1. Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon
2. Department of Animal Biology, Higher Teacher's Training College, University of Yaoundé I, Yaoundé, Cameroon
3. Department of Biomedical Sciences, Faculty of Health Sciences, University of Buea, Buea, Cameroon
4. Institute of Medical Research and Study of Medicinal Plants (IMPM), Yaoundé, Cameroon