Mechanism of the Protective Effect of Yulangsan Flavonoid on Myocardial Ischemia/Reperfusion Injury in Rats

Aims: Effect and mechanism of Yulangsan flavonoid (YLSF) on rat myocardial ischemia/reperfusion injury (MI/RI) has been investigated. Methods: Sprague-Dawley (SD) rats were randomly divided into seven groups (sham group, model group and NS group: 2 mL of normal saline/kg body weight was administered; diltiazem group: 5 mg of diltiazem hydrochloride/kg body weight was administered; YLSFL, YLSFM and YLSFH groups: 20, 40 and 80 mg of YLSF/kg body weight was administered) and the MI/RI model was established. Myocardial infarct area, levels of myocardial enzymes and nitric oxide synthase (NOS) were measured. Caspase-3 and adenine nucleotide translocator-1 (ANT1) mRNA expression were evaluated by reverse transcription polymerase chain reaction (RT-PCR). Pathological structure and cardiocyte ultrastructure were also analysed. Results: Compared with the MI/RI group, pretreatment with YLSF or diltiazem hydrochloride decreased the infarct area, levels of inducible nitric oxide synthase (iNOS), caspase-3 as well as the leakage of myocardial enzyme and increased activities of total nitric oxide synthase (tNOS) as well as constitutive nitric oxide synthase (cNOS). Cellular edema and the infiltration of inflammatory cells were alleviated. Conclusions: The experiment showed that YLSF protected the heart against MI/RI, possibly by reducing lipid peroxidation damage, regulating NOS activity and modulating the apoptosis genes expression.