Matsuya Pharmacy, Niigata, Japan.
Department of Traditional Medicine, Toho University School of Medicine, Tokyo, Japan.
J Nat Med. 2020 Sep;74(4):722-731. doi: 10.1007/s11418-020-01425-6. Epub 2020 Jun 26.
Unprocessed dried tuberous root of Pinellia ternata (Pinellia Tuber) has been used as a component of traditional Japanese Kampo medicine, while this crude drug is usually used after processing with Ginger in traditional Chinese medicine (TCM). It is known that the raphides contained in unprocessed Pinellia Tuber can induce severe acrid irritation of the oral and laryngopharynx mucosa when it is boiled insufficiently. However, the mechanism of the inducing irritation by the raphides nor that of the detoxification by heat or processing with Ginger have been left unclear, mainly because of the difficulties in the extraction and the purification of the raphides and in the assays of acridity. In this study, we developed an easy protocol that can be used to collect raphides from unprocessed Pinellia Tuber and an assay protocol that can be used to evaluate the acridity of the raphides in vitro. The raphides of Pinellia Tuber were discovered to have a lipophilic character and to be collected easily by the extraction using petroleum ether. It was also found that the denaturation of the raphides could be assayed by the dispersity of them in petroleum ether layer of the water/petroleum ether partition, and the acridity of the raphides was found to be in correlation with the assayed denaturation. The raphides were denatured by heat, methanol, or Ginger extract and the denaturing activity of Ginger on raphides was found to be attributable to its lipophilic and thermostable components, which may explain the meaning of the processing of Pinellia Tuber with Ginger in TCM, and may lead to the development of an easier and safer protocol to administer Pinellia Tuber. In addition, it was found that rinsing the mouth with salad oil can effectively relieve irritation of the oral mucosa caused by unprocessed Pinellia Tuber, probably due to the lipophilicity of the raphides.
未加工的干块茎半夏（半夏）已被用作传统日本汉方药的成分，而这种生药通常在传统中药（TCM）中用姜加工后使用。众所周知，未加工的半夏中所含的针晶在煮沸不充分时会引起口腔和喉咽部黏膜严重的辛辣刺激。然而，针晶引起刺激的机制以及热或姜加工解毒的机制尚不清楚，主要是因为难以提取和纯化针晶，也难以进行辛辣度测定。在这项研究中，我们开发了一种简单的方案，可以从未加工的半夏中收集针晶，并开发了一种体外评估针晶辛辣度的测定方案。发现半夏的针晶具有亲脂性，并且可以很容易地通过使用石油醚提取来收集。还发现，通过水/石油醚分配中它们在石油醚层中的分散性可以测定针晶的变性，并且针晶的辛辣度与测定的变性相关。针晶被热、甲醇或姜提取物变性，并且发现姜对针晶的变性活性归因于其亲脂性和热稳定性成分，这可能解释了 TCM 中用姜加工半夏的意义，并可能导致开发出一种更简单、更安全的半夏给药方案。此外，发现用色拉油漱口可以有效缓解未加工半夏引起的口腔黏膜刺激，可能是因为针晶具有亲脂性。
