Pharmacognostical characterization of Piper arboreum var. arboreum and P. tuberculatum (Piperaceae)

ABSTRACT

Piper arboreum Aubl. var. arboreum and P. tuberculatum Jacq. (Piperaceae), both known as "pimenta-longa", are frequently misidentified. Despite the fact that both species are sold as traditional phytotherapeutic products, there are no reports on their quality control. The aim of this study was to prepare and characterize leaf and stem herbal drugs of both species using standard methods aiming to establish parameters for botanical authentication and purity degree for their quality control. Size, shape, color, taste, texture, fracture surface and transection characteristics, and leaf venation patterns are macroscopic diagnostic characters useful to distinguish the herbal drugs when they are not powdered. The following characters are useful for diagnostic purposes of the powdered herbal drugs: cuticular and epicuticular wax patterns, types of trichomes, and wall thickening of the tracheary elements, and shape of the hilum of the starch grains. Emergences are key morphological markers for P. tuberculatum herbal drugs. Physicochemical parameter values were similar in herbal drugs of both species, except acid-insoluble ash value which was higher in the P. arboreum var. arboreum stem herbal drugs. Piper arboreum var. arboreum herbal drugs had the highest metal concentrations. Al, Cu, Mn and V concentrations were the highest, whereas Cd, Co and Hg concentrations were the lowest in the herbal drugs of both species. The results obtained can be used as quality control parameters for the herbal drugs of both species.

Keywords: Pimenta-longa; Traditional phytotherapeutic products; Pharmacognosy; Toxic metals; ICP-OES