Minami Motoyasu, Mori Takako, Yonezawa Takayuki, Saito Yukiko, Teruya Toshiaki, Woo Je-Tae
Department of Environmental Biology, College of Bioscience and Biotechnology, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi, 487-8501, Japan.
Research Institute for Biological Functions, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi, 487-8501, Japan.
J Nat Med. 2018 Jan;72(1):369-374. doi: 10.1007/s11418-017-1143-0. Epub 2017 Oct 23.
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.
尼泊尔蓼（Nepodin）存在于酸模叶蓼（Rumex japonicus Houtt.）（蓼科）的根部，可抑制破骨细胞分化并具有抗糖尿病作用。我们提议将尼泊尔蓼作为新型功能性食品的成分或作为降低骨质疏松症等疾病导致运动能力下降风险的候选药物。虽然此前没有关于在日本各地均有发现的钝叶酸模（R. obtusifolius L.）根部含有尼泊尔蓼的报道，但我们在该物种的根部发现了尼泊尔蓼。因此，钝叶酸模以及酸模叶蓼被视为尼泊尔蓼提取的候选原材料。我们还讨论了酸模叶蓼和钝叶酸模作为琉球群岛上尼泊尔蓼原生原料来源进行种植的适宜性。在本研究中，琉球群岛上的所有标本均被鉴定为酸模叶蓼。相反，日本本土的所有标本均为钝叶酸模。叶绿体trnL - trnF基因间隔区和部分核内转录间隔区的DNA序列与根据花被片形态特征对酸模叶蓼和钝叶酸模的鉴定结果一致。因此，为避免用于提取原材料的植物物种的错误鉴定和误用，最好为这两个区域开发DNA标记。尼泊尔蓼的含量在酸模叶蓼中从不可检测到占鲜重的0.34%（%FW）不等，在钝叶酸模中从不可检测到占鲜重的0.21%FW不等。从药理学角度来看，作为可能适合作为尼泊尔蓼提取原材料的植物，很明显酸模叶蓼和钝叶酸模都可以以相同的预期提取效率使用。基于我们的研究结果，未确认钝叶酸模栖息于琉球群岛。因此，为保护琉球群岛的特有遗传特征并防止钝叶酸模造成遗传污染，琉球群岛上应仅种植酸模叶蓼。
