Objective: To investigate the protection effect of total flavonoids of Puerariae Lobatae Flos on myocardial ischemia-reperfusion injury in rats and explore its possible mechanism. Method: The 72 Wistar rats were randomly divided into sham operation group

myocardial ischemia-reperfusion model group

positive drug control group (Danshen tablets

240 mg·kg-1)

total flavonoids of Puerariae Lobatae Flos low

medium and high dose groups (20

40

60 mg·kg-1). The drugs were given for 28 days as preventive administration. The rat models were established by clamping the artery for 30 min. After successful modeling

the areas of myocardial infarction were determined by triphenyltetrazolium chloride(TTC) staining; the morphological changes of myocardial tissues were observed by htoxylin eosin(HE) staining; the levels of total antioxidant capacity(T-AOC)

adenosine triphosphate(ATP)

adenosine diphosphate(ADP)

aspartate aminotransferase(AST)

lactate dehydrogenase(LDH)

and creatine phosphokinase(CPK) were detected; the levels of tumor necrosis factor-α(TNF-α)

interleukin-6(IL-6) and IL-1β in myocardial tissues were determined by enzyme-linked immunosorbent assay(ELISA); the levels of Bax

Bcl-2 and Caspase-3 were detected by ELISA. Result: As compared with model group

myocardial infarct size in the total flavonoids of Puerariae Lobatae Flos high dose and middle dose groups was significantly decreased(P<0.05

P<0.01); the histopathological changes and cardiomyocytes apoptosis were improved in total flavonoids of Puerariae Lobatae Flos high dose and middle dose groups

and the effect was most obvious in high dose group; the levels of AST

CPK LDH ADP and ATP in serum

as well as TNF-α

IL-6

IL-1β levels in myocardial tissues were decreased significantly in total flavonoids of Puerariae Lobatae Flos high and middle dose groups(P<0.05

P<0.01); total flavonoids of Puerariae Lobatae Flos high and middle dose groups up-regulated the Bcl-2 content in myocardial tissues of rats

and reduced the Bax and Caspase-3 content. Conclusion: Total flavonoids of Puerariae Lobatae Flos could effectively lower the areas of myocardial infarction

and improve the histopathological changes and cardiomyocytes apoptosis

suggesting that total flavonoids of Puerariae Lobatae Flos had protective effects on rats with myocardial ischemia-reperfusion injury

which may be related to its effects on reducing the infiltration of inflammatory cytokines and decreasing the apoptosis of myocardial cells.