.5 g/(kg·d)], and the rats were treated with saline placebo（0.2 mL/d）as control group,until the rat fecal occult blood test results were all negative. The vein blood samples were collected before and after the treatment,respectively. The count of platelet,platelet membrane glycoprotein（GP）Ⅱb/Ⅲa,P selectin and endothelin 1（ET-1） levels were determined,and the changes of different dose groups before and after the treatment were compared. Results The rat fecal occult blood test results in the medium dose group turned negative earliest after the treatment for 6 d,but at the same time,the low dose group had 3 positive cases,and the placebo group and the high dose group were all positive in the rat fecal occult blood test results （all the test groups turned to be negative after 3 d,while the placebo group was still positive）. The platelet counts of all test groups were significantly lower than that in healthy control group （P<0.05）, and the platelet counts increased after the treatment（P<0.05 or P<0.01）. The 3 dose groups had no statistical significance with health control group after the treatment for platelet counts （P>0.05）,and they were still lower than that in healthy control group (P<0.05),which the medium dose group was the most significant （P<0.01）,but the placebo group was not significant （P>0.05）. GPⅡb/Ⅲa in all test groups were lower than that in healthy control group before the treatment （P<0.05）,and that of each dose group increased after the treatment,but only the medium dose group had statistical significance （P<0.01）,which was higher than that of healthy control group （P<0.05）. However,that of placebo group had no difference before and after the treatment（P>0.05）. P selectin in all test groups were lower than that in healthy control group before the treatment without statistical significance （P>0.05）,and after the treatment,those of low,medium and high dose groups increased （P<0.05 or P<0.01）,and that in low dose group had no statistical significance with the level of healthy control group （P>0.05）,however,those in medium and high dose groups were higher than that in healthy control group （P<0.05）,but the placebo group had no significant difference （P>0.05）. ET-1 in all test groups before the treatment had no significant difference （P>0.05）,that in each dose group increased after the treatment,but only low dose group was statistically significant and reached the level of healthy control group （P<0.01）,those in medium and high dose groups increased compared with those before the treatment without significant difference （P>0.05）,which were higher than the level of healthy control group (P<0.05). There was no significant change in the placebo group （P>0.05）. Conclusions Sedum aizoon L stops bleeding by increasing the number of platelet and improving platelet aggregation and releasing function. The effects of low dose group on vascular endothelial cells are obvious. The curative effect of medium dose Sedum aizoon L is the best.

Key words: Platelet, P selectin, Glycoprotein Ⅱb/Ⅲa, Endothelin 1, Sedum aizoon L, Aspirin