[Sesamin Preconditioning Attenuates Myocardial Ischemia Reperfusion Injury in Rats Through Activation of Akt/eNOS Signaling Pathway].

Objective: To investigate the protective effect of sesamin on myocardial ischemia reperfusion injury in rats, and to study the possible mechanism. Methods: 50 SD rats were randomly divided into control group, sham operated group, model group, high-dose sesamin group( 160 mg / kg) and low-dose sesamin group( 80 mg / kg),with 10 rats in each group. Rats in sesamin groups were administered intragastrically with sesamin for 7 d. Then all rats except those in sham operated group were subjected to myocardial ischemia-myocardial ischemia reperfusion injury model by coronary artery ligation for 40 min and subsequent reperfusion for 120 min. Serum cardiac troponin Ⅰ( c TnⅠ) and lactate dehydrogenase( LDH),levels of total antioxidant capacity( TAOC) and nitric oxide( NO) in serum and myocardial tissues,Caspase-3 activity in myocardial tissues were detected by colorimetric assay. Cardiomyocyte apoptosis was evaluated by TUNEL assay. Phosphorylation level of endothelial nitric oxide synthase( eNOS) and Protein kinase B( Akt), protein expression of superoxide dismutase( SOD) in cardiac tissue were determined by Western blot. Results: Pretreatment with sesamin significantly ameliorated myocardial injury in rats which induced myocardial ischemia and reperfusion injury by reduced levels of serum c TnⅠand LDH( P <0. 05 or P < 0. 01). Supplementation with sesamin resulted in a significant increasing of total antioxidant capacity and NO level in serum and myocardial tissues and cardiomyocyte apoptosis( P < 0. 05 or P < 0. 01),and remarkable decrease the Caspase-3 activity in myocardial tissues and cardiomyocyte apoptosis( P < 0. 05 or P < 0. 01). Sesamin significantly up-regulated the protein expression of SOD in cardiac tissues, and the levels of phosphorylated eNOS and Akt increased notably( P < 0. 05 or P < 0. 01). Conclusion: Pretreatment with sesamin effectively ameliorated myocardial ischemia reperfusion injury in rats, and the mechanism might be related to enhancing its antioxidant capacity and the activation of Akt / eNOS signaling pathway and subsequent increase of NO synthesis and suppression of cardiac myocyte apoptosis.

[The effect of Salvianolic Acid B on the Apoptosis of HUVECs Induced by Intermittent High Glucose].

Objective: To investigate the effect of Salvianolic acid B (Sal B) on the apoptosis of human umbilical vein endothelial cells (HUVECs) induced by intermittent high glucose and to explore the possible mechanisms. Methods: HUVECs were preincubated with Sal B for 24 h, followed by incubation with intermittent high glucose (IHG, 5.5 mmol/L 12 h, 33.3 mmol/L 12 h) for 72 h. The viability of the HUVECs was determined by MTT assay, and the cells apoptosis was measured flow cytometry, respectively. The levels of nitric oxide (NO), total antioxidant capacity (T-AOC), malondialdehyde (MDA), and Caspase-3 activity were determined by colorimetric method. Intracellular ROS was evaluated by fluorescent microscopy. The protein levels of NOX4, p-eNOS, BAX, and BCL-2 were determined by Western-blot. Results: Pretreatment with Sal B significantly ameliorated IHG-induced cells injury as was manifested by increased cell viability, up-regulated eNOS activation, and promoted the release of NO in HUVECs (P < 0.05 or P < 0.01). Sal B evidently suppressed IHG-induced cell apoptosis, down-regulated the expression of BAX protein and up-regulated the expression of BCL-2 protein. The activity of Capase-3 was also significantly reduced. Pre-incubation with Sal B led to a significant enhancement of antioxidant capacity and a reduction of NOX4 protein expression, accompanied by a remarkable decrease of intracellular ROS and MDA content (P < 0.05 or P < 0.01). Conclusion: Sal B is capable of suppressing IHG-induced injury and apoptosis in HUVECs, which might be attributed to the attenuation of oxidative stress, regulation of BCL-2/BAX protein expression, and subsequent suppression of Caspase-3 activity.

[Effect of Danzhi Jiangtang Capsule on Myocardial Fibrosis in Diabetic Rats].

OBJECTIVE: To investigate the effect of Danzhi Jiangtang Capsule on myocardial fibrosis in diabetic rats with fluctuated blood glucose and the possible mechanisms implicated. METHODS: Following induction of diabetes with intraperitoneal injection of streptozotocin (STZ), rats were administered with insulin or glucose at different time during a day to induce blood glucose fluctuation. After treatment with Danzhi Jiangtang Capsule for six weeks, rats were sacrificed and the hearts were collected for the determination of cardiac mass index. Cardiac levels of angiotensin II (Ang II), type I and type III collagens and transforming growth factor-ß1 (TGF-ß1) were assayed by ELISA. Levels of Smad3 phosphorylation and protein expression of matrix metalloproteinase-2 ( MMP-2) and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) were determined by Western blot analysis. Total antioxidant capacity and malondialdehyde (MDA) content in cardiac tissues were measured colorimetrically. RESULTS: Treatment with Danzhi Jiangtang Capsule for six weeks significantly reduced cardiac mass index and cardiac levels of type I and type III collagens (P < 0.05 or P < 0.01). Levels of Ang II, TGF-ß1 and Smad3 phosphorylation in cardiac tissues were also decreased markedly (P < 0.05 or P < 0.01). Supplementation with Danzhi Jiangtang Capsule resulted in an evident up-regulation of MMP-2 protein and down-regulation of TIMP-2 protein expression in cardiac tissues (P < 0.05 or P < 0.01). In addition, Danzhi Jiangtang Capsule significantly enhanced total antioxidant capacity in diabetic rats, while cardiac content of MDA was decreased markedly( P < 0.05 or P < 0.01). CONCLUSION: Danzhi Jiangtang Capsule significantly ameliorated myocardial fibrosis in diabetic rats with fluctuated blood glucose, which might be derived from enhancement of antioxidant capacity, suppression of RAS and TGF-ß1/Smad3 signaling pathway and regulation of MMP-2/TIMP-2 protein expression.

[Effect of Serum Containing Sesamin on Angiotensin II-Induced Apoptosis in Rat Cardiomyocytes].

OBJECTIVE: To investigate the effect of serum containing sesamin on angiotension II (Ang II)-induced apoptosis in rat cardiomyocytes and the possible mechanisms. METHODS: H9c2 rat cardiomyocytes were preincubated with serum containing sesamin or blank serum for 12 h, followed by incubation with Ang II for 24 h. Cell viability was assessed by MTT assay and cell apoptosis was evaluated by flow cytometric analysis. Protein expression of BCL-2, BAX, Caspase-3, p47phox and superoxide dismutase (SOD) was determined by Western blot analysis. Levels of intracellular reactive oxygen species (ROS), total antioxidant capacity (T-AOC) and malondialdehyde (MDA) were measured colorimetrically. RESULTS: Preincubation with serum containing sesamin significantly improved cell viability and suppressed cell apoptosis in H9c2 rat cardiomyocytes exposed to Ang II (P < 0.05 or P < 0.01), with the expression of BAX, Caspase-3 and p47phox protein down-regulated and BCL-2 and SOD protein up-regulated markedly (P < 0.05 or P < 0.01). The levels of T-AOC were effectively increased in serum containing sesamin groups, while the levels of intracellular ROS and MDA contents were decreased significantly (P < 0.05 or P < 0.01). Control serum had no influence on the above mentioned measurements. CONCLUSION: Sesamin is capable of suppressing Ang II-induced apoptosis in H9c2 rat cardiomyocytes, which might be derived, at least partly, from amelioration of oxidative stress, regulation of BAX/BCL-2 protein expression and suppression of Caspase-3 protein expression.