Pharmacognostic Study of three species of Tephrosia Pers. (Fabaceae) harvested in Mali

Plants of the genus Tephrosia are very widespread in West Africa. They are used in traditional medicine to treat various diseases mainly inflammatory diseases. The objective of this study was to determine the pharmacognostic parameters of the leafy stems of Tephrosia bracteolata Guill. & Perr., Tephrosia mossiensis A. Chev. and Tephrosia linearis (Willd.) harvested in Mali in order to contribute to the writing of their monographs. The pharmacognostic parameters of the leafy stems of three species of Tephrosia harvested in Mali, have been characterized. Macroscopic, organoleptic features and microscopic elements determined. Extracts were prepared. Main chemical components and antiradical constituents were characterized. The stems of all three Tephrosia species are generally erect, cylindrical, and solid. The leaves are odd-pinnate and alternate with a variable number of pairs of leaflets which are of various shapes. The powders of the leafy stems of the three Tephrosia species had a lichen-green color, an uncharacteristic odor, a tasteless flavor, and a semi-coarse texture. Micrography revealed the presence of specific elements which are multicellular covering trichomes, straight and slightly curved unicellular covering trichomes, and starch grains. The moisture contents were less than 10%. The contents of insoluble ashes in diluted HCl were less than 1%. Main chemical components revealed in all three samples are polyphenols, sterols, and triterpenes. Both aqueous and hydroethanolic extracts exhibited antiradical activity by reducing the DPPH radical. Data from this study contributed to monographs of the leafy stems of these plants and will be helpful in the quality control of leafy stem samples from these plant species.