Cardioprotective effect of oregano oil against doxorubicin-induced myocardial infarction in rats

Aim: The objective of the study was to evaluate the cardioprotective effect of oregano oil (O.OIL) in doxorubicin (DOX)-induced myocardial infarction (MI) in rats. Materials and Methods: O.OIL (100 mg/kg and 200 mg/kg, p.o) was administered for 21 days in rats. MI was induced by DOX (5 mg/kg, i.p.) administered on the 7th, 14th, and 21st day of the study to obtain a cumulative dose of 15 mg/kg. On day 22, changes in electrocardiogram (ECG); force of contraction; serum markers: lactate dehydrogenase (LDH), creatine kinase (CK) MB isoenzyme, troponin I; lipid profile: total cholesterol and triglycerides; antioxidant enzymes level: malondialdehyde (MDA) and glutathione (GSH); heart and body weight; and histopathology of heart were determined. Results: Pretreatment with O.OIL significantly protected the myocardium from the toxic effects of DOX by reducing the elevated level of CK-MB, LDH, and troponin I to the normal levels. O.OIL increased the GSH levels and decreased the MDA levels in cardiac tissue. It also restored the changes in ECG and force of contraction and showed significant recovery of heart tissue in histopathological studies. Statistical analysis: All results are expressed as mean ± standard error of the mean. The results were analyzed for statistical significance by one-way ANOVA followed by Dunnet's Multiple Comparison Test using GraphPad version 5.01, P < 0.01 was considered statistically significant. Conclusion: O.OIL (100 and 200 mg/kg p.o.) reduced cardiac complications in DOX-induced MI in rats.