Effects of renal denervation on inflammatory factors in a rabbit model of early atherosclerosis

AIM: To evaluate the effects of renal denervation (RDN) on the expression of tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α) and interleukin-6 (IL-6) in a rabbit model of early atherosclerosis. METHODS: New Zealand male rabbits were divided into control group, RDN+ high-fat diet (HFD) group (RDN group), sham+HFD group (sham group) and HFD group. The rabbits in later 3 groups were fed with 2% cholesterol for 8 weeks to establish an early atherosclerosis model. The blood samples were collected to test the levels of lipids, norepinephrine (NE), TNF-α, IL-1α and IL-6. The protein expression of angiotensin Ⅱ (Ang Ⅱ) was detected by the method of immunohistochemistry. The levels of nuclear factor-κB (NF-κB) and Ang II 1 type receptor (AT1R) were evaluated by Western blot. The mRNA expression of TNF-α, IL-1α and IL-6 was determined by real-time PCR. RESULTS: After 1 d of RDN procedure, the NE level was lower in RDN group than that in sham group (P<0.01). After 8 weeks, the NE level was lower in RDN group than that in sham group and HFD group (P<0.05), and triglyceride (TG) was lower in RDN group than that in HFD group (P<0.05). The protein expression of Ang II was decreased in RDN group compared with sham group and HFD group (P<0.01). The protein expression of NF-κB was lower in RDN group than that in sham group (P<0.05). The plasma levels of TNF-α and IL-1α were reduced in RDN group compared with sham group and HFD group (P<0.05). The mRNA expression of TNF-α, IL-1α and IL-6 was reduced in RDN group compared with sham group (P<0.05). CONCLUSION: RDN inhibits sympathetic activity, decreases the plasma level of TG, and alleviates inflammatory reactions in the rabbits with atherosclerosis.     

Effects of different group B streptococci strains on platelet activation

AIM: To explore the ability of different group B streptococci (GBS) strains on inducing platelet activation. METHODS: Six strains of GBS, separated from the septic patients with thrombocytopenia, were used as the inducers. Light transmission aggregometry was used to measure platelet aggregation. Scanning electron microscopy (SEM) was performed to investigate the interaction of platelets with bacteria. The expression of platelet CD62P, Toll-like receptor 2 (TLR2) and TLR4 was determined by flow cytometry and Western blotting. Furthermore, the activity of platelet TLR2 (or TLR4) was blocked by anti-TLR2 (or anti-TLR4) monoclonal antibody, and the platelet aggregation induced by GBS was detected. RESULTS: Only 3 of 6 GBS strains isolated from the septic patients induced platelet aggregation and up-regulated the expression of CD62P and TLR2 in the platelets (P < 0.05), but not TLR4. Incubation with anti-TLR2 antibody, but not anti-TLR4 antibody, significantly blocked platelet aggregation induced by GBS.CONCLUSION: Some GBS strains from the patients are able to trigger platelet activation in vitro, and platelet TLR2 may play an important role in the interaction between GBS and platelets.     

Effects of Tongxinluo on connexin 43 remodeling and ventricular arrhythmia after myocardial infarction in rats

AIM: To determine the effects of Tongxinluo(TXL) on connexin 43(Cx43) remodeling and ventricular arrhythmia(VA) after myocardial infarction(MI) in rats. METHODS: Male SD rats were randomly divided into sham-operated(sham) group(n=25) and operation group(n=75). The left anterior descending(LAD) was ligated in operated group, while the rats in sham group only underwent pericardiotomy. The rats in operation group which survived for 3 d after operation were randomly assigned to TXL group and MI group. The rats in TXL group was administrated with TXL(2 g·kg^-1·d^-1, intragastric administration) for 4 weeks, while normal saline was applied to the rats in sham group and MI group. The levels of interleukin-1β(IL-1β) and endothelin-1(ET-1) in the tissue from the border zone were measured by ELISA after treatment. The distribution and the mRNA and protein expression of Cx43 were detected by immunohistochemical staining, RT-PCR and Western blotting, respectively. The burst pacing was used to induce ventricular arrhythmia(VA). RESULTS: Compared with sham group, the levels of IL-1β and ET-1 and the incidence of VA were significantly increased, while the mRNA and protein expression of Cx43 was markedly reduced with irregular distribution in MI group(P<0.05). Compared with MI group, the levels of IL-1β and ET-1 and the incidence of VA were significantly reduced, while the expression of Cx43 at mRNA and protein levels was markedly increased with augmented linear distribution in the myocardial cell intercalated disc in TXL group(P<0.05). CONCLUSION: TXL reduces the incidence of VA after MI via inhibiting the Cx43 remodeling.     

Effect of thrombopoietin on platelet activation invitro

AIM:To study the effects of thrombopoietin(TPO) and other hematopoietic cytokines on platelet activation. METHODS: Using fluorescent-labeled monoclonal antibodies and flow cytometry. RESULTS:The percentage range of platelets activated by 120 ng/mL TPO was 8.89%~39.92%,mean value was 17.43%; However,there were no effects of TPO 40 ng/mL and GM-CSF 100 ng/mL and IL-3 100 ng/mL on platelet activation. CONCLUSION:Higher concentration of TPO directly stimulated platelet activation.     

Effects of cimetidine on platelet function and thrombosis

AIM:To observe the effects of cimetidine(Cim) on platelet function and thrombosis. METHODS:After incubated with Cimin vitro, rat platelets were activated with ADP or thrombin. The platelet aggregation, platelet malondialdehyde(MDA) formation, platelet intracellular free calcium( [Ca²⁺]_i), and thromboxane B₂ (TXB₂) were measured. The effects of Cim on electric-induced thrombosis in rat carotid artery were examined. RESULTS:Cim potentiated ADP induced platelet aggregation, increased the thrombin induced [Ca²⁺]_i and MDA formation, decreased TXB₂. Also, Cim shortened the duration of electric-stimulated occlution time in rat carotid artery. CONCLUSION:Cim increased platelet function and accelerated thrombosis.     

Changes of metallothionein contents in plasma and tissues of rabbit with atherosclerosis

AIM: To observe the level of metallothionein (MT) in liver, aorta and plasma of rabbit with atherosclerosis (AS) in order to recognize the alteration of oxidative defense system in body when AS occurred.METHODS:Preparation of AS model of rabbit induced by having high-fat diet for eight weeks; the levels of MT and malondialdehyde (MDA) were measured in the tissues of liver and aorta and plasma of rabbit.RESULTS:The MT levels in liver tissues and plasma in atherosclerotic group increased 318%(P＜0.01) and 62% (P＜0.01), compared with control group, but its level in aortic tissue in atherosclerotic group decreased 33% (P＜0.01). The MDA levels in liver, aortic and plasma in atherosclerotic group increased 95%(P＜0.01), 76%(P＜0.01) and 42%(P＜0.01), respectively, compared with control group. The changes of contents of MT in liver and plasma have relation with level of MDA in liver tissues and plasma.CONCLUSION:The alteration of MT in liver tissues and plasma in atherosclerotic rabbits may be related to lipid hyperoxidative injury.     

Effects of Sini decoction on atherosclerosis and ceramide content of aorta in rabbits

AIM:To observe the effects of Sini decoction on atherosclerosis(AS) and ceramide content of aorta in rabbits. METHODS:28 rabbits were randomly divided into three groups. Control group was fed with a normal diet; High cholesterol group was fed 1% cholesterol and 5% fat diet; Sini decotion+ high cholesterol group was fed 1% cholesterol and 5% fat diet plus Sini decotion (4.2 g·kg^-1·d^-1). At the end of study, the plaque area were measured, the atorta ceramide and cell apoptosis were also detected. RESULTS:Sini decotion diminished lipid plaque area on the aortic endothelium, reduced the levels of aorta ceramide and the apoptosis index. CONCLUSION:Sini decoction has an inhibitory effect on AS, the mechanism may be that Sini decotion reduces concentration of ceramide in aorta.     

Effect of Jinlida combined with Tongxinluo on apoptosis of renal microvascular endothelial cells in high-glucose environment

AIM To observe the effect of Jinlida combined with Tongxinluo on the apoptosis of renal microvascular endothelial cells in the high-glucose environment, and to explore their mechanism of protecting renal microvascular endothelial cells. METHODS The renal microvascular endothelial cells cultured in vitro were divided into control group, high glucose group, Tongxinluo group, Jinlida group, and Tongxinluo+Jinlida group. After intervention for 24 h, CCK-8 assay was used to measurethe cell viability. The apoptotic rate and reactive oxygen species (ROS) level were measured by flow cytometry. Western blot was used to determine the protein levels of protein kinase R-like endoplasmic reticulum kinase (PERK), phosphorylated PERK (p-PERK), glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), caspase-12 and Bcl-2. RESULTS Compared with control group, the viability of renal microvascular endothelial cells in the high-glucose environment was decreased, the apoptotic rate, the ROS level and the protein levels of PERK, p-PERK, GRP78, CHOP and caspase-12 were increased, while Bcl-2 protein was decreased (P<0.05). In comparison with high glucose group, the viability of renal microvascular endothelial cells in Tongxinluo, Jinlida and Tongxinluo+Jinlida groups was increased to varying degrees, the apoptotic rate, the ROS level and the protein levels of PERK, p-PERK, GRP78, CHOP and caspase-12 were decreased, while Bcl-2 protein was increased (P<0.05). Compared with Jinlida group and Tongxinluo group, the improvement of each index in Jinlida+Tongxinluo group was statistically significant. CONCLUSION Jinlida and Tongxinluo attenuate the damage of renal microvascular endothelial cells in the high-glucose environment, and the mechanism may be related to the reduction of endoplasmic reticulum stress-mediated apoptosis pathway. The combined application of Jinlida and Tongxinluo synergistically enhances the protective effect of the drugs on the renal microvascular endothelial cells.     

Effects of nitric oxide and inducible nitric oxide synthase on process of atherosclerosis

AIM：To explore the dynamic changes of nitric oxide and inducible nitric oxide synthase during the process of atherosclerosis, and to analyze their influence on the formation of atherosclerosis. METHODS：SD rats (n=60) were randomly divided into control group and atherosclerosis group (30 rats in each group). Atherosclerosis model was induced by feeding high-fat diet and vitamin D3. The values of blood biochemical were analyzed enzymatically using bioMérieux kit. The concentration of serum nitric oxideing was detected by a colorimetric method. The success of atherosclerosis modeling was determined by pathological examination. The protein expression of inducible nitric oxide synthase in atherosclerotic plaque was detected by the method of immunohistochemistry. RESULTS：The atherosclerosis model was successfully established in 90 d. The concentration of serum nitric oxide gradually decreased in atherosclerosis group, and a significant difference among groups was observed. Atherosclerosis index was positively correlated with calcium ion, and negatively correlated with nitric oxide. The protein expression of inducible nitric oxide synthase in the atherosclerotic plaque after 90 d was found. CONCLUSION:The protein expression of inducible nitric oxide synthase in the plaque area of aorta increases and the concentration of serum nitric oxide decreases with the process of atherosclerosis. The anti-atherosclerosis role of nitric oxide is gradually decreased.     

Role of ERK5 in platelet activation in vitro and arterial thrombosis in vivo

AIM: To investigate the role of extracellular signal-regulated kinase 5 (ERK5) in platelet aggregation in vitro and arterial thrombosis in vivo. METHODS: The expression and phosphorylation levels of ERK5 in human platelet were detected by Western blot. The effects of ERK5 selective inhibitor XMD8-92 on platelet aggregation and dense granule secretion were detected by Chrono-Log aggregometer. The effect of ERK5 on in vivo thrombosis was analyzed using an FeCl₃ artery thrombosis model. The effects of XMD8-92 on protein kinase B (PKB/Akt) and phosphatase and tensin homolog deleted on chromosome ten (PTEN) phosphorylation levels were determined by Western blot. RESULTS: ERK5 was stably expressed in human platelets and its phosphorylation level increased significantly after platelet activation (P<0.05). XMD8-92, a selective inhibitor of ERK5, inhibited platelet aggregation and dense granule secretion in response to several platelet stimulators (P<0.05). The results of Western blot showed that XMD8-92 inhibited Akt phosphorylation level by down-regulating PTEN Ser370 phosphorylation and enhancing PTEN activity. The pathway was further confirmed using platelet specific PTEN deficiency mice. The first occlusion time was obviously extended in the mice intravenously given XMD8-92 in the FeCl₃-induced carotid artery injury model. CONCLUSION: ERK5 plays a role in platelet activation and arterial thrombosis by influencing PTEN and Akt phosphorylation.     

Effect of amiodarone and metoprolol on platelet activation,fibrinolytic activity and vasoactive mediators in acute myocardial infarction in rabbits

AIM:To explore the significance of platelet activation, fibrinolytic activity and the changes of vasoactive mediators in acute myocardial infarction in rabbits and the intervention of amiodarone and metoprolol.METHODS:Fifty New Zealand white rabbits were randomly assigned to five groups, ten for each. Group Ⅰ: sham group, group Ⅱ: acute myocardial infarction(AMI) group, group Ⅲ: AMI and lidocaine group, group Ⅳ: AMI and amiodarone group, group Ⅴ: AMI and metoprolol group.The middle point of left ventricular coronary artery was ligated (groupⅡ,Ⅲ, Ⅳ and Ⅴ ) or a sham ligation(group Ⅰ). Four hours later, blood was collected for measuring plasma concentration of TXB₂, 6-Keto-PGF_1α, ET, NO, plasma activity of t-Pa and PAI.After that, the heart was taken out to evaluate the infarction size(IS).RESULTS:Plasma concentration of TXB₂, ET, NO and plasma activity of PAI were significantly higher in groupⅡ,Ⅲ, Ⅳ and Ⅴ than those in group Ⅰ(P＜0.01), but the plasma concentration of 6-Keto-PGF_1α and plasma activity of t-Pa were remarkably lower in groupⅡ,Ⅲ, Ⅳ and Ⅴ than those in group Ⅰ(P＜0.01). There were no difference in plasma concentration of TXB₂, 6-Keto-PGF_1α, t-Pa activity and infarction size in group Ⅱ,Ⅲ and Ⅳ(P＞0.05).Compared to group Ⅱ, plasma concentration of ET, NO and PAI activity were significantly decresed (P＜0.01)in group Ⅳ. Plasma concentration of TXB₂, ET, NO and plasma activity of PAI were significantly lower in groupⅤ than those in group Ⅱ(P＜0.01). Conversely, plasma concentration of 6-Keto-PGF1 and plasma activity of t-Pa were remarkably higher in group Ⅴ than those in group Ⅱ(P＜0.01). The infarction size was remarkly decrease(P＜0.01)in group Ⅴ.CONCLUSIONS:Amiodarone inhibited PAI avtivity, decreased release of ET and NO in AMI in rabbits. Metoprolol inhibited platelet activation, improved fibrinolytic, decreased release of ET and NO, and reduced myocardial infarction size in AMI in rabbits; Lidocaine had no effect above.     

Effects of Chaihu-Shugan decoction on ROCK/JNK signaling pathway and atherosclerosis in spontaneously hypertensive rats

AIM To observe the effect of Chaihu-Shugan decoction (CHSGD) on atherosclerosis in spontaneously hypertensive rats (SHR) and its possible mechanism. METHODS The male SHR (n=50) were randomly divided into model group (gavage of normal saline), compound kendir leaves (CKL) group (gavage of 0.5 g/kg CKL), and low-, medium- and high-dose CHSGD (CHSGD-L, CHSGD-M and CHSGD-H) groups (gavage of 2.5, 5 and 10 g/kg CHSGD, respectively), and another 10 male Wistar rats of the same origin were selected as normal control （NC) group (gavage of normal saline). The blood pressure was measured by intelligent noninvasive sphygmomanometer. The levels of blood lipids were measured by automatic biochemical analyzer. The expression of oxidative stress-related indexes, nitric oxide (NO), malondialdehyde (MDA) and superoxide dismutase (SOD), were detected by colorimetry. HE staining was used to detect the degree of atherosclerosis, and Western blot was used to detect the expression of Rho-associated kinase (ROCK)/c-Jun N-terminal kinase (JNK) signaling pathway-related proteins, RhoA, ROCK1 and JNK. RESULTS After 4 weeks of treatment, compared with NC group, the blood pressure, the serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and MDA, and the protein expression of RhoA, ROCK1 and JNK in aortic tissues of the rats in model group were significantly increased (P<0.05), and the serum levels of high-density lipoprotein cholesterol, NO and SOD were significantly decreased (P<0.05). HE staining showed that the diameter of aortas in the rats was thickened, a large number of foam cells were formed under the endothelium, and the proliferation of smooth muscle cells was observed. Compared with model group, the blood pressure, the serum levels of TG, TC, LDL-C and MDA, and the protein expression of RhoA, ROCK1 and JNK in aortic tissues of the rats in CKL, CHSGD-L, CHSGD-M and CHSGD-H groups were significantly decreased (P<0.05), and the serum levels of NO and SOD were significantly increased (P<0.05). HE staining showed that the structure of each layer of rat aortas gradually returned to normal, the vascular cells were in good order, and the inflammatory cell infiltration was slight. Compared with CKL group, the blood pressure, the serum levels of TG, TC, LDL-C and MDA, and the protein expression of RhoA, ROCK1 and JNK in aortic tissues of the rats in CHSGD-L and CHSGD-M groups were significantly increased (P<0.05), and the serum levels of NO and SOD were significantly decreased (P<0.05). No significant difference of the above indexes between CHSGD-H group and CKL group was observed (P>0.05). CONCLUSION Chaihu-Shugan decoction may attenuate the oxidative stress response via inhibition of ROCK/JNK signaling pathway, thus alleviating the symptoms of atherosclerosis in SHR.     

ceRNA mechanism of circRNA-miRNA-mRNA in atherosclerosis

Atherosclerosis (AS) is a common cardiovascular disease and a major cause of coronary heart di-sease, cerebral infarction and peripheral vascular disease. Circular RNA (circRNA) is a class of circularly closed non-co-ding RNAs that play an important role in the formation of AS. Physiological and pathological significances of the processes such as lipid metabolism, endothelial cell damage, vascular smooth muscle cell proliferation and migration, monocyte pha-gocytosis and foam-like cell formation, and inflammatory responses are involved in the development of AS. Most circRNA adjust mRNA expression by regulating microRNAs (miRNAs). circRNA provides new ideas and targets for the diagnosis and treatment of AS.     

Role of fibrinogen activity in the progress of coronary artery disease

AIM:To detect the role of fibrinogen activity (Fa) in the progress of coronary artery disease (CHD).METHODS:Fa was measured with hemorheology methods in patients with CHD stable phase (n=30) and angina pectoris (n=27).RESULTS: (1) Levels of plasmatic fibrinogen and plasmatic viscosity in patients with CHD were higher than that of control group (P＜0.01,P＜0.05).(2)Fa and platelet aggregation activity (Pt max, Pt H, Pt K) in patients with CHD angina pectoris were very much higher than that of control group (P＜0.01, respectively).(3)There was a negative correlation between PT max, Pt H and Fa(r=-0.8379,P＜0.01;r=-0.8784,P＜0.01 respectively) in patients with CHD angina pectoris.CONCLUSION: Fa may play a role in the progress of CHD.     

Effects of butylphthalide on atherosclerosis lesion and VCAM-1 expression in aortic wall of ApoE-/- mice

AIM: To observe the protective effects of butylphthalide on atherosclerosis lesion and vascular cell adhesion molecular-1 (VCAM-1) expression in the aortic wall of ApoE^-/- mice, and to explore the possible mechanism underlying these beneficial effects.METHODS: Male ApoE^-/- mice at 6 weeks of age (n=90) were randomly divided into 3 groups. Thirty ApoE^-/- mice fed with high-fat diet and treated with saline simultaneously were defined as model group. Thirty ApoE^-/- mice fed with high-fat diet and treated with butylphthalide (100 and 200 mg·kg^-1·d^-1) were defined as treatment groups. Thirty wild-type C57BL/6J mice treated with saline were defined as control group. Fifteen mice in each group were sacrificed both at the ages of 18 and 30 weeks. The body weight, food intake and water intake were monitored weekly through the experiment. The lipid profiles were determined both at 18 and 30 weeks of age. Aortic roots were stained with hematoxylin and eosin for pathological examination. Serum ox-LDL, CRP, TNF-α and IL-6 were examined by ELISA. The expression of VCAM-1 at mRNA and protein levels was determinate by real-time PCR and Western blot in the thoracic aortas. RESULTS: Compared with control group, at 18 and 30 weeks of age, the body weight, serum lipid profiles and inflammatory factors were increased, while the atherosclerotic plaques were raised. The mRNA and protein levels of VCAM-1 were up-regulated. However, serum lipid levels in butylphthalide treatment groups (both at doses of 100 and 200 mg·kg^-1·d^-1) were decreased significantly. Serum ox-LDL, CRP, TNF-α and IL-6 were also decreased by butylphthalide treatment. Furthermore, atherosclerotic plaque areas in the aortic roots were reduced by butylphthalide treatment. In addition, the expression of VCAM-1 at mRNA and protein levels in the thoracic aortas was down-regulated by butylphthalide treatment.CONCLUSION: Butylphthalide delays the occurrence of high-fat diet-induced atherosclerosis and down-regulates the expression of VCAM-1 in the ApoE^-/- mice, which may be due to its alleviative effects on hyperlipidemia and inflammation.     

Inhibitory effects of propolis on platelet adhesion in flowing blood in vitro

AIM:To investigate effects of propolis-ethanol extract on platelet activity in flowing blood. METHODS:Intima-injury model was made by in vitro perfusion. Coverslips was coated by using fibrinogen and human Ⅲ type collagen to detect platelet adhesive rate when blood went through fibrinogen and collagen surface in 1 000/s shear rate. Three experimental groups were set up: negative control group (24% ethanol), experimental group (0.1 g/L, 24% propolis-ethanol extract) and positive control group (0.1 g/L, ferulic acid). RESULTS:Intima-injury model was made. On fibrinogen and collagen, platelet adhesion on area of experimental group was lower than that in negative control group (P<0.01). There was no significant difference between experimental group and positive control group (P>0.05). Propolis-ethanol extract decreased more obviously the platelet adhesion area on fibrinogen surface than that in collagen surface (P<0.01). CONCLUSION:Propolis-ethanol extract inhibits platelet activation and reduces its adhesion on fibrinogen and collagen surface, especially in fibrinogen surface.     

Effect of polymorphonuclear leukocytes on washed platelet aggregation

AIM:To investigate the effect of non-activated or activated polymorphonuclear leukocytes(PMN) on washed platelet aggregation. METHODS:Born's method was used to determine platelet aggregation.RESULTS:non-activated PMN (5×10⁹ cells/L) significantly suppressed washed platelet aggregation induced by ADP or arachidonic acid. Aspirin enhanced this inhibition. N-formyl-methiongl-leucy-phenylalanine (fMLP)-or platelet-activating factor (PAF)-stimulated PMN strongly induced platelet aggregation, and the induction effect of PMN suspension was more active than that of PMN supernatant. Aspirin had no significant inhibitory effect on platelet aggregation induced by fMLP-or PAF-activated PMN. CONCLUSIONS:Different conditions of PMN (activated or non-activated) had the nearly opposite action on normal platelet reactivity. Briefly, non-activated-PMN inhibited platelet reactivity, whereas activated PMN stimulated it.     

Tongxinluo improves anti-hypoxia ability of vascular endothelial cells via PI-3K/Akt/HIF pathway

AIM: To investigate the effects of PI-3K/Akt/HIF pathway on anti-hypoxia ability of vascular endothelial cells influenced by Tongxinluo under hypoxic condition. METHODS: Human umbilical vein endothelial cells (HUVECs) were divided into the following groups: control group, Tongxinluo (100 mg/L) group, hypoxia group and hypoxia+Tongxinluo (100 mg/L) group. The CCK-8 assay were used to detect the viability and proliferation rate of the cells in each group. The protein levels of HIF-1α, Bcl-2, Mcl-1, Bax and phosphorylated Akt were studied by immunoblotting analysis. The HUVECs were transiently transfected with the dominant negative mutant of HIF-1α (DN-HIF). The apoptotic rates were analyzed by flow cytometry (FCM). The HUVECs were transiently transfected with the dominant negative mutant of PI-3K (Δp85) or Akt (DN-Akt) to investigate the role of PI-3K/Akt signal pathway in the anti-hypoxia ability of Tongxinluo on endothelial cells. RESULTS: Under hypoxic condition, although the proliferation rate increased significantly in Tongxinluo group compared with hypoxia group, the degree was notably weak compared with control group. The protein levels of HIF-1α, Bcl-2, Mcl-1 and phosphorylated Akt were up-regulated by Tongxinluo. Meanwhile, the expression of Bax was down-regulated. Inhibition of HIF-1α activation by DN-HIF and inhibition of the PI-3K/Akt pathway by Δp85 or DN-Akt attenuated the increase in HIF-1α expression and HUVEC viability induced by Tongxinluo. The percentage of apoptotic HUVECs was down-regulated to a certain extent by Tongxinluo. CONCLUSION: Tongxinluo improves the anti-hypoxia ability of vascular endothelial cells by up-regulating the protein level of HIF-1α, promoting the expression of anti-apoptotic factors, improving the cell viability and eventually reducing the apoptotic rate.These effects of Tongxinluo depend on PI-3K/Akt signal pathway.