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Cracking down on counterfeits: Creating a DNA barcode reference library of commercial herbal products traded in South Africa
Letlhogonolo Sello, Ryan D Rattray, Michelle van der Bank
The African Centre for DNA Barcdoing (ACDB), Department of Botany & Plant Biotechnology, University of Johannesburg, P. O. Box 524 Auckland Park, South Africa - 2006
Background: Herbal products have been used for different purposes throughout human history, especially to treat numerous health ailments. Generally, it is believed that herbal products are affordable and safer to use compared to modern medications. The increase in the demand for herbal products places suppliers under immense pressure to deliver. Subsequently, commercial herbal products are often subjected to contamination or substitution of the main plant ingredient listed on the product label. This can result in reduced therapeutic potential and poses a serious health risk for consumers. Currently, there are no standard practices or systems available for the identification of species used in herbal products in South Africa, other than chemical analyses alone. As a result, the industry suffers from fraudulent and unethical practices. Results: A list consisting of 70 native plant species used in commercial herbal products traded in South Africa were compiled. All reference samples and look-alike species (1 to 5 individuals per species) were sequenced using the core barcoding regions rbcLa and matK to compile the DNA database. The database was then used to authenticate local products. Significance: This DNA barcode reference library, the first of its kind in South Africa, can provide pharmaceutical companies with a database against which they are able to compare their sourced raw materials and verify their authenticity.
INTRODUCTION & AIM
The increase in the demand for commercial herbal products (CHP) place suppliers under immense pressure to deliver and this results in increased concerns related to the safety and efficacy of the products (Ramanujam et al., 2017). Not being able to distinguish authentic products in their raw form or processed materials from their close relatives, inferior substitutes, adulterants, and counterfeits is a great challenge (Sun et al., 2016).
The absence of standard practices (other than phytochemical profiling) for the identification and authentication of species used in South Africa, subjects the industry to unethical and fraudulent practices (Vassou et al., 2016). These practices may be prevented by enforcing a standard authentication system that will enable the marketing of authentic herbal products (Wallace et al., 2012).
Our aim was to create a DNA barcode reference library that can provide pharmaceutical companies with a database against which to verify the authenticity of their sourced raw materials.
MATERIAL & METHODS
REFRENCES & ACKNOWLEDGEMENTS Newmaster, S.G., Grguric, M., Shanmughanandhan,D., Ramalingam, S., and Ragupathy, S. 2013. DNA barcoding detects contamination and substitution in North
American herbal products. BMC Medicine, 11:222 http://www.biomedcentral.com/1741-7015/11/222 Ramanujam, S., Kumar, J.U.S., Seethapathy, G.S., Newmaster, S.G., Ragupathy, S., Ganeshaiah, K.N., Shaanker, R.U., and Ravikanth, G. 2017. Species Adulteration
in the Herbal Trade: Causes, Consequences and Mitigation. Drug Safety. doi: 10.1007/s40264-017-0527-0 Sun,W., Li,J.J., Xiong, C., Zhao, B., and Chen, S.L. 2016. The Potential Power of Bar-HRM Technology in Herbal Medicine Identification. Frontiers in Plant Science,7
(367): 1-10. Vassou, S.L., Nithaniyal, S., Raju, B., and Parani, M. 2016. Creation of a reference DNA barcode library and authentication of medicinal raw drugs used in
Ayurvedic medicine. BMC Complementary and Alternative Medicine, 16, 9-15. Wallace, L.J., Boilard, S.M.A.L., Eagle, S.H.C., Spall, J.L., Shokralla, S., Hajibabaei, M. 2012. DNA barcodes for everyday life: Routine authentication of Natural
Health Products. Food Research International, 49: 446–452.
Figure 1: Schematic diagram showing the process of creating the DNA barcode library and authenticating commercial herbal products sold on the South African market.
PHOTO CREDITS: Aloe:By Gil Walker https://flic.kr/p/a8k6Md Emex: By Forest and Kim Starr https://flic.kr/p/EcYzUX Prosopis: By Dinesh Valke https://flic.kr/p/4onPEe Lessertia: By Eric Lux https://flic.kr/p/6tbZuz
Based on the results obtained, 71% of the tested products were found to be authentic and 29% of the products were determined to be substituted (Fig. 2A). High quality PCR products were obtained for rbcLa as compared to matK. This coincides with the findings of Newmaster et al., 2013, who determined that matK is usually associated with poor PCR amplifications. Figure H & I show the plant species that were used as substitutes of some of the herbal products tested.
The significance of this study was to create a DNA barcode reference library, the first of its kind in South Africa, that can be used to authenticate CHPs. DNA barcoding provides a quick, easy and accurate method of authentication. Though most of the products in this particular study were authentic, there may be many subject to fraudulent activities. It is suggested that barcoding be incorporated as a quality control mechanism to thwart such practices and protect the consumer market.
Figure 2: A. Pie chart showing the percentage of authentic and unauthentic South African commercial herbal products tested. Figure B. to G., shows several of the species listed on the products tested: B. Lessertia frutescens, C. Harpagophytum procumbens, D. Aloe ferox, E. Warbugia salutaris, F. Agathosma betulina & G. Prosopis juliflora. H. Camellia sinensis & I. Emex spinosa.
DISCUSSION & CONCLUSION
POSTER ID: 680
Authentic Unauthentic Authentic VS Unauthentic CHP tested in this study
G H I
D E F