Objective To evaluate the cardioprotective effect of Nigella sativa L. (N. sativa) in isoproterenol-induced myocardial infarction (MI). Methods Groups were treated with different doses of ethanol extract of N. sativa (EENS) and N. sativa oil alone and along with enalapril for 28 days. MI was induced by subcutaneous administration of isoproterenol (85 mg/kg) in two consecutive doses. Levels of cardiac biomarkers and antioxidant enzymes such as creatine kinase–N-acetyl-L-cysteine, lactate dehydrogenase, aspartate aminotransferase, malondialdehyde, superoxide dismutase, reduced glutathione and catalase were evaluated along with gross histopathological examination. Results Isoproterenol (85 mg/kg) induced MI by causing the significant (P < 0.01) reduction in the activity of cardiac biomarkers (creatine kinase–N-acetyl-L-cysteine, lactate dehydrogenase, aspartate aminotransferase) and antioxidant markers (superoxide dismutase, catalase, glutathione) along with significant (P < 0.01) increase in the level of malondialdehyde. Furthermore, histopathological evaluation also confirmed the isoproterenol-induced MI. Pretreatment with EENS (800 mg/kg) and combination of EENS (800 mg/kg) with enalapril (1 mg/kg) significantly (P < 0.01) prevented the development of these alteration and restored activity of cardiac biomarkers as well as antioxidant markers almost near to normal levels. Histopathological evaluation of cardiac tissue further confirmed the restoration of biochemical activity. Conclusions Experimental findings thus indicate that EENS (800 mg/kg) demonstrated cardioprotective effect against isoproterenol-induced MI by restoring cardiac biomarkers and antioxidant status.

ABSTRACT: Hepatic damage is a global metabolic and epidemic disease, affecting essential biochemical activities in almost every age group. Conventional drugs used in the treatment of liver disorders are often inadequate. Also, the spectrum of liver abnormalities caused by allopathic drugs is found to be broad. In view of severely undesirable side effects of synthetic agents, it is necessary to search for alternative drugs for the treatment of liver diseases to replace the currently used drugs, which are of doubtful efficacy and safety. Therefore, there is growing focus to follow systematic research methodology and to evaluate scientific basis for the traditional herbal medicines that are claimed to possess hepatoprotective activities. Use of herbal drugs in the treatment of liver diseases has a long tradition, especially in Eastern medicine and can be traced back as far as 2100 B.C. in ancient China (Xia Dynasty) and India (Vedic period), but evidence for efficacy is sparse. The current study is aimed at providing an overview of clinical and experimental studies carried out on the most effective and commonly used hepatoprotective plants and their beneficial aspects.