Abstract
The formulation of any herbal product starts with the raw plant material supply chain where it is crucial to have an in-depth understanding of the molecular and chemical composition and discrepancies in the plant material to ensure a standardized, effective, and reliable consumer product. The issue of plant substitution is noteworthy in the two genera under investigation: Harpagophytum spp (Devil’s claw) and Agathosma spp (Buchu). Currently, the preferred species for Devil’s claw herbal products is H. procumbens, which is often substituted with H. zeyheri. Similarly, the preferred species in Buchu herbal products is A. betulina, which is commonly substituted with A. crenulata. In both instances, species share some taxonomic similarities but are not chemically equivalent. The practice of species substitution may reduce the quality of the therapeutic effect and pose risks to the consumer. Considering the popularity of both Harpagophytum spp and Agathosma spp as indigenous herbal drugs, the study aimed to establish whether molecular techniques (DNA barcoding) could be used to authenticate these herbal products. Quality assessment concerns associated with Devil’s claw and Buchu were addressed in a two-pronged approach. Firstly, separate Reference DNA Barcode Library (RDBL) were generated for Harpagophytum spp and Agathosma spp using a variety of plastid regions (matK, trnL-F, and ycf1) and expertly identified material of known provenance. Respective commercial herbal products allegedly containing H. procumbens or A. betulina were then purchased online from various health outlets, which were then analysed for their authenticity. Secondly, phytochemical analysis was used to identify the biological markers, present in the respective genera. The Character-Based Barcode Recognition Obtained with Nucleotide eXpose´s (BRONX) sequence identification engine (SIDE) was implemented using the RDBL to authenticate the taxonomic identity of the Devil's claw and Buchu commercial herbal products...