Microscopic features and phytochemistry of two Congolese medicinal plants: Aframomum alboviolaceum (Ridley) K. Schum, and Aframomum angustifolium (Sonn.) K. Schum. (Zingiberaceae).

Abstract

The leaves and seeds of Aframomum alboviolaceum and Aframomum angustifolium are specifically used by traditional healers in the Democratic Republic of Congo (DRC) for the treatment of several pathologies. The aim of present study was to determine the microscopic characteristics and phytochemical composition of these species of the genus Aframomum. The microscopic study of these plants revealed the presence of punctate vessels, fiber cluster with calcium oxalate crystals, isolated unicellular hair, fibers, starch grains, spiral vessel fragments, fiber fragments, and indistinct parenchyma fragments. Phytochemical screening revealed several chemical groups such as phenolic acids, flavonoids, coumarins, alkaloids, terpenes, iridoids, saponins etc. The determination of total polyphenols, flavonoids and tannins gave contents ranging from 14.95 ± 0.45 and 63.98 ± 2.04 mgGAE/g, 0.16 ± 0.01 and 10.68 ± 0.32 mgQE/g and between 1.28 ± 0.03 and 28.51 ± 0.56 mg CAE/g respectively. In general, the leaves are richer in secondary metabolites, polyphenols, flavonoids and tannin than the seeds. Both plants also contain iron, magnesium, calcium and sodium. To our knowledge, this is the first time that histological elements have been identified in the leaves and seeds of A. angustifolium.