灯盏花素对糖尿病大鼠肾组织巨噬细胞浸润的影响

目的探讨灯盏花素对糖尿病大鼠肾组织巨噬细胞浸润的影响。方法建立STZ诱导的单侧肾切除糖尿病模型,随机分:对照组、模型组、灯盏花素给药组与MMF给药组。8wk末检测尿白蛋白排泄率(AER)、肾组织蛋白激酶C(PKC)活性,应用免疫组化方法检测肾组织ED1及单核细胞趋化蛋白1(MCP1)与细胞间黏附因子1(ICAM1)表达。结果灯盏花素或MMF给药组大鼠肾重、肾重/体重、AER明显低于模型组(P<0.05)。模型组肾组织细胞浆、细胞膜及细胞总PKC活性明显高于对照组(P<0.01),灯盏花素给药组肾组织PKC活性明显低于模型组(P<0.05),MMF给药组肾组织PKC活性与模型组相比无差异。模型组肾小球ED1阳性细胞数及MCP1、ICAM1表达明显高于对照组(P<0.01),灯盏花素或MMF给药可明显缓解这些变化(P<0.05)。结论灯盏花素对糖尿病大鼠肾脏有明显保护作用,其机制可能部分与抑制肾组织巨噬细胞浸润有关。     

高糖对体外培养的人脐静脉内皮细胞中c-fos的影响研究

目的观察高糖作用人脐静脉内皮细胞时c—fos基因mRNA和蛋白的表达的变化。方法提取并体外培养人脐静脉内皮细胞,分别加入不同浓度葡萄糖（5．5mmol/L、11mmol/L、22mmol/L、44mmol/L）并分别作用不同时间,应用逆转录聚合酶链反应（RT—PCR）检测c—fos基因mRNA的表达,免疫细胞化学检测c—fos蛋白表达。结果经高糖处理的人脐静脉内皮细胞中,c—fos基因mRNA的转录水平明显高于对照组（P〈0．05或P〈0．01）。但是脐静脉内皮细胞经22mmol/L葡萄糖作用1h,c—fos基因的mRNA水平不再升高,而呈下降趋势（P〈0．05）。经22mmol/L葡萄糖作用2h后,c—fns蛋白表达达到最高峰。结论高糖能引起脐静脉内皮细胞c—fosmRNA和蛋白表达增高。     

灯盏花素对慢性低氧大鼠PKC的影响

目的　探讨灯盏花素对慢性低氧大鼠PKC信号途径的影响。方法　将SD大鼠分为 :对照组 (A) ,低氧组 (B) ,低氧 +灯盏花素组 (C) ,低氧时间为 4wk。采用透射电镜、放射活性测定法、免疫组化等方法研究灯盏花素对慢性低氧大鼠肺动脉平均压 (mPAP)、左右心室重量比 (RV/LV +S)、肺细小动脉管壁面积 /管总面积 (WA/TA)、中膜平滑肌细胞核密度 (SMC)、肺细小动脉超微结构、肺组织PKC活性、肺细小动脉管壁PKC的影响。结果　 (1)B组mPAP、RV/LV +S明显高于A组 (P <0 0 1) ,C组mPAP、RV/LV +S明显低于B组 (P <0 0 1) ;(2 )光镜下B组WA/TA、SMC明显高于A组 (P <0 0 1) ,C组WA/TA、SMC明显低于B组 (P <0 0 1) ;电镜显示B组肺动脉中膜平滑肌细胞增生 ,胶原纤维丰富 ;C组肺动脉中膜平滑肌细胞、胶原纤维较B组明显减少 ;(3)B组肺组织PKC总活性 (PKCt)、胞膜PKC活性(PKCm)、胞质PKC活性 (PKCc)及胞膜PKC活性 (PKCm)占PKC总活性 (PKCt)的百分比明显高于A组 (P <0 0 1) ,C组PKCt、PKCm、PKCc及PKCm占PKCt的百分比明显低于B组 (P <0 0 1) ;(4 )免疫组化显示B组肺细小动脉 (直径约10 0～ 2 0 0 μm)PKC含量明显高于A组 (P <0 0 1) ,C组较B组明显为低 (P <0 0 1)。结论　灯盏花素抑制PKC信号途径可能是其抑制慢性低氧     

灯盏花提取物对心脏移植异基因大鼠蛋白激酶C的作用

目的:利用异基因大鼠心脏移植模型研究中药灯盏花提取物对蛋白激酶C(proteinkinaseC,PKC)的抑制作用。方法:以Wistar大鼠为供体,SD大鼠为受体,建立大鼠腹腔异位心脏移植模型,分为灯盏花提取物低剂量组(5mg·kg-·1d-1)、中剂量组(10mg·kg-·1d-1)、高剂量组(15mg·kg-·1d-1)和对照组。移植术后各实验组受体腹腔注射药物至移植心停跳。用底物磷酸化激酶测定法检测受体外周血淋巴细胞PKC的活性并用Westernblot印迹法鉴定;用酶联免疫吸附法检测受体外周血液中白细胞介素-2(IL-2)的水平。结果:各实验组受体外周血淋巴细胞PKC活性及表达和IL-2的水平明显较对照组低。结论:在异基因大鼠心脏移植中灯盏花提取物可对PKC的活性产生抑制作用。     

灯盏花素对急性脑缺血大鼠脑自由基及脑源性神经生长因子的影响

目的 探讨灯盏花素对大鼠急性脑缺血自由基水平和皮层脑源性神经生长因子(BDNF)表达的影响.方法 采用线栓法制备大鼠大脑中动脉缺血-再灌注模型,分假手术组、生理盐水对照组和灯盏花素干预组,各组再分6、12、24、48 h 4个亚组.检测各组脑组织不同时间点过氧化物歧化酶(SOD)、丙二醛(MDA)含量,用RT-PCR和Western blot检测皮层BDNF mRNA和蛋白质表达变化.结果 与对照组比较,干预组MDA含量降低,SOD活性增加.于48 h时点,干预组BDNF mRNA表达较对照组明显增加.结论 灯盏花素具有较明显的清除自由基作用,但对缺血后脑皮层BDNF蛋白的表达无显著影响.     

卡托普利和低剂量阿司匹林相互作用对心衰大鼠左室心肌组织c-fos蛋白表达的影响

目的 观察卡托普利和低剂量阿司匹林相互作用对冠状动脉结扎致心衰大鼠模型左室心肌组织c—fos蛋白表达的影响。方法 采用冠状动脉结扎致急性心肌梗死和心梗后慢性心力衰竭大鼠模型，按照正交设计试验方案给药5wk，采用免疫组织化学方法观察联用两药对左室心肌组织c—fos蛋白表达的影响。结果 急性心肌梗死组c—fos蛋白阳性颗粒数目明显增多，卡托普利各剂量组对心肌组织c—fos蛋白表达均无影响，且与低剂量阿司匹林无显的相互作用，而低剂量阿司匹林增加c—fos蛋白免疫反应阳性细胞分布，尤以急性心肌梗死组多见。结论 低剂量阿司匹林介导c—fos蛋白表达增加，可能是其拮抗卡托普利减轻心衰大鼠左室重建作用的机制之一。     

银杏内酯抗过氧化氢致神经细胞损伤和对即早基因表达的影响

目的 :探讨银杏内酯 (ginkgolides ,Gin)对过氧化氢 (H2 O2 )诱导的皮层神经细胞损伤的保护作用及其机制。方法 :在小鼠皮层神经细胞的培养基中加入H2 O2 ,建立神经细胞氧化损伤模型 ,利用MTT比色法检测细胞存活率 ,Westernblot技术分析c fos、c jun基因表达产物C FOS蛋白、C JUN蛋白的变化。结果 :H2 O2 可诱导原代培养的神经细胞损伤和存活率降低 ,其损伤作用呈现浓度和时间依赖性 ;同时可诱导神经元C FOS、C JUN表达增加。Gin预处理2 4h可明显减轻神经细胞形态学改变 ,提高神经细胞存活率 ,且在 0～ 37.5mg·L-1范围内呈现浓度依赖关系。Gin能明显逆转H2 O2 诱导的C JUN蛋白表达的增高 ,对H2 O2 刺激的C FOS蛋白表达无明显影响。结论 :Gin可对抗H2 O2 引起的神经细胞损伤 ,该保护作用与其抑制细胞c jun基因过度表达有关。     

硒对大鼠肝细胞凋亡和原癌基因c-myc、c-fos和c-jun表达的影响

目的　研究亚硒酸钠对大鼠肝细胞凋亡和原癌基因c myc、c fos和c jun表达的影响。方法　选用大鼠 ,每组 5只 ,用 5、10和 2 0 μmol/kg亚硒酸钠腹腔注射染毒。用末端标记法 (TUNEL)、流式细胞术检测细胞凋亡 ,用Northern斑点杂交方法研究原癌基因c myc、c fos和c jun的表达。结果　 5、10和 2 0 μmol/kg的亚硒酸钠染毒大鼠 ,不仅能诱导大鼠肝细胞凋亡 ,细胞凋亡率均较对照组 ( 2 2 2± 0 43 ) %显著增高 ,分别为 ( 3 72± 1 76) % (P <0 0 5 )、( 5 82± 1 42 ) % (P <0 0 1)和 ( 11 76± 1 87) % (P <0 0 1) ,而且还存在着明显的剂量 反应关系。 5、10和 2 0 μmol/kg的亚硒酸钠也能引起大鼠肝细胞c myc、c fos和c junmRNA明显增多 ,免疫组化分析可以检测到表达产物c Myc ,c Fos和c Jun蛋白 ,说明这 3种原癌基因表达增强。结论　一定剂量的亚硒酸钠可以诱导大鼠肝细胞凋亡和原癌基因c myc、c fos和c jun的表达增强     

异氟烷和七氟烷对缺血神经元c-fos蛋白表达的影响和保护作用

目的　了解吸入麻醉药异氟烷和七氟烷对脑缺血神经元c fos蛋白表达的影响和保护作用。方法　用苏木素 伊红 (HE)染色法检测大鼠脑缺血梗塞体积和海马结构CA1～CA4亚区神经元损伤程度。用免疫组化法检测海马结构c fos蛋白的表达。结果　缺血 1h再灌 72h异氟烷组和七氟烷组脑梗塞体积显著小于缺血组 ;海马CA3和CA4亚区神经损伤程度也显著小于缺血组。缺血 1h再灌 4h ,在海马齿回 ,CA4亚区c fos蛋白样免疫反应率 ,吸入麻醉药组明显低于未吸入组。结论　异氟烷和七氟烷对缺血神经元有一定的保护作用。它们对c fos蛋白表达的衰减作用可能与其拮抗NMDA受体性质有关     

葛根素对单侧肾切除糖尿病大鼠肾脏的保护作用

目的探讨葛根素对单侧肾切除糖尿病大鼠(DN)肾脏的保护作用及机制.方法葛根素治疗DN大鼠6周后,检测其体重、肾脏指数(肾重/体重)、尿微量白蛋白(Ualb)、血糖、血管紧张素Ⅱ(AngⅡ)含量及肾组织蛋白激酶C(PKC)活性、转化生长因子-β1(TGF-β1)和Ⅳ型胶原(CoⅣ)蛋白表达.结果与DN组比较,葛根素治疗组大鼠体重、肾脏指数、Ualb明显减少,血糖和AngⅡ含量下降,肾皮质胞膜PKC活性降低,肾组织中TGF-β1、CoⅣ蛋白表达下降.结论葛根素可通过改善DN大鼠肾脏功能、降低血糖、AngⅡ含量和肾皮质胞膜PKC活性,下调TGF-β1蛋白表达,减少细胞外基质(ECM)的沉积,延缓DN的发生发展.     

缬沙坦对高糖培养的肾小球系膜细胞p38MAPK传导通路的影响

目的探讨高糖状态下肾小球系膜细胞中p38丝裂原活化蛋白激酶(p38 MAPK)、其上游因子MAPK激酶3/6(MKK3/6)和下游因子cAMP反应元件结合蛋白1(CREB1)的表达以及血管紧张素受体1拮抗剂(AT1Ra)缬沙坦的影响。方法体外培养大鼠肾小球系膜细胞,分别给予高糖和缬沙坦干预,采用Western bolt检测MKK3/6、p38 MAPK和CREB1及其磷酸化蛋白的表达,逆转录-聚合酶链反应(RT-PCR)检测系膜细胞内TGF-β1和FN mRNA的表达。放免法测定细胞上清液中纤维连接蛋白(FN)和IV型胶原的含量。MTT法检测缬沙坦在不同时间、不同药物浓度对细胞增殖状态的影响。结果①与低糖对照组相比,高糖组系膜细胞p-p38 MAPK、p-MKK3/6和p-CREB1表达明显上调,TGF-β1和FN mRNA的表达增加,FN和IV型胶原含量增加。②缬沙坦组p-p38 MAPK、p-MKK3/6和p-CREB1的表达明显下调,TGF-β1和FN mRNA的表达降低,同时FN和IV型胶原的含量减少。③MTT法检测显示不同浓度的缬沙坦对细胞增殖状态都有所抑制,并随药物浓度的增加而作用增强。结论缬沙坦抑制肾小球系膜细胞TGF-β1的表达和细胞外基质的分泌可能部分是通过影响p38 MAPK传导通路的激活来实现的。     

厄贝沙坦对高糖刺激的大鼠肾小球系膜细胞结缔组织生长因子及膜型基质金属蛋白酶-1表达的影响

目的研究血管紧张素Ⅱ受体1拮抗剂厄贝沙坦对高糖刺激的大鼠肾小球系膜细胞结缔组织生长因子(CTGF)和膜型基质金属蛋白酶-1(MT1-MMP)表达的影响。方法体外培养的大鼠肾小球系膜细胞,分别给予高糖和厄贝沙坦干预,采用RT-PCR及Western blot法分别检测CTGF和MT1-MMP的mRNA及蛋白的表达,用酶联免疫吸附法(ELISA)检测培养上清中Ⅳ型胶原的含量。结果与对照组相比,高糖组各时间点系膜细胞CTGF表达明显上调,Ⅳ型胶原的分泌增加,且二者随时间持续增高;而MT1-MMP的表达则随时间呈明显下降趋势。厄贝沙坦能够抑制高糖引起的上述变化。结论高糖可诱导肾小球系膜细胞CTGF表达增加,抑制MT1-MMP的表达。厄贝沙坦抑制肾小球系膜细胞基质分泌的作用可能部分通过抑制CTGF,增加MT1-MMP的表达而实现。     

Activation of the activator protein-1 by the peroxisome proliferator clofibric acid in rat H4IIEC3 hepatoma cells

Clofibric acid (CA), a potent peroxisome proliferator (PP), has been shown to cause tumor formation in rat liver. The precise mechanism of action of PPs remains largely unknown. However, it has been proposed that they act by increasing reactive oxygen species (ROS), leading to a cellular oxidative stress. In the present study, we have investigated the effect of CA on the activator protein-1 (AP-1) expression in PP-responsive H4IIEC3 rat hepatoma cells. Electrophoretic mobility shift assays demonstrated that AP-1 activation was induced in cells treated with CA for 24 h at all concentrations of the fibrate. This activation was prolonged up to 48 h. Using transfection experiments with H4IIEC3 cells, we found that CA induced the expression of a reporter gene driven by AP-1 and that of the glutathione S-transferase P target gene. By supershift experiments, jun and fos proteins were identified as components of the CA-activated AP-1 complexes. Western blot analyses revealed that the induction of the AP-1 activity was not dependent to an increase in the levels of jun and fos proteins. Cotreatment of H4IIEC3 cells with CA and the antioxidant N-acetylcysteine or calphostin C, a specific inhibitor of protein kinase C (PKC), blocked the AP-1 activation and the expression of the AP-1-driven luciferase reporter gene. These results demonstrate that CA activates AP-1 in H4IIEC3 cells and that this induction is mediated via ROS and PKC.     

Downregulation of vasopressin V(1A) receptors and activation of mitogen-activated protein kinase in rat mesangial cells cultured under high-glucose conditions

SUMMARY: In the present study we examined the effects of high extracellular glucose concentrations on vasopressin (AVP) V(1A) receptor kinetics and signal transduction in cultured rat mesangial cells. Scatchard analysis of [(3) H]-AVP binding to mesangial cell plasma membranes showed that although high glucose (30?mmol/L) decreased V(1A) receptor numbers relative to cells cultured in normal glucose (10?mmol/L), receptor affinity was not affected. This V(1A) receptor downregulation was associated with an attenuated increase in AVP-stimulated cytosolic free calcium concentrations ([Ca(2+) ](i) ). In addition, high glucose increased both the basal and AVP-stimulated activity of the classic mitogen-activated protein kinase, namely extracellular signal-regulated kinase (ERK). Furthermore, high glucose induced activation of protein kinase C (PKC) in mesangial cells that could be inhibited by coincubation with the PKC inhibitor staurosporine (10?nmol/L). Staurosporine also markedly attenuated the high glucose-induced downregulation of V(1A) receptors on mesangial cells and blocked the depressed [Ca(2+) ](i) response and increased ERK activity induced by AVP. The results indicate that high extracellular glucose downregulates V(1A) receptors on rat mesangial cells and modulates their signal transduction properties via PKC activation.     

缬沙坦对高糖培养系膜细胞信号转导和转录活化因子1、3表达的影响

目的探讨高糖状态下肾小球系膜细胞中信号转导和转录活化因子1、3的改变以及血管紧张素受体1拮抗剂(AT1Ra)缬沙坦的影响。方法体外培养大鼠肾小球系膜细胞,分别给予高糖和缬沙坦干预,采用W estern印迹检测信号转导和转录活化因子1、3(STAT1、STAT3)及其磷酸化蛋白(p-STAT1、p-STAT3)的表达,酶联免疫吸附实验(ELISA)和放免法测定细胞上清液中TGF-β1、纤维连接蛋白(F ibronectin,FN)和IV型胶原的含量,逆转录-聚合酶链反应(RT-PCR)检测TGF-β1mRNA的表达。结果与低糖对照组相比,高糖组系膜细胞p-STAT1和p-STAT3表达明显上调,TGF-β1、FN和IV型胶原含量增加,TGF-β1mRNA的表达增加。缬沙坦组p-STAT1和p-STAT3的表达明显下调,TGF-β1、FN和IV型胶原的含量减少,同时TGF-β1mRNA的表达降低。结论高糖状态下p-STAT1和p-STAT3表达明显升高,缬沙坦抑制肾小球系膜细胞TGF-β1和细胞外基质的分泌可能部分是通过影响STAT1和STAT3的激活而实现。     

褪黑素对小鼠视交叉上核c-fos基因表达的影响

目的　观察褪黑素对幼龄、老龄及光制颠倒条件下小鼠视交叉上核内c fos基因蛋白和mRNA水平的影响。方法　采用冰冻切片免疫组织化学染色法 ,观察褪黑素对小鼠视交叉上核c fos蛋白水平的影响 ;采用RT PCR法 ,扩增视交叉上核内c fosmRNA ,用琼脂糖凝胶电泳法检测扩增产物。结果　幼龄鼠c fos蛋白水平及mRNA水平均高于老龄鼠 ;光制颠倒条件下 ,c fos蛋白及mRNA水平均受抑制 ;给予褪黑素 ,c fos蛋白及c fosmRNA水平均提高。结论　c fos基因表达水平随年龄增加而降低 ;光制颠倒可抑制c fos基因的表达 ;施用褪黑素 ,c fos基因表达水平提高 ,说明褪黑素可对抗增龄及光制颠倒对c fos表达的抑制作用 ,从而发挥抗衰老作用。     

氟伐他汀对高糖培养的大鼠肾小球系膜细胞外基质 p38 MAPK表达的影响?

研究HMG-CoA还原酶抑制剂氟伐他汀 (fluvastatin) 对高糖状态下肾小球系膜细胞中p38丝裂原活化蛋白激酶 (p38 mitogen-activated protein kinase, p38 MAPK) 及其下游因子cAMP反应元件结合蛋白1 (cAMP response element-binding protein, CREB₁) 表达的影响。采用体外培养大鼠肾小球系膜细胞, 分别给予高糖和氟伐他汀干预, 应用Western blotting检测p38 MAPK和CREB₁及其磷酸化蛋白 (p-p38 MAPK、p-CREB₁)的表达; 逆转录-聚合酶链反应 (RT-PCR) 检测转化生长因子β₁ (TGF-β₁) 和纤维粘连蛋白 (FN) mRNA的表达; 放射免疫法测定细胞上清液中层连接蛋白 (LN) 和IV型胶原蛋白的含量。结果表明, 与低糖对照组相比, 高糖组的系膜细胞p-p38 MAPK、p-CREB₁表达明显上调, TGF-β₁ mRNA和FN mRNA的表达增加, 细胞上清液中LN和IV型胶原蛋白含量增加。氟伐他汀组的p-p38 MAPK、p-CREB₁表达明显下调, TGF-β₁ mRNA和FN mRNA的表达降低, 同时LN和IV型胶原蛋白的含量减少。因此氟伐他汀抑制肾小球系膜细胞TGF-β₁的表达和细胞外基质的分泌可能部分是通过影响p38 MAPK及其下游因子CREB₁的激活而实现的。     

Ginsenoside Rb3 Inhibits Angiotensin II‐Induced Vascular Smooth Muscle Cells Proliferation

Abstract: This study was designed to examine the effect of ginsenoside Rb₃ on angiotensin (Ang) II‐induced proliferation of cultured rat vascular smooth muscle cells (VSMCs). VSMCs proliferation was evaluated by [³H]Thymidine incorporation. The cell cycle was examined by flow cytometry. The expression of mRNA of proto‐oncogene c‐myc, c‐fos and c‐jun was observed by RT‐PCR. Ginsenoside Rb₃ had no effects on VSMCs proliferation in physiological condition. Ang II significantly increased the proliferation of VSMCs and the expression of mRNA of proto‐oncogene c‐myc, c‐fos and c‐jun. Ginsenoside Rb₃ markedly inhibited Ang II‐induced VSMCs proliferation. Concomitantly, ginsenoside Rb₃ decreased cell cycle progression from G₀/G₁ to S phase. Furthermore, ginsenoside Rb₃ significantly attenuated the expression of mRNA of proto‐oncogene c‐myc, c‐fos and c‐jun. This study showed that ginsenoside Rb₃ inhibited Ang II‐induced VSMCs proliferation, at least in part by inhibiting Ang II‐induced G₀/G₁ to S phase transition and attenuating the expression of mRNA of c‐fos, c‐jun and c‐myc. The findings may explain the beneficial effects of ginsenoside Rb₃ in cardiovascular diseases, and it will be useful to develop prevention and therapeutics of cardiovascular diseases.     

Hyperglycemia induced down-regulation of renal P-glycoprotein expression

The purpose of this study is to investigate the regulation of P-glycoprotein expression in the kidney under diabetic condition. Renal P-glycoprotein expression was examined in inbred mice with type 1 or type 2 diabetes by Western blotting. The underlying mechanisms of P-glycoprotein regulation were examined in Madin-Darby canine kidney type II (MDCK-II) cells by Western blotting or qRT-PCR. (3)H-digoxin uptake was measured for P-glycoprotein activity in cells under various treatments. The results showed that P-glycoprotein expression was lower in kidneys of diabetic mice than in controls. In MDCK-II cells, treatments with insulin or IL-6 did not cause any change in P-glycoprotein expression, whereas TNF-α tended to increase P-glycoprotein expression at a concentration of 1 ng/ml. On the other hand, P-glycoprotein expression was reduced under high glucose conditions (450 mg/dl), while superoxide production was increased, and the reduction in P-glycoprotein expression was abolished by N-acetylcysteine (an antioxidant) and staurosporine (a nonselective PKC inhibitor). Treatment with oxidizing agents (H(2)O(2), BSO) or PMA (a PKC activator) reduced P-glycoprotein expression. Antioxidant (N-acetylcysteine or glutathione) co-treatment abolished the H(2)O(2)-induced and BSO-induced reduction in P-glycoprotein expression, whereas it did not prevent the effect of PMA. The PMA-induced P-glycoprotein down-regulation was prevented by co-treatment of LY333531 (a PKC-β inhibitor). (3)H-digoxin levels were higher in MDCK-II cells with high glucose, PMA or H(2)O(2) treatments. In conclusion, P-glycoprotein expression is lower in kidneys of diabetic mice and in MDCK-II cells under high glucose conditions. Hyperglycemia induced reactive oxygen species and activated PKC in MDCK-II cells, leading to the decrease in P-glycoprotein expression.     

Tribulosin suppresses apoptosis via PKC epsilon and ERK1/2 signaling pathway during hypoxia/reoxygenation in neonatal rat ventricular cardiac myocytes

Tribulosin (tigogenin 3-O-β-D-xylopyranosyl(1-2)-[β-D-xylopyranosyl (1-3)]-β-D-glucopyranosyl (1-4)-[a-L-rhamnopyranosyl(1-2)]-β-D-galactopyranoside), a component of gross saponins of Tribulus terrestris, has been shown to produce cytoprotective effects in heart. Yet, the precise mechanisms are not fully understood. We examined the mechanisms of tribulosin on myocardial protection. Ventricular myocytes were isolated from the heart of neonatal rats and were exposed to 3 h of hypoxia followed by 2 h reoxygenation. Apoptosis was induced by hypoxia/reoxygenation (H/R), and the expression of protein kinase C epsilon (PKC?) and extracellular signal-regulated kinase 1 and 2 (ERK1/2) in cultured neonatal rat cardiac myocytes was detected. The results indicated that treatment with tribulosin in the culture medium protected cardiac myocytes against apoptosis induced by H/R. PKC? and ERK1/2 expression increased after pretreated with tribulosin. In the presence of PKC? inhibitor co-treated with tribulosin, the expression of ERK1/2 was decreased in H/R cardiac myocytes. While preconditioned with PD98059, ERK1/2 inhibitor, no effects on the expression of PKC? were detected. Tribulosin has protective effects on cardiac myocytes against apoptosis induced by H/R injury via PKC? and ERK1/2 signaling pathway.