Rat Platelets Research Articles

Salicylic acid fails to inhibit generation of thromboxane A2 activity in platelets after in vivo administration to the rat.

Arachidonic acid-induced aggregation of rat platelets and the accompanying generation of thromboxane A2 activity were inhibited by aspirin, whereas 20 times higher doses of salicylic, gentisic and salicyluric acids were inactive. Salicylic acid administered to the rats before aspirin prevented the inhibition of the cyclo-oxygenase-mediated effects of arachidonic acid. These results do not support the hypothesis that the anti-inflammatory activity of salicylic acid is due to inhibition of prostaglandin systhetase (cyclo-oxygenase) by an unknown metabolite and indicate that salicylic acid displays an anti-inflammatory activity independent inhibition of prostaglandin biosynthesis.

In-vitro platelet responses to arachidonic acid in the rat.

Using both the turbidimetric and the conductive methods to study aggregation of platelets, we found that arachidonic acid stimulated rat washed platelets in a dose-dependent manner (40 microM-0.5 mM). Although a high concentration of arachidonic acid (0.5 mM) produced an increase in light transmission both in the presence of 2 mM CaCl2 and EGTA (45.8 +/- 2.8 and 50.4 +/- 0.8% respectively) no changes in impedance were detected. Lysis caused by this concentration of arachidonic acid was very high at all the concentrations of calcium used (mean of 81.3%). In addition, the turbidimetric response induced by 0.5 mM arachidonic acid implied an initial decrease in light transmission but did not correlate with a real shape change. Forty micromolar arachidonic acid induced a calcium-dependent aggregation measured both by aggregometry and impedance. Morphology of aggregates induced by both concentrations was also studied. These results suggest that the optimal concentration for studying rat platelet activation by arachidonic acid is 40 microM; high concentrations (0.5 mM) cause aspecific effects not correlated to a physiological activation response.

Characterization of the T-lymphocyte response elicited by mouse immunization with rat platelets

Immunization of normal CBA mice with rat platelets leads to an autoantibody response directed against mouse platelets. The purpose of this work was to determine the involvement of T lymphocytes in this response. T-lymphocyte responses were analyzed in vivo by depletion and transfer experiments and ex vivo by proliferation assay and cytokine measurements. Mouse immunization with rat platelets induced production of antibodies reacting with rat and mouse platelets. This response was found to depend on CD4(+) T-helper lymphocytes reacting with rat, but not with mouse platelets. These anti-rat platelet T-helper cells were mainly of the Th1 phenotype. When transferred into naïve mice, they enhanced the anti-mouse platelet antibody response induced by subsequent immunization with rat platelets. In addition, depletion of CD25(+) cells enhanced the thrombocytopenia induced by immunization with rat platelets, whereas adoptive transfer of CD4(+)CD25(+) cells from immunized mice suppressed it. Our results suggest that activation of anti-rat platelet T-helper cells can bypass the mechanism of tolerance and result in the secretion of autoreactive antibodies, but this response is still controlled by regulatory T cells that develop progressively after immunization.

Antiplatelet Activity of Phellinus baummii Methanol Extract is Mediated by Cyclic AMP Elevation and Inhibition of Collagen‐activated Integrin‐αIIbβ3 and MAP Kinase

Phellinus baumii is a mushroom that has been used as folk medicine against various diseases and is reported to have antidiabetic, anticancer, antioxidant, antiinflammatory and antihypertensive activities. However, information on the effects of P. baumii extract in platelet function is limited. Therefore, the aim of this study was to examine the impact of a P. baumii methanol extract (PBME) on platelet activation and to investigate the mechanism behind its antiplatelet activity. PBME effects on agonist-induced platelet aggregation, granule secretion, [Ca²⁺](i) mobilization, α(IIb) β₃ activation, cyclic AMP release and mitogen-activated protein kinase (MAPK) phosphorylations were studied using rat platelets. PBME dose-dependently inhibited collagen, thrombin and ADP-induced platelet aggregation with an IC₅₀ of 51.0 ± 2.4, 54.0 ± 2.1 and 53.0 ± 4.3 μg/mL, respectively. Likewise, thrombin-induced [Ca²⁺](i) and collagen-activated ATP secretions were suppressed in PBME treated platelets. Aggregation and ATP secretion were also markedly attenuated by PBME alone or in combination with PP2 (Src inhibitor) and U-73122 (PLC inhibitor) in collagen-stimulated platelets. Besides, PBME treatment elevated basal cyclic AMP levels and inhibited collagen-induced integrin-α(IIb) β₃ activation. Moreover, PBME attenuated extracellular-signal-regulated protein kinase 2 (ERK2) and c-Jun N-terminal kinase 1 (JNK1) phosphorylations. Further PD98059 (ERK inhibitor) and SP60025 (JNK inhibitor) reduced collagen-induced platelet aggregation and ATP secretion. In conclusion, the observed PBME antiplatelet activity may be mediated by activation of cyclic AMP and inhibition of ERK2 and JNK1 phosphorylations. Finally, these data suggest that PBME may have therapeutic potential for the treatment of cardiovascular diseases that involve aberrant platelet function.

Ent-16β,17-dihydroxy-kauran-19-oic acid, a kaurane diterpene acid from Siegesbeckia pubescens, presents antiplatelet and antithrombotic effects in rats

The antiplatelet and antithrombotic effects of ent-16β,17-dihydroxy-kauran-19-oic acid (DDKA) isolated from Siegesbeckia pubescens were investigated with different methods both in vitro and in vivo. We tested the antithrombotic activity of DDKA in arterio-venous shunt model. The effects of DDKA on adenosine diphosphate (ADP)-, Thrombin-, Arachidonic acid-induced rat platelets aggregation were tested in vitro. We also assessed its bleeding side effect by measuring coagulation parameters after intravenous administration for 5 days and investigated the potential mechanisms underlying such activities. In vivo, DDKA significantly reduced thrombus weight in the model of arterio-venous shunt. Meanwhile, DDKA increased plasma cAMP level determined by radioimmunoassay in the same model. Notably, DDKA prolonged PT and APTT in rats after intravenous administration DDKA for successive 5 days. In vitro, pretreatment with DDKA on washed rat platelets significantly inhibited various agonists stimulated platelet aggregation and caused an increase in cAMP level in platelets activated by ADP. These findings support our hypothesis that DDKA possesses antiplatelet and antithrombotic activities. The mechanisms underlying such activities may involve the anticoagulatory effect and cAMP induction.

Antiplatelet effects of Cyperus rotundus and its component (+)-nootkatone

Cyperus rotundus, a well-known oriental traditional medicine, has been reported to exhibit wide spectrum activity in biological systems including the circulatory system, however, little information is available on its antiplatelet activity. This study was undertaken to investigate the antiplatelet effects of Cyperus rotundus EtOH extract (CRE) and its constituent compounds. The antiplatelet activities of CRE and its eight constituent compounds were evaluated by examining their effects on rat platelet aggregations in vitro and ex vivo, and on mice tail bleeding times. During the in vitro platelet aggregation study, CRE showed significant and concentration-dependent inhibitory effects on collagen-, thrombin-, and/or AA-induced platelet aggregation. Of its eight components, (+)-nootkatone was found to have the most potent inhibitory effect on collagen-, thrombin-, and AA-induced platelet aggregation. In addition, CRE- and (+)-nootkatone-treated mice exhibited significantly prolonged bleeding times. Furthermore, (+)-nootkatone had a significant inhibitory effect on rat platelet aggregation ex vivo. This study demonstrates the antiplatelet effects of CRE and its active component (+)-nootkatone, and suggests that these agents might be of therapeutic benefit for the prevention of platelet-associated cardiovascular diseases.

The peridontal anaerobe Porphyromonas gingivalis induced platelet activation and increased aggregation in whole blood by rat model

Introduction More and more evidence show that periodontal anaerobes contribute to pathogenesis of peripheral artery diseases. As a typical oral anaerobe that results in periodontitis, P.gingivalis aggregats platelets in PRP in vitro and participated in artery thrombosis. However, in vivo effect on platelet activation and aggregation remains unclear. This study aimed to clarify its role on platelets activation on more physiological environment, that is, on whole blood and systemic circulation. Materials and methods To fully estimate platelet activation, CD62P(P-selectin) expression on platelet surface and fibrinogen binding of platelet via conjugated glycoprotein GPIIb/IIIa in whole blood were assayed by flow cytometry, and platelet aggregation was measured on an impedance aggregometor. As primary study, platelet reactivity was assessed after in vitro rat whole blood incubation with P.gingivalis strain 381 in tubes, followed or not followed by ADP and arachidonic acid stimulation. In addition, PBS solution of P.gingivalis was infused into rat to produce transient bacteremia model for 5 minutes and blood samples were subjected to analysis for platelet activation in vivo. Results P.gingivalis could not induce rat platelet aggregation in whole blood in vitro, but increased aggregation when irritated by collagen stimulation. Flow cytometric study showed that incubation with P.gingivalis increased CD62P expression and fibrinogen binding of platelet. Moreover, further stress by 10 μmol/L ADP and 260 mmlol/L arachidonic acid yielded additional expression. As in vivo study, after P.gingivalis solution challenged, rat platelet aggregability was enhanced, and CD62P positive percentage of platelets and further reactivity to ADP stimulation improved. Conclusion In whole blood and in systemic circulation, P.gingivalis could induce rat platelet activation and increase aggregability transiently. The results helped to understand the mechanism underlining which P.gingivalis promoted arteriosclerosis and thrombo-embolic disorders. Further study about chronic infection with P.gingivalis on platelet activity is expected.

Differential Proteomic Analysis of Platelets Suggested Possible Signal Cascades Network in Platelets Treated with Salvianolic Acid B

BackgroundSalvianolic acid B (SB) is an active component isolated from Danshen, a traditional Chinese medicine widely used for the treatment of cardiovascular disorders. Previous study suggested that SB might inhibit adhesion as well as aggregation of platelets by a mechanism involving the integrin α2β1. But, the signal cascades in platelets after SB binding are still not clear.Methodology/Principal FindingsIn the present study, a differential proteomic analysis (two-dimensional electrophoresis) was conducted to check the protein expression profiles of rat platelets with or without treatment of SB. Proteins altered in level after SB exposure were identified by MALDI-TOF MS/MS. Treatment of SB caused regulation of 20 proteins such as heat shock-related 70 kDa protein 2 (hsp70), LIM domain protein CLP-36, copine I, peroxiredoxin-2, coronin-1 B and cytoplasmic dynein intermediate chain 2C. The regulation of SB on protein levels was confirmed by Western blotting. The signal cascades network induced by SB after its binding with integrin α2β1 was predicted. To certify the predicted network, binding affinity of SB to integrin α2β1 was checked in vitro and ex vivo in platelets. Furthermore, the effects of SB on protein levels of hsp70, coronin-1B and intracellular levels of Ca(2+) and reactive oxygen species (ROS) were checked with or without pre-treatment of platelets using antibody against integrin α2β1. Electron microscopy study confirmed that SB affected cytoskeleton structure of platelets.Conclusions/SignificanceIntegrin α2β1 might be one of the direct target proteins of SB in platelets. The signal cascades network of SB after binding with integrin α2β1 might include regulation of intracellular Ca(2+) level, cytoskeleton-related proteins such as coronin-1B and cytoskeleton structure of platelets.

Activities of adenine nucleotide and nucleoside degradation enzymes in platelets of rats infected by Trypanosoma evansi

Nucleotide and nucleoside-degrading enzymes, such as nucleoside triphosphate diphosphohydrose (NTPDase), 5′-nucleotidase and adenosine deaminase (ADA) are present in the surface membranes of platelets, involved in clotting disturbances of Trypanosoma evansi-infected animals. Thus, this study was aimed at evaluating the activities of these enzymes in platelets of rats experimentally infected with T. evansi. Animals were divided into four groups, according to the level of parasitemia. Blood samples were collected on days 3 (group A: at the beginning of parasitemia), 5 (group B: high parasitemia) and 15 (group C: chronic infection), post-infection. Group D (control group) was composed of non-infected animals for platelet count, separation and enzymatic assays. Animals from groups A and B showed marked thrombocytopenia, but platelet count was not affected in chronically infected rats. NTPDase, 5′-nucleotidase and ADA activities decreased (p<0.05) in platelets from rats of groups A and B, when compared to the control group. In group C, only NTPDase and 5′-nucleoside activities decreased (p<0.001). The correlations between platelet count and nucleotide/nucleoside hydrolysis were positive and statistically significant (p<0.05) in groups A and B. Platelet aggregation was decreased in all infected groups, in comparison to the control group (p<0.05). It is concluded that the alterations observed in the activities of NTPDase, 5′-nucleotidase and ADA in platelets of T. evansi-infected animals might be related to thrombocytopenia, that by reducing the number of platelets, there was less release of ATP and ADP. Another possibility being suggested is that changes have occurred in the membrane of these cells, decreasing the expression of these enzymes in the cell membrane.

Studies on Screening, Isolation and Purification of a Fibrinolytic Protease from an Isolate (VK12) of Ganoderma Lucidum and Evaluation of its Antithrombotic Activity

Antithrombotic activity of a protease purified from a medicinal mushroom, Ganoderma lucidum, has been evaluated platelet aggregation in vitro and pulmonary thrombosis in vivo. The purified protease exhibited concentration dependent inhibitory effects on platelet aggregation induced by ADP (adenosine diphosphate), with an IC(50) value of 2.4 mg/mL. The purified protease protected mice against thrombotic death or paralysis induced by collagen and epinephrine in a dose dependent manner when administered orally. It produced a significant inhibition of thrombotic death or paralysis at 60 µg/kg body weight, while aspirin produced a significant inhibition of thrombosis at 10-20 mg/kg body weight. The purified protease also has showed fibrinolytic activity and alters coagulation parameters such as activated partial thromboplastin time (APTT), and thrombin time (TT) in rat platelet. These results suggested that the antithrombotic activity of Ganoderma lucidum protease might be due to antiplatelet activity rather than anticoagulation activity.

Role of newly formed platelets in thrombus formation in rat after clopidogrel treatment: comparison to the reversible binding P2Y12 antagonist ticagrelor

Platelet P2Y₁₂ receptors play an important role in arterial thrombosis by stimulating thrombus growth. Both irreversibly (clopidogrel) and reversibly binding (ticagrelor, AZD6140) P2Y₁₂ antagonists are clinically used for restricted periods, but possible differences in platelet function recovery after drug cessation have not been investigated. We treated WKY rats with a single, high dose of 200 mg/kg clopidogrel or 40 mg/kg ticagrelor. Blood was collected at different time points after treatment. Flow cytometry confirmed full platelet protection against ADP-induced αIIbβ₃ activation shortly after clopidogrel or ticagrelor treatment. At later time points after clopidogrel treatment, a subpopulation of juvenile platelets appeared that was fully responsive to ADP. Addition of ticagrelor to clopidogrel-treated blood reduced αIIbβ₃ activation of the unprotected platelets. In contrast, at later time points after ticagrelor treatment, all platelets gradually lost their protection against ADP activation. Perfusion experiments showed abolishment of thrombus formation shortly after clopidogrel or ticagrelor treatment. Thrombus formation on collagen was determined under high shear flow conditions. At later time points, large thrombi formed in the clopidogrel but not in the ticagrelor group, and unprotected, juvenile platelets preferentially incorporated into the formed thrombi. However, platelets from both groups were still similarly reduced in assays of whole blood aggregation. Conclusively, recovery of rat platelet function after ticagrelor differs mechanistically from that after clopidogrel. This difference is masked by conventional platelet aggregation methods, but is revealed by thrombus formation measurement under flow. Juvenile platelets formed at later time points after clopidogrel treatment promoted thrombus formation.

Immunoglobulin M antiplatelet autoantibodies from mice immunized with rat platelets induce thrombocytopenia and platelet function impairment

Antiplatelet monoclonal autoantibodies (mAbs) were derived from CBA mice immunized with rat platelets. Two IgM antiplatelet mAbs were further analyzed. L1C43 mAb bound a 150-160 kDa antigen, recognized activated platelets better than resting ones and impaired platelet adhesion, but not clot retraction. L1H31 mAb recognized a ±95 kDa molecule, bound similarly activated and resting platelets and did not modify platelet adhesion, but inhibited clot retraction. Both mAbs induced in vivo thrombocytopenia most likely through phagocytosis of opsonized platelets. These autoreactive antibodies can thus induce both platelet destruction and impairment of their function. They are reflective of autoantibodies found in human patients and may serve for further analysis of antiplatelet autoantibody pathogenicity and mechanisms of autoimmune disease.

Ellagic Acid-induced Hypercoagulable State in Animals: a Potentially Useful Animal Hypercoagulable Model for Evaluation of Anticoagulants

To establish and evaluate a hypercoagulable animal model for the assessment of anticoagulants. Forty mice, thirty-two rats, and twenty-four rabbits were randomly and equally divided into control group (saline) and three ellagic acid (EA)-treated groups (low, middle, and high doses). In the mice, bleeding time (BT) was estimated with tail transaction, and clotting time (CT) with template method. Prothrombin time (PT) and the activated partial thromboplastin time (APTT) in rats and rabbits were measured by means of Quick's one-stage assay and modified APTT assay respectively. In addition, thrombin activity was estimated in rats with PT assay using a hemagglutination analyzer. The circulating platelet aggregates were detected in rabbits through platelet counting and presented as the circulating platelet aggregate ratio (CPAR). EA shortened BT and CT in mice, PT and APTT in rats, and increased thrombin activity and CPAR, all in a dose-dependent manner. EA also brought reduction of PT and APTT in rabbits in dose- and time-dependent manners. EA could induce hypercoagulable state through activating coagulation system and platelets in mice, rats, and rabbits.

Characterizing effects of solvent specific Mori Ramulus components on rat platelet aggregation, vascular tension and macrophage nitrite production

To study the effects of different solvent extractions of Mori Ramulus on platelet aggregation, vascular tension, and nitrite production from macrophages stimulated by lipopolysaccharides and interferon-gamma. The components of Mori Ramulus were extracted by EtoAc, n-BuOH and chloroform respectively. Platelet aggregation was induced by ADP, arachidonic acid and collagen in vitro; nitrite production of activated macrophages was measured by Griess assay, and the vasodilatory effects of three extractions were investigated by isometric tension changes of aortic rings. Chloroform extraction concentration-dependently inhibited platelet aggregation by arachidonic acid, and reduced vascular tension of PE preconstricted aorta rings with or without endothelium. On the other hand, extractions of EtoAc and n-BuOH demonstrated dose-dependent inhibition on macrophage NO production stimulated by LPS/IFN-gamma. Pharmacological activities of Mori Ramulus depend on solvent specific components. Chloroform extraction of Mori Ramulus may benefit cardiovascular diseases through its properties of anti-platelet aggregation and vasodilatation. The inhibition of macrophage activity by EtoAc and n-BuOH extractions suggested an anti-inflammation effect of the compound.

Global analysis of the rat and human platelet proteome – the molecular blueprint for illustrating multi‐functional platelets and cross‐species function evolution

This article was originally published in Proteomics 2010, 10, 2444–2457, DOI 10.1002/pmic.200900271

Metabolic profiling of murine plasma reveals an unexpected biomarker in rofecoxib-mediated cardiovascular events

Chronic administration of high levels of selective COX-2 inhibitors (coxibs), particularly rofecoxib, valdecoxib, and parecoxib, increases risk for cardiovascular disease. Understanding the possibly multiple mechanisms underlying these adverse cardiovascular events is critical for evaluating the risks and benefits of coxibs and for development of safer coxibs. The current understanding of these mechanisms is likely incomplete. Using a metabolomics approach, we demonstrate that oral administration of rofecoxib for 3 mo results in a greater than 120-fold higher blood level of 20-hydroxyeicosatetraenoic acid (20-HETE), which correlates with a significantly shorter tail bleeding time in a murine model. We tested the hypothesis that this dramatic increase in 20-HETE is attributable to inhibition of its metabolism and that the shortened bleeding time following rofecoxib administration is attributable, in part, to this increase. The s.c. infusion of 20-HETE shortened the tail bleeding time dramatically. Neither 20-HETE biosynthesis nor cytochrome P4A-like immune reactivity was increased by rofecoxib administration, but 20-HETE production increased in vitro with the addition of coxib. 20-HETE is significantly more potent than its COX-mediated metabolites in shortening clotting time in vitro. Furthermore, 20-HETE but not rofecoxib significantly increases rat platelet aggregation in vitro in a dose-dependent manner. These data suggest 20-HETE as a marker of rofecoxib exposure and that inhibition of 20-HETE's degradation by rofecoxib is a partial explanation for its dramatic increase, the shortened bleeding time, and, possibly, the adverse cardiovascular events associated with rofecoxib.

Novel astaxanthin prodrug (CDX-085) attenuates thrombosis in a mouse model

Background Cardiovascular disease remains the leading cause of morbidity and premature mortality in most industrialized countries as well as in developing nations. A pro-oxidative state appears to promote and/or exacerbate vascular disease complications. Furthermore, a state of low-grade chronic inflammation can promote increased oxidative stress and lead to endothelial cell and platelet dysfunction ultimately contributing to thrombogenesis. Objectives In this study, the effect of a proprietary astaxanthin prodrug (CDX-085) on thrombus formation was investigated using a mouse model of arterial thrombosis. The influence of free astaxanthin, the active drug of CDX-085, on human endothelial cells and rat platelets was evaluated to investigate potential mechanisms of action. Methods and results Oral administration of CDX-085 (0.4% in chow, approximately 500 mg/kg/day) to 6-8 week old C57BL/6 male mice for 14 days resulted in significant levels of free astaxanthin in the plasma, liver, heart and platelets. When compared to control mice, the CDX-085 fed group exhibited significant increases in basal arterial blood flow and significant delays in occlusive thrombus formation following the onset of vascular endothelial injury. Primary human umbilical vein endothelial cells (HUVECs) and platelets isolated from Wistar-Kyoto rats treated with free astaxanthin demonstrated significantly increased levels of released nitric oxide (NO) and significantly decreased peroxynitrite (ONOO-) levels. Conclusion Observations of increased NO and decreased ONOO- levels in endothelial cells and platelets support a potential mechanism of action for astaxanthin (CDX-085 active drug). These studies support the potential of CDX-085 and its metabolite astaxanthin in the treatment or prevention of thrombotic cardiovascular complications.

Perfluorinated carboxylic acids inhibit cyclooxygenase pathway more potently than 12-lipoxygenase pathway in rat platelets

Two perfluorinated carboxylic acids (PFCAs), pentadecafluorooctanoic acid (PDFOA) and heptadecafluorononanoic acid (HDFNA), were investigated for potential modulatory effects on the cyclooxygenase (COX) and 12-lipoxygenase (LOX) metabolisms in rat platelets. Both PDFOA and HDFNA dose-dependently inhibited the formation of a COX metabolite, 12-HHT, without any effect on that of a LOX metabolite, 12-HETE, at concentrations ranging from 10 to 100μM. These two PFCAs up to 100μM did not affect platelet membrane integrity, and COX-1 and -2 protein expression levels in Caco-2 cells. These results suggest that PDFOA and HDFNA have the potential to modify platelet function by inhibiting the COX pathway at activity level, but not at protein level.

Global analysis of the rat and human platelet proteome – the molecular blueprint for illustrating multi‐functional platelets and cross‐species function evolution

Emerging evidences indicate that blood platelets function in multiple biological processes including immune response, bone metastasis and liver regeneration in addition to their known roles in hemostasis and thrombosis. Global elucidation of platelet proteome will provide the molecular base of these platelet functions. Here, we set up a high-throughput platform for maximum exploration of the rat/human platelet proteome using integrated proteomic technologies, and then applied to identify the largest number of the proteins expressed in both rat and human platelets. After stringent statistical filtration, a total of 837 unique proteins matched with at least two unique peptides were precisely identified, making it the first comprehensive protein database so far for rat platelets. Meanwhile, quantitative analyses of the thrombin-stimulated platelets offered great insights into the biological functions of platelet proteins and therefore confirmed our global profiling data. A comparative proteomic analysis between rat and human platelets was also conducted, which revealed not only a significant similarity, but also an across-species evolutionary link that the orthologous proteins representing "core proteome", and the "evolutionary proteome" is actually a relatively static proteome.

Effect of essential oil of Syringa pinnatifolia Hemsl. var. alashanensis on ischemia of myocardium, hypoxia and platelet aggregation

Aim of the study To investigate the cardioprotective potential of Syringa pinnatifolia Hems1. var. alashanensis essential oil (SPEO) against experimental acute myocardial ischemia (AMI), hydrogen peroxide (H 2O 2)-induced myocyte injury and activities against hypoxia and platelet aggregation. Materials and methods Wistar rats, Kunming mice and primary cultured rat neonatal myocytes were used in this study. AMI in rats was induced by ligation of the left anterior descending (LAD) coronary artery, and deviation of ST-segment, as well as changes of myocardial enzyme activities were observed. Hypoxia test in Kunming mice was performed to evaluate the effect of SPEO against hypoxia. The protective effect of SPEO on H 2O 2-induced cell injury was evaluated in terms of cell viability assay. The in vitro effect of SPEO against platelet aggregation was studied using adenosine 5′-diphosphate (ADP) as agonist. Results Administration of SPEO reduced deviation of ST-segment, decreased the levels of lactate dehydrogenase (LDH), creatine kinase (CK) and Troponin T (TnT) while increased the activities of superoxide dismutase (SOD). The protective role of SPEO was further confirmed by histopathological examination. In the hypoxia test, both 8 and 32 mg/kg of SPEO could prolong survival time of mice under hypoxia condition. At the meantime SPEO showed remarkable protective effect on cultured rat myocyte death induced by H 2O 2. SPEO also inhibited ADP-induced rat platelet aggregation by 47.4%, 37.0% and 32.9% at the dose of 5, 2.5 and 1.25 μg/mL, respectively. Conclusions These results suggest that SPEO possessing activities against hypoxia, oxidative stress and platelet aggregation has a significant protective effect against experimental myocardial ischemia.