Anatomical identity parameters of the crude drug Psidii guajavae folium

Abstract The leaves of Psidii guajavae L. (Myrtaceae) (Guava) are popularly used in tropical countries to prepare a remedy for the treatment of patients suffering of liquid stools; this traditional use is now scientifically supported by the existence in the leaf of a group of quercetin-derived flavonoids with intestinal anti-motility, spasmolytic and anti-inflammatory properties. Consequently, herbal products prepared with Psidii guajavae folium are now clinically used to treat Acute Diarrheic Disease and some are commercialized as phyto-drugs. However, there are no studies on morphology of this plant drug, particularly to determine the anatomical characters required for quality control of the raw material used in the preparation of guava-leaf phytodrugs. The present paper provides the anatomical and morphological characters that help in the authentication of Psidii guajavae leaf. Guava leaf surfaces were dissected and stained with cresyle-violet; transversal cuttings of the lamina and petiole were stained using safranine-fast green; samples were studied using procedures of light, scanning-electron and laser-scanning con-focal microscopy. Anomocytic and anisocytic stomatas in the abaxial epidermis, long unicellular trichomes and schizolysigenous secretory cavities are proposed as anatomical parameters to establish authenticity of guava leaf crude drug.