Comparative Anatomical, Proximate and Elemental Analyses of the Bark of Three Khaya Species Growing in Nigeria for Medicinal Use
O. A. Oyedapo
*
Drug Research and Production Unit, Faculty of Pharmacy, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria.
I. I. Ogunlowo
Department of Pharmacognosy, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria.
F. M. Ojo
Department of Biological Sciences (Botany Programme), Olusegun Agagu University of Science and Technology, Okitipupa, Ondo State, Nigeria.
S.T. Akinyele
Drug Research and Production Unit, Faculty of Pharmacy, Obafemi Awolowo University, Ile Ife, Osun State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Phytochemicals are chemical compounds that occur naturally in plants. The efficiency of medicinal plants for therapeutic purposes is often based on their organic constituents such as flavonoids, tannins, alkaloids and essential oils. Three Khaya species found in Nigeria are all from the family Meliaceae, namely Khaya senegalensis (KS), Khaya grandifoliola (KG) and Khaya ivorensis (KI). The three species are being used to treat diseases, among which includes malaria and sickle cell anaemia. All Khaya species are generally referred to as Oganwo by the Yoruba people of Nigeria. As much as being in used the traditional medical practitioners in Nigeria find it difficult to differentiate them because of their phenotypic similarities. There is a need, therefore, to identify differentiating characteristics to aid proper identification during collection and also to determine the putative quantitative and qualitative usefulness of these species in the treatment of diseases, hence this study.
Transverse sections, longitudinal sections, and macerates of stems and root bark were prepared for anatomical features. The proximate and elemental analysis of the bark was carried out using a standard procedure. The three Khaya species bark microscopic study reveals anatomical similarities and distinctive diagnostic means of identification. The cuticle shape and type, epidermal cell shape and cell inclusions show some similarities. The cuticle was striated, the shape of the cuticle ranges from circular, oval, polygonal and cylindrical elongated cells. Sclereids are present and prominent. However, there were characters that seemed to be species specific in the number of outer bark cell layers, cuticle thickness, numerosity of crystal druses, and types of sclereids present in the cell. The presence of stylliod crystal in the cell of Khaya grandifoliola distinguished it from the two-other species. The proximate and elemental analysis shows the presence of nutritive values, essential micro and macro nutrients in the right quality and quantity that support their potency in their use for the treatment of diseases and for classification.
Keywords: Khaya, transverse, longitudinal, macerates, proximate, elemental, standardization