title: DNA barcoding for species identification from dried and powdered plant parts: a case study with authentication of the raw drug market samples of Sida cordifolia.
abstract: The majority of the plant materials used in herbal medicine is procured from the markets in the form of dried or powdered plant parts. It is essential to use authentic plant materials to derive the benefits of herbal medicine. However, establishing the identity of these plant materials by conventional taxonomy is extremely difficult. Here we report a case study in which the species identification of the market samples of Sida cordifolia was done by DNA barcoding. As a prelude to species identification by DNA barcoding, 13 species of Sida were collected, and a reference DNA barcode library was developed using rbcL, matK, psbA-trnH and ITS2 markers. Based on the intra-species and inter-species divergence observed, psbA-trnH and ITS2 were found to be the best two-marker combination for species identification of the market samples. The study showed that none of the market samples belonged to the authentic species, S. cordifolia. Seventy-six per cent of the market samples belonged to other species of Sida. The predominant one was Sida acuta (36%) followed by S. spinosa (20%), S. alnifolia (12%), S. scabrida (4%) and S. ravii (4%). Such substitutions may not only fail to give the expected therapeutic effect, but may also give undesirable effects as in case of S. acuta which contains a 6-fold higher amount of ephedrine compared to the roots of S. cordifolia. The remaining 24% of the samples were from other genera such as Abutilon sp. (8%), Ixonanthes sp., Terminalia sp., Fagonia sp., and Tephrosia sp. (4% each). This observation is in contrast to the belief that medicinal plants are generally substituted or adulterated with closely related species. The current study strongly suggests that the raw drug market samples of herbal medicines need to be properly authenticated before use, and DNA barcoding has been found to be suitable for this purpose.
authors.affiliation: Department of Genetic Engineering, Center for DNA Barcoding, School of Bioengineering, SRM University, Kattankulathur 603203, India.
authors.forename: Sophie Lorraine
authors.initials: SL
authors.lastname: Vassou
authors.affiliation: Pharmacy Department, Captain Srinivasa Murti Research Institute for Ayurveda and Siddha Drug Development (CSMRIASDD), Under Central Council for Research in Ayurvedic Sciences (CCRAS), Department of AYUSH, Ministry of Health and Family Welfare, Government of India, Anna Hospital Campus, Arumbakkam, Chennai 600106, India.
authors.forename: G
authors.initials: G
authors.lastname: Kusuma
authors.affiliation: Department of Genetic Engineering, Center for DNA Barcoding, School of Bioengineering, SRM University, Kattankulathur 603203, India. Electronic address: parani.m@ktr.srmuniv.ac.in.
authors.forename: Madasamy
authors.initials: M
authors.lastname: Parani
mesh_terms: D058893:DNA Barcoding, Taxonomic; D017343:Genes, Plant; D019660:Malvaceae / Q000235:genetics*; D008517:Phytotherapy; D010940:Plant Proteins / Q000235:genetics*; D010946:Plants, Medicinal / Q000235:genetics*
chemical_list: D010940:Plant Proteins
keywords: DNA barcoding; ITS2; Raw drugs; Sida; psbA-trnH