Preliminary Standardization of Fadogia cienkowskii Schweinf (Rubiaceae) Leaves and Evaluation of the Anti-inflammatory Activity of the Methanol Extract

Abstract

Fadogia cienkowskii (family, Rubiaceae) has shown diverse activities in ethnomedicine. However, there are no established pharmacognostic standards for the plant. The study evaluated the phytochemical, proximate, microscopic and macroscopic properties of F. cienkowskii leaf and its methanol extract´s anti-inflammatory effects in animal models. The phytochemical and proximate analyses were evaluated by standard methods. The sodium hypochlorite (3.5%)-stained leaf was subjected to macroscopic examination. The leaf was bleached with and stained with safranin solution for light microscopic examination. An acute toxicity test in mice adopted the Lorke method, while an anti-inflammatory study in rats adopted egg albumin- and xylene-induced models. Alkaloids, saponins, tannins and flavonoids were detected in the extract. The proximate composition showed high moisture, total and sulphated ash values of 2.33, 3.85 and 3.0% respectively. The leaf (8 x 2.5 cm size) appeared rough in texture with a pubescent surface and bitter taste. Microscopic examination showed the stomata density, index, length, width, size and shape of 98.82 mm-2, 18.92, 19.70, 14.11 and 227.97 µm, respectively, with the upper epidermis covered by a cuticle to prevent excessive perspiration. With LD50 > 5000 mg/kg, a 200 mg/kg dose of methanol extract elicited 75.20 and 56.74% inhibition of egg albumin- and xylene-evoked paw and topical ear oedema, respectively, in rats with no significant difference (p > 0.05) compared with diclofenac (68.8 and 69.3 %). The phytochemical, proximate, macroscopic and microscopic characteristics of the leaf provided empirical data necessary for establishing the standards for the crude herbal anti-inflammatory property of F. cienkowski.