Protective effect of fenugreek on cobalt chloride -induced hypoxia in cardiomyocytes from neonate rats

Cardiovascular disease (CVD) is the second leading cause of death in the world, and ischemic heart disease is the major cause of CVD that leads to death. In 2019, 8.9 million of overall deaths were due to ischemic disease. Ischemic heart disease leads to myocardial infarction and heart attack due to cardiomyocyte cell death. Apoptosis occurs as programmed cell death activates cysteine proteases called caspases, ceasing cellular functions. Hypoxic microenvironment (hypoxia, lack oxygen) is a mimicking condition of ischemic heart disease-chemically-induced chemically using cobalt chloride (CoCl2). Different kinds of herbs are proposed for treating heart diseases, such as garlic, guggul, Terminalia arjuna, and hawthorn. Fenugreek was suggested as a therapeutic drug to promote cardio protection against injuries due to hypoxia. However, the effect of fenugreek on the heart is limited. Thus, we aim to identify the effect of fenugreek on the cardiomyocytes of hypoxic neonatal rat. The ventricles of the foetal heart of Sprague-Dawley rats (0 - 2 days old) were isolated for primary cell culture of cardiomyocytes. Cardiomyocytes were later incubated with different concentrations (0 μg/mL, 10 μg/mL, 20 μg/mL, 40 μg/mL, 80 μg/mL, 160 μg/mL, 320 μg/mL) and different durations (24 hr, 48 hr, 72 hr) of fenugreek and CoCl2-induced hypoxia. The treated cardiomyocytes were subjected to a cell viability assay, cell cytotoxicity assay, calcium signalling assay, beating assessment, protein expression, and gene expression quantification. Our results demonstrate that 160 μg/mL fenugreek is not toxic to the cells and optimally protected cardiomyocytes from cobalt chloride-induced hypoxic microenvironment. An improved beating rate was recorded in fenugreek-treated cardiomyocytes. The calcium signals were higher in fenugreek-treated cardiomyocytes. There was upregulation of hypoxia gene Hif-1α, apoptotic caspases gene (-3, -9, -8, -12), and downregulation of Bcl-2 activity in CoCl2 treatment while vice versa in fenugreek treatment. Fenugreek plays a role as a therapeutic cardioprotection drug against injury due to CoCl2.