Allicin improves cardiac function by protecting against apoptosis in rat model of myocardial infarction.

OBJECTIVE: To study the effects of allicin on cardiac function and underlying mechanism in rat model of myocardial infarction (MI). METHODS: Ninety-four Wistar rats were randomly assigned to 6 groups (n=14-16 per group): sham control group [underwent thoracotomy without left anterior descending (LAD) occlusion and only received an injection of the same amount of citrate buffer], MI control group (subjected to LAD occlusion and only received an injection of same amount of citrate buffer), positive control group (subjected to LAD occlusion and received an injection of diltiazem hydrochloride at the dose of 1.5 mg/kg), and MI + allicin groups (subjected to LAD occlusion and received an injection of allicin at the doses of 1.2, 1.8, and 3.6 mg/kg). All of the drugs were administered intraperitoneally daily for 21 days. The infarct area was measured by myocardial staining. Hematoxylin-eosin staining was used to observe the pathological changes. Cardiac function parameters were assessed by echocardiography. The myocardial apoptotic index was estimated by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining. The expression of Bax and Bcl-2 were detected by quantificational real-time polymerase chain reaction and Western blot. RESULTS: Treatment with allicin could attenuate the myocardial infarct area (P<0.05) and relieve the changes of the myocardium. The left ventricular anterior wall diastolic and systolic thicknesses were increased in the allicin-treated groups (P<0.05), while there was no signifificant difference in the left ventricular posterior wall diastolic and systolic thickness (P>0.05). The left ventricular internal diameter in systole, ejection fraction, fractional shortening, and stroke volume were dramatically elevated in allicin-treated rats (P<0.05). Allicin dose-dependently reduced creatine kinase and lactate dehydrogenase levels (P<0.05). The myocardial apoptotic index was also markedly lowered, and Bax expression was signifificantly decreased, whereas Bcl-2 expression exhibited an opposite trend in allicin-treated rats (P<0.05). CONCLUSION: Allicin appears to exert a cardioprotective effect that may be linked to blocking Bcl-2/Bax signaling pathway-denpendent apoptosis, further improving cardiac function.

[Effect of allicin on myocardial fibrosis after myocardial infarction in rats and its relationship with TGFß/Smads signal transduction].

Allicin is the internationally accepted active substance of garlic, and has cardiovascular protective effect. This research was designed to investigate the effect of allicin on myocardial fibrosis after myocardial infarction and explore the relationship between the effect and TGFß1/Smads signaling pathway. The rat myocardial infarction model were made by ligating the left anterior desending coronary artery. The drugs were administered intraperitoneally 24 h after the operation. After 21 days, the rats were sacrificed and myocardial collagen fibres were observed by Masson staining. The protein expression of Ⅰ, Ⅲ collagen and TGFß1, Smad3, Smad7 in the myocardium was measured by the immunohistochemistry. The results showed that myocardial fibrosis was serious and the expression of Ⅰ, Ⅲ collagen was increased in model group. After treatment with allicin, the myocardial fibrosis could be relieved markedly, and the expression of collagen was down-regulated. Meanwhile, TGFß1 and Smad3 in heart tissue could be down-regulated and Smad7 could be up-regulated in allicin groups. So allicin may exhibit anti-myocardial fibrosis effect on rats, and the mechanism of this is related to TGFß/Smads signal transduction.