DNA-based phylogenetic analysis of mugwort for moxibustion from Japan, China, and South Korea

Moxibustion, along with acupuncture, is an important therapeutic approach in traditional East Asian medicine. As such, the burning of moxa floss on the skin to thermally stimulate body surfaces. Presently, moxa floss is manufactured from mugwort leaves mainly in Japan, China, and South Korea. The genus Artemisia, to which the mugwort belongs, reportedly includes more than 250 wild species in the world and more than 30 in Japan. This study was conducted to characterize Japanese moxa floss by identifying various varieties of moxa floss mugwort (MFM) material collected from leading places of moxa floss production in the world by DNA-based phylogenetic analysis. DNA was extracted from Japanese mugwort (9 families), South Korean dry mugwort (1 family), and Chinese dry moxa floss (4 types), and the nuclear DNA ITS and chloroplast DNArpl32-trnL, trnQ-5′rps16, and trnH-psbA regions were sequenced. All Japanese mugwort samples were found to have the same DNA sequence in the ITS region; there were no location-specific sequences. Chinese and South Korean mugwort samples were found to have species-specific mutations, and their mutated sequence was found to be identical to the sequence ofA. argyi, a species remote from Japanese Artemisia. By identifying the various MFM varieties in Japan as the same species, this study showed that Japanese moxa floss can be characterized not only by manufacturing process, but also by raw material. The identification is also believed to provide basic information to understand the historical changes of places of MFM production.