1Department of Biomedical Science, College of Veterinary Medicine and Agriculture, Addis Ababa University, P.O.Box 34, Bishoftu, Ethiopia, E-mail: takele.beyene@aau.edu.et
2Department of Pharmacology, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia, E-mail: takele.beyene@aau.edu.et