The cardioprotective effect of rosmarinic acid on acute myocardial infarction and genes involved in Ca²⁺ homeostasis

Abstract

Acute myocardial infarction (AMI) is a common cause of hospitalisation and high mortality due to lethal arrhythmias. Sarcoplasmic reticulum Ca²⁺ ATPase (SERCA₂) and ryanodine receptor (RyR₂) regulate the cytosolic Ca²⁺ ion concentration. Rosmarinic acid (RA) is one of the most common caffeic esters in Rosmarinus officinalis. The present study was conducted to test the hypothesis whether RA can protect cardiac function against AMI and arrhythmias induced by isoproterenol through the regulatory effect of SERCA₂ and RyR₂ gene expression. To this aim, male Sprague–Dawley rats were allocated into in vivo and ex vivo studies and received RA (10, 15, and 30 mg/kg; 14 days). AMI was induced by two consecutive subcutaneous injections of 100 mg/kg isoproterenol. Blood pressure (BP), heart rate, electrocardiography (ECG) parameters, plasma levels of cardiac biomarkers, and antioxidative enzymes were evaluated (in vivo study). Cardiac functions were measured in isolated hearts using Langendorff set up. Gene expressions of SERCA₂ and RyR₂ were measured in left ventricular heart. Isoproterenol administration showed a significant decline in BP, QRS voltage, activities of antioxidant enzymes, cardiac function, and gene expressions of SERCA₂ and RyR₂. The results also indicated a significant increase in heart rate, ST-elevation, cardiac biomarkers, and antioxidant enzymes. RA at 30 mg/kg dosage showed the best effect on the improvement of the mentioned factors. This study suggests that RA has potent cardioprotective effects against AMI and arrhythmia, which may be due to its ability to enhance expression of plasma antioxidant enzymes and genes involved in Ca²⁺ homeostasis SERCA₂ and RyR₂. The protective role of RA is also possibly related to its antiadrenergic effects.

Keywords:

• Rosmarinic acid
• SERCA₂
• RyR₂
• cardiac functions
• acute myocardial infarction

Acknowledgements

The source of data used in this paper was from the Ph.D thesis of Mrs. Somayeh Javidanpour, a student of physiology at Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

Authors gratefully acknowledge the help and financial support of the Physiology Research Center of Ahvaz Jundishapur University of Medical Sciences [No. APRC-9414].