Phytochemical, Anatomical, and Histochemical Investigation of Felicia abyssinica: A Chemical Analysis of Tissues in Relation to Their Structural Organization

Abstract

The genus Felicia, family Asteraceae, is used in South African folk medicine. The Zulu and Xhosa healers prescribed the aqueous extract of Felicia species to treat headaches, fever, stomach diseases, and catarrh due to its analgesic, anthelmintic, antibacterial, antifungal, and anti-inflammatory properties. This study examines Felicia abyssinica aerial parts to disclose the chemical nature of its secondary metabolites as well as their histochemical localization. The freshly prepared extracts were qualitatively examined to detect phytochemical constituents using different chemical reagents. Selected plant sections and powdered parts were investigated using a light microscope. The transverse sections of stems and leaves were stained with chemical reagents specific for detecting various phytoconstituents. We detected high amounts of nitrogenous compounds, flavonoids, phenolic compounds, steroids, and low quantities of carbohydrates, glycosides, mucilage, and saponins. The leaves showed anomocytic and anisocytic stomata, one layer of epidermis, dorsiventral mesophyll, and a collateral vascular bundle. The multicellular, uniseriate, non-glandular trichomes with tapered apical cells are characteristic of the leaves. The stem shows a multicellular uniseriate stalk with multicellular head glandular trichomes. In the leaves, nitrogenous compounds were localized in the mesophyll, phenolics, and lignins in the xylem vessels, while flavonoids in the epidermis and xylem. However, in the stem, nitrogenous compounds, flavonoids, and lignins were found in hypodermis; and the area of vascular bundles, including xylem vessels and fibers. This study for the first time, investigates the anatomy of F. abyssinica L aerial parts and also correlates the phytochemical analysis with the structural organization of F. abyssinica tissues.