Cardioprotective molecular mechanism of syringic acid against isoproterenol induced post- myocardial toxicity in male albino wistar rats

Abstract

Background: Syringic acid (SA) is a natural phenolic compound and act as anti-diabetic, anti-cancer, anti-inflammatory agents. In our current research, investigation was carried out on the effect of SA on post conditioning on isoproterenol (ISO) induced myocardial injury in wistar rats. Methods: Male albino wistar rats were administered with ISO (30 mg/kg bw) to second, third and fourth group rats on 1st and 2nd days (with a 24 h interval) of experimental period. SA and metoprolol were orally given immediately after the second dose of ISO to second and fourth group of rats respectively. Myocardial damage was assessed by estimating the cardiac marker enzymes such as creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH) and gamma glutamyl transferase (GGT), anti-oxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT), inflammatory markers such as nuclear factor-kappa B (NF-kB), tumor necrosis factor-α (TNF-α) and high sensitivity-C reactive protein (hs-CRP) along with body and heart weights. Transmission electron microscopy (TEM) was utilized to find any ultra-structural alterations in the heart tissues. Results: CK-MB, LDH and GGT levels and hs-CRP levels were found to be increased in serum while decreased in hearts of ISO group of rats. SOD and CAT were found to be decreased significantly while NF-kB and TNF-α expression levels were significantly increased in heart tissues of ISO administered rats. Body weights were decreased significantly and heart weights were increased significantly in ISO group of rats. TEM study showed alterations in ISO group hearts. Post-treatment with SA significantly recovered myocardial damage caused by ISO administration. Conclusion: By counteracting with the above mentioned effects of ISO, our natural compound, SA exhibited recovery of myocardial damage caused by ISO administration in wistar rats. This is the first report revealing the cardioprotective activity of SA in post-myocardial infarction in rats. Keywords: Syringic acid, Isoproterenol, NF-kB, TNF-α, Transmission electron microscopy