PHARMACOGNOSTIC STANDARDIZATION OF NAUCLEA DIDERRICHII (DE WILD AND T. DURAND) MERRILL (RUBIACEAE) LEAF

Abstract

Establishment of the pharmacognostic profile of the leaf of Nauclea diderrichii used by traditional medical healers
in the treatment of skin diseases, measles, fever, stomach problem, gonorrhea, menstral problem, tumours and
diarrhea will assist in standardization, quality assurance, purity and sample identification. Evaluation of the fresh,
powdered and anatomical sections of the leaf were carried out to determine the macro morphological, micro
morphological, chemo microscopical, physical leaf constants, physicochemical parameters, fluorescence and
phytochemical profiles. Macroscopical studies indicated the presence of simple leaf that was odourless, an entire
margin, acute apex, symmetrical base, reticulate venation and oppositely arranged. The petiole is 3 cm, lamina of
average length of 17.2 cm and breadth of 13 cm. Microscopically, the studies revealed the presence of paracytic
stomata and trichomes on the lower surface and calcium oxalate deposits along the veins and veinlets. Epidermal
cells are polygonal in shapes with straight walls. Physicochemical evaluation of the powdered leaf revealed the
following parameters; water soluble extractive of 22.13 %, alcohol soluble extractive of 27.73 %, percentage
moisture content of 8.0 %, total ash value of 6.0 %, acid insoluble ash value of 2.0 % and water soluble ash value of
4.3 %. Chemo microscopic characters presented include; lignin, cellulose, starch, tannins, aleurone grains, calcium
carbonate, inulin, suberin and calcium oxalate. Fluorescence analysis of the powdered leaves with some chemical
reagents depicted characteristic reactions such as brick red, brown, dirty green, light green and yellow under the day
and ultra violet lights. Preliminary phytochemical screening of the n- hexane, ethyl acetate and methanolic extracts
of the leaves revealed the presence of carbohydrates, saponins, tannins, alkaloids, cardiac glycoside, phenolic
compounds, phytosterols, triterpenes and flavonoids. The findings also included quantitative leaf microscopy. These
findings could serve as a basis for proper identification, collection and investigation of Nauclea diderrichii leaf,
hence it should be suitable for inclusion in the Pharmacopoeia of Nigerian Medicinal plants.