Antithrombotic activity of methanolic extract of Umbilicaria esculenta

Antithrombotic activity of methanolic extract of an edible lichen, Umbilicaria esculenta, was evaluated on platelet aggregation in vitro and pulmonary thrombosis in vivo. The extract showed concentration dependent inhibitory effects on platelet aggregation induced by ADP, with IC(50) value of 2.4 mg/mL. Orally administered extract protected mice against thrombotic death or paralysis induced by collagen and epinephrine in a dose dependent manner. It produced a significant inhibition of thrombotic death or paralysis at over 100 mg/kg body weight, while aspirin produced a significant inhibition of thrombosis at 10-20 mg/kg body weight. Mouse tail bleeding time was significantly prolonged by addition of the extract. On the other hand, the extract did not show any fibrinolytic activity and alter coagulation parameters such as activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) in rat platelet. These results suggested that the antithrombotic activity of Umbilicaria esculenta extract might be due to antiplatelet activity rather than anticoagulation activity.     

Antiplatelet and antithrombotic activity of indole-3-carbinol in vitro and in vivo

Indole-3-carbinol, a natural compound found in cruciferous vegetables, is known to have anticancer activity. In the present study, the antiplatelet and antithrombotic activities of indole-3-carbinol were investigated in vitro and in vivo. Indole-3-carbinol significantly inhibited collagen-induced platelet aggregation in human platelet rich plasma (PRP) in a concentration-dependent manner. Indole-3-carbinol significantly inhibited fibrinogen binding to the platelet surface glycoprotein IIb/IIIa (GP IIb/IIIa) receptor by flow cytometric analysis. In addition, the levels of thromboxane B2 (TXB2) and prostaglandin E2 (PGE2) in collagen stimulated PRP were significantly inhibited in a concentration-dependent manner by indole-3-carbinol. Furthermore, indole-3-carbinol dose-dependently suppressed the death of mice with pulmonary thrombosis induced by intravenous injection of collagen and epinephrine. These results suggest that indole-3-carbinol can be a potent antithrombotic agent with antiplatelet activity through the inhibition of GP IIb/IIIa receptor and thromboxane B2 formation.     

毛冬青皂苷B3的抗血栓作用研究

目的从毛冬青根中分离、鉴定毛冬青皂苷B3,研究其抗血栓作用。方法色谱法、重结晶法分离、精制毛冬青皂苷B3,薄层色谱对照及波谱分析法对毛冬青皂苷B3进行结构鉴定。采用体内血栓形成试验、体外血凝块溶解试验及二磷酸腺苷(ADP)诱导血小板聚集试验,观察毛冬青皂苷B3的抗血栓作用。结果体内抗血栓试验显示,毛冬青皂苷B3对胶原蛋白-肾上腺素诱发的血栓形成所致小鼠的偏瘫和死亡及FeCl3诱导的大鼠腹主动脉血栓形成均有明显的抑制作用;在体外实验中,对家兔血凝块无明显的溶解作用,对ADP诱导的离体家兔血小板聚集也无明显的抑制作用。结论毛冬青皂苷B3可能为毛冬青抗血栓作用的物质基础之一,其体内抗血栓形成的作用可能与其促进血凝块溶解和抗ADP诱导的血小板聚集无关。     

定量无梗五加果提取物的体内抗血栓与抗血小板凝集活性(英文)

目的:研究无梗五加果乙醇提取物的大鼠体内抗血栓与抗血小板凝集活性及其三萜皂苷类成分。方法:采用大鼠动-静脉旁路血栓模型的测定无梗五加果醇提物的体内抗血栓活性;采用血小板凝集仪测定其体内抗ADP诱导的血小板凝集活性;采用UPLC-MS/MS法同时对无梗五加根提取物中10种三萜皂苷类成分进行含量测定并采用比色法对其总三萜皂苷成分的含量进行了测定。结果:连续灌胃给予大鼠无梗五加醇提物(125,250,500及1000mg·kg-1/d)15天后,其体内抗血栓活性显示出剂量依赖关系(P<0.05)。同时,提取物也显著抑制了大鼠体内ADP诱导的血小板凝集活性(P<0.05)。不同剂量提取物(125,250,500及1000mg/kg·d-1)下的抑制率分别为(16.3±4.7)%,(28.6±4.1)%,(47.9±4.0)%与(61.3±6.6)%,阳性对照阿司匹林组(27mg·kg-1/d)的抑制率为(55.4±7.5)%。提取物中3个主要三萜皂苷成分22α-hydroxychiisanoside,momordin Ib以及chiisanogenin的含量分别为(3755±51.3),(2461±73.0)和(11...     

穿心莲抗血小板聚集功能的研究

通过对体外纽61例和体内组8例的实验观察,我们发现穿心莲提取物对ADP 诱导的血小板聚集反应有显著的抑制作用(P<0.001)。在体外,这种作用的程度稍强于川芎嗪、潘生丁注射液。穿心莲还可增强纤溶系统活力。     

Antithrombotic Effect of a Polysaccharide Fraction from Laminaria japonica from the South China Sea

Some in vitro studies have identified an antithrombotic effect of polysaccharides from Laminaria japonica, but this activity remains to be confirmed in vivo. In this study a polysaccharide fraction termed PLG was extracted from L. japonica in the Beibu Gulf in Guangxi, China, and its antithrombotic effects explored in rat models of carotid and venous thrombosis. Its anticoagulation and antiplatelet properties were assessed by measuring the prothrombin time (PT), activated partial thromboplastin time (APTT) and ADP‐induced platelet aggregation rate (Agg_max). Its effects on bleeding time were measured using the tail transection method. It was found that pretreatment with an intraperitoneal injection of PLG at 2.5 or 5.0 mg/kg significantly prolonged the occlusion time in the carotid thrombosis model, and a dose of 5.0 mg/kg reduced the thrombus weight in the venous thrombosis model. Pretreatment with PLG (5.0 mg/kg) increased the APTT and decreased the ADP‐induced platelet Agg_max. Neither dose of PLG significantly prolonged the bleeding time compared with the control group. In an in vitro anticoagulation assay using human plasma, PLG at 57.14, 28.57 and 28.57 μg/mL inhibited APTT and PT in a concentration‐dependent manner. The results show that PLG possesses antithrombotic activity in a rat model, and that it may prove to be clinically useful in humans. Copyright © 2011 John Wiley & Sons, Ltd.     

The antithrombotic effect of borneol related to its anticoagulant property

Borneol is consumed excessively in China and Southeast Asian countries particularly in combined formula for preventing cardiovascular disease, but few studies were conducted on its effects on thrombosis. In this study, the antithrombotic and antiplatelet activities of borneol were investigated on thrombosis in vivo and on platelet aggregation ex-vivo. In addition, the coagulation parameters and influence on fibrinolytic activity were also assessed. The results showed that borneol had concentration dependent inhibitory effects on arterio-venous shunt and venous thrombosis but no effect on ADP and AA-induced platelet aggregation. Meanwhile, borneol prolonged the coagulation parameters for prothrombin time (PT) and thrombin time (TT), but did not show any fibrinolytic activity. It suggested that the antithrombotic activity of borneol and its action in combined formula for preventing cardiovascular diseases might be due to anticoagulant activity rather than antiplatelet activity.     

Methanol extract of the oyster mushroom, Pleurotus florida, inhibits inflammation and platelet aggregation

The antiinflammatory and platelet aggregation inhibiting activities of the methanol extract of Pleurotus florida Eger, an edible and commercially grown mushroom, were investigated. The extract showed significant activity in ameliorating acute inflammation induced by carrageenan and chronic inflammation by formalin at 500 and 1000 mg/kg body weight. The effect was comparable to the standard reference drug, diclofenac. The extract also showed significant platelet aggregation inhibiting activity of washed human platelets. Adenosine 5'-diphosphate (ADP) induced platelet aggregation was inhibited by 88% to 95% at a concentration of 500 microg/mL of the extract after a preincubation time of 5, 10 and 20 min. The marked antiinflammatory and platelet aggregation inhibiting properties of this mushroom suggest its potential therapeutic use against vascular disorders.     

In vitro antioxidant and antithrombotic activity of Hemidesmus indicus (L) R.Br

The methanolic extract of Hemidesmus indicus (L) R.Br. (Asclepiadaceae) roots was found to inhibit lipid peroxidation and scavenge hydroxyl and superoxide radicals in vitro. The amount required for 50% inhibition of lipid peroxide formation was 217.5 micro g/ml. The concentrations needed to scavenge hydroxyl and superoxide radicals were 73.5 and 287.5 micro g/ml, respectively. The intravenous administration of this extract (5mg/kg body weight) in rabbits delayed the plasma recalcification time and enhanced the release of lipoprotein lipase enzyme significantly. The extract also inhibited ADP-induced platelet aggregation in vitro (50-250 micro g), which was comparable to commercial heparin.     

缩醛基毛冬青化合物R4的抗血栓作用研究

目的研究缩醛基毛冬青化合物R4的抗血栓作用。方法采用小鼠体外凝血时间及家兔血浆凝血酶原时间(PT),家兔血浆白陶土部分凝血活酶时间(KPTT)及家兔血浆凝血酶时间(TT),大鼠血清NO水平,ADP诱导的家兔血小板聚集实验来观察缩醛基毛冬青化合物R4的抗血栓作用。结果缩醛基毛冬青化合物R4 1,2,4 mg/kg能显著延长小鼠体外凝血时间;缩醛基毛冬青化合物R4 0.625,1.25,2.5 mg/kg能明显延长家兔PT、KPTT及TT,并能显著抑制ADP引起的血小板聚集;缩醛基毛冬青提取化合物R4 0.75,1.5,3.0 mg/kg能显著增加大鼠血清NO水平。结论缩醛基毛冬青化合物R4具有明显的抗血栓形成作用,机制可能与干扰内源性凝血系统因子的活性、抗血小板聚集及促进NO释放等有关。     

Blockade of glycoprotein IIb/IIIa mediates the antithrombotic activity of butanol fraction of Actinostemma lobatum Maxim

AIM OF THE STUDY: Actinostemma lobatum Maxim, a wildlife plant of Cucurbitaceae family, has been utilized for the prevention or treatment of cardiovascular diseases as a folk remedy in Korea. However, its scientific evidence remains unclear. Thus, in the present study, we examined the effects of butanol fraction of Actinostemma lobatum Maxim (BFALM) on the in vitro and in vivo antithrombotic activity and possible mechanisms were elucidated for the first time. MATERIAL AND METHODS: To elucidate the antithrombotic mechanism of BFALM, platelet aggregation assay, coagulation assay, glycoprotein IIb/IIIa assay, thromboxane A(2) assay and in vivo pulmonary thromboembolism experiment were performed. RESULTS: BFALM significantly inhibited collagen, adenosine diphosphate (ADP) and thrombin-induced platelet aggregation in a concentration dependent manner. Consistently, oral administration of BFALM resulted in a dose-dependent increase of survival rates of mice with pulmonary thromboembolism induced by intravenous injection of collagen and epinephrine. In mechanism assays for the antithrombotic activity of BFALM, BFALM significantly inhibited the fibrinogen binding to the platelet surface Glycoprotein IIb/IIIa (GP IIb/IIIa) receptor in a concentration dependent fashion, as well as reduced the level of thromboxane A(2) at 400microg/ml. Furthermore, BFALM significantly prolonged the prothrombin time (PT) and activated partial thromboplastin time (APTT) compared with untreated control. CONCLUSIONS: These results suggest that BFALM may exert antithrombotic activity through inhibition of platelet aggregation via GP IIb/IIIa and thromboxane A(2) pathways, along with anticoagulatory activity through intrinsic and extrinsic pathways.     

Effect of hsien-ho-t'sao (Agrimonia pilosa) on experimental thrombosis in mice

The water extract of Hsien-Ho-T'sao (HHT) prolonged the tail bleeding time in conscious mice. This antihemostatic effect was dose-dependent and exhibited a biphasic pattern; i.e. its activity declined at doses higher than 0.5 mg/kg. the prolonged bleeding time persisted for at least 12 hr and maximal effect was observed at 3 hr after the oral administration of HHT 500 mg/kg. HHT was effective in preventing ADP-induced acute pulmonary thromboembolic death in mice, while aspirin and indomethacin had no effect on this model. HHT, like aspirin and indomethacin, also reduced the mortality in collagen- and sodium arachidonate-induced thromboembolic death. All three drugs caused no significant protection in endotoxin shock. HHT was found to suppress platelet aggregation markedly, but little effect on blood coagulation. In conclusion, HHT was proved to be effective in the treatment of acute pulmonary thromboembolism, and this effect was mainly due to its antiplatelet action.     

Iridoid glycosides extracted from Zhizi (Fructus Gardeniae) decrease collagen-induced platelet aggregation and reduce carotid artery thrombosis in an in vivo rat model

Objective

To investigate the anti-platelet aggregation and antithrombotic effects in rats of iridoid glycosides extracted from Zhizi (Fructus Gardeniae).

Methods

The present study evaluated the antithrombotic activity of iridoid glycosides (IGs) in a rat model of carotid artery thrombosis. The effects on coagulation, such as thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT), and the effect on collagen-induced platelet aggregation in vivo were investigated. Rats were intragastrically administered IGs (50, 100 or 200 mg/kg) twice daily for 3 days.

Results

IGs were shown for the first time to have an antithrombotic action through the inhibition of platelet aggregation, with little effect on the coagulation time of peripheral blood. Our results also showed that IGs may significantly and dose-dependently reduce arterial thrombus load in a model of carotid artery thrombosis and inhibit collagen-induced platelet aggregation in rats. IGs (100 or 200 mg/kg) had no significant effect on APTT and PT, but did lengthen TT at a higher dose.

Conclusion

These data, together with the previously reported neuroprotective effects of IGs in rats with cerebral ischemia, suggest that the antithrombotic action of IGs may potentially contribute to the treatment of cerebral ischemic diseases, including cerebral apoplexy.     

Inhibition of rat platelet aggregation by Urtica dioica leaves extracts

Platelet hyperactivity plays an important role in arterial thrombosis and atherosclerosis. The present study was undertaken to investigate the effects of different extracts of Urtica dioica leaves on platelet aggregation. Rat platelets were prepared and incubated in vitro with different concentrations of the tested extracts and aggregation was induced by different agonists including thrombin (0.5 U/mL), ADP (10 microm), epinephrine (100 microm) and collagen (5 mg/mL). The crude aqueous extract inhibited thrombin-induced platelet aggregation in a dose-dependent manner. At 1 mg/mL, the percent inhibition was 17.1 +/- 4.2%. Soxhlet extraction of the plant leaves with different successive solvents showed that the ethyl acetate extract exhibited the most antiaggregant effect with an inhibition of 76.8 +/- 6.1% at 1 mg/mL. Flavonoids isolated from the plant leaves, produced a strong inhibitory effect on thrombin-induced platelet aggregation with an IC(50) of 0.25 +/- 0.05 and 0.40 +/- 0.04 mg/mL for genins and heterosidic flavonoids, respectively. Flavonoids also markedly inhibited platelet aggregation induced by ADP, collagen and epinephrine. It is concluded that Urtica dioica has an antiplatelet action in which flavonoids are mainly implicated. These results support the traditional use of Urtica dioica in the treatment and/or prevention of cardiovascular disease.     

苄基丹皮酚肟抗血栓活性的初步研究

目的探讨苄基丹皮酚肟(benzyl paeonol oxime,BPO)的抗血栓活性。方法采用全自动凝血因子分析仪,检测家兔血浆PT、APTT和TT;比浊法检测血小板聚集率;ELISA法检测大鼠血浆中PC、PS、AT-Ⅲ、GPⅡb/Ⅲa和cAMP含量。结果BPO对APTT有延迟作用,对ADP、AA、胶原诱导的血小板聚集有抑制作用,可升高血浆中蛋白C的浓度,降低抗凝血酶Ⅲ的浓度,但未引起蛋白S的浓度变化;同时BPO可升高血浆中GPⅡb/Ⅲa的浓度,而对cAMP的浓度无影响。结论BPO具有优良的抗凝血活性和抗血小板聚集活性,其抗凝血机制可能与增强PC活性和促进AT-Ⅲ与凝血酶结合有关;抗血小板聚集机制可能与抑制纤维蛋白原和GPⅡb/Ⅲa的结合有关。     

Antithrombotic activity of ternatin,a tetramethoxy flavone from Egletes viscosa less

Ternatin, a tetramethoxy flavone isolated from Egletes viscosa Less. was evaluated for a possible antithrombotic acitivity on in vitro platelet aggregation induced by ADP and in vivo mouse model of tail thrombosis induced by kappa-carrageenan (KC). ADP-induced platelet aggegation was inhibited by ternatin in a concentration-dependent manner with an IC₅₀ of 390 μM. It also provided marked protection of mice from thrombotic challenge with KC. Tail thrombosis was totally prevented in mice that received ternatin prophylactically (1 h prior to KC injection) whereas therapeutically (4 h after KC injection) administered ternatin effectively reduced the length of the thrombosed/infarcted part of the tail. The observations suggest an antithrombotic action of ternatin.     

赤芍总苷静脉给药抗血栓形成作用研究

目的:研究赤芍总苷(TSP)静脉给药时抗凝和抗血栓形成作用.方法:TSP按18.8,37.5,75mg/kg三种剂量尾静脉注射,测定其对于小鼠凝血时间、复合诱导剂致肺栓塞的死亡率和角叉菜胶致尾血栓的长度比值及电刺激大鼠动脉血栓形成时间的影响.结果:TSP能显著延长小鼠凝血时间,降低肺栓塞死亡率,缩短尾血栓的长度比值,延长动脉血栓形成时间,0.375%浓度下未见溶血反应.结论:TSP静脉给药时具有显著抗凝和抗血栓形成作用.     

β-榄香烯抗凝血溶血栓活性研究

目的：研究β-榄香烯体外抗凝血与溶血栓活性以及体内抗凝血,抗血小板聚集作用,为探讨β-榄香烯活血化瘀药效提供参考。方法：采用新西兰兔体外抗凝血法、血浆复钙时间实验及体外血栓法、全血块法研究β-榄香烯的体外抗凝血、溶血栓作用;采用皮下注射盐酸肾上腺素和冰水刺激复制大鼠急性寒凝血瘀证模型,通过观察凝血酶原时间（PT）、凝血酶时间（TT）以及二磷酸腺苷（Adenosine diphosphate,ADP）和花生四烯酸（Arachidonic acid,AA）诱导血小板最大聚集率,研究β-榄香烯口服制剂对血瘀大鼠体内凝血功能的影响。结果：β-榄香烯各剂量组均能延长新西兰兔血浆复钙时间（P〈0.05）,加快体外血栓及全血凝块的溶解（P〈0.05）;β-榄香烯口服制剂高剂量组延长寒凝血瘀大鼠的凝血酶原时间（PT）（P〈0.05）,β-榄香烯口服制剂各剂量组延长寒凝血瘀大鼠的凝血酶时间（TT）（P〈0.01）,且对ADP和AA诱导的血小板最大聚集率有显著的抑制作用（P〈0.01）。结论：β-榄香烯具有抗凝血和溶血栓的作用。     

In vivo antimalarial activities of Quassia amara and Quassia undulata plant extracts in mice

Extracts obtained from two Nigerian Simaroubaceae plants, Quassia amara L. and Quassia undulata (Giull and Perr) D. Dietr were screened for antimalarial properties using a total of six extracts. The plant extracts showed significant antimalarial activities in the 4 day suppressive in vivo antimalarial assay in mice inoculated with red blood cells parasitized with Plasmodium berghei berghei. Plant extracts were studied at 100 mg and 200 mg per kg body weight mouse per day, respectively. At a concentration of 100 mg/kg of mouse, Q. amara leaf hexane extract had the highest suppressive activity with a parasite density of 0.16 +/- 0.001%. Q. amara leaf methanol extract had an outstanding activity; of 0.05 +/- 0.03% at 200 mg/kg. Chloroquine (10 mg/kg, positive control) had a suppressive activity of 0.34 +/- 0.02 in the same assay on day 4.