Morphoanatomical and physicochemical profile of Piper callosum: valuable assessment for its quality control

Abstract

Piper callosum Ruiz & Pav., Piperaceae, popularly known as “elixir-paregórico” and “matricá” in Brazil,is used in folk medicine to treat gonorrhea, general pain, and digestive disorders, and has repellent,astringent, diuretic, depurative, and haemostatic properties. Despite the fact that this plant is sold as atraditional phytotherapeutic product, we did not find reports on its quality control. We, therefore, per-formed macroscopic, microscopic, histochemical, and physicochemical analyses using standard methodsto establish botanical authentication and purity degree parameters for leaves and stem of this species intwo forms: medicinal plant and herbal drug. We observed the size, shape, color, texture, fracture surfaceand transection characteristics, leaf venation patterns, and calluses are valuable diagnostic charactersto identify the herbal drugs when they are not ground or powdered. Since medicinal plants and herbaldrugs did not differ anatomically, the following key anatomical characters for P. callosum can be used fordiagnostic purposes of both types raw plant materials: epicuticular wax and cuticular flanges patterns;collenchyma features; fibers in the midrib; arrangement pattern of the vascular bundles of the midrib andpetiole; shape of the midrib, leaf margin, petiole, and stem; occurrence of raphides; and morphology ofthe starch grains. Acid lipids, essential oils, oleoresins, steroids, tannins and flavonoids were histochem-ically identified. Total ash (leaves: 11.25%; stem: 5.25%), sulphated ash (leaves: 68.02%; stem: 12.50%),acid-insoluble ash (leaves: 2.82%; stem: 0.27%), moisture (leaves: 8.60%; stem: 6.10%), loss on drying(leaves: 11.08%; stem: 8.58%), and pH (leaves: 5.57, stem: 5.28) values were determined. The order ofanalyzed metal levels in leaf and stem herbal drugs was Al > V > Cu > Mn > Cr > Ni. Similar levels of Cd andCo and low levels of Hg were found. The results obtained can be used as quality control parameters formedicinal plants and herbal drugs of P. callosum.