IOSR Journal Of Pharmacy And Biological Sciences (IOSR-JPBS) e-ISSN:2278-3008, p-ISSN:2319-7676. Volume 15, Issue 2 Ser. I (Mar –Apr 2020), PP 65-76 www.Iosrjournals.Org DOI: 10.9790/3008-1502016576 www.iosrjournals.org 65 | Page The methanol stem extract of Moringa oleifera mitigated isoproterenol-induced myocardial infarction through cardiac troponin and NF-kB signaling pathways in rats Adeolu Adedapo 1* , Utibe Etim 1 , Olufunke Falayi 1 , Ademola Oyagbemi 2 , Temidayo Omobowale 3 and Bisi Adeoye 1 1 Department of Veterinary Pharmacology and Toxicology, University of Ibadan, Nigeria 2 Department of Veterinary Physiology and Biochemistry, University of Ibadan, Nigeria 3 Department of Veterinary Medicine, University of Ibadan, Nigeria *Corresponding author: Adeolu Adedapo Abstract: Cardiovascular diseases remain a health challenge globally, affecting approximately one third of the world’s human population with a larger percentage occurring in developing countries. While the pathogenesis of this disease condition is yet to be fully elucidated, many studies have shown that isoproterenol provides a standard model that closely mimics human myocardial infarction by inducing myocardial ischemia, hypoxia, cell death, and reduced myocardial compliance.This study was designed to describe the protective effect of methanol stem extract of Moringa oleifera on isoproterenol-induced myocardial infarction in rats. Thirty-five adult male wistar rat were randomly sorted into five groups of seven animals each. Control received distilled water alone, Untreated group received single Isoproterenol (100 mg/kg) subcutaneously, two groups were pretreated orally with 50 and 100 mg/kg of Moringa oleifera respectively for seven days and then injected with a single Isoproterenol (100 mg/kg) subcutaneously on day eight. Another group received oral administration of Moringa oleifera alone at 100 mg/kg for seven days. Twenty-four hours after Isoproterenol was administered, blood pressure and electrocardiogram values were taken. Serum and cardiac homogenate analysis revealed that isoproterenol induced significant increases in creatine kinase myocardial band, nitric oxide, malondialdehyde, protein carbonyl, myeloperoxidase, advanced oxidative protein products alongside a decrease in superoxide dismutase, reduced glutathione, glutathione peroxidase and an increase in the expression of cardiac Troponin 1 and NF-kB with immunohistochemistry. Treatment with Moringa oleifera at both doses used brought on a reversal of these. Collectively, these submit that Moringa oleifera exerts its cardioprotective effect via antioxidant/NF-kB/Cardiac troponin signaling pathways. Key words: Oxidative stress, inflammation, myocardial damage, isoproterenol --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 03-03-2020 Date of Acceptance: 18-03-2020 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction: Worldwide, myocardial infarction induced mortalities remain one of the leading causes of death, it occurs as a result of an imbalance between blood demand and supply in the coronary vessels (Chatterjee et al., 2018). The heart is an organ that requires a lot of energy mostly derived from fatty acid metabolism and in cases of myocardial injury, the myocardium is unable to obtain the full benefits of fatty acid metabolism (Yuan et al., 2008). The formation of reaction oxygen species, products of lipid peroxidation, release of pro-inflammatory cytokines, and imperfections in the antioxidant defense are characteristics of myocardial infarction (Zhang et al., 2018). It is usually accompanied by pathological lesions and is a major cause of death and disability worldwide (Zhang, et al., 2019). Moringa oleifera, commonly known as horse radish tree is a popular plant in tropical and sub-tropical regions of the world with every part appropriate for both commercial and nutritional purposes (Gopalakrishnan et al., 2016). The plant is rich in minerals and phytochemicals such as tannins, saponins and alkaloids, it also contain linoleic, oleic and palmitic acid (Sánchez-Machado et al., 2010). Moringa oleifera has been regarded as a cure-all, reported to possess various therapeutic properties including antidiabetic, anticancer, neuroprotective and anti-infective properties (Gopalakrishnan et al., 2016). In this study, Isoproterenol was used to induce myocardial infarction, this is an ideal andconventional model of instigating myocardial infarction. Isoproterenol works by triggering widespread strain to the myocardium with subsequent lesions that mimics infarcts, it also restricts the supply of energy to the myocardial cells resulting in the compromise of the structural and functional integrity of the heart (Khan et al., 2019). Isoproterenol is also said to cause myocardial infarction through the generation of reactive oxygen species