Objective: To investigate the protective effect of Ligustrazine

Shenfu injection and their combined pretreatment on heat shock protein 70 (HSP70)

p38 mitogen activated protein kinase (p38 MAPK) expression and antioxidant ability at left ventricular anterior wall ischemia myocardial tissues of rats with myocardial ischemia reperfusion injury. Method: The 50 Wister rats were randomly divided into 5 groups: sham operation group (sham) and cerebral ischemia reperfusion group (IR): normal saline ip for 3 d; Ligustrazine injection-pretreated group (LI): Ligustrazine injection ip for 3 d (20 mg · kg-1 · d-1) before surgery; Shenfu injection preconditioning group (SFI): Shenfu injection ip for 3 d (10 mg · kg-1 · d-1) before surgery; Combined Ligustrazine and Shenfu Injection-pretreated group (LI+SFI): Ligustrazine (20 mg · kg-1 · d-1) + Shenfu Injection (10 mg · kg-1 · d-1) ip for 3 d before surgery. The myocardial ischemia reperfusion injury model in rat was prepared. The myocardial tissue ischemia lasted for 30 min

myocardial tissue reperfusion lasted for 120 min

myocardial tissues at left ventricular anterior wall ischemia position were collected to prepare 10% homogenate supernatant. The superoxide dismutase (SOD) activity was determined by xanthine oxidase. Glutathione peroxidase (GSH-Px) activity was determined by dithio dinitrotoluene. The immunohistochemical streptavidin peroxidase (S-P) method was used to detect heat shock protein 70 (HSP70) and p38 mitogen activated protein kinase (p38 MAPK) protein expressions at left ventricular anterior wall myocardial tissues. Result: IR group showed significantly lower SOD

GSH-Px activity(P <0.01) and higher HSP70

p38 MAPK positive expression than sham group (P <0.01). Compared with IR group

the SOD activity increased significantly (P <0.01)

and the activity of GSH-Px (P <0.05)

HSP70 was significantly increased (P <0.01)

the positive expression of p38 MAPK protein were significantly decreased (P <0.01) in LI group. Compared with IR group

SFI group showed increases in SOD

GSH-Px

HSP70 (P <0.05)

and decrease in expression of p38 MAPK (P <0.05). Compared with IR group

SOD

GSH-Px activity increased significantly (P <0.01)

HSP70 was significantly increased (P <0.01)

the positive expression of p38 MAPK protein were significantly decreased (P <0.01) in LI+SFI group. Compared with LI group (P <0.05)

SFI group (P <0.01)

LI+SFI group showed increase in SOD activity. Compared with SFI group

LI+SFI group showed increases in GSH-Px activity(P <0.05) and positive expression of HSP70 (P <0.05) and decrease in the positive expression of p38 MAPK (P <0.05). Conclusion: Pretreatment with Ligustrazine

Shenfu Injection could antagonize myocardial ischemia reperfusion injury

particularly with their combination. The mechanism may be correlated with increase activity in SOD

GSH-Px

increase expression of HSP70 and inhibition of p38 MAPK expression.