Applying DNA Barcoding to identify species of medicinal plants

Abstract

According to the World Health Organization (WHO), in recent years, 80% of the population made use of some kind of medical plant in search of relief from any painful or unpleasant symptoms [1]. In 2003, Herbert Paul proposed the use of “DNA Barcoding” as a method to identify species using a small gene sequence from part of the genome of the species [2]. In this way to confirm the species of four compounds of medicinal tea widely consumed by Brazilian population – Melissa officinalis, Mykania laevigata, Vernonia polyanthes and Solanum lycocarpum – we have used the technique of DNA Barcode. For this purpose, the DNA were extracted using the CTAB protocol (cetyl trimethyl ammonium bromide) [3]. The PCR reaction was done using the following primers pairs: rbcLa, psbA – trnH and ITS2. The samples were applied in capillary electrophoresis on ABI 3500 Genetic Analyzer (Applied Biosystems). The table shows the results. The DNA Barcoding results allowed to confirm the identity of M. Laevigata, but not for the other analyzed species. The leaves from S. lycocarpum and V. polyanthes were confirmed by macroscopic and microscopic analyzes when the exsicata were making, which demonstrated that this new methodology helps to improve the studies for the identification using new primers increasing the genetic database of Brazilian species of medicinal plants. Keywords: Brazilian medicinal plants, DNA Barcoding, species identification