Haematological and Hepatotoxic Potential of Onion (Allium cepa) and Garlic (Allium sativum) Extracts in Rats

Aims: To evaluate and compare the effects of single and combined oral administration of fresh aqueous onion (Allium cepa) and garlic (Allium sativum) extracts at different concentrations (200mg/kg/d, 400mg/kg/d and 600mg/kg/d) on some haematological and hepatotoxicity indicator parameters in treated rats.
Study Design: Cross-sectional nonclinical study in animal model.
Place and Duration of Study: The study was carried out at the Department of Physiology, Department of Biochemistry and Department of Haematology, College of Health Sciences, Igbinedion University Okada, Edo state, Nigeria between the month of July and August, 2011.
Methodology: Following 30 days post-oral administration of extracts in 36 treated male albino rats as well as 4 controls, haematological parameters were determined using the Sysmex® Automated Haematology Analyzer, while serum levels of liver enzymes were evaluated using the Reflotron® Plus Auto-Analyzer and liver weight was determined using electronic sensitive weighing balance.

Results: Red blood cell count (RBC), Packed cell volume (PCV), Haemoglobin concentration (HGB), Total White blood cell count (TWBC), Absolute Count of Neutrophil (NEUT#), Absolute Count of Lymphocyte (LYM#), Absolute Count of the summation of Monocyte, Eosinophil and Basophil (MXD#) and Platelet count (PLT) were significantly increased (P<0.05) to varied extent, except Mean cell volume (MCV), Mean cell haemoglobin (MCH) and Mean cell haemoglobin concentration (MCHC) while Alanine aminotransferase (ALAT) and Aspartate aminotransferase (ASAT) serum levels were significantly decreased (P<0.001) and liver weight (LW) was non-significantly (P>0.05) reduced in a dose-dependent manner when compared to the control. Synergistic effect was not observed in the haematological parameters when the two extracts were combined.
Conclusion: The results of this study reveal the haematological potential of onion and garlic extracts with no potential risk of hepatotoxicity (at the concentrations tested) as earlier anticipated. It also further confirms the higher efficacy of garlic over that of onion, but the molecular mechanism behind their combined effect would require further investigation.