[Herbalogical study on Liangmianzhen (Zanthoxyli Radix)].

Liangmianzhen(Zanthoxyli Radix) has long been used as medicine. The current medicinal parts are different from those in the ancient. As recorded in the Chinese Pharmacopeia, the medicinal part is root. However, in ancient works, the medicinal parts include root, stem, leaf, and fruit. In an attempt to find the historical basis that stem is a reasonable medicinal part, the herbalogical study was carried out on this medicinal based on the formal names, synonyms, original plant, medicinal parts, habitat of the medicinal plant, producing area, processing and preparation methods, efficacy, and indications recorded in ancient Chinese materia medica and local gazetteers. The results showed that Liangmianzhen was firstly recorded as a medicinal in Shennong's Classic of Materia Medica with the formal name of "Manjiao". "Manjiao" was adopted from the Han Dynasty to the Qing Dynasty when it was changed to "Rudijinniu", the name originating from the folk in the south of the Five Ridges. Now, the formal name is "Liangmianzhen", which was firstly recorded in Wuxuan County Gazetteer in 1914 and then as a synonym in the Updated Records of Picking Herbs in the South of the Five Ridges. According to the formal names, synonyms, and the descriptions of the original plant, the medicinal plants of Liang-mianzhen have the characteristics of shrub-like young seedlings, vine adult seedlings, corymbiform thyrsus, stems with thorns, amphitropous golden-yellow roots with horn-like branches, and thorns on both sides of the leaves. Thus, "Manjiao", "Rudijinniu", and "Liangmianzhen" were from the same species of Zanthoxylum nitidum(Rutaceae), which was also verified based on the growth environment, habitat, processing and preparation methods, efficacy, and indications. In ancient times, the stem and root were the main medicinal parts and leaves and fruits were also used. However, in the Chinese Pharmacopeia, root is recorded as the only medicinal part, which is obviously inconsistent with the records in the ancient classics. In light of the limited medicinal resources for Liang-mianzhen, other medicinal parts of Z. nitidum is recommended. This study clarified the medicinal parts of Z. nitidum in history. It is recommended that the stem be added to the medicinal parts of Z. nitidum in the next edition of Chinese Pharmacopeia.