1. Laboratory of Physiology and Natural Products Research, Department of Life and Earth Sciences, Higher Teachers' Training College University of Maroua Maroua Cameroon
2. Department of Animal Biology and Physiology, Faculty of Science University of Yaoundé Yaounde Cameroon
3. Department of Chemistry, Faculty of Science University of Ngaoundere Ngaoundere Cameroon
4. Department of Chemical Sciences, Faculty of Sciences University of Johannesburg Doornfontein South Africa