Journal of Natural Medicines

, Volume 72, Issue 1, pp 369–374 | Cite as

Evaluation of raw nepodin extraction from Rumex japonicus and R. obtusifolius and their DNA polymorphisms

  • Motoyasu MinamiEmail author
  • Takako Mori
  • Takayuki Yonezawa
  • Yukiko Saito
  • Toshiaki Teruya
  • Je-Tae Woo
Natural Resource Letter


Nepodin, found in the roots of Rumex japonicus Houtt. (Polygonaceae), inhibits osteoclast differentiation and has an antidiabetic effect. We propose nepodin as an ingredient of new functional foods or as a drug candidate for reducing the risk of reduced locomotion resulting from diseases such as osteoporosis. Although there are no previous reports of R. obtusifolius L., which is found throughout Japan, having roots containing nepodin, we found nepodin in the roots of this species. Therefore, R. obtusifolius as well as R. japonicus was considered a candidate raw material for nepodin extraction. We also discuss the suitability of R. japonicus and R. obtusifolius as sources of raw nepodin for cultivation on the Ryukyu Islands. In this study, all specimens on the Ryukyu Islands were identified as R. japonicus. Conversely, all specimens on mainland Japan were R. obtusifolius. The DNA sequence of the chloroplast trnL–trnF intergenic spacer region and partial nuclear internal transcribed spacer was consistent with the identification of R. japonicus and R. obtusifolius by morphological characteristics of the perianth segments. Therefore, to avoid erroneous identification and misuse of the plant species used for extraction of raw materials, it is preferable to develop DNA markers for these two regions. The content of nepodin varied from undetectable to 0.34% of the fresh weight (%FW) in R. japonicus and from undetectable to 0.21%FW in R. obtusifolius. From a pharmacological perspective, as plants that might be suitable as raw materials for nepodin extraction, it became clear that both R. japonicus and R. obtusifolius can be used with the same expected extraction efficiency. Based on our findings, R. obtusifolius could not be confirmed as inhabiting the Ryukyu Islands. For this reason, to conserve the endemic genetic characteristics of the Ryukyu Islands and to prevent genetic pollution by R. obtusifolius, only R. japonicus should be cultivated on the Ryukyu Islands.


Nepodin Rumex japonicus R. obtusifolius Ryukyu Islands trnL–trnF intergenic spacer region ITS 



The authors thank Mr. Masaki Matayoshi of the Okinawa Technology Licensing Organization Co. Ltd. for his support. This study was supported by a project commissioned by the Okinawa Prefectural Government.


  1. 1.
    Tawada M, Ohta H (1985) Okinawa no Yakusou Hyakka. Nahashuppan, Naha (in Japanese)Google Scholar
  2. 2.
    Hasegawa S, Teruya T, Yonezawa T, Cha BY, Nagai K, Woo JT (2006) Inhibition of octeoclast differentiation by nepodin isolated from Rumex japonicus. J JSMUFF 4:37–41 (in Japanese) Google Scholar
  3. 3.
    Ha BG, Yonezawa T, Son MJ, Woo JT, Ohba S, Chung UL, Yagasaki K (2014) Antidiabetic effect of nepodin, a component of Rumex roots, and its modes of action in vitro and in vivo. BioFactors 40:436–447CrossRefGoogle Scholar
  4. 4.
    Minami M, Nishio K, Ajioka Y, Kyushima H, Katsuki S, Kinjo K, Yamada K, Nagai M, Satoh K, Sakurai Y (2009) Identification of Curcuma plants and curcumin content level by DNA polymorphisms in the trnS-trnfM intergenic spacer in chloroplast DNA. J Nat Med 63:75–79CrossRefGoogle Scholar
  5. 5.
    Minami M, Mia W, Sakai E, Nishi K, Satake M, Kondo S, Nunoura Y, Shibata T (1999) Variations in flowering date, shoot growth and contents of choleretic substances in capitulum in Artemisia capillaris collected from various locations in Japan. Plant Prod Sci 2:241–246CrossRefGoogle Scholar
  6. 6.
    Yonekura K (2006) Rumex L. In: Iwatsuki K, Boufford DE, Ohba H (eds) Flora of Japan Volume IIa. Kodansha, Tokyo, pp 123–131Google Scholar
  7. 7.
    Minami M, Hosokawa K, Mia W, Sakai E, Satake M, Kondo S, Oka K, Ban K, Kayano T, Tanaka H, Shibata T (2003) Morphological, chemical and molecular biological comparison among Artemisia capillaris, A. japonica and their natural hybrids. J Nat Med 57:1–6Google Scholar
  8. 8.
    Hongo A (1987) Morphological characters of Rumex plants collected from sown grasslands in Eastern Hokkaido. Res Bull Obihiro Univ Ser I 15:229–235 (in Japanese with English summary) Google Scholar
  9. 9.
    Taberlet P, Gielly L, Pautou G, Bouvet J (1991) Universal primers for amplification of non-coding regions of chloroplast DNA. Plant Mol Biol 17:1105–1109CrossRefGoogle Scholar
  10. 10.
    Long C, Kakiuchi N, Takahashi A, Komatsu K, Cai S, Mikage M (2004) Phylogenetic analysis of the DNA sequence of the non-coding region of nuclear ribosomal DNA and chloroplast of Ephedra plants in China. Planta Med 70:1080–1084CrossRefGoogle Scholar
  11. 11.
    Tamura K, Stecher G, Peterson D, Filipski A, Kumar S (2013) MEGA6: molecular evolutionary genetics analysis version 6.0. Mol Biol Evol 30:2725–2729CrossRefGoogle Scholar
  12. 12.
    Jensen HW (1936) Meiosis in Rumex. I. Polyploidy and the origin of new species. Cytologia 7:21–22CrossRefGoogle Scholar
  13. 13.
    Hatusima S (1975) Rumex L. In: Flora of the Ryukyus. Okinawa Association of Biology Education, Naha, p 249 (in Japanese)Google Scholar
  14. 14.
    Walker EH (1976) Rumex L. Flora of Okinawa and the southern Ryukyu Islands. Smithsonian Inst. Press, Washington DC, pp 425–426Google Scholar
  15. 15.
    Kitagawa M (2006) Rumex L. In: Satake Y, Ohwi J, Kitamura S, Watari S, Tominari T (eds) Wild flowers of Japan II. Heibonsha, Tokyo, pp 14–16 (in Japanese) Google Scholar
  16. 16.
    Vasas A, Orsolya OG, Judit H (2015) The Genus Rumex: review of traditional uses, phytochemistry and pharmacology. J Ethnopharmacol 175:198–228CrossRefGoogle Scholar

Copyright information

© The Japanese Society of Pharmacognosy and Springer Japan KK 2017

Authors and Affiliations

  • Motoyasu Minami
    • 1
    Email author
  • Takako Mori
    • 1
  • Takayuki Yonezawa
    • 2
  • Yukiko Saito
    • 3
  • Toshiaki Teruya
    • 3
  • Je-Tae Woo
    • 1
    • 4
  1. 1.Department of Environmental Biology, College of Bioscience and BiotechnologyChubu UniversityKasugaiJapan
  2. 2.Research Institute for Biological FunctionsChubu UniversityKasugaiJapan
  3. 3.Faculty of EducationUniversity of the RyukyusNishiharaJapan
  4. 4.Okinawa Research Center Co. Ltd.Okinawa Health Biotechnology Research and Development CenterUrumaJapan

Personalised recommendations