Bar-HRM for Authentication of Plant-Based Medicines: Evaluation of Three Medicinal Products Derived from Acanthaceae Species

Abstract

Medicinal plants are used as a popular alternative to synthetic drugs, both in developed and developing countries. The economic importance of the herbal and natural supplement industry is increasing every year. As the herbal industry grows, consumer safety is one issue that cannot be overlooked. Herbal products in Thai local markets are commonly sold without packaging or labels. Plant powders are stored in large bags or boxes, and therefore buying local herbal products poses a high risk of acquiring counterfeited, substituted and/or adulterated products. Due to these issues, a reliable method to authenticate products is needed. Here DNA barcoding was used in combination with High Resolution Melting analysis (Bar-HRM) to authenticate three medicinal Acanthaceae species (Acanthus ebracteatus, Andrographis paniculata and Rhinacanthus nasutus) commonly used in Thailand. The rbcL barcode was selected for use in primers design for HRM analysis to produce standard melting profiles of the selected species. Melting data from the HRM assay using the designed rbcL primers showed that the three chosen species could be distinguished from each other. HRM curves of all fifteen test samples indicated that three of tested products did not contain the indicated species. Two closely related species (A. paniculata and R. nasutus), which have a high level of morphological similarity, were interchanged with one another in three tested products. Incorrect information on packaging and labels of the tested herbal products was the cause of the results shown here. Morphological similarity among the species of interest also hindered the collection process. The Bar-HRM method developed here proved useful in aiding in the identification and authentication of herbal species in processed samples. In the future, species authentication through Bar-HRM could be used to promote consumer trust, as well as raising the quality of herbal products.

DNA Barcoding and Pharmacovigilance of Herbal Medicines

“…The first study reporting the use of Bar-HRM to study herbal medicine substitution has recently been reported in a study on species substitution among three medicinal species of Acanthaceae [84]. Bar-HRM has also been used in a number of comparable methodologies [85], such as for authentication of an EU Protected Designation of Origin product made from Lathyrus clymenum [86], olive oil and adulterants [87], subspecies cultivar identification in eggplant [88], identification of closely related species relevant to TDG [89,90], species distinction in Mediterranean pines [91], detection of allergenic hazelnut contamination [92], and processed bean crops [93][94][95].…”

Detection of Adulteration by Wedelia calendulacea in Eclipta alba through ISSR and RAPD Markers

“…Therefore, DNA-based technologies, which are more stable and reliable, have clear advantage over these traditional methods. Although DNA barcoding, extreme PCR, or high-resolution melting analysis provide more authentic and accurate results, cost-effective and reliable identification tools like ISSR and RAPD markers have been considered advantageous since they can be carried out in reasonably equipped laboratories [19,[21][22][23]. In the present study, phylogenetic inference coupled with PCA and PCoA effectively resolved and clearly differentiated W. calendulacea from E. alba.…”

Study of Commercially Available Lobelia chinensis Products Using Bar-HRM Technology

“…HRM technology has been utilized for discriminating cultivated varieties, medicinal plant species, herbal tea, wine authenticity (Jung et al, 2010; Osathanunkul et al, 2015, 2016; Costa et al, 2016; Li et al, 2016; Song et al, 2016; Pereira et al, 2017). However, a reliable HRM approach to identify herbal medicines on Chinese herb market is still lacks.…”