ABSTRACT
In the treatment of hypertensive crisis, the novel Rho kinase inhibitor DL0805-2 can rapidly lower systematic blood pressure, reduce pulmonary artery pressure, and has a significant protective effect on lung injury. This experiment intends to evaluate the efficacy of DL0805-2 against pulmonary arterial hypertension (PAH) and preliminarily reveals its underlying mechanism. Animal welfare and experimental procedures are in accordance with the provision of the Animal Ethics Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences. Sprague Dawley (SD) rats were randomly divided into DL0805-2 low, medium, and high dose groups (1, 3, and 10 mg·kg-1), bosentan positive control group, model group, and blank control group. The drug was administered daily on the 7th day after model establishment by monocrotaline injection. On the 25th day of the experiment, relevant indicators were examined to observe the therapeutic effect of DL0805-2 on pulmonary hypertension. DL0805-2 significantly relieved the abnormal changes in the physiological parameters related to PAH induced by monocrotaline, including reducing right ventricular systolic pressure, alleviating cardiac damage caused by pressure overload, and reducing the levels of endothelin-1 and inflammatory factors in lung tissues. DL0805-2 also attenuated pulmonary arteries remodeling. It was preliminarily discovered that DL0805-2 exerts preventive and therapeutic effect on PAH through Rho-kinase pathway. Our results suggested that DL0805-2 had good therapeutic effects on monocrotaline-induced PAH rat model. It intervened early in the disease process, effectively prevented the development of the disease, and reduced the mortality of the diseased animals. The mechanism is related to Rho-kinase pathway.
ABSTRACT
This study is to investigate the effect of total flavonoids of Uygur medicine bugloss (BTF) on rats with myocardial ischemia/reperfusion injury, and to explore the mechanisms by which it acts. Left anterior descending (LAD) coronary artery in rats was occluded for 30 min followed by 4 h reperfusion. Meanwhile, BTF dissolved in saline was administered intraperitoneally at dosage of 10, 30 and 50 mg x kg(-1). Electrocardiograph, infarction index, serum myocardial enzymes and heart function were determined to evaluate the effect of BTF. Some other observations were carried out to explore whether inhibiting inflammation and apoptosis is involved in the mechanisms underlying BTF. Our results showed that in ischemia/reperfusion injured rats BTF could dose-dependently reduce myocardial infarction index and myocardial enzyme leakage, and enhance heart function, indicating that it possesses significant cardio protection. ELISA analysis showed that BTF could decrease the content of myocardial inflammatory cytokines such as IL-1beta, IL-6 and TNF-alpha. Western-blotting confirmed that BTF could increase the expression of anti-apoptotic protein Bcl-2 and reduce the expression of proapoptosis protein Bax. Further more, the phosphorylation level of PI3K and Akt was upregulated by BTF treatment. BTF can protect rat against myocardial ischemia/reperfusion injury. Anti-inflammation and inhibition of apoptosis through upregulating PI3K/Akt signal pathway may contribute to the protective effect of BTF.