Assessment of cardiotoxic potential of methanol extract of red cultivar<i> Allium cepa</i>

Abstract

The effects of oral administration of crude methanol extract of red cultivar Allium cepa (Onion) on serum cardiac troponin (cTnI) in cardiac muscle and some haematological parameters were investigated in this study. Fifty five (55) male albino rats were housed and fed with standard growers ration and water ad libitum. There were three major groups; A, B and C containing twenty five (25), twenty five (25) and five (5) rats respectively. Group C was the control group while groups A and B were sub-divided into 5 groups of 5 rats each. Group A was administered with red cultivar A. cepa extract at doses of 100 mg/kg, 200 mg/kg, 400 mg/kg, 800 mg/kg and 1200 mg/kg for 14 days while group B rats were administered with the doses of red cultivar A. cepa for 28 days. Blood samples were collected from the retro-orbital sinus for haematology and cardiac troponin-I assay, histopathological examination of the heart was also done. Haematology showed significant (p<0.05) progressive decrease in packed cell volume (PCV), red blood cell (RBC) and haemoglobin (Hb) concentration and there was progressive elevation of mean corpuscular volume (MCV). Dose-independent elevation of serum cardiac troponin-I (cTnI) with varying degrees of myocardial injuries was observed. This study further postulates a correlation between the A. cepa-induced anaemia and increased cTnI which may be caused by myocardial ischaemia. In conclusion, this study reported the capability of red cultivar A. cepa to induce anaemia and cause myocardial injury as expressed with statistical significant (p<0.01) increase in serum cTnI. Medicinal use of red cultivar A. cepa is therefore recommended to be limited to lower doses and for short duration to prevent the haemotoxic and cardiotoxic potentials.

Keywords: Allium cepa, Cardiac troponin-I, Cardiotoxicity, Haemotoxicity, Medicinal, Red cultivar