Ginkgo biloba extract-761 protects myocardium by regulating Akt/Nrf2 signal pathway.

OBJECTIVE: The aim of this study was to investigate the protective effect and mechanism of Ginkgo biloba extract-761 (EGb 761) in the rat with myocardial ischemia-reperfusion injury (MIRI). MATERIALS AND METHODS: Forty Sprague Dawley rats were randomly divided into following four groups: sham group, I/R group and EGb 761 groups (20 and 40 mg/kg). MIRI model was established after 14 days of administration. The myocardial infarct size and myocardial histology were measured and compared. Meanwhile, the levels of creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), troponin T (TnT), TNF-α, IL-6, IL-1ß, superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were evaluated. Western blot was used to detect the expression of Caspase-3, Bax, Bcl-2, HO-1, Nrf2, Akt, p-Akt and nuclear protein Nrf2. RESULTS: The levels of infarct size, CK-MB, LDH, TnT, TNF-α, IL-6 and IL-1ß in the EGb 761 groups were significantly lower than those in the ischemia/reperfusion (I/R) group. The content of MDA was lower in the myocardium, whereas the activities of SOD and GSH-Px were higher than those in the I/R group. The expressions of Caspase-3 and Bax in the EGb 761 groups were significantly lower than those in the I/R group, whereas the expressions of Bcl-2, p-Akt and HO-1 and nuclear protein Nrf2 in the EGb 761 groups were higher than those in the I/R group. CONCLUSION: EGb 761 might inhibit the apoptosis of myocardial cells and protect the myocardium by activating the Akt/Nrf2 pathway, increasing the expression of HO-1, decreasing oxidative stress and repressing inflammatory reaction.

The association between an endothelial nitric oxide synthase gene polymorphism and coronary heart disease in young people and the underlying mechanism.

With the development of molecular biological technology, the association between genes and diseases has drawn increasing attention of researchers; the endothelial nitric oxide synthase (eNOS) gene has been reported to be a candidate gene for cardiovascular disease (CHD). The present study aimed to investigate the association between a polymorphism of eNOS and the risk of CHD in young people (≤40 years old), in addition to the underlying mechanism. A total of 234 cases of CHD in young individuals were collected as the CHD group and 228 cases of healthy individuals as the control group. Peripheral blood was collected and the genotype of the eNOS G894T polymorphism was identified by polymerase chain reaction-restriction fragment length polymorphism, the gene frequency was calculated and the distributions of genotype and allele frequency between the two groups were compared. Bioinformatics tools were employed to analyze the differences in the local protein structures of the eNOS G894T polymorphism and the biological mechanism was preliminary discussed. The results demonstrated that there were significant differences in the distribution of genotype frequency and allele frequency of the eNOS G894T gene polymorphism between the CHD group and control group (P<0.05). The risk of CHD in GT and TT genotypes were higher compared with the GG genotype (P<0.05). The G894T polymorphism led to Glu298Asp mutation of encoded protein, which is within the active site of eNOS, and partial structures of the protein were converted from random coil to α­helix. In conclusion, the eNOS G894T gene polymorphism was associated with the occurrence and development of CHD in young people. The potential mechanism is that the G894T polymorphism leads to altered protein structure, which affects the function of eNOS in generating nitric oxide and cardiovascular diastole. The results of the present study suggested a potential target gene for the prevention and treatment of CHD in young people (≤40 years old).