Establishment of conventional PCR and real-time PCR assays for accurate, rapid and quantitative authentication of four mistletoe species

Adulterants in processed food and herbal medicines reduce their safety, quality control, or pharmacological efficacy. Four mistletoe species, including Viscum coloratum, inhabit Korea. Leaves and branches of V. coloratum, defined as edible or medicinal mistletoe species in Korean, are used to prepare Korean herbal medicines as well as leached tea. However, other mistletoe species including Taxillus sutchuenensis var. duclouxii, Korthalsella japonica, and Loranthus tanakae are frequently distributed as authentic V. coloratum in Korean markets because of similarities in the branches morphology and Korean names of these species with V. coloratum. Although herbal medicines and food products prepared from the other mistletoe species are inauthentic, they are sold at high prices because of the rarity of these species. Thus, it is important to distinguish between authentic and inauthentic adulterant mistletoe species. In this study, we developed species-specific primer, based on matK sequences, suitable for both conventional PCR and real time PCR (qPCR) assay. These assays allowed rapid discrimination among all four mistletoe species. Moreover, qPCR assay enabled the detection of trace amounts of adulterant mistletoe species in V. coloratum samples. Furthermore, we used these assays to monitor commercial mistletoe products distributed in Korean markets. Our data suggest that these methods would serve as a reliable genetic tool to prevent adulteration and standardize the quality of commercial V. coloratum products.