Authentication of Akebia quinata DECNE. from its common adulterant medicinal plant species based on the RAPD-derived SCAR markers and multiplex-PCR

Akebiae Caulis, 'Mutong' in Chinese, refers to the stem of Akebia quinata in the Korean modern pharmacopoeia. The stems of Aristolochia manshuriensis and Clematis armandii have also been traditionally used for clinical purposes, and are often marketed as 'Mutong' under the names 'Guan-Mutong and Chuan-Mutong', respectively. Furthermore, due to the morphological similarity of the herbal medicines, their correct identification by traditional subjective methods is difficult. Therefore, to develop a reliable method for discriminating these three herbal medicines, we applied the tools of molecular genetics, including random amplified polymorphic DNA (RAPD) and sequence characterized amplified region (SCAR) marker development using samples of Akebia quinata, Akebia trifoliata, Aristolochia manshuriensis, and Clematis armandii. By comparative analysis of RAPD polymorphisms, we identified several potential PCR products that can be used to distinguish the herbal materials of each species. Using these RAPD products, we developed unique sequence characterized amplified region (SCAR) markers for determination of the species of plant materials; the products were 590 bp for A. quinata, 300 bp for A. trifoliata, 373 bp for A. manshuriensis, and 432 bp for C. armandii. Furthermore, we optimized SCAR markers for simultaneous discrimination of the four species by multiplex-PCR. These markers allow efficient identification of closely related herbal medicines originating from Akebia, Aristolochia, and Clematis species, and have potential uses in preventing the distribution of adulterants, as they can be used to identify each species and distinguish them from inauthentic substitutes.