Pharmacognostic characterization and development of standardization parameters for the quality control of aidia genipiflora (dc.) dandy

Abstract

The stem bark and leaves of Aidia genipiflora (DC.) Dandy (Rubiaceae) have several ethnomedicinal uses and are recently being commercialized by some traditional healers in Ghana, as anti-inflammatory and antimicrobial agents. This study sought to establish pharmacognostic parameters for the stem bark and leaves of the plant in order to set standards for identification and quality control. The organoleptic, macro-morphological, qualitative and quantitative micro-morphological features were analysed for the whole and powdered leaves and stem bark. Fluorescence, physicochemical and phytochemical analysis and thin layer chromatography (TLC) were also performed using standard methods. The leaf is elliptical in shape with acuminate apex, entire margin, acute base, reticulate venation and pubescent on both the adaxial and abaxial surfaces. The leaf has wavy-walled epidermal cells with uniseriate clothing trichome. The midrib and petiole have concave-shaped vascular bundles. Starch grains, fibres, cork cells, stone cell, prismatic calcium oxalate crystals and uniseriate clothing trichomes were present in the leaves and stem bark powder. Physicochemical constants for ash content, solvent soluble extractives and pH revealed differences between the stem bark and leaves. The plant materials contained lead, cadmium and arsenic but below the limit values. They also contained varying levels of copper, zinc, calcium and potassium. Fluorescence analysis, Thin layer chromatography and UV-vis fingerprint also revealed notable differences in the stem bark and leaves. This result provides important diagnostic features to aid the correct identification and authentication of Aidia genipiflora for research and commercial purposes.