Origanum majorana L. Extract Protects Against Isoproterenol-Induced Cardiotoxicity in Rats.

Coronary artery diseases are the major causes of disabilities and death worldwide. Evidence from the literature has demonstrated that Origanum majorana L. (marjoram) acts as an antioxidant, anti-inflammatory, antiplatelet, and assists in hormonal regulation. However, there is limited scientific evidence describing the signaling pathways associated with the marjoram's positive effect on cardiac injury. Therefore, we aimed to understand the mechanistic protective effects of marjoram on isoproterenol (ISO)-induced myocardial injury in rats. Sprague Dawley rats were randomly assigned into six groups. Marjoram was administrated by oral gavage and isoproterenol was administrated subcutaneously (ISO; 85 mg/kg). Heart weight, cardiac enzymes, inflammatory, and oxidative stress biomarkers were measured. The ISO-induced cardiac injury was confirmed by the significant increase in the levels of cardiac enzymes (P value < 0.05), whereas pre-treatment with marjoram normalized these cardiac injury parameters. We also determined that marjoram had a protective effect against ISO-induced increase in C-reactive protein (CRP), IL-6, IL-13, and TNF-α. Additionally, marjoram significantly decreased cardiac thiobarbituric acid reactive substances (TBARS) levels (P value < 0.05) and protected against ISO-induced oxidative stress. We have demonstrated that marjoram decreased both cardiac oxidative stress and inflammation, thus establishing the beneficial effects of marjoram on ISO-induced cardiac injury in rats.