A DNA barcoding approach for identifying species in Amazonian traditional medicine: The case of Piri-Piri

The progressive loss of knowledge about the use of plants in traditional medicine practices is an issue of major concern with social, economic, and health implications for local communities, especially in developing countries. The Peruvian Amazon is one of the principal scenarios where this phenomenon is occurring at a growing rate. We investigated the case of Piri-Piri (Cyperus articulatus L.), a species of sedge used by native populations of Peru as an antiemetic, an anti-diarrheal, a sedative, an anti-venom, and to treat other symptoms or to conduct ritual practices. In this study, we collected 19 samples of Piri-Piri from different natives' familiar nuclei in four Amazonian villages, and we used the molecular tool DNA barcoding to verify the corrected species identification. The identification performances of four barcode loci (rbcL, matK, trnH-psbA and ITS) were evaluated. RbcL and matK were not able to univocally identify the Piri-Piri samples; however, they indicated that one sample did not match with the expected C. articulatus (local misidentification). This finding was further confirmed at both trnH-psbA and ITS regions. These two loci designated the remaining 18 samples to the correct species, C. articulatus. Based on our results, we propose DNA barcoding as a reliable tool for preserving the genetic identity and the exploitation of Piri-Piri by the local traditional medicine. This universal and fast molecular characterization method should be included in Internet-based Automated Identification Technology systems to enhance the spread of traditional medicine and prevent the erosion of ancient traditional knowledge.