[Study on mechanisms and myocardial protective effect of Qishen Yiqi dropping pills on rats with myocardial infarction].

OBJECTIVE: To approach the mechanisms and myocardial protective effect of Qishen Yiqi dropping pills on rats with myocardial infarction. METHODS: ), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured by enzyme linked immunosorbent assay (ELISA); the changes of the indexes of hemodynamic [left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), the maximal rate of increase/decrease in left ventricular pressure (±dp/dt max)], the ratio of the heart weight/body weight, and the ratio of the left ventricular weight/heart weight (LVW/HW), the myocardial infarction area, myocardial histopathological changes were observed in the three groups; myocardial tissues inflammatory related factors [the mRNA and protein expressions of cytosolic phospholipase A2 (cPLA2), cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX)], and the expression levels of transforming growth factor-β (TGF-β)/Smads signal transduction pathway related protein (TGF-β1, Smad2/3, Collagen I, Collagen III) and cell apoptosis related factors (Bcl-2, Bax) protein were measured. RESULTS: (ng/L): 48.75±26.35 vs. 131.25±29.75, TNF-α (μg/L): 177.28±22.65 vs. 248.47±16.21, IL-6 (μg/L): 493.22±165.99 vs. 638.41±191.66], LVEDP [mmHg (1 mmHg = 0.133 kPa): -2.03±2.98 vs. 7.03±1.39], the ratio of the heart weight/body weight [(6.53±0.11)% vs. (7.14±0.24)%], LVW/HW (0.26±0.01 vs. 0.32±0.02), myocardial infarction area [(27.21±2.87)% vs. (44.98±1.52)%], mRNA and protein expression of myocardial inflammatory factors, the expression of TGF-β/Smads signal transduction pathway related protein, and the protein expression of Bax were all significantly decreased in observation group (all P < 0.05), LVSP (mmHg: 129.01±11.93 vs. 108.11±12.69), the +dp/dt max (mmHg/s: 3 101.3±378.6 vs. 2 105.3±245.9), the -dp/dt max (mmHg/s: 2 612.4±249.7 vs. 1 654.4±188.1), while the protein expression of Bcl-2 in observation group were obviously increased (all P < 0.05). It was demonstrated by hematoxylin-eosin (HE) staining that there were no obvious pathological changes in the sham operation group; obvious infiltration of inflammatory factors in myocardium was shown in model group; pathological changes in the observation group were significantly improved as compared with those in the model group. It was shown by Masson staining that there were slight hyperplasia of myocardial fibers and no obvious pathological changes in the sham operation group. Severe collagen hyperplasia was found in model group, and the degree of fibrosis in the observation group was significantly improved. CONCLUSIONS: Qishen Yiqi dropping pills can reduce the degree of myocardial fibrosis and inhibit the ventricular remodeling via TGF-β/Smads signal transduction pathway. The dropping pills can also suppress the release of inflammatory factors by reducing cPLA2 to decrease the inflammatory response and inhibit apoptosis and alleviate myocardial injury by up-regulating the expression of Bcl-2 and down-regulating the expression of Bax.