Pharmacognostic Evaluation of the Leaves of Manihot esculenta Crantz. (Euphorbiaceae)

Abstract

Manihot esculenta Crantz (Euphorbiaceae) is used ethnomedicinally in the management of pain, prostate cancer, diabetes and bacterial infections. This study evaluated quality-control parameters of M. esculenta leaves to support the identification and standardisation of the medicinal plant. The leaves were collected, identified, air-dried, pulverised and stored in containers. Standard procedures were used to determine the microscopic features of fresh and powdered samples, micromeritic properties, chemomicroscopic and fluorescence characteristics, moisture content, ash values and soluble extractive values. Microscopic examination revealed paracytic stomata on the abaxial and adaxial surfaces, indicating an amphistomatic leaf, with stomatal indices of 4.95% and 0.23% and stomatal numbers of 40.1 and 1.20, respectively. The powdered leaf had an angle of repose of 34.60°, a Carr’s index of 19.3% and a Hausner’s ratio of 1.24, indicating good-to-fair flow properties. Moisture content, total ash, acid-insoluble ash and water-soluble ash values were 16.8% w/w, 5.8% w/w, 0.5% w/w and 1.5% w/w, respectively. Water-, methanol- and ethanol-soluble extractive values were 17.3% w/w, 14.3% w/w and 13.7% w/w, respectively. Chemomicroscopy indicated the presence of mucilage, cellulose, starch, lignin, calcium oxalate crystals and protein. These findings provide diagnostic and physicochemical data that may support the identification, authentication and preliminary pharmacopoeial standardisation of fresh and powdered M. esculenta leaf material.