Application of Light and Scanning Electron Microscopy in the Identification of Herbal Medicines

Herbal drug technology includes all the necessary steps for the conversion of botanical materials into medicines, where standardization and quality control are essential analytical tools to assure the correct identification of drugs. Advances in microscope technology and improvements in light and scanning electron microscopes have increased the accuracy and capabilities of microscopy as a mean of botanical identification. The objective of this chapter is to present a set of the most relevant histological characters by which some selected herbal drugs must be identified, taking into account the corresponding plant part used, namely, bark, root and rhizome, leaf, flower, fruit and seed. The botanical control by microscopic examinations, using histological identification, can be used as a rapid and inexpensive identification technique, but requires highly trained individuals and a limited standard references libraries are available for comparison. This approach aims at the establishment of botanical biomarkers based on the major microscopic features observed in the studied drugs.