Pharmacognostic and Phytochemical Studies of the Leaves and Stembark of Anogeissus leiocarpus (DC.) Gill (Combretaceae)

Background & Aim: Anogeissus leiocarpus is native to the savannas of tropical Africa. Many of its traditional uses are reported all over Africa. In Burkina Faso, Nigeria, Niger, Ivory-coast and Ghana, decoctions of various parts of A. leiocarpus are used against abdominal pain, ulcers, skin infectious diseases, fungal infection, for bacterial vaginosis and wound healing. The present study aimed to investigate the pharmacognostic characters and phytochemical constituents of A. leiocarpus with a view to establishing parameters that can be used for identifying and detecting adulteration in the plant sample, considering its wide applications in traditional medicine. Methods: Pharmacognostic investigations, namely, macro and microscopical examinations, chemomicroscopic studies and physicochemical determinations, were carried out on the leaves and stems of the plant using standard procedures. Phytochemical screening of the ethanol and ethyl acetate fractions was performed using standard procedures to determine the presence of phytochemicals. Results: Microscopic examinations of the leaves showed the presence of anomocytic stomata, oval-shaped starch grains, druse crystals and unicellular non-glandular trichomes. Spongy and palisade parenchyma, as well as a closed vascular bundle, were observed on the transverse section of the leaf. Longitudinal and transverse sections of the stem bark showed the presence of a single layer of epidermal cells, 3-4 layers of cork cells, cork cambium and cortex. Radially arranged polygonal-shaped cork cells and fibres were observed in the powdered sample of the stem bark. Chemomicroscopic studies revealed the presence of cellulose, lignin, gums and mucilage, starch, tannins, fats, fixed oils and calcium oxalate crystals; calcium carbonate was absent. Physicochemical parameters, namely, moisture content (5.98%±0.23), total ash (7.50%±0.54), acid-insoluble ash (1.34%±0.82), water-soluble ash (2.60%±0.65), alcohol (9.40%±0.85) and water extractive values (6.50%±0.33) were also determined. Phytochemical test and TLC revealed the presence of numerous phytochemicals in the leaves and stem bark of the plant. Conclusion: The study showed A. leiocarpus stembark contains important pharmacognostic features that can be used as fingerprints for the correct taxonomic identification and description of the plants. The findings from this study will also help to check adulteration of products from the plant.