Abstract
Curcumin is a natural polyphenol with powerful antioxidant and anti-inflammatory properties. The present study evaluated the protective effect of curcumin on myocardial injury in rats as well as the mechanisms underlying these effects, and examined the expression of nuclear factor-κB (NF-κB), peroxisome proliferator-activated receptor-γ (PPAR-γ) and B-cell leukemia/lymphoma-2 (Bcl-2) following myocardial infarction. A rat model of myocardial infarction was successfully established. Hematoxylin and eosin staining showed cellular atrophy and hyperchromatic cytoplasm in the myocardial infarction area. The myocardial cells displayed lysis and breakage of cardiac muscle fibers, karyopyknosis and karyorrhexis associated with infiltration of inflammatory cells and proliferation of fibrous tissue. Curcumin treatment at a dosage of 150 mg/kg/body weight resulted in an increase in surviving cells, fewer apoptotic cells, decreased proliferation of fibrous tissue and reduced infiltration of inflammatory cells, though necrosis was still present compared with the rats without curcumin treatment. The immunohistochemical assay demonstrated that curcumin treatment inhibited the expression of NF-κB, but increased the expression of PPAR-γ. The results of the reverse transcription-polymerase chain reaction indicated that curcumin treatment significantly increased the mRNA expression levels of Bcl-2 (P<0.01). Therefore, curcumin antagonizes cardiomyocyte apoptosis and inhibits inflammatory cell infiltration following myocardial infarction, which may be associated with its inhibitory effects on the expression of NF-κB, and activating effects on the expression of PPAR-γ and Bcl-2 in myocardial cells. Curcumin may be useful in clinical practice for saving more living heart muscle in the area of myocardial infarction and improving cardiac function following the elective opening of obstructed coronary arteries.