DNA Barcoding in Medicinal Plant Authentication: Principles, Applications and Future Perspectives

Plant medicinal provides therapy or medicine for the prevention and treatment of diseases. Many medicinal plants are used as source of therapy in modern medicine. However, correct identification of many medicinal plants is often difficult due to apparent morphology, extensive habitats and increasing adulteration in herbal products. Traditional taxonomy-based identification method is found sometimes unfruitful, especially when plant material is processed or chopped. Molecular approaches, especially DNA barcodes using small portions of plant DNA, have been proposed as efficient and reliable techniques for identification and authenticity assessment of medicinal plant species. This review discusses the principles and applications of DNA barcoding technology for the identification and authentication of medicinal plants. We mainly focus on three commonly used barcode regions: rbcL and matK from chloroplast DNA, and the nuclear internal transcribed spacer (ITS). We describe the workflow of DNA extraction, PCR amplification and sequencing, and sequence analysis using bioinformatics tools. Case studies demonstrate the role of the DNA barcodes in detecting adulterants, in distinguishing closely related species and in quality control in the herbal medicine industry.