| Background:Myocardial ischemia reperfusion cure is the most effective way to limit acute myocardial ischemic necrosis. However, the final result of myocardial ischemia reperfusion depends not only on the duration of ischemia, but also depends on the degree of reperfusion injury occurred. Reperfusion accompanying oxygen free radicals increasing, ntracellular calcium overloading, microvascular injury, polymorphonuclear accumulation and activating of inflammation can lead to myocardial ischemia reperfusion injury(MIRI) and aggravated cell damage. Moreover, in open heart surgery, myocardial ischemia injury and reperfusion, caused by extracorporeal circulation reperfusion, are the key factor that influence the recovery of the heart function.People pays more and more attention to the injury. Finding the most effective way to cure myocardial ischemicnecrosis reperfusion injury has been the focus of research in the field of cardiovascular surgery.In recent years, the research about Traditional Chinese Medicine, especially the extracts from Chinese herbal medicine, which has proved protection to MIRT, has attracted people’s attention. Correlational studies have proved the effectiveness and practicality in MIRI. We choose dried leaves of Cajanns cajan and twigs, which are deciduous shrubs belonged to legume pigeonpea spieces in our research. Leaves of Cajanus cajan which contain kinds of flavonoids such as vitexin, isovitexin and luteolin, have the effects of lowering blood pressure, antispasmodic, anti-infective, antibiosis, radiation protection and free radical scavenging. For the past few years, the studies about extracts extracts have got a lot of exposure, while there is little concerning on pharmacological reseaches of cardiovascular diseasese. Therefore, it has broad prospects to explore leaves extracts of Cajanus cajan for preventing and curing cardiovascular diseases. With the further clinical research on the leaves of Cajanus cajan and its extracts, the quality control of leaves of Cajanus cajan are getting people’s attention.At present, researchers often use vitexin and isovitexin as indicators for the quality control of leaves of Cajanus cajan, but only relying on a single or several chemical components can not fully reflect the efficacy or evaluate the quality of leaves of Cajanus cajan overally. It’s not conductive to clinical applications and internationalization. Fingerprinting technology can ensure Chinese medicine and its ingredients consistently, efficacy safely and reliabiy.So, we made acute myocardial ischemia reperfusion model of rats, investigated and compared the effect to reperfusion injury with various doses of leaves extracts of Cajanus cajan, and explore the probable mechanisms.Objective:(1) The fingerprinting chromatograms are established to identify and control the quality of leaves of Cajanus cajan. (2)To simulate myocardial ischemia reperfusion by overall animal level, investigate the protective to damaged myocardial by leaves extracts of Cajanus cajan, and study if there is difference to rats myocardial ischemia reperfusion with various doses of leaves extracts of Cajanus cajan. (3)To estimate the harm to H9c2 cell with H2O2 by detecting various index sign to determine the optimal doses. At the same time, observing the protective to H9c2 cell redox damage by H2O2 with leaves extracts of Cajanus cajan. (4)To observe the express of VEGF, eNOS and P-eNOS in H9c2 cell which damages by H2O2 and the probable signal modulation mechanisms.Methods:(1) The fingerprinting chromatograms were established of leaves extracts of Cajanus cajan. The analysis was performed on a Diamonsil Ci8(2) (250 mm×4.6 mm,5μm)with Methanol-1% 11AC as mobile phase in a gradient mode at a flow rate of 1.0 mL-min-1, and at a column temperature of 40℃. The detection of wavelength was 268 nm. (2) To study the protective of SD rats with acute myocardial ischemia reperfusion injury by leaves extracts of Cajanus cajan. Rreperfusion after ligating left anterior descending coronary atery for 30min, we establish the model of myocardial ischemia reperfusion. Then, examine the change of the heart fuction during ischemia/reperfusion, record the biochemical indicators of rats serum such as LHD, SOD, MDA, NO, GSH-PX and CK, analyze data about the area of myocardial infarction with the statistics method, observing the morphology of dyig myocardium ischemia reperfusion cells with HE. (3)To study protective and the mechanisms about leaves extracts of Cajanus cajan which act on the H9c2 cell damaged by H2O2. With H2O2 as the exogenous redox stimulation, exploreing the activity of the damaged H9c2 cell and the optional doses of the H2O2 and leaves extracts of Cajanus cajan by MTT test. To analyse the effect on the quantity of the p-Akt, eNOS, p-eNOS in H9c2 cell which are restrained by PI3K.Results:Overall animal experiment shows that the model simulates the same pathophysiological process that most cardiovascular diseases have, growing in the quantity of oxygen free radical.The leaves extracts of Cajanus cajan can improve the heart fuction of rats, realize the edema and hyperemia degree of muscle cells damaged by reperfusion, It also can narrow the damaged area, reduce the content of the LDH, MDA and CK in serum,while improve SOD, NO and GSH-PX. Cell experiments show that it can rise the H9c2 cell viability by inhibiting the cell apoptosis which is caused by H2O2, raise the expressing protein quantity of p-Akt, eNOS and p-eNOS. Combination of the PI3K inhibitor of LY294002 can compete to it. The results tell us that PI3K is probable the signal targets on protecting the cell with leaves extracts of Cajanus cajan.Conclusions:Leaves extracts of Cajanus cajan have the ability to protect myocardial ischemia reperfusion against ligating left anterior descending coronary and damaged H9c2 cells by H2O2. The preliminary estimate suggest that it can relieve free radical injury resulted from ischemia reperfusion by improving the antioxidative enzy activities of rats and enhancing the ability to eliminate free radical. The probable mechanism infers it induces muscle cells to release proper amount of NO which activates lower PI3K as triggers to have the preconditioning protective. It can raise the expressing amount of p-Akt, eNOS and p-eNOS to protect cardiocytes, while the increasing eNOS can promote the creation of NO, too. |
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